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HomeMy WebLinkAbout2021-03-16; City Council; ; Coastal Development Permit and Variance for an Unpermitted Retaining Wall at 939 Begonia CourtMeeting Date: March 16, 2021 To: Mayor and City Council From: Scott Chadwick, City Manager Staff Contact: Jessica Evans, Associate Planner jessica.evans@carlsbadca.gov, 760-602-4631 Subject: Coastal Development Permit and Variance for an Unpermitted Retaining Wall at 939 Begonia Court District: 3 Recommended Action Hold a public hearing and adopt a resolution (Exhibit 1) denying Coastal Development Permit No. 2020-0026 and Variance No. V 2020-0004 for an unpermitted retaining wall located at 939 Begonia Court. Executive Summary This is a request to approve a variance and a coastal development permit to authorize the installation of an unpermitted retaining wall within the backyard of a single-family residence, at 939 Begonia Court. The retaining wall starts at the base of the slope and extends approximately two-thirds up the grade toward the rear property line. The slope has been graded and filled without a required grading permit, and each level between the multitiered system is flat and designed in a manner that could be used as recreation areas (Exhibit 2 and 3). The retaining wall does not meet city standards and cannot be approved as constructed. To obtain permits for the retaining wall as it is currently constructed, the property owner applied for a variance for relief from the design standards in the Hillside Development Regulations, under Carlsbad Municipal Code Section 21.95.140. The request also requires a coastal development permit for deviations to grading of steep slopes in the Coastal Zone in keeping with Section 21.203.040A(3). For the reasons further explained below, the Planning Commission and staff are unable to make the required findings for either request and therefore recommend that the City Council deny the applicant’s petitions. The project is being presented before the City Council because the Carlsbad Municipal Code requires City Council approval for coastal development permit requests to deviate from development standards for steep slopes. Because the permit requires City Council approval, CMC Section 21.54.040 C requires that all concurrently processed development permits – in this case, the variance – also be considered by the City Council. March 16, 2021 Item #4 Page 1 of 193 Discussion Project description The site is developed with a two-story, single-family residence. The property comprises an uphill slope with a gradient of approximately 55%. The lot is surrounded by single-family residences to the north, south, east and west. The existing single-family residence is in the Coastal Zone and is used as a short-term vacation rental.1 The property has one open code enforcement violation for the existing and unpermitted retaining wall system. According to a geotechnical report (Exhibit 4), the property owner began unpermitted grading and construction of the multitiered retaining wall system into the uphill slope located in the backyard in March 2016. Code enforcement staff issued a notice of violation in February 2019 and a final notice of violation in June 2019. Construction stopped in approximately June 2019 and the property owner chose to pursue a variance and coastal development permit application. The notice of violation referenced violations of municipal code Section 15.16.050 for grading the slope to construct the walls without a grading permit; Section 21.95.140 for constructing a retaining wall system on a manufactured uphill perimeter slope that exceeds the permitted standards; and Section 21.203.040 for the construction of the wall system without approval of a coastal development permit. To ensure the health and safety of the occupants during this review process, the Code Enforcement Division required the area of the unpermitted walls be sectioned off with a gate and caution tape to restrict entering or engaging in recreational activities on the slope that has been structurally compromised and to disclose the restriction in rental marketing materials. Staff conferred with the property owner on several occasions since 2018 regarding potential corrective actions. The actions discussed were: A. Apply for and obtain a grading permit to remove the unpermitted walls and restore the slope above to its original condition; or B. Apply for a variance and coastal development permit application to request the approval for the unpermitted retaining wall system to remain. Staff told the property owner that the department could not support making the required findings for a variance and a coastal development permit for the reasons further explained below. Despite staff’s recommendation, the property owner chose to proceed with Option B. Variance request Under CMC Section 21.50.050, variances may be granted where special circumstances that result from the unique size, shape, topography or dimensions of a property act to deprive that property of privileges enjoyed by other properties in the vicinity that fall under the same zoning classification. Variances may not grant a special privilege that is not shared by other properties in the surrounding area. All properties in the vicinity are subject to the same hillside development and design standards in CMC 21.95.140, which prohibit retaining walls from being constructed on a manufactured 1 In accordance with Carlsbad Municipal Code Chapter 5.60 – Short-Term Vacation Rentals, property owners in the Coastal Zone may operate a short-term rental with the approval of a short-term vacation rental permit and a business license. March 16, 2021 Item #4 Page 2 of 193 uphill perimeter slope. Except for the subject property, all neighboring properties comply with this requirement. Before the unpermitted grading, the lot was similar in size, shape and topography to surrounding lots. A single-family home was constructed at roughly the same size as the neighboring properties and included a usable front and rear yard, again similar to other properties in the neighborhood. Staff finds that the lot contains no special circumstances or characteristics that deprive it of a privilege enjoyed by other properties in the vicinity. Approval of a variance in this case would grant a special privilege not enjoyed by surrounding properties. Staff therefore recommended denial of the variance request. The full list of variance findings with staff’s analysis can be found in Exhibit 7 – Planning Commission Staff Report, pages 7-12. Coastal development permit request Within the Coastal Zone, applicants may deviate from the grading and development standards for steep slopes through a coastal development permit approved by the City Council. To approve a coastal development permit, the City Council must find that: • The development conforms to the certified Local Coastal Program policies • The subject slope area is stable • Any grading and development impacts are mitigatable for at least 75 years or the life of the structure • Grading of the slope is essential to the development intent and design In addition, any grading that affects steep slopes in the Coastal Zone that is equal to or greater than a 25%gradient may be allowed when it is necessary to preserve natural habitats as required by the city’s Habitat Management Plan. In this case, the project fails to conform to the Local Coastal Program in that it does not preserve or protect steep manufactured slopes or ensure the structural stability of the slope from erosion or geological instability. The unpermitted grading actually created geologic instability. A geotechnical evaluation provided by the applicant and prepared by Advanced Geotechnical Solutions, Inc., dated October 9, 2019 (see Exhibit 4 and 5), confirms the slope stability has been compromised and does not meet minimum safety standards for static or seismic conditions. The geotechnical evaluation offered conceptual options to stabilize the structure. However, the applicant’s engineer did not provide adequate technical information for staff to determine if the subject slope area would be stable or if the impacts would be mitigatable for at least 75 years or for the life of the structure. The grading also cannot be considered essential to the development intent and design, because the grading was performed after the development of the neighborhood and differs greatly from neighboring properties. In addition, the property is not eligible for the natural habitat exception because there is no evidence of any existing or previous habitat on the site. Because the project fails to protect or preserve steep slopes, creates geologic instability and contains no natural habitat, staff cannot support the findings needed to grant the coastal development permit and recommended that the request be denied. The full list of coastal development permit findings with staff analysis can be found in Exhibit 7 - Planning Commission Staff Report, pages 4-7. March 16, 2021 Item #4 Page 3 of 193 Planning Commission hearing The Planning Commission considered the request for the variance and coastal development permit at a public hearing on Dec. 16, 2020. No public comments were read into the record. However, there were 10 public comments received before the Planning Commission meeting (see attachment 11 in Exhibit 7). Nine of the 10 comments were in opposition to the project. Other issues discussed at the hearing included the following: Noise concerns Several concerns were raised regarding short-term vacation rental guests hosting parties and creating noise issues for adjacent neighbors. This concern is not related to the coastal development permit and variance application, but these comments have been addressed and staff has informed neighbors to contact the Police Department for noise complaints related to the short-term vacation rental use. Aesthetics The unpermitted retaining wall system is inconsistent with the city’s Landscape Manual, which recommend slopes be landscaped with native or drought tolerant plants. In addition, hillside development and design standards are intended to enhance the aesthetic qualities of manufactured slopes, and development of the retaining wall system is not a permitted development on an uphill slope. The project is inconsistent with the intent and guidelines for hillside aesthetics. Drainage concern The adjacent property to the south at 937 Begonia Court is at a lower level than the subject site and its owner has raised the concern of drainage issues since the construction of the walls. The neighbor reported being able to see streams of water draining onto their property when there is heavy rainfall. If the project is denied, the property owner will be required to remove the walls and obtain a grading permit from the city to restore the slope to its original condition. The grading permit review will ensure the stability of the slope as well as address drainage issues and should rectify this concern. In addition, planning commissioners asked questions regarding the following: Variance findings Planning commissioners asked the applicant how the project could meet the variance findings. The applicant answered by acknowledging there are no special circumstances related to the property regarding the size, shape or topography and did not address how allowing the project would not constitute a special privilege. The applicant did state that there were special circumstances arising from the unpermitted grading and construction. The applicant stated the variance should be considered in order to avoid impacts to adjacent neighbors. However, the removal of the walls that are not allowed by code and the restoration of the slope should not impact adjacent neighbors any more than retrofitting the existing wall system. Similar walls The applicant provided a list of several walls throughout the city that appear to be similar to the retaining walls in question (see Attachment 9 in Exhibit 7). Most of the walls listed by the applicant are located on project sites that are not similar to his March 16, 2021 Item #4 Page 4 of 193 property. Those projects were subject to other sections of the code or provisions within a master plan development or were necessary, for circulation and roadways; or were required for the preservation of significant natural habitats as required by the city’s Habitat Management Plan; or were approved as concessions for the provision of affordable housing. Some sites cited by the applicant are not subject to the hillside development design standards because the topography does not meet the criteria for the regulations to apply or predate the current Hillside Development Regulations. Continuance The Planning Commission raised the possibility of continuing the matter so that the applicant could return to the commission with the technical information necessary to demonstrate the feasibility of stabilizing the slope and retrofitting the walls. Staff informed the Planning Commission that a continuance of the project to review technical information for retrofitting the walls would not result in findings that would support of the variance and coastal development permit. The Planning Commission deliberated and recommended by a 6-0-1 vote (Commissioner Peter Merz abstained) that the City Council deny the project (Exhibits 6-8). Fiscal Analysis There are no expected costs to the city from this action. Next Steps If the city council denies this request, staff will ensure that the property owner will obtain a grading permit and restore the slope to its previously approved condition. Environmental Evaluation (CEQA) The project is exempt from California Environmental Quality Act environmental review as noted in sections 15061(b)(4) and 15270 of state CEQA guidelines because the act does not apply to projects that a public agency rejects or disapproves. Should the City Council decide to approve Coastal Development Permit No. 2020-0026 and Variance No. V 2020-0004, the project is exempt from environmental review in accordance with Section 15303 - Class 3, for new construction of accessory structures which includes fences and walls. Public Notification and Outreach Public notice of this item was posted in keeping with the Ralph M. Brown Act and it was available for public viewing and review at least 72 hours before the scheduled meeting date. In addition, information regarding public notification of this item such as mailings, public hearing notices posted in the newspaper and on the City of Carlsbad website are available in the Office of the City Clerk. Exhibits 1. City Council resolution 2. Location map 3. Aerial view map 4. Geotechnical report 5. Geotechnical addendum March 16, 2021 Item #4 Page 5 of 193 6. Planning Commission Resolution No. 7394 7. Planning Commission staff report dated Dec. 16, 2020 8. Excerpts of Planning Commission minutes dated Dec. 16, 2020 9. Hillside Development and Design Guidelines Section III.B and Exhibit 9 10. Neighborhood contour map March 16, 2021 Item #4 Page 6 of 193 RESOLUTION NO. 2021-055 A RESOLUTION OF THE CITY COUNCIL OF THE CITY OF CARLSBAD, CALIFORNIA, DENYING A COASTAL DEVELOPMENT PERMIT AND VARIANCE FOR AN UNPERMITTED RETAINING WALL SYSTEM THAT EXCEEDS STANDARDS ON A MANUFACTURED UPHILL PERIMETER SLOPE WITH A GRADIENT GREATER THAN 40 PERCENT AND AN ELEVATION DIFFERENTIAL OF GREATER THAN FIFTEEN FEET LOCATED AT 939 BEGONIA COURT WITHIN THE MELLO II SEGMENT OF THE CITY'S LOCAL COSTAL PROGRAM AND LOCAL FACILITIES MANAGEMENT ZONE 4 CASE NAME: BEGONIA COURT RETAINING WALL CASE NO.: CDP 2020-0026/V 2020-0004 WHEREAS, the City Council of the City of Carlsbad, California has determined that pursuant to the provisions in the Carlsbad Municipal Code, the Planning Commission did, on Dec. 16, 2020, hold a duly noticed public hearing as prescribed by law to consider Coastal Development Permit No. CDP 2020-0026 and Variance No. V 2020-0004, as referenced in Planning Commission Resolution No. 7394; and the Planning Commission adopted Resolution No. 7394 recommending to the City Council that they be denied; and WHEREAS, the City Council of the City of Carlsbad held a duly noticed public hearing to consider said Coastal Development Permit and Variance; and WHEREAS, at said public hearing, upon hearing and considering all testimony and arguments, if any, of all persons desiring to be heard, the City Council considered all factors relating to the Coastal Development Permit and Variance. NOW, THEREFORE, BE IT RESOLVED by the City Council of the City of Carlsbad, California, as follows: 1.That the above recitations are true and correct. 2.That the recommendation of the Planning Commission for the denial of Coastal Development Permit No. CDP 2020-0026 and Variance No. V 2020-0004 are adopted and approved, and that the findings and conditions of the Planning Commission contained in Planning Commission Resolution No. 7394 on file with the City Clerk and incorporated herein by reference, are the findings and conditions of the City Council. 3.This action is final the date this resolution is adopted by the City Council. The Provisions of Chapter 1.16 of the Carlsbad Municipal Code, "Time Limits for Judicial Review" shall apply: March 16, 2021 Item #4 Page 7 of 193 "NOTICE" The time within which judicial review of this decision must be sought is governed by Code of Civil Procedure, Section 1094.6, which has been made applicable in the City of Carlsbad by Carlsbad Municipal Code Chapter 1.16. Any petition or other paper seeking review must be filed in the appropriate court not later than the ninetieth day following the date on which this decision becomes final; however, if within ten days after the decision becomes final a request for the record is filed with a deposit in an amount sufficient to cover the estimated cost or preparation of such record, the time within which such petition may be filed in court is extended to not later than the thirtieth day following the date on which the record is either personally delivered or mailed to the party, or his attorney of record, if he has one. A written request for the preparation of the record of the proceedings shall be filed with the City Clerk, City of Carlsbad, 1200 Carlsbad Village Drive, Carlsbad, CA 92008. PASSED, APPROVED AND ADOPTED at a Regular Meeting of the City Council of the City of Carlsbad on the 16th day of March, 2021, by the following vote, to wit: AYES: Hall, Blackburn, Acosta, Bhat-Patel, Schumacher. NAYS: None. ABSENT: None. MATT HALL, Mayor ,AV0,5/51/17-1 170. (fr-1--, /1)C BARBARA ENGLESON, City Clerk (SEAL) March 16, 2021 Item #4 Page 8 of 193 EXHIBIT 2 March 16, 2021 Item #4 Page 9 of 193 AREA OF EXISTING UNPERMITTED GRADING AND CONSTRUCTION EXHIBIT 3 Exhibit 3March 16, 2021 Item #4 Page 10 of 193 Respectfully Advanced Geotechnicaf Solutions, Inc. AUL J. DERISI, Vice President CEO 2536, Reg. Exp. 5-31-21 DUAL e et Ho 2536 ii I CEFenFfEn ‘$r ENCINLER4NG A GEOLOGi3T 5>%.‘ 1*.E. I. /1 1 L 1404,1 J L"--- N J. DOVVAN, Geotechnical Engineer 6505 LIGE. 2790, Reg. Exp. 6-30-21 Etisuibution (1)Atldwsiv ipdri EXHIBIT 4 G S FUSION ENGINEERING & TECHNOLOGY 4231 Balboa Avenue, Suite 619 San Diego, CA 921 17 ADVANCED GEOTECHNICAL SOLUT1 ONS, I NC. 485 Corporate Drive. Suite B Escondido. California 92029 Telephone: (619)867-0487 Fax: (714) 4(19-3287 October 9. 2019 PM 1907-03 Report No. 1907-03-13-3 Attention: John *Rivera, PE Subject: Geotee.hnical Evaluation of Existing Mechanically •Stabilizcd Earth Walls. 939 Begonia Courts City of Carlsbad, California References: See Appendix Gentlemen, Pursuant to your request, Geotechnical Solutions, Inc., (AGS) has prepared this letter summarizing the results of our geotechnical evaluation of the existing mechanically stabilized earth (MSE) walla located in the rear yard of the existing single-family residence located at 939 Begonia Court, City of Carlsbad, California. Also provided are recommendations for remediatingthe current conditions. AGS appreciates the opportunity to provide you with geoteehnical consulting services on this project. If you have questions concerning this report, please do not hesitate to contact the undersigned at (619) 867- 0487. ORANGE AND L.A. COUNTIES INLAND EMPIRE SAN DIEGO AND IMPERIAL COUNTIES (714) 786-5661 (619) 867-0487 (619) 867-0487 March 16, 2021 Item #4 Page 11 of 193 October 9.2019 NW 1907-03 TABLE OF CONTENTS Page ii Report No. 1907-03-8-3 Page 1.0 INTRODUCTION 1 1.1. Scope of Study I.2. Geotechn ice I Study Limitations 2.0 SITE LOCATION AND DESCRIPTION 2 3.0 SUBSURFACE INVESTIGATION 2 4.0 ENGINEERING GEOLOGY 4.1. Site Geology 4.1.1. Undocumented Artificial Fill 2 4.1.2, Very Old Paralic Deposits 3 4.2. Groundwater 3 5.0 GEOTECHNICAL ENGINEERING 3 5.1. Expansion Potential • 3 5.2. Shear Strength 3 5.3, Earthwork Adjustments . 4 5.4. Relative Compaction of Artificial Fill Materials • 4 5.5. Slope Stability. 4 6.0 CONCLUSIONS 5 7.0 Earthwork Recommendations 5 7.1. Site Preparation and Removals 6 7.2. Remediation Option Recommendations 6 7.2.1, OPTION I- MSE Wall System 7 7.2.2. OPTION 2- Restore Slope with Reinforced Soil Slope 7 7.2,3. Temporary 13ackcut Stabi lity 8 7.3. Geologic Observation During Grading 9 7.4. Seepage 9 7.5. Earthwork Considerations. 9 7.5.1. Compaction Standards 9 7.5.2. Benching 9 7.5.3. Mixing and Moisture Control 10 7.5.4. Haul Roads 10 7.5.5. Import Soils . 10 7.5.6. Fill Slope Construction , 10 7.5.6.1, Overbuilding Fill Slopes 10 7.5.6.2. Compacting the Slope Face I 1 73.6.3. Reinforced Soil Slopes I 1 8.0 DESIGN RECOMMENDATIONS • I 1 8.1. Mechanically Stabilized Earthen Wall Recommendations 1 I 8. Li. Observation During Construction It 8.2. Civil Design Recommendations 12 9.0 SLOPE AND LOT MAINTENANCE. I 2 9.1. Slope Planting 12 9.2. Lot Drainage 12 9.3. Slope Irrigation 12 9.4. Burrowing Animals 13 ADVANCED GEOTECHNICAL SOLUTIONS, INC. March 16, 2021 Item #4 Page 12 of 193 October 9, 2019 Page ii.i PM 1907-03 Report No. 1907-03-B-3 10.0 CLOSURE 13 ATTACHMENTS: Figure I - Site Location Map Plate 1 - Boring Location Map Plate 2 - Geologic Cross Sections Appendix A - References Appendix B - Boring Logs Appendix C - Laboratory Test Results Appendix D — Slope Stability Analysis Appendix E — Earthwork Specifications and Grading Details ADVANCED GEOTECHNICAL SOLUTIONS, INC. March 16, 2021 Item 444 Page 13 of 193 October 9, 2019 Page 1 PAW 1907-03 Report No. 1907-03-B-3 LO INTRODUCTION Advanced Geotechnical Solutions, Inc., (MIS) has prepared this report which presents the results of our subsurface exploration and geotechnical evaluation of existing mechanically stabilized earth (MSE) walls located in the rear yard of the existing single-family residence located at 939 Begonia Court. City of Carlsbad. California. Li. Scope of Stile, The scope of this study included the following tasks: .> Review of pertinent published and unpublished geologic and geotechnical literature, maps, and aerial photographs (Appendix A, References). >Geoteehnic.al site reconnaissance to observe site conditions and select exploratory locations. >Subsurface exploration consisting of four soil borings excavated with a tripod mounted limited access drill rig (Appendix B). Geotechnical laboratory testing on selected soil samples (Appendix C). P Preparation of a plan (utilizing the 10-scale site plan. as a base) showing the approximate locations of borings and geologic cross sections (Plate I); >Prepare geologic cross sections depicting the existing site conditions and anticipated geologic contacts (Plate 2), The proposed design is also shown; P. Compile and analyze data collected from our site reconnaissance, subsurface evaluation, and laboratory testing. Specifically, our analyses included the following: o Evaluation of general subsurface conditions and description of types. distribution, and engineering characteristics of subsurface materials; o Perform slope stability analyses of the existing as-gradedfas-bui lt condition. •Provide recommendations on .rernecliating the current conditions. > Prepare this report describing the work performed, data acquired and our cOncluSions regarding the global stability of the existing tiered MSE wall system as well as providing recommendations on the repair aft existing slope and wall, 1.2. Geotechnical Study Limitations The conclusions and recommendations in this report are professional opinions based on information provided by involved parties and the data developed during this investigation. The conclusions presented herein are based on a limited geotechnical investigation. ACTS did not provide geotechnical testing or observation Services during site grading and wall construction. The materials immediately .adjacent to or beneath those observed may have different characteristics than those observed. No representations are made as the quality or extent of material not observed. Any evaluation. regarding the presence or absence of hazardous material is beyond the scope of this firm's services. ADVANCED GEDIECHNICAL SOLUTIONS, INC. March 16, 2021 Item #4 Page 14 of 193 October 9,2019 Page 2 P/W 1907-03 Report No, 1907-03-8-3 2.0. SITE LOCATION AND DESCRIPTION The subject site is located at 939 Begonia Court, City of Carlsbad, California and currently supports one single-family residence and associated improvetnents incite:Ling an in-ground pool and Jacuzzi in the rear yard. The property is bounded on the west by Begonia Court and on the north, south, and east by existing single-family residences. Site topography ranges from flat to very gently sloping to the west in the lower building pad area and moderately sloping up to the east in the rear portion of the property. Elevations across the site range from approximately 165 feet above mean sea level (artist) at the westerly property boundary to 200 feet amel at the easterly property houndaey. A majority of the rear slope has been graded to support the subject multi-tiered MSE wall system. Based on available information and review of historic satellite imagery, construction of the subject retaining Walls•began in 2016 and continued until recent months. The subject MSE walls were constructed with Keystonee Country Manor retaining wall blocks in a tiered manner with a maximum overall height of approximately 21 feet, Individual wall sections are approximately 5 feet in height and ere horizontally separated by approximately I to 10 feet. Geogrid reinforcement (Miragride 2X1). appears to have been placed at 1-foot vertical increments. Length of the geogrid reinforcement is repelled to be 4 feet. The walls appear to be generally founded in formational materials with the exception of a portion of the lowest wall adjacent to the pool which is founded upon a pre-existing masonry wall. At the time of our site exploration, the uppermost wall was partially constructed. Groundwater seepage was observed coming through the southerly portion of the uppermost wall. 3.0 SUBSURFACE INVESTIGATION On July 18, 2019, AGS conducted subsurface exploration at the subject site. Four (4) exploratory borings (B-1 through 13-4) were excavated with a tripod drill rig to depths ranging from 5.5 to 16.5 feet below ground surface (legs). The materials encountered in the borings were logged by our field personnel. The boring logs are presented in Appendix 8, Upon completion, the borings were backfil led with soil cuttings. The approximate boring locations are showman Figure 2, Boring Location Map. Bulicand relatively undisturbed ring samples of the soils were obtained from the borings at various depths in an effort to evaluate lithologic changes and cinsite geology at the study site. Soil samples were transported to AOS' laboratory and tested for in-situ unit weight and moisture content, shear strength. and maximum density and optimum moisture content. Laboratory results are presented in Appendix C. 4,0 ENGINE,ERING GEOLOGY 4.1. Site Ceolo ere- Current published regional geologic maps indicate the site is underlain by Very Old Paralic Deposits (Kennedy, lvf,Pe and Tan, S.S., 2007). The following is a brief description of the geologic units encountered during our geotechnical exploration. A geologic eross section showing approximate distribution of geologic units encountered ;ensile is presented on Plate 2, 4.1.1. Undocumented Artificial FM Undocumented artificial fill materials were encountered extending to depths ranging from 3 feet to 7 feet termite. These soils appear to be locally derived and generally consist of ADVANCED GEOTECHNICAL SOLUT1CKS, NC. March 16, 2021 Item #4 Page 15 of 193 October 9, 2019 Page 3 P/W 1907-03 Report No. 1907-03-3-3 light yellow brown, silty sand with gravel and cobbles. The artificial 1111 is generally in a dry to slightly moist and loose to moderately dense condition. 4.1,2. Very Old Paretic Deposits Very old piratic deposit were encountered beneath fill soils to the maximum depth explored. As encountered, these soils generally consist of dark yellow brown to orange brown, silty sand with trace clay in e slightly moist to moist and moderately dense to dense condition. 4.2. Groundwater Groundwater was not encountered during our subsurface investigation. No natural groundwater condition is known to exist at the site. However, seepage was observed coming through the uppermost wall near the southerly property boundary. Based on our observations, the seepage does not appear to be naturally occurring and is. most likely related to drainage and/or irrigation water from the easterly superjacent residence. It should be noted that localized perched groundwater may develop at a later date, most likely at or near fill/bedrock contacts,• dUe to fluctuations in precipitation, irrigation practices, or factors not evident at the time of our field explorations. 5.0 GEOTECHN1CAL ENGINEERING Presented herein is a general discussion of the geotechnical properties of the various soil types and the analytic methods used in this report. 5.1. Exnansion Potential Expansive soils are characterized by their ability to undergo significant volume changes (shrink or swell) due to variations in moisture Content. Changes in soil moisture content can result from precipitation, landscape irrigation, utility leakage, roof drainage, perched groundwater, drought, or other factors and may result in unacceptable settlement or heave of structures or concrete slabs supported on grade. Based on our laboratory testing, it is anticipated that the expansion potential of the onsite Materials will be "Very Low" to "Low". 5,2, Shear 5trength Based on our laboratory test results and previous experience in the area with similar soils, the following shear strengths for undocumented artificial fill, engineered artificial fill, and very old paralic deposits are presented on Table 5.2. ADVANCE-0 GEOTECHNICAL SOLUTIONS, INC. March 16, 2021 Item #4 Page 16 of 193 October 9. 2019 Page 4 NW 1907-03 Report No. 1907-03-13-3 TA OLE 5.2 FORDESIcN RECOMMENDED SHEAR STRENGTHS Material Cohesion EPP Friction Angle (degrees) Total Unit Weight (Pa) Artificial Fill, Undocumented (Existing) 50 27 120 Artificial Fill, Engineered (Proposed) 50 30 125 Nrciy Old Faralic Deposits 150 31 _..,.. 125 garthwork Adjustments The following average earthwork adjustment factors are presented for use in evaluating earthwork quantities. These numbers are considered approximate and should be refined during grading when actual conditions are better defined. Contingencies should be made to adjust the earthwork balance during grading if these numbers are adjusted. - TABLE 5.3 •Earthwork Adjustntents Geologic Unit Approximate Range r Exisdn. Fill 15 to 25 percent shrinkage Ve Old Parahe Dep,9sits 0 to 10 percent hulk 5.4. Relative Compaction of Artificial Fill Materials. Some of the fill materials were observed to be loose and dry to slightly moist. Test results indicated that some of the artificial fill materials have relative-compactions that are less than 90 percent when compared to the maXimum dry density (ASTM D1557), 5.5. Slone Stability Slope stability analyses were performed on representative cross-sections and considered both static and pseudo-static conditions to evaluate global stability. AOS evaluated the global stability of the tiered MSE retaining walls using GSTABL7. Geogrid reinforcement was added at a spacing schedule that the owner provided AGS. Per the owner. Mirafi Miragrid 2XT was placed every 12 inches vertically and extended 48 inches beyond the wall. The Long Term Design Strength was used as provided by the geogrid manufacturer. Searches were conducted in CSTABL7 to find the critical failure surface with the lowest factor of safety. The factor of safety was calculated using the Bishop method (circular failures). A pseudo-static analysis was used to evaluate the stability of slopes under seismic loading. A horizontal destabilizing seismic coefficient (kh) of 0.15 was selected for the site. The critical failure surface that was determined for the static analysis was also selected for the pseudo-static analysis, and the factor of safety was calculated using the Bishop method (circular failures). ADVANCED GEOTECHNICAL SOLUTIONS, INC. March 16, 2021 Item #4 Page 17 of 193 October 9, 2019 Page 3 NW° 1907-03 Report No. 1907-03-B-3 The results of the global stability analyses are presented in Appendix C. Based on the results of the analysis, the existing ME retaining wall system has a slope stability Factor .of Safety of Ises than 15 for static conditions and less than 1.0 for seismic conditions. The failure surfaces were shallow and indicate a potential for shallow or localized fitilures. Typically, the standard of practice in southern California, and has been adopted by most agencies, is to show that slopes have a slope stability factor of safety of 1.5 or greater for static conditions and 1.1 or greater for seismic conditions. AGS also conducted a stability analysis wing a proposed design profile consisting of a new toe- of-slope MSE wall, ascending slope and mid-slope MSE wall. This design profile is considered preliminary since the civil engineer has not yet prepared grading plans for the site remediation. The proposed design has factor of safety is greater than 1.5 for static conditions and 1.1 for seismic conditions, which both meet the minimum recommended factors of safety. 6.0 CONCLUSIONS Based on the information gathered and the analyses performed, it is our professional opinion that the existing tiered MSE wall system will not meet current code standards as adopted by the City of Carlsbad. The following two items will need to be mitigated in order to meet the current standards. )1- The 1111 has not. been compacted to a minimum of 90 percent of the relative compaction. Typically, fill should be compacted to a minimum of 90 percent of the relative compaction as determined by ASTM D1557, or as recommended by the geoteehnical consultants. If settlement and material strength is not a concern, then perhaps a lesser relative compaction may be permissible. However, the shear strength of fill would expected to improve with increased compaction. The tiered wall system does not possess an adequate factor of safety for long term global stability. Typically, a minimum factor of safety of 1.5 is needed for long term stability and 1.1 for seismic stability, Mitigation may be needed to improve the stability of the system and demonstrate that the slope and wall system has in adequate .factor of safety. The existing geogrid lengths are not adequate for the overall height of the system. 7.0 EARTHWORK RECOMIVIENDATIQM It is recommended that the existing MSE wall system be rentediated to meet current code standards. AGS considered three options of remediation, described below, I. NEW MSE WALL SYSTEM: Remove the existing MSE walls and undocumented fill. Replace with a new MSE wall system and slope. A five-foot wall can be constructed at .the toe of the slope, with a proposed ascending fill slope located above the wall and a new MSE Willi constructed near the top of the fill slope. Detailed recommendations are provided herein on constructing this option. 2. RESTORE SLOPE WITH REINFORCED SOIL SLOPE: Remove the existing i'vlSE walls and undocumented till. Restore the existing slope by constructing a keyway at the bottom. and fill slope. Portions of the new slope will need to be steeper than 2:1 (I-1:V), which is typically the steepest that is recommended without reinforcement. For the portions that are Steeper than 2:1, ADVANCED GEOTECHNICAL SOLUTIONS, INC. March 16, 2021 Item #4 Page 18 of 193 October 9, 2019 Page 6 P/W 1907-03 Report No. 1907-03-B-3 reinforcement should be added consisting of primary: and secondary .e.eog„rid layers. Reinforced soil slopes are typically more difficult to construtt than unreinforced slopes and are .typically much more expensive. Due to the limited space for stockpiling, the. reinforced soil slope will need to be constructed in sections. Difficulty should be expected when tying each section together, which will increase construction costs. They reinforced soil slopes should be constructed by an experienced contractor. Repair recommendations are provided herein. 3, REINFORCEMENT OF EXISTING SYSTEM: The existing tiered system can be left-in-place with a considerable reinforcement effort. AGS has met with a specialty geotechnical contractor to discuss possible repair options. Such an effort is expected to consist of building a reinforced shotcrete wall in front of each MSE wall. The MSE wall will be cored and a tight spacing of anchors will be drilled through the walls into the formational materials. The MSE walls will need to be cored at each anchor location. The anchor will be connected to the shoterete wall. The MSE walls will essentially be used as formwork for the :shoterete and anchor wall system. Due to the limited access, constructing the shoterete wall and drilling will be completed with small equipment and is expected to take a considerable amount of time to complete. This system would need to be designed by a licensed engineer familiar with these systems. It is our understanding that additional information is being gathered by homeowner in regard to this remediation option. If the homeowner opts to remediate the as-built/as-graded condition through reinfercetnent of the exiSting wall system, additional geotechnical analyses should be performed and repair recommendations provided in a supplemental report. A possible configuration of repair option 1 is shown on the attached geologic cross-sections. The civil engineer will need to provide a grading plan if this option is selected. An MSE wall plan with supporting calculations may need to be prepared by a licensed engineer. It is possible that Keystone may have standard wall plans that can be used in lieu of a.she-specific design, 7.1. Site Preparation and Removals. All grading shall be accomplished under the observation and testing of the project Geotechnical Consultant in accordance with the rcconuttcralatiops contained herein, the cumin outioN practiced by the City of Carlsbad and this firm's Earthwork Specifications (Appendix E). Existing vegetation, trash, debris, and other deleterious materials should be removed and wasted from the site prior to coinniencing removal of unsuitable soils and placement of compacted fill materials. The existing-retaining walls on. the slope should be removed. Within the limits of grading, existing undocumented fill materials and highly weathered Very Old Paralic Deposits should be removed until competent Very Old Paralie Deposits are encountered. In general, the removed materials are suitable to be reused as compacted fill provided deleterious materials are removed. 7,2. Remediation Option Recommendations The following sections provide preliminary recommendations for Options I and 2 as discusSed in Section 7.0 above, to remediate the existing as-graded/as-built condition. Recommendations for Option 3, if reqiiested, can be provided in a supplemental geotechnical report. ADVANCED GEOTECHNICAL SOLUTIONS, INC. March 16, 2021 Item #4 Page 19 of 193 October 9, 2019 Page 7 NW 1907-03 Report No. 1907-03-13-3 7.2.1. OPTION 1- MSE Walt System MSE. walls can be constructed near the toe of the slope. The wall should not be constructed atop or near the influence of the existing cantilever retaining walls. The lower MSE wall should have geogrid lengths of -not less than 8 feet. The limits of the geogrid should be extended to the baekcut, even if shorter geogrid lengths are shown on the wall plans. A minimum horizontal fill width of 8 feet should be maintained on the slope. The fill slope can be constructed as described in Section 7.5.6. A minimum of I subdrain should be installed at the toe of the slope. A second drain may also be needed behind the upper MSE retaining wall. The MSE retaining walls should be embedded as recommended by the designer, but no less than 12 inches at the toe of the slope. MSE walls installed above descending slope should he embedded so that the daylight distance from the bottom of the wall to the slope face is at least 5 feet. 731. OPTION 2- Restore Slope with Reinforced Soil Slope A stabilization keyway should be construeted at the toe of the proposed slope. The limits of this keyway should be based on the final slope design, but should be no less than 12 feet wide. Reinforced soil slopes (RSS) should be constructed oil fill slopes steeper than 2:1. The grading contractor Should have experience in the construction of a RSS. There are several methods art constructing a RSS, such as using temporal,: wooden formwork or permanent wire mesh forms (See Figure 72.2, below), and the grading contractor should select the most economical method of construction. The constructiOn method should allow for the fill to be compacted out to the slope face without damaging the reinforcement. ADVANCED GEOTECHNICAL SOLUTIONS, INC. March 16, 2021 Item #4 Page 20 of 193 October 9, 2019 NW 1907-03 WAS MSOH — • 'ISMPORAR 1RMNO*Ic N., ^ YEGSIATION• Page 8 Report No. 1907-03-8-3 ,—..-ssccoaDARy reaNFORCEMENT WRAP RONFORCEMEAT --ago 1v,xr.i.e WRAP AT PACE win /..r.s1.4 FAcitica • OR TEMPORARY FOFMWORK - OA RemrortcatEta AP > PRIMARY ReNvOriCEMEN I .1/ "N)-• "N"-7\707\7S"\-\,,>\:\,." /lc ' 1.7 - "'• e" Figure 7.2.2 Alternative Methods of RSS coullruction (from TenCa t 6"/ 2 010 ) The primary reinforcement can include plating layers of Mirafi Miragrid 3XT (or approved equivalent) every 4 feet vertically starting from the bottom of the keyway. The primary geogrid layers should extend from the slope face to the backcut. The primary geogrid should be oriented so that the primary strength is perpendicular to the slope face.. Splices in the primary direction should be avoided. A secondary layer of reinforcement consisting of Mimfi lvIiramesh TR (or approved equivalent) should be wrapped around the slope face and embedded a Millittilitn of 5 feet with a maximum vertical spacing of 18 inches. The Miramesh vertical spacing can be reduced to every 2 to 4 feet if the primary geogrid layer • is wrapped on the outside of the Mirartiesh and the primary geogrid is embedded a minimum of 8 feet as measured from the slope face. Geogrid reinforced slopes are expected to be globally and surticially stable to inclinations up to 1:1 (1-1:.V). Splicing of the SeCondary layer shall not be conducted. 7.2.3,, Temporary Backcut Stability During grading operatiOns, temporary bacI5.cnts will be requited to accomplish removals and provide room to place geogrid. Care should be taken during batkcut construction and back:fill should be placed expeditiously in order to minimize risk of failure. Complete removal of the failed materials will be required should failure occur. ADVANCED GEOTECHNICAL SOLUTIONS. INC. March 16, 2021 Item #4 Page 21 of 193 • October 9, 2019 NW 1907-03 Page 9 Report No. 1907-03-B-3 Backcuts exposing competent Very Old Paralic Deposits should be made no steeper than 1:1 to heights of up to 20 feet. Steeper backcuts may be possible for small sections but should be evaluated by AO& Shallower backcuts are recommended below existing walls or within undocumented fill. Close geologic mapping of the stabilization and buttress key backcuts should be provided to document the exposed conditions. Revised recommendations may be necessary should areas of instability be encountered. In consideration of the inherent instability created by temporary construction of backeuts, it is imperative that grading schedules be coordinated to minimize the unsupported exposure time of these excavations. Once starred those excavations and subsequent fill operations should be maintained to completion without intervening delays imposed by avoidable circumstances. In cases where five-day workweeks comprise a normal schedule, grading should be planned to avoid exposing at-grade or near-grade excavations through a non-work weekend, Where improvements may be affected by temporary instability, either on or offsite, further restrictions such as slat cutting, extending work days, implementing weekend schedules, and/or other requirements considered critical to serving specific circumstances may be imposed. '73, Geologic Observation During Grading All temporary slope excavations, including front, side and backcuts, and all cut slopes should be mapped to verify the geologic conditions that were modeled prior to grading. 7.4. Seenage Seepage, if encountered during grading, should be evaluated by the Geotechnical Consultant. If seepage is excessive, remedial measures such as horizontal drains or under drains may need to be installed. 7.5. Earthwork Considerations 7.5.14 compaction Standards .All tills should be compacted at least 90 percent of the maximum .dry density as determined by MTN! D1557. All loose and ar deleterious soils should be removed to expose firm native soils or bedrock. Prior to the placement of fill, the upper 6 to 8 inches of suitable material should be ripped, moisture conditioned to optimum moisture or slightly above optimum, and compacted to a minimum of 90 percent of the maximum dry density (ASfivi 01557). FIE should be placed in thin (6 to 8-inch) lifts, moisture conditioned to optimum moisture or slightly above, and compacted to at least 90 percent of the maximum dry density (ASTM 01557) until the desired grade is achieved. 7.5.2. Benching Where the natural slope is steeper than 5-horizontal to 1-vertical and where determined by the Geotechnical Consultant, compacted fill material shall be keyed and benched into competent materials. ADVANCED GEOTECHNICAL SOLUTIONS, INC, March 16, 2021 Item 444 Page 22 of 193 October 9, 2019 Page 10 l'/W 1907-03 Report No. 1907-03-13-3 15.3. Mixing and Moisture Control in order to prevent layering of different soil types and/or different moisture contems, mixing and moisture control of materials will be necessary. The preparation of the earth materials through mixing and moisture control should be accomplished prior to and as part of the compaction of each fill lift. Water trucks or other. water delivery means may be necessary for moisture control. Discine may be required when either excessively dry or we; materials are encountered. 73.4. Raul Roads All haul roads, ramp tills, and tailing areas shall be removed prior to engineered Oil placement. 7.5.5. Import Soils Import soils, if required, should consist of clean, structural quality, compactable materials similar to the on-site soils and should be free of trash, debris or other objectionable materials. Import soils should be tested and approved by the Geotechnical Consultant prior to importing, At least three working days. should he allowed in order for the geotochnical cOnsultant to sample and test the potential import material. 7.5.6. Pill Slope Construction Fill slopes may be constructed by preferably overbuilding and cutting back to the compacted core or by back-rolling and compacting the slope face. The following recommendations should be incorporated into construction orthe proposed fill slopes. Care should be taken to avoid spillage of loose materials down the face of any slopes during grading. Spill fill will require complete removal before compaction, shaping and grid rolling. Seeding and planting of the slopes should follow as soon as practical to inhibit ero5ion and deterioration of the slope surfaces, Proper moisture control will enhance the long- term stability of the finish slope surface. 7.5.6.1, Overbuilding Fill Slopes Fill slopes should be overfilled to an extent determined by the contractor, but not less than 2 fee measured perpendicular to the slope face, so that when trimmed back to the compacted cOrt, the compaction of the slope face meets the minimum project requirements for compaction. Compaction of each lift should extend out to the temporary slope face, The sloped should be back-rolled at fill intervals not exceeding 4 feet in height unless a more extensive overfilling is undertaken. ADVANCED GEOTECHNICAL SOLUTIONS, INC. March 16, 2021 Item #4 Page 23 of 193 October 9, 2019 Page I I PAV 1907-03 Report No, 1907-03-8-3 7.5.6.2. Compacting the Slope Face As an alternative to overbuilding the fill slopes, the slope races may be back- rolled with a heavy-duty loaded sheepsfoot or vibrator:yr roller at maximum 2-foot fill height intervals. Back-rolling at more frequent intervals may be required. Compaction of each fill should extend to the face of the slope. 7.5.6.3. Reinforced Soil Slopes Reinforced soil slopes should be constructed by an experienced contractor. Compaction of the slope face is. often achieved through the use of temporary .or permanent forms. 8.0 DESIGN RECOMMENDATIONS 8.1. :Mechanically Stabilized Earthen Wall Recominendations The base of the proposed !VISE wail should be founded on compacted fill or on 'competent formational materials. The wall designer should provide specifications on the materials placed in the retained and reinforced zones. Assuming materials derived from onsitC sources are used, to backfill the MSE walk, the wall may be designed using the parameters presented in Table 8.1. More stringent criteria may be required by the wall designer. Testing should be conducted during grading to verify that the backfill materials meet the design criteria shown on the retaining wall plans. TABLE 8.1 MSE WALL DESIGN PARAMETERS' Zone Moist Unit Weight (Pe() Shear Strength Cohesion Ultimate (OM Friction Angle Ultimate (degrees) Reinforced and Retained Soil Zarien 12.i 50 30. Foundation Zone 125 50 30 Notos- ' Assumios fill lt dorpasi front onsite sources 8.1.1. Observation During Construction During construction of the MSE walls, the geotechnical consultants should observe the following operations: ) Grading to create wail foundation support and to verity competency of foundation materials; Block type and sin; 0' Reinforcement type; 34, Placement of geogrid at design elevation, strength direction, and embedment; Drain placement; ADVANCED GEOTECHNICAL SOLUTIONS, INC. March 16, 2021 Item #4 Page 24 of 193 October 9, 2019 Page 12 PM 1907-03 Report No. I 907-03-B-3 Gradation and placement of drainage rock; Gradation, shear strength. compaction, and moisture content of reinforced soils. 'ee Observations of operations not included above (including watt batter, connections, and block placement) are the responsibility of the wall designer and the contractor. The geotechnical consultant's observation of these operations in no way relieves the contractor of his obligation to construct the wall system in accordance with approved plans and-speeifications. 8.2. Civil Desitm Recommendations Final site grading should assure positive drainage away from. structures. A concrete swain should be constructed at the top of the slope to capture offsite irrigation and rainfall runoff. Planter areas should be provided with area drains to transmit irrigation and rain water away from structures. The use of gutters and down spouts to carry roof drainage well away front structures is recommended. Raised planters should be provided with a positive means to remove water through the face of the containment Wall, 9.0 SLOPE AND LOT MAINTENANCE Maintenance of improvements is essential to the long-term performance of structures and slopes. Although the design and construction during mass grading created slopes that are considered both grossly and surficially stable, certain factors are beyond the control of the soil engineer and geologist. The homeowners must implement certain maintenance procedures. The following recommendations should be implemented, 9.1. toe Planting Slope planting should consist of ground cover, shrubs and trees that possess deep, dense root structures and require a minimum of irrigation. The resident should be advised of their responsibility to maintain Such planting. 9.2. 1„,0t Drainage Roof, pad and lot drainage should be collected and directed away from strUctures.and slopes and toward approved disposal areas. Design fine-grade elevations should be maintained through the life of the Structure, or if design flee grade elevations are altered, :adequate area drains should he installed in order to provide rapid discharge of water away from structures and slopes. Residents should be made aware that they are responsible for maintenance and cleaning of all drainage terraces, downdrains, and other devices that have been installed to promote structure and slope stability. 9.3. Slone irrigation The resident; homeowner and Homeowner Association should be advised of their responsibility to maintain irrigation systems. Leaks should be repaired immediately. Sprinklers should be adjusted to provide maximum uniform coverage with a .nlinimum of water usage and overlap. Overwatering With consequent wasteful run-off and ground saturation should be avoided, if ADVANCED GEOTECHNICAL SOLUTIONS, INC. March 16, 2021 Item #4 Page 25 of 193 October 9, 2019 Page 13 PAV 1907-03 Report No. 1907-03-8-3 automatic sprinkler systems are installed, their use must be adjusted to account for natural rainfall conditions. 9.4. Burrowinn Animals Residents or homeowners should undertake a program for the elimination of burrowing animals. This should be an ongoing program in order to maintain slope stability. 10.0 CLOSURE The findings and recommendations in this report are based on the specific excavations, observations, and tests results as noted herein. The findings are based on the review of the field and laboratory data combined with an interpolation and extrapolation of conditions between and beyond the exploratory excavations. The results reflect art interpretation of the direct evidence obtained. Services performed by AGS have been conducted in a manner consistent with that level of care and skill ordinarily exercised by members of the profession currently practicing in the same loeality under similar conditions. No other representation, either expressed or implied, and no warranty or guarantee is included or intended. The recommendations presented in this report are based on the assumption that an appropriate level of field review will be provided by geotechnical engineers and engineering geoloOsts who are familiar with the design and site geologic conditions. That field. review shall be sufficient to confirm that geotechnical and geologic conditions exposed during grading are consistent with the geologic representations and corresponding recommendations presented in this report. If the project description varies from what is described in. this report, AGS must be consulted regarding the applicability of. and the necessity for, any revisions to the recommendations presented herein.. AGS should review structural plans to veri.fy whether the recommendations presented herein are incorporated into the design. AGS accepts no liability for any use of its recommendations if the project description or final design varies and AGS is not consulted regarding the changes. The data, opinions, and recommendations of this report are applicable to the specific design of this project as discussed in this report. They have no applicability to any other project or to any other location, and any and nil subsequent uscrs accept any and all liability resulting from any use or reuse of the data,. opinions, and recommendations without the prior written consent of AGS. AGS has no responsibility for construct on means, methods, techniques, sequences, or procedures, or for safety precautions or programs in connection with the construction, for the acts or omissions of the CONTRACTOR, or any other person performing any of the construction, or for failure of any of them to carry out the construction in accordance with the final design drawings and specifications. ADVANCED GEOTECHNICAL SOLUTIONS, INC. March 16, 2021 Item #4 Page 26 of 193 APPENDIX A REFERENCES ADVANCED GEOTECHNICAL SOLUTIONS, INC. March 16, 2021 Item #4 Page 27 of 193 October 9, 2019 Page A-1 PRY 1907-03 Report No, 1907-03-B-3 REFERENCES Fusion Engineering and Technology, Preliminary Site Plan for Lichiman Residence, 939 Begonia Court, City of Carlsbad, California, Map I of 1, 10-Scale, undated. Kennedy, M.P., and Tan, S.S., 2007, Geologic Map of the Oceanside 30' x 60' Quadrangle, California Geological Survey: Scale 1:100,000. ADVANCED GEOTECHNICAL SOLUTIONS, INC, March 16, 2021 Item #4 Page 28 of 193 APPENDIX B BORING LOGS ADVANCED GEOTECHNICAL SOLUTIONS, INC. March 16, 2021 Item #4 Page 29 of 193 a- AGS I AllIANCIA) CAOTECHNICAL SOLLTIONS. Pic, CLIENT BORING NUMBER B-1 PACE 1 OF 1 PROJECT NAME Begonia Court PROJECT NUMBER 1907-03 PROJECT LOCATION 939 Begonia Ct.. Carlsbad DATE STARTED 7/16,19 COMPLETED Than 9 GROUND ELEVATION ft HOLE see 6 ,A6 DRILUNG DONTRACY0kNativel)rilling GROUND WATER LEVELS: DRILLING METHOD Tr-Pod AT TIME OF DRILLING — LOGGED BY SS CHECKED BY PJU AT END OF DRILUNG — NOTES AFTER DRILLING — ,..-, .0 C 0 k2 (7 ..• 0 g co D MATERIAL DESCRIPTION SAMPLE TYPE NUMBER BLOW COUNTS (NI VALUE) DRY UNIT WI. (PO) MOISTURE CONTENT (%) SAT URATION (%) OTHER TESTS I A TTERBERG LIMITS FINES CONTENT (%) cii 1- =2 rD [-PLASTIC I UNIT PLASTICITY INDEX -:•.i; '• 8M P Shil ' WA Artificial Fill - Undocumented. a(u) 104 94 7.5 9.6 32 33 Max hear SILTY SAND, fine- to coarse-grained, light yellow brown, dry to slightly moist, riled urn dense; with some sub-rounded gravel to cobble 0 1.5 ft, Poorly graded SAND with trace CLAY. tine- to medium-grained. slightly moist, medium dense tfp... 3.0 ft., SILTY SAND, fine- to coarse-grained, slightly moist to moist 06.0 ft.. CLAYEY SAND, tine- to coarse-grainad, yellow brown to orange brown, moist, medium dense . DU s mc.: 4-8-10 SPT 6-8-9 (17) ., 10 SPT 4-9-7 (15) .. • . : ' VON OldParalle Deposits. fOirop) SILTY SAND wfth trace CLAY, fine- to coarse-grained, red brownie orange brown, moist to very moist., medium dense: micaceous Ci.. 15,0 ft., dense SPY 12-1142 (23) 15 MC 14-14-12 (2a) MC 11-16-17 (33) Total Depth .-4- 16.5 feet No grOuldwater encountered Backfrlied math S011 cuttings March 16, 2021 Item 444 Page 30 of 193 •(. GEOTECHAIM $00.11045, is4C4 CLIENT BORING NUMBER B-2 PAGE 1 OF 1 PROJECT NAME Begonia Court PROJECT NUMBER 1907-03. PROJECT LOCATION 939 Begoni Ct„ Carlsbad DATE STARTED 7118119 COMPLETED .7118/19 GROUND ELEVATION 182 ft HOLE SIZE 6 DRILLING CONTRACTOR Native Drilling GROUND WATER LEVELS: DRILUNG METHOD Tr-Pod AT TIME OF DRILLING — LOGGED BY SS CHECKED BY RID AT END OF DRILLING — NOTES AFTER DRILLING — 0 MATERIAL DESCRIPTION SAMPLE TYPE NUMBER BLOW COUNTS (N VALUE) _ 5 z u in MOISTURE CONTENT (10 SATURATION (%) a.- D ' OTHER TESTS ATTERBERS _,..tAirs o- FINES CONTENT (e/0 •SM Artificial Fill - Undocumented, tofu} . SILTY SAND. fine- to medium-grained, light yellow brown, dry to slightly moist. medium dense; with some sub-rounded gravel to cobble . , MC 3-3-3 ,, ku l 81 4.1 10 "Shila — .. • SPT 4-5-8 (13) S'M Very Old Peralic DeeositeJCwocq , . SILTY SAND with Irace CLAY, fine- to coarse-grained, dark yellow brown to orange brown. slightly moist to moist, medium dense, micaceous a 6.0 ft., dense c. 11-18- 33 0 9) 97 8.8 32 Sheal Total Depth = 7.5 feet Na groundwater encountered Backfilled with soil catengs March 16, 2021 Item #4 Page 31 of 193 BORING NUMBER B.3 i ( i PAGE 1 OF 1 )AGS Woman GEN ECUMCAL SOLLIIONS, INC4 CUENT PROJECT NAME I3egonla Court PROJECT NUMBER 1907-03 PROJECT LOCATION S-39 accionia CL. Carlsbad DATE STARTED 7/18119 COMPLETED 7i18/19 GROUND ELEVATION 17a ft HOLE SIZE 6 DRILLING CONTRACTOR Native. Drillino GROUNDWATER LEVELS: DRILLING METHOD Tr-Pod AT TIME OF DRILLING — LOGGED BY SS CHECKED BY PJD AT END OF DRILUNG — NOTES AFTER DRILLING — L GRAPHIC LOG c-i MATERIAL DESCRIPTION SAMPLE TYPE NUMBER BLOW COUNTS (N VALUE) DRY ma tar. (Kr) ct i /R— co ILI _ u- , ER- z < n c3 z OTHER rEsTs ATTERBERG LIMITS I FINES CONTENT (%) LIQUID LIMIT PLASTIC LIMIT 5 6 , • •-, • :S . SM ' [ SM S. Artific(al Fill - Undocumente-d. efu) 101 8,0 32 MI Y SAND with trace CLAY, fine- to tnediurn-grained, light • yellow brown, dry to slightly moist, medium dense; with some sub-rounded gravel to cobble fix 64-6 (161 Very Old Paretic DeposIts,f0von) SILTY SAND with trace CLAY, fine- to coarse-grained, orange brown, slightly moist to moist, medium dense micaceous @ 4.6 ft.. dense 7-20-20 00) Shear Total Depth = 6.0 feet No groundwater encountered BaafiNed with soil cuttings March 16, 2021 Item #4 Page 32 of 193 I r GS `41;v4e4c6g GEOTIMICAL SOL1110/45, INC CLIENT BORING NUMBER B4 PAGE i OF 1 PROJECT NAME Begonia Court PROJECT NUMBER 1907-D3 PROJECT LOCATION 939 Begonia Cl.. Carlsbad .. DATE STARTED 7118/19 COMPLETED 7/18119 GROUND ELEVATION 174 ft HOLE SIZE 6 DRILLING CONTRACTOR Native Drilling GROUND WATER LEVELS: DRILLING METHOD Tn-Pod AT TIME OF DRILLING -- LOGGED SY SS . CHECKED BY PJD AT END OF DRILLING -- NOTES AFTER DRILLING — = o co MATERIAL DESCRIPTION SAMPLE TYPE NUMBER BLOW COUNTS (N VALUE) > 1— ,,. a n MOISTURE CONTENT (%) SATURATION 4%) I co i— to UJ ATTERBERG LIMITS FINES CONTENT (%) Z:2 PLASTIC LIMIT •'• cc z . S?.,1 • , .' SM Artificial FIII - Undocumented, WO SILTY SAND, fine- to coarse-gralned, gray brown, dry to slightly moist, loose; with some sub-roundod gravel 10.5) rAC 3-5-6 WI) Vero Old Paretic Deposits, (Guido SILTY SAND with trace CLAY, fine- to coarse-grained, orange brown. moist, medium derme, micaceous @ ALE it„ dense 12-20.25 mr, Total Depth = 5.5 fact No groundwater encountered Back/filed with soil cuttings March 16, 2021 Item #4 Page 33 of 193 APPENDIX C LABORATORY TEST RESULTS ADVANCED GEOTECHNICAL SOLUTIONS INC. March 16, 2021 Item #4 Page 34 of 193 October 9, 2019 Page C-1 PM 1907-03 Report No. 1907-03-R-3 APPENDIX C LABORATORY TESTING Classi fieation Soils were visually and texturally classified in accordance with the Unified Soil Classification System (USCS) in general accordance with ASTM D2488. Soil classifications are indicated on the boring logs in Appendix B. Modified Proctor Density The maximum dry density and optimum moisture content of a selected representative soil sample was evaluated using the Modified Proctor method in general accordance with ASTM 01557. The results of these tests are summarized herein. Direct Shear Direct shear tests were performed on relatively undisturbed samples in general accordance with ASTM D3080- to evaluate The shear strength characteristics of selected materials. The samples were inundated during shearing to represent adverse field conditions. The results are shown herein. ADVANCED GEOTECHNICAL SOLUTIONS, INC. March 16, 2021 Item #4 Page 35 of 193 ADVANCED GEOTECHNICAL SOLUTIONS, INC. MAXIMUM DENSITY - ASTM 01557 AGS FORM E-E1 Project Name: 939 begonia Cl. Excavation: 8-1 Location: Carlsbad Depth: 0-3 ft NW No.: 1907-03 Soil Type: afu Date: 7/2/2019 Tested by: EV Checked by: PJ Method: A Oversize Retained; 5.3 % Point No. 1 2 3 4 Dry Density (pct) 113.2 116.5 11132 115.6 Moisture Content (%) 8.2 10,2 12.3 14.3 MAXIMUM DENSITY CURVE 140.0 • . , \ • --;,•• •; 135.0 —4-- Test Curve Zero Air Voids Curves 1- SG22.8 — — SG=2.7 — — SGm2.8 130.0 ; %. 125.0 • DRY DENSITY (pcf) ; •f. 120.0 115.0 110.0 - ••.• ' 100.0 ' 'N.... • '". :•, 0 0 50 10.0 15.0 20.0 26.0 30.0 MOISTURE (%) Corrected Max. Dry Density 120.1 pcf Corrected Moisture 11.8 % Max. Dry Density 118.2 pcf Optimum Moisture 12.3 % March 16, 2021 Item #4 Page 36 of 193 1130 •- 10E1 I soo 2000 1800 1500 1400 a 7; 1200 It.; 1000 g 500 coa , 250 0 0.00 0.10 0.20 0.10 0,00 0.10 0.20 0.30 Displacement (in} Displacement lini ADVANCED GEOTECHNICAL SOLUTIONS, INC. DIRECT SHEAR - ASTM D3080 Project Name: 939 Begonia Ct. Excavation: B-1 Location: Carlsbad Project No.. 1907-03 Date: 712312019 Samples Tested 1 2 3 trifle! Moisture (%) 7.5 7.5 7.5 Initial Dry Density (pef) 104.0 106.7 105,9 Normal Stress (psf) 500 1000 2000 Peak Shear Stress Cost) 456 816 1740 Lilt. Shear Stress (00 /156 744 1596 Depth: 2.5-3 ft Tested by: FV Reviewed by: Soil Type: Yellow SC-SM Test Undisturbed Method Drained Consolidation: Yes Saturation: Yea Shear Rate (Inimtn): 0.01 Strength Parameters Peak Ultimate Friction Angle, phi (deg) 41 39 Cohesion (psf) 0 0 2E410 2000 1500 4.4n. 10o0 SOO SOO 1000 1500 2000 2500 3000 3500 Normal Stress (psf) March 16, 2021 Item #4 Page 37 of 193 Shear Stress v. Displacement ,,, •-• Vertical Deformation v. Displacemeat •MO I 30011 I !4+.1 0.03 0.04 0.03 0.02 •0.01 .1.31 •0 CO SI .0.01 .0.02 0 Peak Dryak Ii Mare (.13timam ADVANCED GEOTECHNICAL SOLUTIONS, INC. DIRECT SHEAR - ASTNI D3080 Project Name: 939 Begonia Ct. Location: Carlsbad Project No.: 1907-03 Date: 7/23/2019 Samples Tested 1 2 3 Intial Moisture (%) 4.1 4.1 4,1 Initial Dry Density (ad) 80.6 81.7 ale Normal Stress {pet) 500 1000 2000 Peak Shear Stress psf) 432 628 1368 Ult. Shear Stress (osf) 408 816 1308 Excavation: 3-2 Depth: 3-3.5 ft Tested by; FV Reviewed by: Soil Type. Light Brn Sc Test: Uriciisturbsd Method: Drained Consolidation: Yes Saturation: Yes Shear Rate (in/min): 0.01 Strength Parameters - Peak Ultimate Friction Angle, phi tdeg) 32 32 Cohesion (psf) 125 76 2500 e .. .0 .0 e - .0 e r r • e e e .. e ... e ... r 0 Peak P,ak ultimate ultimate , e a — .... — I 2000 rg. 1500 tol sel" w 1000 500 3500 2000 Normal Stress (psf) 0 500 1000 2500 3000 3500 shear Stress v. Displacement - " r I --s7s7i5-11 1 - - - • . :IOW I 0.10 0.20 Displacement (in} Vertical Deformation v. Displacement , • •7.7 7. ----i--------1-- -.:•:.7-17::: ''' : .17,,,..!.. . zbriq 920 1 loco, , 1 ------ 0,10 0.20 0:30 Displacement (in) 1600 1400 1201 1003 •,1 800 tJ 600 0.05 0.03 0.02 0.02 0,02 0.00 .0.01 -0.02 400 200 0.00 0,30 0.00 March 16, 2021 Item #4 Page 38 of 193 Shear Stress v. Displacement I ,,,,,,,,, _ tt*, via 0.10 0,20 Displacement OM Vertical Deformation v. Displacement --.... ......_.. `.-• w-wse.--• - ....-.,-, i ! , ••• --..... ---- •• • 1003 I, 0.10 0.20 9,30 Displacement (h) 1600 1400 1200 e• 1000 800 600 •400 .200 0 0:00 0.19 0.00 0.05 0.04 ; 0.02 * :0 001 o .0.01 ADVANCED GEOTECHNICAL SOLUTIONS, INC. DIRECT SHEAR - ASTM D3080 Project Name; 939 Begonia Ct. Excavation: B-2 Location: Carlsbad Depth: 7-7.5 ft Project No.: 1907-03 Tested by: FV Date: 75/2019 Samples Tested 1 2 3 Inbal Moisture CVO 8.8 8,8 8.8 Initial Dry Density (poi) 99_4 102.0 100,5 Normal Stress (psf) 500 1000 2000 Peak Shear Stress (psf) 432 708 1428 UIL Shear Stress (psi) 408 684 1404 Reviewed by: AS Soil Type: Reddish Bm, Test: ILWistorbed Method: Drained Consolidation: Yes Saturation: Yes Shear Rate (intr), 0.01 Strength Parameters Peak Ultimate Friction Angle, phi (deg) 34 34 Cohesion (psf) 75 26 2500 2000 500 a Peak 1:3 Ultirriato Ultimate 500 1000 1500 2000 2500 3000 3500 Normal Stress (psf) March 16, 2021 Item #4 Page 39 of 193 2500 2000 4) 1000 -0.02 Vertital Deformation (In] .0.01 0.05 0.04 0.03 0.02 0.03 0.03 ADVANCED GEOTECHNICAL SOLUTIONS, INC. DIRECT SHEAR - ASTM 03080 Project Name: 939 Begonia Ct. excavation: 13-3 Location: Carlsbad Project No.: 1907-03 Date: 7/25/2019 Samples Tested 1 2 3 Wel Moisture (%) 8.0 8.0 8.0 Initial Dry Density (pot) 103.9 98.0 96.4 Normal Stress (psi) 500 1000 2000 Peak Shear Stress (psf) 456 780 1416 Ult. Shears Stress (psi) 444 72 1344 Depth: 5-5.6 ft Tested by: FV Reviewed by: Soil Type: Reddish Brn. SC-SM Test: Undisturbed Method: Drained Consolidation: Yes Saturation: Yes Shear Rate (%n): 0.01 Strength Parameters Peak Ultimate Friction Angle, phi (deg) 32 31 Cohesion (psf) 160 150 O Peak Peak Ultimate — Ultimate 0 500 1000 1500 2000 2500 3000 3500 Normal Stress (psf) 500 0 Shear Stress V. Displatentent .. . 1 ....... 103 1 scro , 10 0.20 Displacement (in) Vertical Deformation v. Displaceniefit •.._ 0. 0 0.20 0.30 Displacement (in) 1600 1400 1200 t000 500 400 4(10 200 0 0.00 0.30 0.00 March 16, 2021 Item #4 Page 40 of 193 APPENDIX D SLOPE STABILITY ANALYSIS ADVANCED GEOIECIINICAL sourrums, INC. March 16, 2021 Item 444 Page 41 of 193 240 260 260 270 160 170 180 190 200 210 220 230 GSTABL7 v.2 FSmin=1.474 Safety Factors Are Calculated By The Modified Bishop Method TZOZ "9T LID-le1A1 E61 10 Z.17 aSed '1907-03 Section Ae-Aes Static - Existing z:1proJect Me-3%1907-03 begonia cl wall evaleationWalc.s & analysisil 007-03 secton ae slano.p/2 Run By: AGS 1018/2019 0520PM #FS Soil Soil Total Saturated Cohesion Friction Pore Pressure Piez, 1 a 1.474 Dem Type Unit WI Unit Wt. Intercept Angle Pressure Constant Surface-, b 1.492 No. (pcf) (pcf) (psf) (deg) Pararn. (pst) N. . afu 1 125.0 125.0 50.0 27.0 0.00 0.0 0 Quop 2 125,0 125.0 150.0 31,0 0.00 0.0 0 c 4.5w t/ 1-553l e t .573' I 1,584 9 1,514 h 1.623 i 1.623 0`. 9 21.4: :JO*, 2 —.,,V14 1/1?o• / 2 70 60 40 30 [ 10 - I 1002019 05:22PM 1907-03 Section Ae-Ae' - Pseudostatic - Existing zAproject iles‘1907.03 begonia cl wall evaluation‘calcs & analysis11907.03 section ae static surface /A.01 Run By: AGS -, I • „ Soil Soil Total Saturated Cohesion Frbtion Pore Pressure Piez. I Load Value I Desc. Type Unit M. Unit Wt. Intercept Angle Pressure Constant Skirface Peak(A) 0.470(g) I No. (PCO (pct) (ost) (mg) Parain. (psi) No. afu 1 125.0 125.0 5ao 27.0 0.99 0.0 0 kir Coe(. 0.150(9)< Crwop 2 125.0 125.0 150.0 31.0 0.00 0.0 0 70 IZOZ '9I 1-10-lelN 60 60 40 - 2 / 2 - 2 30 20 10 E6T Jo El7 aSed I_ I i •, _ 1 . I L._ _I I_.........1 170 180 190 200 210 220 230 240 250 260 270 GSTABL7 v.2 FSmin=1.134 Factor 01 Safety Is Calculated By The Modified Bishop Method 0 160 IZOZ `9T LIDieV\I E6I 10 1717 aed 1907-03 Section Be-Be' - Static - Existing 70 z: 4:ogled files11907-03 begonia ot waft evaluation'scalcs $. analysis%1907-03 section 3-3 static,p12 — Run By: AGS 10/8,(2019 05:05PM # FS ! a 1.107i' b 1,111 i c 1.1,2: d 1.117 —CF i i ' Soil Soil Total Saturated Cohesion Friction Pore Pressure Piz. Oesc. Type Unit VW. Unit Wt. taterospl Angle Pressure Constant Suiface No, (pet) (pc() (psi) (deg) Parant (psi) No. aft u 1 125.0 125.0 50,0 27,0 0.00 0.0 0 Ovop 2 125.0 125.0 150.0 31.0 0.00 0.0 0 ! r I 60 I.: 1...118 f 1.126 g 1,12$ 1.12 r-1 i 1.1331 2 60 13 2 40 a )4 •1,?; !•) 1 •I it,/ 2 -or•• ' i:A 4,4 ....:••••G ••••• 30 , 2 ;: •1:41,,..1.,-• 46, • v < • cmkr_ 20 2 10 0 . 1 10 20 30 40 50 60 70 80 90 100 GSTABL.7 v.2 FSmin=1.107 Safety Factors Are Calculated By The Modified Bishop Method 110 1907-03 Section Be-Be' Pseudostatic - Existing z.:1project Cles11907-03 begonia ct vial evaluatIon1calcs & analysisl1907-03 section be-be static. surface #1.p11 Run By; AGS 10/8/2019 05:09Phil 70 So4 Soil Total Saturated Cohesion 0.-rbtion Pore Pressure Piez,. Load Value Desc. Type Unit lAtl, Unit Wt. Intercept Asgle Pressure Constant Surface Peak(A) 0.470(g) No, (pcf) (pet) (psf) (deg) Param. (psf) No. kb Coe. 0.150(9).c afu 1 125.0 125.0 50.0 27.0 0.00 0.0 0 Clop 2 125.0 125,0 150.0 31.0 0.00 0.0 0 so 60 2 .„ 11..;;;•D „ tbs??1 1 IV 2 '" '' • 0 z 'SO • .34,2 ITN `9T golelAl 40 30 20 10 2 E61 40 St aed 0 1 L 1 i 1 .___I 0 10 20 30 40 60 60 70 80 GSTABL7 v.2 FSrnin=0.895 Factor Of Safety is Calculated By The Modified Bishop Method 90 100 110 TO Z `91 LID-lelN EEC 10 917 aged a 7 1 „CAI-- AUtr--1-v t t'• A( 6 7,,i.:0.---leAgt,--1.i.p;6 4 •.' 15 ffi"-2 '2 2 h 2 •1907-03 Section Ap-Ap - Static 8 ft. Key - Proposed eiproject filess.1807-03 begonia el wall evaluationscalcs & analysis11907-03 section ap aft key and grid.pI2 Run By AGS 1002019 04:47PM # FS a 1.543 I Soil Solt Total Saturated Cohesion Friction Pore Pressure PieZ.. Desc. Type Urill Wt. Unit Aft Herc.ept Angle Pressure Constant Surface . b 1.576 Na. (pcf) (pcf) (psf) (deg) Paten', (psf) No. C 1.581 afe 1 120.0 125.0 50.0 30.0 0.00 0.0 0 d 1.602 Gvop 2 125.0 125.0 150.0 31.0 0.00 0.0 0 e 1.603 1.605 9 1.611'f n 1.616 i 1.620i 70 60 50 40 30 1-• 20 270 2 10 160 170 180 190 200 210 220 230 GSTABL7 u.2 FSmin=1.543 Safety Factors Are Calculated By The Modified Bishop Method 240 250 260 1907-03 Section Ap-Apt Pseudostatic 8 ft. Key - Proposed zVroiect files‘1907-03 begonia ct wall evatuationscalcs & analysis11907-03 section ap 8tt key and grid surface #1.plt Run Eiy: AGS 10/8/2019 04:48PM 70 1 -1 r i a i- --1-- 1 soo Soil Total Saturated Cohesion tridion Pore Pressure Piez. Load Value Casa. Type Unit Wt. Unit Wt. Intercept Angle Pressure Constant Surface Peak(A) 0.470(g) No. (pet) (pc!) (psf) (deg) Pararn. (psf) No. kh Coe. 0.150{g}< ale 1 120.0 125.0 50,0 30.0 0.00 0.0 0 Qvop 2 125.0 125.0 150,0 310 0.00 0.0 0 SQ - 2 50 - IZOZ '9I LIDJBLA1 RC( 7 elf+ ky 2 ii 2 cq, 2 2 / 2 40 30 : • .5¢1CVA.,11 20 10 Ea 10 Lt7 aed 0 ..1. i I 1 i ..L 1 .._.1 160 170 180 190 200 210 220 230 240 250 260 270 •GSTABL7 v.2 FSmin=1.166 Factor Of Safety Is Calculated By The Modified Bishop Method 1907-03 Section Bp-Bp' - Static 8 ft. Key - Proposed etproject filesl1907-03 begonia &kali evalualiontalcs & analysisA907-03 section bp 8fl key and grid.p1.2 Run STAGS 10/8/2019 04:46PM 1— 1 Soft Sol Total Saturated Cohesion Friction Pore Pressure Plea. Desc. Type Unit Wt. Unit WL Intercept Angle Pressure Constant Surface No. (pot) (pt.* (pat) (deg} Param. (pst) ale 1 125.0 125.0 50.0 30.0 0,00 0.0 Qvisp 2 125.0 125.0 150.0 31.0 0.00 0.0 60 7 4. 2 40 a ri g ets 1 4.5.41.. • — gb 2 80 5 FS a 1.668 b 1.572 1.594 d 1.613 a 1.5n 1.658 g 1.662 h 1.534 I 1.$70 IZOZ '9I t-lilelAl 7,tt. - 0 • 20 y 2 E6T JO 817 aed 0 L 160 180 200 220 GSTABL7 v.2 FSmin=1.669 Safety Factors Are Calculated By The Modified Bishop Method 240 260 2 1907-03 Section Bp-B' Pseudostatic 8 ft. Key - Proposed z:Vroject filest1907-03 begonia ct wall evaluation‘calts & analysisk1907-03 section bp 8ft key and arid sutface #1.olt Run By: AGS 10i812019 0444PM Soil Soil Total Saturated Cohesion friction Pore Pressure Ram Load Value Vesc. Type Unit WI, Unit Wt. Intercept Angle Pressure Constant Surface Peek(A). 0.470(g) No. (pc1) (pcf) (psi) (deg) Parana. (Psf) No. -kb Coef. oiso(g)‹ ate 1 125.0 125.0 50.0 30.0 0.00 0.0 0 Ovop 2 125:0 125.0 150.0 31.0 0.00 0.0 0 80 -HOZ `9T t-PielAl 60 40 11 01T" ft..= 2 15 i y 2 20 0 - 160 180 2 6T JO 617 aed 200 220 240 260 GSTABL7 v.2 FSinin=1.210 Factor Of Safety Is Calculated By The Modifiod Bishop Method APPENDIX E GENERAL EARTHWORK SPECIFICATIONS AND GRADING DETAILS ADVANCED GEOTECHNICAL SOLUTIONS, INC. March 16, 2021 Item #4 Page 50 of 193 General Earthwork Specifications Page I GENERAL EARTHWORK SPECIFICATIONS I. General A. General procedures and requirements for earthwork and grading are presented herein. The earthwork and grading recommendations provided in the geotechnical report are considered part of these specifications, and where the general specifications provided herein conflict with those provided in the geotechnical report, the recommendations in the geotechnical report shall govern. Recommendations provided herein and in the geotechnical report may need to be modified depending on the conditions encountered during grading. 3. The contractor is responsible for the satisfactory completion of all earthwork in accordance with the project plans, specifications, applicable building codes, and local governing agency requirements. Where these requirements conflict, the stricter requirements shall govern. C.It is the contractor's responsibility to read and understand the guidelines presented herein and in the geotechnical report as well as the project plans and specifications. Information presented in the geotechnical report is subject to verification during grading. The information presented on the exploration logs depict conditions at the particular time of excavation and at the location of the excavation. Subsurface conditions present at other locations may differ, and the passage of time may result in different subsurface conditions being encountered at the locations of the exploratory excavations. The contractor shall perform an independent investigation and evaluate die nature of the surface and subsurface conditions to be encountered and the procedures and equipment to be used in performing his work. D.The contractor shall have the responsibility to provide adequate equipment and procedures to accomplish the earthwork in accordance with applicable requirements. When the quality of work is less than that required, the Geotechnical Consultant may reject the work and may recommend that the operations be suspended until the conditions are corrected. E.Prior to the start of grading, a qualified Geotechnical Consultant should be employed to observe grading procedures and provide testing of the fills for conformance with the project specifications, approved grading plan, and guidelines presented herein. All clearing and grubbing, remedial removals clean-outs, removal bottoms, keyways, and subdrain installations should be observed and documented by the Geotechnical Consultant prior to placing fill. It is the contractor's responsibility to apprise the Geotechnical Consultant of their schedules and notify the Geotechnical Consultant when those areas are ready for observation. F.The contractor is responsible for providing a safe environment for the Geotechnical Consultant to observe grading and conduct tests. IL Site Preparation A. Clearing and Grubbing: Excessive vegetation and other deleterious material shall be sufficiently removed as required by the Geotechnical Consultant, and such materials shall be ADVANCED GEOTECHNICAL SOLUTIONS, INC. March 16, 2021 Item #4 Page 51 of 193 General Earthwork Specifications Page 2 properly disposed of offsite in a method acceptable to the owner and governing agencies. Where applicable, the contractor may obtain permission from the Geotechnical Consultant owner, and. governing agencies to dispose of vegetation and other deleterious materials in designated areas onsite. B.Unsuitable Soils Removals: Earth materials that are deemed unsuitable for the support of fill shall be removed as necessary to the satisfaction of the Geotechnical Consultant. C.Any underground structures such as cesspoles, cisterns, mining shafts, tunnels, septic tanks, wells, pipelines, other utilities, or other structures located within the limits of grading shall be removed and/or abandoned in accordance with the requirements of the governing agency and to the satisfaction of the Geotechnical Consultant, Environmental evaluation of existing conditions is not the responsibility of the Geotechnical Consultant D, Preparation of Areas to Receive Fill: After removals are completed, the exposed surfaces, shall be processed .or scarified to a depth of approximately 8 inches, watered or dried, as needed, to achieve a generally uniform moisture content that is at or pear optimum moisture content. The scarified materials shall then be compacted to the project requirements and tested as specified. E. All areas receiving fill shall be observed and approved by the Geotechnical Consultant prior to the placement of fill. A licensed surveyor shall provide survey 'control for determining elevations of processed areas and keyways. III. Placement of Fill A.Suitability alit! materials: Any materials, derived onsite or imported, may be utilized as fill provided that the materials have been determined to be suitable by the Geotechnical Consultant. Such materials shall be essentially free of organic matter and other deleterious materials, and be of a gradation, expansion potential, and/or strength that is acceptable to the Geotechnical Consultant. Fill materials shall be tested in a laboratory approved by the Geotechnical Consultant, and import materials shall be tested and approved prior to being imported. B.Generally, different fill materials shall be thoroughly mixed to provide a relatively uniform blend of materials and prevent abrupt changes in material type, Fill materials derived from benching should be dispersed throughout the till area instead of placing the materials withireonly an equipment-width from the cut/fill contact. C.Oversize Materials: Rocks greater than 12 inches in largest dimension shall be disposed of offsite or be placed in accordance with the recommendations by the Geotechnical Consultant in the areas that are designated as suitable for oversize rock placement. Rocks that are smiler than 8 inches in largest dimension may be utilized in the till provided that they are not nested and are their quantity and distribution are acceptable to the Geotechnical Consultant and do not inhibit the ability to properly compact fill materials. ADVANCED GEOTECHNICAL SOLUTIONS, INC. March 16, 2021 Item #4 Page 52 of 193 General Earthwork Specifications Page 3 D.The fill materials shall be placed in thin, horizontal layers such that, when compacted, shall not exceed 6 inches. Each layer shall be spread evenly and shall be thoroughly mixed to obtain a near uniform moisture content and uniform blend of materials. E.Moisture Content: Fill materials shall be placed at or above the. optimum moisture content or as recommended by the geotechnical report. Where the moisture content of the engineered fill is less than recommended, water shall be added. and the fill materials shall be blended so that a near uniform moisture content is achieved. If the moisture content is above the limits specified by the Geotechnical Consultant, the fill materials shall be aerated by discing, blading, or other methods until the moisture content is acceptable. F.Each layer of fill shall be compacted to the project standards in accordance to the project specifications and recommendations of the Geotechnical Consultant, Unless otherwise specified by the Geotechnical Consultant, the till shall be compacted to a minimum of 90 percent of the maximum dry density as determined by ASTM Test Method; DI 557. G.Benching: Where placing fill on a slope exceeding a ratio of $ to I (horizontal to vertical), the ground should be keyed or benched. The keyways and benches shall extend through all unsuitable materials into suitable materials such as firm materials or sound bedrock or as recommended by the Geotechnical Consultant. The minimum keyway width shall be 15 feet and extend into suitable materials, or as recommended by the geoteChnical report and approved by the Geotechnical Consultant. The minimum keyway width for fill over cut slopes is also 15 feet, or as recommended by the geotechnical report and approved by the Geotechnical Consultant As a general rule, unless otherwise recommended by the Geotechnical Consultant, the minimum width of the keyway shall be equal to V2 the height of the fill slope. H.Slope Face; The specified minimum relative compaction shall be maintained out to the finish face of fill and stabilization fill slopes. Generally, this may be achieved by overbuilding the slope and cutting back to the compacted core. The actual amount of overbuilding may vary as field conditions dictate. Alternately, this may be achieved by backrolling the slope face with suitable equipment or other methods that produce the designated result. Loose soil should not be allowed to build up on the slope face. If present, loose soils shall be trimmed to expose the compacted slope face. I.Slope Ratio: Unless otherwise approved by the Geotechnieal Consultant and governing agencies, permanent fill slopes shall be designed and constructed no steeper than 2 to I (horizontal to vertical). J.Natural Ground and Cut Areas: Design grades that are in natural ground or in cuts should be evaluated by the Geotechnical Consultant to determine whether scarification and processing of the ground and/or overexcavation is needed. K.Fill materials shall not be placed, spread, or compacted during unfavorable weather conditions. When grading is interrupted by rain, filing operations shall not resume until the Geotechnical Consultant approves the moisture and density of the previously placed compacted fill. ADVANCED GEOTECHNICAL SOLUTIONS, INC. March 16, 2021 Item #4 Page 53 of 193 General earthwork Specifications Page 4 IV. Cut Slopes A.The Geotechnical Consultant shall observe all cut slopes, including fill over cut slopes, and shall be notified by the contractor when cut slopes are started. B.if adverse or potentially adverse conditions are encountered during grading, the Geotechnical Consultant shall investigate, evaluate, and make recommendations to mitigate the adverse conditions. C.Unless otherwise stated in the geotechnical report, cut slopes shall not be excavated higher or steeper than the requirements of the local governing agencies. Short-term stability of the cut slopes and other excavations is the contractor's responsibility. V. Drainage A.Backdrains and Subdrains: Backdrains and subdrains shall be provided in fill as recommended by the Geotechnical Consultant and shall be constructed in accordance with the governing agency andior recommendations of the Geotechnical Consultant. The location of subdrains, especially outlets, shall be surveyed and recorded by the Civil Engineer. B.Top-of-slope Drainage: Positive drainage shall be established away from the top of slope. Site drainage shall not be permitted to flow over the tops of slopes. C.Drainage terraces shall be constructed in compliance with the governing agency requirements and/or in accordance with the recommendations of the Civil Engineer. D.Non-erodible interceptor swales shall be placed at the top of cut slopes that face the same direction as the prevailing drainage. VI. Erosion Control A.All finish cut and fill slopes shall by protected from erosion and/or planted in accordance with the project specifications and/or landscape architect's recommendations. Such measures to protect the slope face shall be undertaken as soon aS practical after completion of grading. B.During construction, the contractor shall maintain proper drainage and prevent the pending of water. The contractor shall take remedial measures to prevent the erosion of graded areas until permanent drainage and erosion control measures have been installed. VII. Trench Excavation and Backfill A. Safety: The contractor shall follow all OSHA requirements for safety of trench excavations. Knowing and following these requirements is the contractor's responsibility. All trench excavations or open cuts in excess of 5 feet in depth shall be shored or laid back. Trench excavations and open cuts exposing adverse geologic conditions may require further evaluation ADVANCED GEOTECHNICAL SOLUTIONS, INC. March 16, 2021 Item 444 Page 54 of 193 General Earthwork Specifications Page 5 by the Geotechnical Consultant. If a contractor fails to provide safe access for compaction testing, backfill not tested due to safety coneems may be subject to removal. B.Bedding: Bedding materials shall be non-expansive and have a Sand Equivalent greater than 30. Where permitted by the Geotechnical Consultant, the bedding materials can be densified by jetting. C.Backfill: Jetting of backfill materials to achieve compaction is generally not acceptable. Where permitted by the Geotechnical Consultant, the bedding materials can be densified by jetting provided the backfill materials are granular, free-draining and have a Sand Equivalent greater than 30. Geoteehnieat Observation and Testing During Grading A.Compaction Testing: Fill will be tested and evahlated by the Geotechnical Consultant for evaluation of general compliance with the recommended compaction and moisture conditions. The tests shall be taken in the compacted soils beneath the surface if the surficial materials are disturbed. The contractor shall assist the Geotechnical Consultant by excavating suitable test pits for testing of compacted fill. B.Where tests indicate that the density of a layer of fill is less than required, or the moisture content is not within specifications, the Geotechnical Consultant shall notify the contractor of the unsatisfactory conditions of the fill. The portions of the, fill that are not within specifications shall be reworked until the required density and/or moisture content has been attained. No additional fill shall be placed until the last lift of fill is tested and found to meet the project specifications and approved by the Geotechnical Consultant, C.If, in the opinion of the Geotechnical Consultant, unsatisfactory conditions, such as adverse weather, excessive rock or deleterious materials being placed in the fill, insufficient equipment, excessive rate of fill placement, results in a quality of' work that is unacceptable, the consultant shall notify the contractor, and the contractor shall rectify the conditions, and if necessary_ stop work until conditions are satisfactory. D.Frequency of Compaction Testing: The location and frequency of tests shall be at the Geotechnical Consultant's discretion. Generally, compaction tests shall be taken at intervals approximately two feet in fill height. E.Compaction Test Locations: The Geotechnical Consultant shall document the approximate elevation and horizontal coordinates of the compaction test locations. The contractor shall coordinate with the surveyor to assure that sufficient grade stakes are established so that the Geotechnical Consultant can determine the test locations. Alternately, the test locations can be surveyed and the results provided to the Geotechnica I Consultant. F.Areas of fill that have not been observed or tested by the (=technical Consultant may have to be removed and recompacted at the contractor's expense. The depth and extent of removals will be determined by the Geotechnical Consultant. ADVANCED GEOTECHNICAL SOLUTIONS, INC. March 16, 2021 Item #4 Page 55 of 193 Cieneral Earthwork Specifications Page 6 G.Observation and testing by the Geotechnical Consultant shall be conducted during grading in order for the Geotechnical Consultant to state that in his opinion, grading has been completed in accordance with the approved geotechnical report and project specifications. H.Reporting of Test Results: After completion of grading operations, the Geotechnical Consultant shall submit reports documenting their observations during construction and test results, These reports may be subject to review by the local governing agencies. ADVANCED GEOTECHNICAL SOLUTIONS, INC. March 16, 2021 Item #4 Page 56 of 193 E61 JO LS aEd IZOZ `91 1714 WD11 BEGONIA COURT ,,Pla ;.5,44 f.$ Cr;1.41:11 eta e.r J r * ..›*-1•Ar....• Att. ftAtr e;:-...;17:2:4711.11 ;11E.. * V*. 0.0.4VMAP!,(11 aAan TO Z `9-E Lip-leiAl CROSS-SECTION f'. E6T 10 8S aed Pr - CROSS-SECTION PLIAE I •r....r.e..a.v....aria %OAGS .• kevormoor4i %:41Allin ',NM; PIN - 1/......121100.1501* EXHIBET5 PDVPNCED GEOTECHNCPL SOLUTIONS, I NC. 485 Corporate Drive, Suite B Escondido, Ca 92029 Telephone: (619) 867-0487 FUSION ENGINEERING & TECHNOLOGY 4231 Balboa Avenue, Suite 619 San Diego, CA 92117 Attention: John Rivera, PE September 10, 2020 P/W 1907-03 Report No. 1907-03-B4 Subject: Geotechnical Addendum, Response to City of Carlsbad Engineering Review Comments, Lichtman Residence, 939 Begonia Court, City of Carlsbad, California. References: Appendix Gentlemen: In accordance with your request and authorization, Advanced Geotechnical Solutions, Inc., has prepared this response to Engineering Review Comments provided by the City of Carlsbad Community Development Department regarding the existing Mechanically Stabilized Earth (MSE) retaining walls in the rear yard of the Lichtman Residence located at 939 Begonia Court, City of Carlsbad, California. More specifically, this letter has been prepared in response to Engineering review comments la through lg from the 1St Review for CDP 2020-0026/V 2020-0004 (DEV 2020-0134) - Begonia Court Retaining Wall dated June 29, 2020 and provided to AGS on September 9, 2020. Unless superseded in the text of this addendum report, the conclusions and recommendations presented in referenced geotechnical report (AGS 2019) remain valid and applicable and should be properly implemented. hi preparing this response to cycle review comments we have first presented the review comment followed by our response. City of Carlsbad- Submit supplemental geotechnical report to the report dated October 9, 2019 by AGS expanding on analysis and recommendations of the third option chosen to reinforce the existing system. Include in the supplemental geotechnical report: la — Recommendations for anchor locations, lengths, spacing, etc. and specify which walls shall be anchored. AGS Response — It is our understanding that stabilization of the existing MSE retaining walls will be performed on a design-build basis. The design-build contractor will provide the locations, lengths, spacing, etc. of the soil nails/tie-backs and determine which walls will be anchored. Any MSE retaining walls not stabilized with a shotcrete and soil nail/tie-back system should be evaluated by AGS and may require reconstruction using the appropriate geogrid type, length, and spacing and the reinforced and retained soils compacted to a minimum of 90 percent of the dry density per ASTM D- 1557. The shotcrete with soil nail/tie-back system should be designed by a licensed engineer familiar with these systems. The soil nail/tie-back capacity is dependent on the drilling and grouting methods and should be estimated by the design-build contractor. Testing should be conducted during construction. For preliminary estimating purposes, ultimate anchor capacities in the formational materials (sandstone) can be assumed to be 4,300 pounds per square foot (30 psi). Since the above friction capacities are considered ultimate, an appropriate factor of safety should be incorporated into the design. Soils nails should be embedded a minimum of 10 feet into competent formational ORANGE AND L.A. COUNTIES INLAND EMPIRE SAN DIEGO AND IMPERIAL COUNTIES (714) 786-5661 (619) 708-1649 (619) 867-0487 March 16, 2021 Item #4 Page 59 of 193 _Page 2 September 10, 2020 Report I 907-03-B-4 P/W 1907-03 materials. The soil nail/tie-back reinforcement system should be designed to support an active pressure corresponding to an equivalent fluid weight of 40 pcf for level backfill and 60 pcf for sloping backfill, and should also consider the surcharges of the tiered walls. When a design is available, it should be reviewed by AGS and a global stability analysis performed. lb— Installation methods and procedures. AGS Response — Installation methods and procedures should be provided by the design-build contractor. Typically, this type of reinforcement may first include coring through the MSE wall blocks at predetermined locations. Hand drills would be used to advance an inclined hole to the design length. The soil nail would be placed in the hole and possibly tubes for primary and post grouting. Testing of selected soil nails would be completed after grouting. Drain boards may be installed on the outside of the MSE wall blocks and a reinforcement mat may be installed. Bearing plates would be affixed to the end of the nails and possibly tied to the reinforcement mat on the outside of the MSE wall. Shotcrete would then be applied to complete the wall. lc — Assess overall feasibility of the project. AGS Response — Stabilization of the existing MSE retaining wall system with soil nails/tie-back anchors is considered feasible from a geotechnical perspective. Plans for the stabilization of the existing retaining walls should be reviewed by AGS when they are available. ld— Location Map. AGS Response — Figure 1- Site Location Plan is included herewith. le — Describe impacts on adjacent properties/improvements as a result of site grading and construction. AGS Response — It is anticipated that the impacts on adjacent properties/improvements as a result of site grading and construction will be negligible to favorable. It should be noted that depending on the fmal design length of the soil nails/tie-backs, they may encroach into the superjacent parcel(s) and require permission from the adjacent property owner(s). if— Reference applicable building/grading codes/ordinances. AGS Response — Applicable building/grading codes/ordinances should be provided by the design engineer and included on the project plans. le — Recompaction requirements as the fill has not been recompacted to a minimum of 90% of relative compaction per the conclusions in Section 6.0 of October 9, 2019 report. Is recompaction of slopes and level areas between wall required for this remediation option? Design engineer shall also estimate remediation quantities for recompaction in their grading quantity assessment. AGS Response — AGS is unaware of slopes between walls with the exception of the stairs. Provided that there are no structural or settlement sensitive improvements constructed in the project area and that some settlement of the retained soils is acceptable to the property owner, recompaction of the existing retained fill soils is not required. The recommended design active pressure for the ADVANCED GEOTECHNICAL SOLUTIONS, INC. March 16, 2021 Item #4 Page 60 of 193 HN J. DOdOVAN CE 65051, GE 2790, Reg. Exp. 6-30-21 Distribution: (3) Addressee Attachments: References Figure 1 — Site Location Map PAUL J. DERIS1 CEG 2536, Reg. Exp. 5-31-21 4. Q LP No. 2536 -- _4 CERTIFIED ENGINEERING GEOLOGIST Page 3 September 10, 2020 Report 1907-03-B-4 P/W 1907-03 reinforcement system and the shear strengths provided in the referenced report that should be used for the global stability analysis have considered the current condition of the existing fill. Advanced Geotechnical Solutions, Inc. appreciates the opportunity to provide you with geotechnical consulting services and professional opinions. Should you have any questions, please contact the undersigned at (619) 867-0487. Respectfully Submitted, Advanced Geotechnical Solutions, Inc. ADVANCED GEOTECHNICAL SOLUTIONS, INC. March 16, 2021 Item #4 Page 61 of 193 Page 4 September 10, 2020 Report 1907-03-B-4 P/W 1907-03 REFERENCES Advanced Geotechnical Solutions, Inc. (2010). "Geotechnical Evaluation of Existing Mechanically Stabilized Earth Walls, 939 Begonia Court, City of Carlsbad, California," dated October 9, 2019, Report No. 1907-03-B-3. Fusion Engineering and Technology, Preliminary Site Plan for Lichttnan Residence, 939 Begonia Court, City of Carlsbad, California, Map 1 of 1, 10-Scale, undated. Kennedy, M.P., and Tan, S.S., 2007, Geologic Map of the Oceanside 30' x 60' Quadrangle, California Geological Survey: Scale 1:100,000. ADVANCED GEOTECHNICAL SOLUTIONS, INC. March 16, 2021 Item #4 Page 62 of 193 SCALE 1:48000 P/W 1907-03 FIGURE 1 AGS ADVANCED GEOTECHNICAL SOLUTIONS, INC. 485 Corporate Drive, Suite B Escondido, CA 92029 Telephone: (619) 867-0487 Fax: (714) 409-3287 SITE LOCATION MAP 939 BEGONIA COURT, CARLSBAD, CALIFORNIA SOURCE MAP - U.S.G.S. TOPOGRAPHIC MAP OF THE ENCINITAS 7.5 MINUTE QUADRANGLE, SAN DIEGO COUNTY, CALIFORNIA (2018) March 16, 2021 Item #4 Page 63 of 193 EXHIBIT 6 PLANNING COMMISSION RESOLUTION NO. 7394 A RESOLUTION OF THE PLANNING COMMISSION OF THE CITY OF CARLSBAD, CALIFORNIA, RECOMMENDING THAT THE CITY COUNCIL DENY A COASTAL DEVELOPMENT PERMIT AND VARIANCE TO ALLOW AN UNPERMITTED RETAINING WALL SYSTEM THAT EXCEEDS STANDARDS ON A MANUFACTURED UPHILL PERIMETER SLOPE WITH A GRADIENT GREATER THAN 40 PERCENT AND AN ELEVATION DIFFERENTIAL OF GREATER THAN FIFTEEN FEET LOCATED AT 939 BEGONIA COURT ON PROPERTY LOCATED AT 939 BEGONIA COURT WITHIN THE MELLO II SEGMENT OF THE CITY'S LOCAL COASTAL PROGRAM AND LOCAL FACILITIES MANAGEMENT ZONE 4. CASE NAME: BEGONIA COURT RETAINING WALL CASE NO: CDP 2020-0026/V 2020-0004 WHEREAS, Rene Lichtman, "Developer/Applicant," has filed a verified application with the City of Carlsbad regarding property owned by Valerie Lichtman, "Owner," described as Lot 138 of Carlsbad Tract No. 73-79, Spinnaker Hill Unit #3, in the City of Carlsbad, County of San Diego, State of California, according to map thereof no. 8453, filed in the Office of the County Recorder of San Diego County on December 29, 1976 ("the Property"); and WHEREAS, said verified application constitutes a request for a Coastal Development Permit and Variance as shown on Exhibit(s) "A" dated December 16, 2020, attached hereto and on file in the Carlsbad Planning Division, CDP 2020-0026/V 2020-0004 — BEGONIA COURT RETAINING WALL, as provided in Chapters 21.201 and 21.50 of the Carlsbad Municipal Code; and WHEREAS, the Planning Commission did, on December 16, 2020, hold a duly noticed public hearing as prescribed by law to consider said request; WHEREAS, at said public hearing, upon hearing and considering all testimony and arguments, if any, of all persons desiring to be heard, said Commission considered all factors relating to the Coastal Development Permit and Variance. NOW, THEREFORE, BE IT HEREBY RESOLVED by the Planning Commission of the City of Carlsbad, as follows: A) That the above recitations are true and correct. March 16, 2021 Item #4 Page 64 of 193 B) That based on the evidence presented at the public hearing, the Commission RECOMMENDS DENIAL of CDP 2020-0026/V 2020-0004 — BEGONIA COURT RETAINING WALL, based on the following findings and subject to the following conditions: Findings: Coastal Development Permit (CDP 2020-0026) 1.The proposed development is not in conformance with the Certified Local Coastal Program and all applicable policies in that the site is known for geologic instability due to the unpermitted grading and construction of an unpermitted retaining wall system. A geotechnical evaluation provided by the applicant and prepared by Advanced Geotechnical Solutions, Inc., dated October 9, 2019 (see Attachment 8) confirms the slope stability has been compromised and does not meet minimum safety standards for static or seismic conditions. The geotechnical evaluation offered conceptual options to mitigate the structure; however, the applicant's engineer did not provide adequate technical information to determine if the subject slope area would be stable or if the impacts would be mitigatable for at least seventy-five years or for the life of the structure. The city requested specific structural details related to the retaining walls and retrofitting of the walls. The applicant refused to provide the information and the applicant's engineer stated that the specifics regarding the retrofit would be on a design-build basis (see Attachment 9). A design- build basis implies that the necessary information to demonstrate the feasibility of the retrofit would only be provided after the coastal development permit and variance are approved, but the city does not have the information to rely upon in order to approve the project. Therefore, staff does not have the necessary information to make the determination that the slope would be stable, or if the impacts would be mitigatable for at least seventy-five years or for the life of the structure. In addition, the geotechnical evaluation did not address compliance with the requirements of the Coastal Zone or Zoning Ordinance. Therefore, the project is not consistent with the intent and purpose of the Certified Local Coastal Program in that it does not preserve or protect steep manufactured slopes, nor does the project ensure structural stability of the slope . from erosion, geological instability or destruction of the site or surrounding area. The project does • not meet this finding. 2.The project is not consistent with the provisions of the Coastal Resource Protection Overlay Zone (Chapter 21.203 of the Zoning Ordinance) because the geotechnical evaluation did not provide adequate information for staff to confirm that the project will avoid increased urban runoff, pollutants and soil erosion and there is a steep slope (equal to or greater than 25 percent gradient) of approximately 55 percent locatecion the subject property. The project does not meet this. finding based on the analysis in finding number 1 above. a. The applicant provided a geotechnical evaluation that was prepared by a licensed engineer who inspected the unpermitted retaining wall system and determined the wall system is structurally faulty because the fill has not been compacted to a minimum percentage that is safe. In addition, the evaluation finds that the slope is not safe for long term stability for static conditions or seismic conditions. The geotechnical evaluation included three options to remediate the wall system to make it structurally sound which are: A) remove the existing walls and undocumented fill and replace it with a new five-foot wall near the toe of the slope with an ascending fill slope located above the wall, and rebuild a new wall system constructed near the top of the fill slope; B) remove the walls and undocumented fill and restore the existing slope; or C) leave the existing walls in place with considerable reinforcement effort, which may require encroachment onto the adjacent properties that will require authorization MarabstEV 002194 -2- Item #4 Page 65 of 193 from the property owners. Although the geotechnical evaluation offered conceptual options to mitigate the structure, the applicant's engineer did not provide adequate technical information to determine if the subject slope area would be stable or if the impacts would be mitigatable for at least seventy-five years or for the life of the structure as described in more detail in Section III(C)(1)(a) of the staff report above. b. The grading of the manufactured uphill perimeter slope is not essential for the development intent and design of a single-family residential property. If it were essential, it would have been done with the original grading of the overall subdivision development. Grading is only necessary to retain the unpermitted retaining wall system, but the walls are not a permitted structure-on a manufactured uphill perimeter slope in accordance with CMC Chapter 21.95 — Hillside Development Regulations. In addition, grading on a manufactured uphill perimeter slope beyond the six-foot limitation is only allowed in the Coastal Zone when it is necessary to preserve onsite natural habitat as required by the city's Habitat Management Plan. The project site is in the Coastal Zone but there is no natural habitat onsite that is required to be preserved; therefore, the grading of the slope is not essential to the development. The project does not meet this finding. Variance (V 2020-0004) 3.The applicant's justification does not speak to special circumstances related to the subject property, or loss of privileges enjoyed by other properties, but instead speaks to circumstances the applicant created through the illegal grading and construction of the retaining wall system. There are no special circumstances associated with the property, including size, shape, topography, location or surroundings, such that the strict application of the zoning ordinance would deprive the property of privileges enjoyed by the other homes in the vicinity and in the R-1 Residential zone. The property is of average size (17,146 sq. ft.) in the neighborhood and is a typical pie-shaped lot that is found on a cul-de-sac street. The other lots in the vicinity range in size from about 12,000 to about 19,000 square feet in size. The 55 percent manufactured uphill perimeter slope is characteristic of the adjacent properties and other properties in the vicinity. The strict application of the zoning code does not deprive the property of privileges enjoyed by other property owners because retaining walls that exceed the hillside development standards on a manufactured uphill perimeter slope are unpermitted for all residential properties. The retaining wall system is decorative and does not constitute relief from unique difficulties or hardships associated with the property in question. 4.The variance would constitute a grant of special privileges that is inconsistent with the limitations upon other properties in the vicinity and zone. All properties in the vicinity and the R-1 Residential zoning designation in the Coastal Zone are subject to the same Hillside Development Ordinance regulations that are in effect, which prohibit retaining walls from being constructed beyond what is allowed on a manufactured uphill perimeter slope. No other properties in the vicinity have similar, permitted retaining walls on the manufactured uphill perimeter slope. To approve the subject variance would be a grant of special privileges to this property that other properties in the vicinity do not enjoy. 5.The granting of this variance would authorize a use or activity which is not otherwise expressly authorized by the zone regulation governing the subject property. The fact that the retaining wall system is existing because it has been constructed without city approval is not appropriate justification to approve the variance. As designed, the unpermitted retaining wall system is iteME10116020294 -3- . Item #4 Page 66 of 193 prohibited per CMC Chapter 21.95 — Hillside Development Regulations which governs •development on manufactured uphill perimeter slopes. CMC Chapter 21.95 allows for modifications to development on slopes; however, modifications are prohibited in the Coastal Zone unless it is necessary to preserve natural habitat as required by the city's Habitat Management Plan. The subject property is in the Coastal Zone, but there is no native habitat on site and the project is not necessary to preserve natural habitat Therefore, granting the variance would authorize an activity that is expressly not authorized within the applicable zoning regulations. 6.The granting of this variance is not consistent with the general purpose and intent of the General Plan. The subject property is designated Residential (R — 4) General Plan Land Use designation and although walls are a typical component of residentially designated areas, the subject retaining wall system is not consistent with the development of single-family lots with a manufactured uphill perimeter slope within the Coastal Zone. The subject retaining wall system also does not promote the Hillside Development Ordinance intent to enhance the aesthetic qualities of manufactured slopes and is not consistent with the Hillside Development and Design Guidelines acknowledgment that manufactured slopes of greater than 40% gradient and greater than 15 feet in height are regarded as important aesthetic, visual resources because they provide visually open, vertical separations between developed pads in hilly areas and between developed pads and roadways. As a result, the project does not preserve the existing neighborhood atmosphere and identity of the existing residential area. 7.The granting of this variance would not be consistent with the general purpose and intent of the certified local coastal program and does reduce or adversely affect the requirements for protection of coastal resources. One of the purposes of the certified local coastal program is to preserve and protect natural and manufactured slopes in the coastal resource protection overlay zone area and to ensure stability and structural integrity of the slopes from erosion, geologic instability, or destruction of the site. The unpermitted grading that has occurred to construct the unpermitted and unengineered retaining wall system has compromised the stability of the slope. To retain the wall system will require considerable reinforcement and the structural integrity of reinforcing the walls has not been determined since the applicant has refused to provide such information at this time as described in detail previously in the staff report. Therefore, the feasibility of retaining the wall system and stabilizing the slope in accordance with the requirements for protection of the local coastal resources is unknown. Condition: 1. Within 60 days from the date of the City Council action, or as otherwise specified in the Code Compliance Agreement and Release for Code Enforcement Case No. CC 2018-0902, the property owner shall apply for the necessary permits such as but not limited to a grading permit and coastal development permit to remove the unpermitted retaining wall system and restore the slope to comply with CMC Section 21.95.140(C)(1)(a)(i). rf6W9d`,19oR94 -4- Item #4 Page 67 of 193 PASSED, APPROVED, AND ADOPTED at a regular meeting of the Planning Commission of the City of Carlsbad, California, held on December 16, 2020, by the following vote, to wit: AYES: Chair Anderson, Commissioners Geldner, Lafferty, Luna, Meenes and Stine NOES: ABSENT: ABSTAIN: Commissioner Merz VELYN ANDERSON, Chair CARLSBAD PLANNING COMMISSION ATTEST: DON NEU City Planner fklaaMS92029.4 -5: Item #4 Page 68 of 193 PLANNING COMMISSION Staff Report EXHIBIT 7 Item No. P.C. AGENDA OF: December 16, 2020 Application complete date: October 8, 2020 Project Planner: Jessica Bui Project Engineer: David Rick SUBJECT: CDP 2020-0026/V 2020-0004 (DEV2020-0134) — BEGONIA COURT RETAINING WALL - Request for a Coastal Development Permit and a Variance to allow an unpermitted retaining wall system that exceeds standards on a manufactured uphill perimeter slope with a gradient greater than 40 percent and an elevation differential of greater than fifteen feet on property located at 939 Begonia Court within the Mello II Segment of the city's Local Coastal Program and Local Facilities Management Zone 4. The project site is not within the appealable area of the California Coastal Commission. The City Planner has determined pursuant to Sections 15061(b)(4) and 15270 of the state CEQA Guidelines that the project is exempt from CEQA because CEQA does not apply to projects which a public agency rejects or disapproves. RECOMMENDATION That the Planning Commission ADOPT Planning Commission Resolution No. 7394 RECOMMENDING that the City Council DENY Coastal Development Permit CDP 2020-0026 and Variance V 2020-0004 based upon the findings and subject to the conditions contained therein. II. PROJECT DESCRIPTION AND BACKGROUND Project Site/Setting: The 0.39-acre (17,146 square feet) project site is located at 939 Begonia Court as shown on the attached location map. The site is developed with a two-story, single-family residence. The property slopes from a high point of approximately 204 feet above mean sea level at the rear of the lot to a low point of approximately 166 feet above mean sea level adjacent to the street, Begonia Court. The eastern half of the property, or the backyard area (above 168 feet contour line) is comprised of an uphill slope with a gradient of approximately 55 percent. The lot is surrounded by single-family residences to the north, south, east and west. Table "A" below includes the General Plan designations, zoning and current land uses of the project site and surrounding properties. TABLE A Location General Plan Designation Zoning Current Land Use Site R — 4 Residential R — 1 One — Family Residential Single—Family Residence North, South, East and West R — 4 R — 1 Single — Family Residence March 16, 2021 f 1/4.3 Item #4 Page 69 or-193 CDP 2020-0026/V 2020-0004 (DEV2020-0134) — BEGONIA COURT RETAINING WALL December 16, 2020 Page 2 Project Background: The existing single-family residence is in the Coastal Zone and is used as a short-term vacation rental (STVR)1. The property has one open Code Enforcement violation for the existing and unpermitted retaining wall system. The Code Enforcement Division opened a case against the property owner in late 2018 upon discovering unpermitted grading and ongoing construction on the property. Code Enforcement issued a notice of violation against the property owner in February 2019 and a final notice of violation in June 2019. Construction stopped in approximately June 2019 as described below, although the violations have not been corrected to date. Instead, property owner chose to pursue this variance application. According to its geotechnical report, the property owner began unpermitted grading and construction of the multi-tiered retaining wall system into the uphill slope located in the backyard in March 2016 and continued until approximately June 2019. The city issued a notice of violation to the property owner for violations of Carlsbad Municipal Code (CMC) Section 15.16.050 of the Grading Ordinance because the property owner graded the slope to construct the walls without a grading permit; CMC Section 21.95.140 of the Hillside Development Ordinance for constructing a retaining wall system on a manufactured uphill perimeter slope that exceeds the permitted standards; and CMC Section 21.203.040 for the construction of the wall system without approval of a coastal development permit to ensure compliance with the required provisions in the Coastal Resource Protection Overlay Zone. To ensure the health and safety of STVR guests or other individuals during this review process, the Code Enforcement Division required the area of the unpermitted walls be sectioned off with a gate and caution tape to restrict entering or recreating on the slope that has been structurally compromised, and to disclose the restriction in rental marketing materials. The Planning Division, Engineering Division, Code Enforcement and City Attorney's Office conferred with the property owner on several occasions since 2018 regarding potential corrective actions. The actions discussed were: A) apply for and obtain a grading permit to remove the unpermitted walls and bring the system into compliance with the Hillside Development Ordinance and restore the slope above to its original condition; or B) apply for a coastal development permit and variance application to request the approval for the unpermitted retaining wall system to remain. Option A may not require a coastal development permit because bringing the wall into compliance with the Hillside Development Ordinance should avail the applicant of the standard exemption for typical improvements associated with a single- family residence outside the Coastal appeal area. However, staff advised the property owner that a recommendation for denial would likely result from Option B, the application for a coastal development permit and variance, because the walls do not meet code requirements of CMC Section 21.203.040 — Coastal Resource Protection Overlay Zone, CMC Section 21.95.140 — Hillside Development Ordinance, and the required findings for CMC Section 21.50— Variances. A detailed analysis for each zoning code violation is discussed in Section III —Analysis of this staff report. Project Description: The property owner chose to proceed with option "B." The request for a coastal development permit and variance is to allow an existing and unpermitted retaining wall system to remain on an uphill perimeter slope with a gradient over 40 percent and an elevation differential of greater than fifteen feet ("manufactured uphill perimeter slope") located within the backyard of a single-family residence. The wall system starts at the base of the slope and extends approximately two thirds up the slope toward the rear property line. The wall system is multi-tiered with four levels and is accessed by stairs that start at the toe of the slope, which is adjacent to a swimming pool and spa. The slope has been graded and filled to accommodate the wall system without a required grading permit, and each level In accordance with CMC Chapter 5.60 — Short-Term Vacation Rentals, property owners in the Coastal Zone may operate a short-term rental with the approval of a STVR pennit and a business license. March 16, 2021 Item #4 Page 70 of 193 CDP 2020-0026/V 2020-0004 (DEV2020-0134) — BEGONIA COURT RETAINING WALL December 16, 2020 Page 3 between the multi-tiered system is flat and designed in a manner that could be used as recreation areas. However, a retaining wall or walls are only permitted within an area that is a maximum height of six feet above the grade elevation at the toe of the slope within a manufactured uphill perimeter slope per Carlsbad Municipal Code (CMC) Section 21.95.140.C.1(a) and the Hillside Development and Design Guidelines Section III.B and Exhibit 9 (see Attachment 5). Proposed Grading: The grading quantities (cubic yards of cut and the cubic yards of fill) from the unpermitted grading that had occurred to construct the unpermitted retaining wall system is unknown. Estimated grading quantities will be determined by the applicant's licensed engineer's plan to either remove and remediate the slope or to structurally retrofit the existing wall in place. The CDP and Variance would normally be heard by the Planning Commission as the final decision-maker. However, one aspect of the project's CDP application for deviations to grading of steep slopes within the Coastal Zone requires action by the City Council. Therefore, per CMC Section 21.54.040, Decision-making authority for multiple development permits, both applications require City Council action. The Planning Commission's action on the project will be a recommendation. If the project is denied by the City Council, the walls will be conditioned to be removed and the slope must be restored in accordance with the provisions of CMC Chapter 21.95 — Hillside Development Regulations. The removal of the walls, restoration of the slope, and the retainment or construction of a compliant retaining wall that is a maximum height of six feet tall measured from the grade at the toe of the slope will require the applicant to obtain a grading permit. Furthermore, if the removal and restoration is consistent with the Hillside Development Regulations it will not require a hillside development permit due to the exemption for single family residences. If no impacts are found to coastal resources, a CDP will not be required because improvements normally associated with residences such as this are exempt from the CDP procedures. A CDP may be required if the remediation impacts the property or adjacent properties to an extent that would be considered an impact on coastal resources. The extent of the remediation and CDP requirement would be determined at the time that specific details provided by the applicant's engineer are submitted to the city for review. III. ANALYSIS The project is subject to the following regulations and requirements: A.Grading and Erosion Control (CMC Chapter 15.16); B.Hillside Development Regulations (CMC Chapter 21.95); C.Coastal Development Regulations for the Mello II Segment of the Local Coastal Program (CMC Chapter 21.201) and the Coastal Resource Protection Overlay Zone (CMC Chapter 21. 203); and D.Variances (CMC Chapter 21.50). The recommendation for denial of this project was developed by analyzing the project's inconsistencies with the applicable city regulations and policies. The project is not in compliance with the applicable regulations and is discussed in detail in the sections below. Furthermore, there is no known alternative design or modifications that can be made to this project that would be compatible with the aforementioned applicable regulations short of the removal of the walls, restoration of the slope, and the retainment or construction of one compliant retaining wall that is a maximum height of six feet tall at the toe of the slope. March 16, 2021 Item #4 Page 71 of 193 CDP 2020-0026/V 2020-0004 (DEV2020-0134) — BEGONIA COURT RETAINING WALL December 16, 2020 Page 4 A.Grading and Erosion Control (CMC Chapter 15.16) The Engineering Department determined that the property was in violation of CMC Section 15.16.050 because the hillside was cleared and graded to construct the retaining wall system without the approval of a grading permit. If the project is denied, the applicant will be required to apply for and obtain a grading permit to restore the slope and bring it into compliance with CMC Chapter 21.95 — Hillside Development Regulations B.Hillside Development Regulations (CIVIC Chapter 21.95) The project site has a manufactured uphill perimeter slope as defined in CMC Section 21.95.140.0 with a gradient greater than 40 percent and an elevation differential of greater than fifteen feet located in the backyard into which the unpermitted retaining wall system is constructed. CMC Section 21.95.140 contains provisions related to design standards for development of manufactured uphill perimeter slopes, and development is limited to a main building, accessory structure and a retaining wall up to a maximum cut into the slope of six vertical feet measured from the existing grade at the toe of the slope. Stairs are also allowed to be constructed onto the slope in order to access the area for landscape maintenance. In addition, CMC Section 21.95.140 allows the construction of decks on the manufactured uphill perimeter slope up to the required building setback of the zoning designation. Per CMC Section 21.95.040, improvements to single family residences are exempt from having to apply for a hillside development permit (HOP), provided that the development complies with CMC Section 21.95.140 of the Hillside Development Regulations and the city's hillside development and design guidelines. However, walls and retaining walls built beyond the maximum six-foot cut as measured from the toe of the slope such as the project in question are not permitted per those standards and guidelines, so the project would not be exempt from an HDP. Modifications to the development and design standards of the Hillside Development Ordinance and Hillside Development and Design Guidelines are only permitted outside of the Coastal Zone with the approval of a HDP. Because the subject property is in the Coastal Zone, modifications to the design standards are prohibited unless it is necessary to preserve onsite natural habitat as required by the city's Habitat Management Plan. There is no natural habitat present on the site. Therefore, an application for a HDP to seek design standards and guidelines modifications would not be applicable, and the applicant is instead seeking approval of a variance to deviate from the requirements of the CMC Chapter 21.95 — Hillside Development Regulations. C.Coastal Development Regulations for the Mello II Segment of the Local Coastal Program and Coastal Resource Protection Overlay Zone (CMC Chapter 21.201 and 21.203) The project site is located within the Mello II Segment of the Local Coastal Program and is not in the appeal jurisdiction. The site is also located within and subject to the Coastal Resources Protection Overlay Zone. Improvements typically associated with a single-family residence outside the Coastal appeal area, such as retaining walls, are exempt from a coastal development permit (CDP). The exemption assumes the proposed work complies with the rest of the Zoning Ordinance, so a project that does not comply with the Hillside Development Ordinance is not exempt from a CDP. Therefore, the request to allow the unpermitted retaining wall system to remain is subject to a CDP and the regulations in CMC Sections 21.201 and 21.203 as described below: 1. Mello II Segment of the Certified Local Coastal Program and all applicable policies. March 16, 2021 Item #4 Page 72 of 193 CDP 2020-0026/V 2020-0004 (DEV2020-0134) — BEGONIA COURT RETAINING WALL December 16, 2020 Page 5 The project is located in the Mello II Local Coastal Program Segment. The project consists of the construction of an unpermitted retaining wall system more than six vertical feet above the toe of a manufactured uphill perimeter slope. The proposed retaining wall system is not compatible with the surrounding development of one and two-story single-family structures in that construction of retaining walls extending more than six feet above the toe of the slope is not permitted for manufactured uphill perimeter slopes. The retaining wall system is in an area of known geologic instability that has been created by the applicant due to the unpermitted grading, construction of unengineered retaining walls and filling of the slope. Each finding below must be met in order to support a coastal development permit: a.That the proposed development is in conformance with the Certified Local Coastal Program and all applicable policies. The proposed development is not in conformance with the Certified Local Coastal Program and all applicable policies in that the site is known for geologic instability due to the unpermitted grading and construction of an unpermitted retaining wall system. A geotechnical evaluation provided by the applicant and prepared by Advanced Geotechnica I Solutions, Inc., dated October 9, 2019 (see Attachment 7) confirms the slope stability has been compromised and does not meet minimum safety standards for static or seismic conditions. The geotechnical evaluation offered conceptual options to mitigate the structure; however, the applicant's engineer did not provide adequate technical information to determine if the subject slope area would be stable or if the impacts would be mitigatable for at least seventy-five years or for the life of the structure. The city requested specific structural details related to the retaining walls and retrofitting of the walls. The applicant refused to provide the information and the applicant's engineer stated that the specifics regarding the retrofit would be on a design-build basis (see Attachment 8). A design- build basis implies that the necessary information to demonstrate the feasibility of the retrofit would only be provided after the coastal development permit and variance are approved, but the city does not have the information to rely upon in order to approve the project. Therefore, staff does not have the necessary information to make the determination that the slope would be stable, or if the impacts would be mitigatable for at least seventy-five years or for the life of the structure. In addition, the geotechnical evaluation did not address compliance with the requirements of the Coastal Zone or Zoning Ordinance. Therefore, the project is not consistent with the intent and purpose of the Certified Local Coastal Program in that it does not preserve or protect steep manufactured slopes, nor does the project ensure structural stability of the slope from erosion, geological instability or destruction of the site or surrounding area. The project does not meet this finding. b.The proposal is in conformity with the public access and recreation policies of Chapter 3 of the Coastal Act. This finding is not applicable because the property is not adjacent to the coastal shoreline; and therefore, will not interfere with the public's right to physical access or water-oriented recreational activities. C. The project is consistent with the provisions of the Coastal Resource Protection Overlay Zone (Chapter 21.203 of the Zoning Ordinance) in that the project will adhere to the city's Master Drainage Plan, Grading Ordinance, Storm Water Ordinance, BMP Design Manual and Jurisdictional Runoff Management Program (JRMP) to avoid increased urban runoff, pollutants, and soil erosion. No steep slopes or native vegetation is located on the subject property and March 16, 2021 Item #4 Page 73 of 193 CDP 2020-0026/V 2020-0004 (DEV2020-0134) — BEGONIA COURT RETAINING WALL December 16, 2020 Page 6 the site is not located in an area prone to landslides, or susceptible to accelerated erosion, floods, or liquefaction. The project is not consistent with the provisions of the Coastal Resource Protection Overlay Zone (Chapter 21.203 of the Zoning Ordinance) because the geotechnical evaluation did not provide adequate information for staff to confirm that the project will avoid increased urban runoff, pollutants and soil erosion and there is a steep slope (equal to or greater than 25 percent gradient) of approximately 55 percent located on the subject property. The project does not meet this finding based on the analysis in finding number 1 above. 2. Coastal Resource Protection Overlay Zone The project is not consistent with the provisions of the Coastal Resource Protection Overlay Zone (CMC Chapter 21.203) in that the subject property includes a steep slope (equal to or greater than 25 percent gradient) and development is proposed on a steep slope. In addition, due to the unpermitted grading of the slope, the site may be prone to landslides, or susceptible to accelerated erosion. Furthermore, CMC Section 21.203.040(A)3 contains specific development standards that are applied to areas within the coastal resource protection overlay zone related to grading and preservation of steep slopes (equal to or greater than 25 percent gradient) and those standards differ depending on the geographic area within the coastal zone. For the project site, the city council may allow exceptions to grading of the steep slope provided all the following applicable mandatory findings to allow exceptions are made: a.A soils investigation conducted by a licensed soil engineer has determined the subject slope area to be stable and grading and development impacts mitigatable for at least seventy-five years, or life of structure. The applicant provided a geotechnical evaluation that was prepared by a licensed engineer who inspected the unpermitted retaining wall system and determined the wall system is structurally faulty because the fill has not been compacted to a minimum percentage that is safe. In addition, the evaluation finds that the slope is not safe for long term stability for static conditions or seismic conditions. The geotechnical evaluation included three options to remediate the wall system to make it structurally sound which are: A) remove the existing walls and undocumented fill and replace it with a new five-foot wall near the toe of the slope with an ascending fill slope located above the wall, and rebuild a new wall system constructed near the top of the fill slope; B) remove the walls and undocumented fill and restore the existing slope; or C) leave the existing walls in place with considerable reinforcement effort, which may require encroachment onto the adjacent properties that will require authorization from the property owners. Although the geotechnical evaluation offered conceptual options to mitigate the structure, the applicant's engineer did not provide adequate technical information to determine if the subject slope area would be stable or if the impacts would be mitigatable for at least seventy-five years or for the life of the structure as described in more detail in Section III(C)(1)(a) of the staff report above. The project does not meet this finding. b.Grading of the slope is essential to the development intent and design. The grading of the manufactured uphill perimeter slope is not essential for the development intent and design of a single-family residential property. If it were essential, it would have been done with the original grading of the overall subdivision development. Grading is only necessary to retain the March 16, 2021 Item #4 Page 74 of 193 CDP 2020-0026/V 2020-0004 (DEV2020-0134) — BEGONIA COURT RETAINING WALL December 16, 2020 Page 7 unpermitted retaining wall system, but the walls are not a permitted structure on a manufactured uphill perimeter slope in accordance with CMC Chapter 21.95 — Hillside Development Regulations. In addition, grading on a manufactured uphill perimeter slope beyond the six-foot limitation is only allowed in the Coastal Zone when it is necessary to preserve onsite natural habitat as required by the city's Habitat Management Plan. The project site is in the Coastal Zone but there is no natural habitat onsite that is required to be preserved; therefore, the grading of the slope is not essential to the development. The project does not meet this finding. c.Slope disturbance will not result in substantial damage or alteration to major wildlife habitat or native vegetation areas. This finding is not applicable to the site. The slope disturbance will not result in substantial damage or alteration to major wildlife habitat or native vegetation areas because the site is a previously developed lot with an existing single-family residence and there is no wildlife habitat or native vegetation areas existing onsite. d.If the area proposed to be disturbed is predominated by steep slopes and is in excess of ten acres, no more than one-third of the total steep slope area shall be subject to major grade changes. This finding is not applicable to the site. The finding applies to sites greater than 10 acres, and the area proposed to be disturbed is not in excess of ten acres. e.If the area proposed to be disturbed is predominated by steep slopes and is less than ten acres, complete grading may be allowed only if no interruption of significant wildlife corridors occurs. The area proposed is less than ten acres and would not interrupt significant wildlife corridors. The project would meet his finding. f.Because north-facing slopes are generally more prone to stability problems and in many cases contain more extensive natural vegetation, no grading or removal of vegetation from these areas will be permitted unless all environmental impacts have been mitigated. Overriding circumstances are not considered adequate mitigation. This finding is not applicable to the site. The slope is not north-facing and does not contain more extensive natural vegetation. Moreover, this finding is understood to apply to natural, not manufactured, slopes as manufactured slopes are engineered and not inherently prone to stability problems. In summary, to comply with CMC Chapters 21.201 and 21.203. Within the Mello II Segment of the Local Coastal Program, all required findings must be made in the affirmative, but finding "a" and "c" cannot be made. Within the Coastal Resource Protection Overlay Zone all mandatory findings must be made to allow grading of a steep slope but finding "a" and "b" cannot be made. Therefore, the coastal development permit cannot be supported, and staff recommends denial of the CDP. D. Variances (CMC Chapter 21.50) Variances are granted to resolve practical difficulties or physical hardships that may result from the unique size, shape, topography or dimensions of a property. Variances are not approved which would have the effect of granting a special privilege not shared by other properties in the surrounding area. In order to March 16, 2021 Item 444 Page 75 of 193 CDP 2020-0026/V 2020-0004 (DEV2020-0134) — BEGONIA COURT RETAINING WALL December 16, 2020 Page 8 support an approval for a variance, all five required findings of fact from CMC Section 21.50.050 must be made. The following five findings with justifications stated by the applicant (see Attachment 9) and staff's analysis are as follows: 1. That because of special circumstances applicable to the subject property, including size, shape, topography, location or surroundings, the strict application of the zoning ordinance deprives such property of privileges enjoyed by other property in the vicinity and under identical zoning classification. Applicant's Justification: The applicant states that the location and size of the existing wall, topography of the area and accessibility make approving the variance and issuing a permit of the current retaining wall with approved retrofitting the optimal alternative in remedying the code violation. Due to the location of the existing retaining wall as constructed, removing it would not only pose a threat of danger of destabilizing the slope/hill, removing the wall, which spans close to 100 feet long and 21 feet in height also poses extreme challenges regarding access to the wall. Such challenges would not only cause substantial nuisances to the neighborhood but would also require considerable use and intrusion of and onto neighboring lots. The applicant included a petition with some 67 signatures of property owners in the neighborhood that not only support permitting the existing wall and allowing it to remain with retrofitting, but that clearly show that requiring the wall to be removed will cause serious concerns of neighboring residents and could possibly result in litigation (see Attachment 6). Staff Response: The applicant's justification does not speak to special circumstances related to the subject property, or loss of privileges enjoyed by other properties, but instead speaks to circumstances the applicant created through the illegal grading and construction of the retaining wall system. There are no special circumstances associated with the property, including size, shape, topography, location or surroundings, such that the strict application of the zoning ordinance would deprive the property of privileges enjoyed by the other homes in the vicinity and in the R-1 Residential zone. The property is of average size (17,146 sq. ft.) in the neighborhood and is a typical pie-shaped lot that is found on a cul-de-sac street. The other lots in the vicinity range in size from about 12,000 to about 19,000 square feet in size. The 55 percent manufactured uphill perimeter slope is characteristic of the adjacent properties and other properties in the vicinity. The strict application of the zoning code does not deprive the property of privileges enjoyed by other property owners because retaining walls that exceed the hillside development standards on a manufactured uphill perimeter slope are unpermitted for all residential properties. The retaining wall system is decorative and does not constitute relief from unique difficulties or hardships associated with the property in question. In regard to nuisances to the neighborhood, construction that occurs within the city boundary must comply with CMC 8.48.010 — Construction Hours Limitations, which limits any type of construction, including the demolition of a structure or grading between 7:00 a.m. to 6:00 p.m. Monday through Friday, 8:00 a.m. to 6:00 p.m. on Saturdays and is not permitted on Sundays and any federal holiday. Therefore, the removal and remediation of the wall would be subject to the regulations that are imposed on all types of construction, demolition or grading. The removal and remediation work would be temporary, must operate during the permitted days and times, and noise and parking impacts March 16, 2021 Item #4 Page 76 of 193 CDP 2020-0026/v 2020-0004 (DEV2020-0134) — BEGONIA COURT RETAINING WALL December 16, 2020 Page 9 would be temporary and minimal to the surrounding neighborhood. In addition, the engineer's evaluation also includes possible impacts on adjacent properties as a result of grading and construction which include encroaching onto the adjacent parcels to reinforce the existing walls if the walls were to remain. The property owner will also be required to obtain authorization from the adjacent property owners to reinforce the existing wall if encroachment is necessary. 2. That the variance shall not constitute a grant of special privileges inconsistent with the limitations upon other properties in the vicinity and zone in which the subject property is located and is subject to any conditions necessary to assure compliance with this finding. Applicant's Justification: The applicant states that granting of the variance would not constitute a grant of special privilege inconsistent with any limitation upon other properties in the vicinity. On the contrary, granting of the variance would be absolutely consistent with the city's explicit or implicit approval of extremely similar retaining walls not only within the City of Carlsbad, but within the very neighborhood of the subject premises. The applicant provided examples of 10 retaining walls within the city limits that appear not to be consistent with CMC Section 21.95.140 (see Attachment 9). The cited retaining walls are on properties including Grand Pacific Palisades Resort/Karl Strauss, Salk Avenue above El Camino Real, Robertson Ranch development, The Crossings Golf Course, and two neighboring single-family residential properties on Azalea Place and Poppy Lane. The applicant states that these walls are evidence that the city has allowed variances to the code and is selectively enforcing the code, so denial of this project would be inconsistent. The applicant further indicates that other homes in the area have retaining walls so approving this project would not prejudice or harm those homeowners. The subject retaining walls not only beautify the subject property but also raise the property values of the property and the surrounding neighborhood. Only one complaint has been filed with the city about the walls since construction began in 2016, more concerned with noise than the wall system. Lastly, the applicant indicates that the wall system does not impede views and states the wall system stabilized the slope and makes the slope more attractive. Staff Response: The variance would constitute a grant of special privileges that is inconsistent with the limitations upon other properties in the vicinity and zone. All properties in the vicinity and the R-1. Residential zoning designation in the Coastal Zone are subject to the same Hillside Development Ordinance regulations that are in effect, which prohibit retaining walls from being constructed beyond what is allowed on a manufactured uphill perimeter slope. No other properties in the vicinity have similar, permitted retaining walls on the manufactured uphill perimeter slope. To approve the subject variance would be a grant of special privileges to this property that other properties in the vicinity do not enjoy. Staff has reviewed the list of walls provided by the applicant. Walls listed by the applicant that are not located within the Coastal Zone are not subject to the same CMC Chapter 21.95 — Hillside Development Regulations as the project site. The majority of the walls listed by the applicant are located on project sites that were part of a master plan or other major discretionary action for complex projects that are not similar to the subject project. Those projects included components that March 16, 2021 Item #4 Page 77 of 193 CDP 2020-0026A/ 2020-0004 (DEV2020-0134) — BEGONIA COURT RETAINING WALL December 16, 2020 Page 10 do not apply to the subject property which were subject to other sections of the code or provisions within a master plan development, including preservation of significant natural habitat as required by the city's Habitat Management Plan or the county Multiple Species Habitat Conservation Plan, were necessary for slope instability corrective work, or were approved as offsets or concessions for the provision of affordable housing. It appears that some of the sites are not subject to the Hillside Development Regulations because the topography of the site does not meet the criteria for the regulations to apply. Some of the properties have retaining walls with no record of permits issued by the city. Lastly, the Hillside Development Regulations were comprehensively updated in 2012, and some of the walls cited by the applicant predate the current code requirements. None of the examples are relevant to the subject request, and do not provide justification to meet this finding. 3.That the variance does not authorize a use or activity which is not otherwise expressly authorized by the zone regulation governing the subject property. Applicant's Justification: The applicant states that granting of the variance does not authorize any use or activity unauthorized by the code. The applicant does not seek a building permit in order to conduct an unauthorized activity or to construct an object that is not there. The subject retaining wall system has already been constructed and the variance seeks to permit the existing wall system after retrofitting. The wall is intended to beautify the subject property, not for any other use or activity and no unauthorized use will be conducted at the property if the project is approved. Staff Response: The granting of this variance would authorize a use or activity which is not otherwise expressly authorized by the zone regulation governing the subject property. The fact that the retaining wall system is existing because it has been constructed without city approval is not appropriate justification to approve the variance. As designed, the unpermitted retaining wall system is prohibited per CMC Chapter 21.95 — Hillside Development Regulations which governs development on manufactured uphill perimeter slopes. CMC Chapter 21.95 allows for modifications to development on slopes; however, modifications are prohibited in the Coastal Zone unless it is necessary to preserve natural habitat as required by the city's Habitat Management Plan. The subject property is in the Coastal Zone, but there is no native habitat on site and the project is not necessary to preserve natural habitat. Therefore, granting the variance would authorize an activity that is expressly not authorized within the applicable zoning regulations. 4.That the variance is consistent with the general purpose and intent of the general plan, and this title and any applicable specific or master plans. Applicant's Justification: The applicant states that granting the variance is consistent with the general purpose and intent of the General Plan as it protects and enhances natural resources. The applicant contends that the retrofitted retaining wall system will protect the integrity of the slope it is built upon, which protects the natural topography of the coastline. The applicant further states that removal of the retaining wall system will not only endanger the integrity of the slope but may cause the slope to become unreflective of its natural state prior to the wall being built. The applicant has added landscape to the slope, and March 16, 2021 Item #4 Page 78 of 193 CDP 2020-0026/V 2020-0004 (DEV2020-0134) — BEGONIA COURT RETAINING WALL December 16, 2020 Page 11 is open to installing native vegetation and trees, which they state will enhance and restore the overall quality of the coastal zone environment and its natural and man-made resources, pursuant to the Coastal Act. Staff Response: The granting of this variance is not consistent with the general purpose and intent of the General Plan. The subject property is designated Residential (R —4) General Plan Land Use designation and although walls are a typical component of residentially designated areas, the subject retaining wall system is not consistent with the development of single-family lots with a manufactured uphill perimeter slope within the Coastal Zone. The subject retaining wall system also does not promote the Hillside Development Ordinance intent to enhance the aesthetic qualities of manufactured slopes and is not consistent with the Hillside Development and Design Guidelines acknowledgment that manufactured slopes of greater than 40% gradient and greater than 15 feet in height are regarded as important aesthetic, visual resources because they provide visually open, vertical separations between developed pads in hilly areas and between developed pads and roadways. As a result, the project does not preserve the existing neighborhood atmosphere and identity of the existing residential area. The stability of the slope has already been compromised by the unpermitted grading and construction that has occurred. The existing slope is a manufactured slope and not a natural slope as described by the applicant. The removal of the walls would not endanger the integrity of the slope because the applicant would also be required to restore the slope to bring it into compliance with CMC Chapter 21.95 — Hillside Development Regulations which is consistent with the general goals and purpose of the General Plan. Appropriate landscaping of hillsides is required by the city's Landscape Manual, including use of native and drought tolerant species when possible. 5. In addition, in the coastal zone, that the variance is consistent with the general purpose and intent of the certified local coastal program and does not reduce or in any manner adversely affect the requirements for protection of coastal resources. Applicant's Justification: The applicant states that the city is to take into consideration what will assure balanced utilization and conservation of coastal zone resources taking into account the social and economic needs of the people of California. The applicant contends the project offers such a balance by retrofitting the existing walls to conserve the coastal zone and add natural resources, while benefitting both the social and economic needs of the community in that the wall brings value to surrounding properties. The applicant raises the previously cited retaining walls and states the city must protect the rights of property owners by allowing similar desirable walls within reason such as the subject retaining walls. The subject wall follows the hillside, it does not reduce or extend it, but was dependent upon its natural state when constructed. The wall merely covers what was there and stabilizes the hillside and will also aid in erosion control. The applicant further contends that approving the retaining wall system will prevent further development on the hillside, minimizing the density of development, and will minimize the opportunity for toxic compounds, oil and grease, heavy metals, nutrients, suspended solids and other pollutants from entering the storm water conveyance system through the hillside. In contrast, denying the variance not only poses a risk to the hillside, will be oppressive to the surrounding neighborhood March 16, 2021 Item #4 Page 79 of 193 CDP 2020-0026/V 2020-0004 (DEV2020-0134) — BEGONIA COURT RETAINING WALL December 16, 2020 Page 12 and a logistical nightmare that some 67 local residents object to. Removal of the wall. The applicant states the hope that the code will not be arbitrarily enforced by the city in a discriminatory and draconian manner that will thwart the city's efforts of coastal protection since the wall system's retrofitting will work to protect the hillside. Staff Response: The granting of this variance would not be consistent with the general purpose and intent of the certified local coastal program and does reduce or adversely affect the requirements for protection of coastal resources. One of the purposes of the certified local coastal program is to preserve and protect natural and manufactured slopes in the coastal resource protection overlay zone area and to ensure stability and structural integrity of the slopes from erosion, geologic instability, or destruction of the site. The unpermitted grading that has occurred to construct the unpermitted and unengineered retaining wall system has compromised the stability of the slope. To retain the wall system will require considerable reinforcement and the structural integrity of reinforcing the walls has not been determined since the applicant has refused to provide such information at this time as described in detail previously in this staff report. Therefore, the feasibility of retaining the wall system and stabilizing the slope in accordance with the requirements for protection of the local coastal resources is unknown. The wall system is not related to density or the city's policies on density or growth management. Allowing the walls to remain will not discourage development on the manufactured slope because housing development is not permitted on this manufactured uphill perimeter slope. Furthermore, because there was not enough information provided by the applicant, it is unknown if there are drainage issues that resulted from the unpermitted grading and construction and if the walls could be retained and retrofitted without drainage issues. The removal and remediation work would not cause impacts to the neighborhood because the work will be temporary and must be completed during the permitted days and times in accordance with city regulations. Noise and parking impacts related to the removal and remediation would be temporary and minimal to the surrounding neighborhood during construction. Furthermore, the code is not being arbitrarily enforced in a discriminatory or draconian manner because the retaining wall system as designed is strictly prohibited and the regulations are applied consistently for all single-family residential property owners in the vicinity and zoning designation. No variances for walls on manufactured uphill perimeter slopes have been approved in the city. Retaining and retrofitting the wall system has not yet been determined to protect the hillside, and retrofitting may require encroaching onto the adjacent neighbor's property, thereby potentially impacting the slopes within the vicinity. IV. ENVIRONMENTAL REVIEW If this Coastal Development Permit No. 2020-0026 and Variance No. 2020-0004 is denied, the project is exempt from environmental review pursuant to Sections 15061(b)(4) and 15270 of the State CEQA Guidelines because CEQA does not apply to projects that a public agency rejects or disapproves. March 16, 2021 Item 44 Page 80 of 193 CDP 2020-0026/V 2020-0004 (DEV2020-0134) — BEGONIA COURT RETAINING WALL December 16, 2020 Page 13 ATTACHMENTS: 1.Planning Commission Resolution No. 7394 2.Location Map 3.Disclosure Form 4.Reduced Exhibits 5.Hillside Development and Design Guidelines Section III.B and Exhibit 9 6.Petition of 67 Signatures 7.Geotechnical Evaluation dated October 9, 2019 8.Geotechnica I Addendum — Response to Engineering Comments dated September 10, 2020 9.Applicant's Justification for Variance 10.Exhibit(s) "A" dated December 16, 2020 11.Public Comments March 16, 2021 Item #4 Page 81 of 193 ATTACHMENT 2 NOT TO SCALE SITE MAP Begonia Court Retaining Wall CDP 2020-0026N 2020-0004 March 16, 2021 Item #4 Page 82 of 193 ATTACHMENT 3 (City of DISCLOSURE STATEMENT Carlsbad P- 1(A) Development Services Planning Division 1635 Faraday Avenue (760) 602-4610 www.carlsbadca.gov Applicant's statement or disclosure of certain ownership interests on all applications which will require discretionary action on the part of the City Council or any appointed Board, Commission or Committee. The following information MUST be disclosed at the time of application submittal. Your project cannot be reviewed until this information is completed. Please print, Note: Person is defined as "Any individual, firm. co-partnership, joint venture, association, social club, fraternal organization, corporation, estate, trust, receiver, syndicate. in this and any ether county, city and county, city municipality, district or other political subdivision or any other group or combination acting as a unit' Agents may sign this document: however, the legal name and entity of the applicant and property owner must be provided below. 1. APPLICANT (Not the applicants agent) Provide the COMPLETE, LEGAL names and addresses of ALL persons having a financial interest in the application. If the applicant includes a corporation or partnership, include the names, titles, addresses of all individuals owning more than 10% of the shares. IF ,NO INDIVIDUALS OWN MORE THAN 10% OF THE SHARES, PLEASE INDICATE NON-APPLICABLE (N/A) IN THE SPACE BELOW. If a publicly-owned corporation, include the names, titles, and addresses of the corporate officers, (A separate page may be attached if necessary.) Person Valerie Licthman Title Trustee of Valerie Licthman Trust Address NC B°1-rwrd \kW- San Bomurdino. CA 944 Corp/Part Title Address Z OWNER (Not the owner's agent) Provide the COMPLETE, LEGAL names and addresses of ALL persons having any ownership interest in the property involved. Also, provide the nature of the legal ownership (Le., partnership, tenants in common, non-profit, corporation, etc.). If the ownership includes a corporation or partnership, include the names, titles, addresses of all individuals owning more than 10% of the shares. IF NO INDIVIDUALS OWN MORE THAN 10% OF THE SHARES, PLEASE INDICATE NON-APPLICABLE (NIA) IN THE SPACE BELOW, If a publicly-owned corporation, include the names, titles, and addresses of the corporate officers. (A separate page may be attached ft necessary.) Person Rene Lichtman Corp/Part Title Agent of Owner and Beneficiary of Trust Title Address 860 Bernard Way Address San Bernardino, CA 92404 P.1 (A) Page : 2 Revised 07/10 March 16, 2021 Item #4 Page 83 of 193 Valerie Lichtman, Trustee Rene Liebman Print or type name of qstner Print or type name of applicant k.ct ignature owner/applicants age applicable/date licno Liontman. Avent 3. NON-PROFIT ORGANIZATION OR TRUST If any person identified pursuant to (1) or (2) above is a nonprofit oroanization or a trypt, list the names and addresses of ANY person serving as an officer or director of the non- profit organization or as trustee or beneficiary of the. Non ProfitiTr Ub7U Non Profit/Trust -no. Owner Address 860 Bernard Way San Bernardino, CA 92404 4, Have you had more than $500 worth of business transacted with any member of City staff, Boards, Commissions. Committees and/or Council within the past twelve (1.2) months? Yes NOTE: Attach additional sheets it necessary. I certify that all the above information Ls true and correct to , t of my ge. S\ctk ' Signature of owner/date Signature of appfi 4t/tfate Print or type name of owner/applicants agent PAW; Page 2 of 2 flEtec5 MO March 16, 2021 Item #4 Page 84 of 193 Title Address [71 No if yes, pleeise indicate person(s): BEGONIA COURT $ 7 8 gaiNP.V."01 f." 'ffia4 \ m.o. • MI 14.7.456e ® ® Vigiri"'32 1500,— tom rwymv. For L'A'w‘ME - snoragadEs:,m, 10 KWIC: 939 BEGONIA COURT LOT 138 OF CT 73-39 PER MAP NO. 8453 APN 214-390-23 PROFILE SCALES HORIZ 1,10' VERT.: 11=10' ACINITY MAP PREPARED BY: FUSION ENGINEERING & TECHNOLOGY 4231 BAUSOA AYE, 0610 SAN DIEGO, 06,92117 (619)736-2900 ATTACHMENT 4 co? 2020-0026/V 2020-0004 DESIGN AND CONSTRUCTION NOTES, •MAI. µV NUM 10 3, AMAMI •relV£ warn M., MCA! 000 •qtrf114 70 . 476 0114 .1V12•Map. rt. 'Mg ., • • 1 • d • RAC r •" 43)4 Mae 1/00i PRELIMINARY SITE PLAN LICHTMAN RESIDENCE 939 BEGONIA COURT CITY OF CARLSBAD. CALIFORNIA 1 MAP 1 OF ErAJIPRIElif PER CCNTRACTOR DORM° 'MICRON sara I 939 BEGONIA COURT A LOT 138'PER MAP NO. 8453 1 •APN 214-390-23 Mit.. VFW AMR. WU LW.. SALL. 10 £CALL - BEGONIA COURT litoazOaktn \ A SECTION A-A SECTION BTIS . ; NUM ROVED REFERRING. I 0 LINN-EHOMERRIG DESIGN AK. CON:RAC 1011 IREMSPAU IA 11,00S. WIL ADIXO R GLQILCPIHICIL IiRPOR I, CURRENT AND FORIKCAIR. PILIAL CNOINEERIKO. FREPAFtED BY, PRELIANANY StrE FLAN LICHTMAN RESIDENCE 939 BEGONIA COURT CRY OF CARLSBAD, CAUFORMA ni"-WaLiVati:XRCarra-=.:K.VALZWM',,. .LALZ.411-4,=‘, 4, RIA'011 Err; Tech 4231 Balboa Ave 8619 San Diego CA (610) 736-2800 ATTACHMENT 5 Hillside Development and Design Guidelines a.The Planning Director to the Planning Commission. b.The Planning Commission to the City Council. H. HILLSIDE MAPPING PROCEDURES The Hillside Mapping Procedures are found in Section 21.95.110 of the Carlsbad Municipal Code. At least three major items are needed to appropriately map and identify a hillside: A.Slope Analysis Exhibit 1 illustrates how to show slope classifications. B.Slope Profiles: Exhibits 2 and 3 illustrate examples of slope profiles. C. Total Area of Grading and Grading Volumes The grading of hillside lands should be kept to a minimum. Exhibits 4 and 5 illustrate clear ways to show the total area of grading and grading volumes. D.Assurance of Accurate Hillside Mapping The assurance of accurate Hillside mapping is to be provided by either a registered landscape architect or civil engineer land surveyor. III. HILLSIDE DEVELOPMENT AND DESIGN STANDARDS The Hillside Development and Design standards address the following development concepts. A.Coastal Zone Hillside Standards B.Development of Manufactured Slopes Greater than 40% Gradient C.Contour Grading D.Screening Manufactured Slopes E.Hillside and Hilltop Architecture HAAdmin\Report1Hillside Guidelines Page 5 March 16, 2021 Item #4 Page 87 of 193 EXHIBIT 1- Slope Analysis: The following graphics illustrate ways to show slope classifications. SITE BOUNDARY SLOPE PERCENTAGE LEGEND AREA 0 0-less .than 15% 18.2ac 0 15.1ess than 25% 16.1ac ei 2540% 3.5as 410 water than 40% 2.7ac 40.5ac TOTAL SITE March 16, 2021 Item #4 Page 88 of 193 EXHIBIT 2, , .,..q0F/L.E.1/1YE SC4t..e A•ilf‘•Ze. . 10"."1.•10 " Item #4 Page 89 of 193 March 16r2021 510 $00 4;0 Profile Line 1 7:1C Cf.:// t 7 -3:S3 tor e• 7-- • 7 I • • -7r- • .• 11 440 -.*** N., 4 •••44... 41/ 4c/ '1=1r.• :7 41;4 _ t, r 44. '0VIP/ • 490 .180 410 SIO SOO 490 480 4/0 49-0 480 PROPOSED STRUCTURE (TYPICA-) SUBDIVISION BOUNDARY EXIBTING TOPOGRAPHY r-- PROPOSED TOPOGRAPHY SUBDIvisinv BOUNDARY' I/ / •le PROFILE A 260-- SUBDIVISION 240 ••• [BOUNDARY F-1 •-•_•• • 220 — 5, • 160 — EXISTING TOPOGRAPHY PROPOSED STRUCTURE s (TYPICAL) SUBDIVISION BOUNDARY —184 I *re. ••• —240 PROPOSED TOPOGRAPHY "PROFILE C PROFILE A TO BE PREPARED AT SAME SCALE AS TENTATIVE MAP PROFILE B S. KEY 14441, .0 A:44:e March 16, 2021 Item #4 Page 90 of 193 EXHIBIT 3; —247 •••• —221 -'160 —140 EXISTING PROPOSED STRUCTURE TOPOGRAPHY (TYP'CAL) SUBDIVISION SUBDIVISION [BOUNDARY 1 ,..7.:__-_-171 , . ----- -- BOUNDARY 1 1 ......- ..-..•• , 4 ...... ...i .j ,__L5.:.„... 1 ......... \_ :11 ............_. 1 1.,..-teT '''''-4.----1 L. .. ,, •!-- n -, .17— . '''... ZOO ••• / . PROPOSED PROFILE TOPOGRAPHY me _ ../„. ------_—:---_,......1 I- ZA.1 —TX —150 — ISO PROFILE C 9100 cy .9ac 10,100 cu yds/ac PROPOSED GRADING rod' FILL .5ac 9100 cY (Larger of two) CUT .4ac 8000 cy TOTAL SITE AREA: lac TOTAL GRADED AREA .9ac `'" .44c 8000 cy cut .5 ic 0000 cy fill- (1 ACRE LOT) r __ • PROPOSED GRADING VA FILL .4ac 2800 cy 1\71 CUT .2ac 2500 cy TOTAL SITE AREA lac TOTAL GRADED AREA 2800 cy .6ac 4667 cu yds/ac Margot* of two) EXHIBIT 4' NOT ACCEPTABLE --EXCEEDS 10,000 cy/ac (1 ACRE LOT) OFFSITE GRADING INCLUDED IN CALCULATIONS ACCEPTABLE zi...., \ U.I ---; ''''' \ -1 1-- 1 \ 4; I CZ ta :i.- , s i 1 I I/... .240 .4ac 2500 cy cut 2800 ay fin OFFSITE GRADING INCLUDED IN CALCULATIONS TOTAL AREA OF GRADING & GRADING VOLUMES City of Carlsbad Item #4 Page 91 of 193 March 16, 2021 -1 3041: Item #4 Page 92 of 193 March 1(4,121A1cuYcligraded ac• EXHIBIT 5 Natural CUBIC YDS, AREA (AC.) . 0 10 243,587 18 . ---30ao, i Cut FIN . 234,711 1.2. 40 Export 8,878 < 243,569 Hillside Development and Design Guidelines F.Building Setbacks G.Roadway Design H.Hillside Drainage The following exhibits illustrate some of these concepts. These illustrations do not include all potential design solutions for meeting the Hillside Development Regulations, however they do show conceptual designs which fulfill the regulations intent. Land planners, site designers, engineers, and architects are encouraged to explore additional design solutions that fulfill the intent, purpose and specific requirements of Carlsbad's Hillside Development Regulations. A. Coastal Zone Hillside Standards Carlsbad's Local Coastal Program (LCP) and Chapters 21.38 and 21.201 - 21.203 of the Carlsbad Municipal Code implements the California Coastal Act. As shown on Exhibit 6, Carlsbad's Local Coastal Program is divided into six segments. Certain segments of Carlsbad's LCP require additional conservation of hillside areas. Wherever LCP hillside restrictions differ from Carlsbad's Hillside Development Regulations, the more restrictive aspect of each regulation shall be met. All segments except the Agua Hedionda segment and the Village Redevelopment segment have the same Hillside Development restrictions. The following regulations are taken directly from Carlsbad's Local Coastal Program. For Agua Hedionda segment the following special requirements must be met: Policy 4.4 Recognizing the unique environmental features of the lagoon and its environs and the sensitivity of the area to soil erodibility and sedimentation, development shall be regulated as follows: a.Development on existing subdivided lots having all of their area in slopes of 25% or greater shall be permitted, but grading shall be limited to minimal site preparation for pole-type footings. Driveway/parking areas shall be limited in size and shall be restricted to an area adjacent to the local streets. On-site vegetation shall not be disturbed beyond the minimal area needed to be cleared for the construction process, which shall be clearly delineated on approved site plans. b.Development, grading and landform alteration in steep slope areas (25%) shall be restricted. Exceptions may include encroachments by roadways and utilities necessary to reach developable area. The maximum allowable density shall be calculated on the total lot area, although this may be modified through setbacks, plan review, or other requirements of this plan and applicable city regulations. c.Use of the Planned Development (PD) Ordinance and cluster development shall be required in areas containing environmentally sensitive resources, extensive steep slope areas and significant natural landform features. Page 6 March 16, 2021 Item #4 Page 93 of 193 CARLSBAD LOCAL COASTAL PROGRAM SEGMENT MELLO 1 MELLO II REDEVELOPMENT AREA AGUA HEDIONDA LAGOON WEST BATIGUITOS LAGOON EAST BATIOUITOS LAGOON 111111111 —.— —5' ...— --. —.--.... -......—..- 4•1111•6=bl=11. 0 'S \ t++++ h++++ March 16, 2021 EXHIBIT 6 Item #4 Page 94 of 193 Hillside Development and Design Guidelines There are no Coastal Zone Hillside Standards within the Village Redevelopment Segment. For all other segments of Carlsbad's LCP the following policy regulates the development of hillsides: Any development proposal that affects steep slopes (25% inclination or greater) shall be required to prepare a slope map and analysis for the affected slopes. The slope mapping analysis shall be prepared during the CEQA environmental review on a project-by-project basis and shall be required as a condition of a coastal development permit. 1) Slopes Possessing Endangered Species and/or Coastal Sage Scrub and Chaparral Plant Communities: For those slopes mapped as possessing endangered plant/animal species and/or coastal sage scrub and chaparral plant communities, the following policy language would apply: a)Slopes of 25% grade and over shall be preserved in their natural state, unless the application of this policy would preclude any reasonable use of the property, in which case an encroachment not to exceed 10% of the steep slope area over 25% grade may be permitted. For existing legal parcels, with all or nearly all of their area in slope area over 25% grade, encroachment may be permitted; however, any such encroachment shall be limited so that at no time is more than 20% of the entire parcel (including areas under 25% slope) permitted to be disturbed from its natural state. This policy shall not apply to the construction of roads on the City's Circulation Element or the development of utility systems. Uses of slopes over 25% may be made in order to provide access to flatter areas if there is no less environmentally damaging alternative available. b)No further subdivisions of land or utilization of Planned Unit Development shall occur on lots that have their total area in excess of 25% slope unless a planned Unit Development is proposed which limits grading and development to not more than 10% of the total site area. c)Slopes and areas remaining undisturbed as a result of the hillside review process, shall be placed in a permanent open space easement as a condition of development approval. The purpose of the open space easement shall be to reduce the potential for localized erosion and slide hazards, to prohibit the removal of native vegetation except for creating firebreaks and/or planting fire retardant vegetation and to protect visual resources of importance to the entire community. 2) All other Steep Slope Areas: I-1:\Admin\Report\Hillside Guidelines Page 7 March 16, 2021 Item #4 Page 95 of 193 Hillside Development and Design Guidelines For all other steep slope areas, the City Council may allow exceptions to the above grading provisions provided the following mandatory findings to allow exceptions are made: a)A soils investigation conducted by a licensed soils engineer has determined the subject slope area to be stable and grading and development impacts mitigatable for at least 75 years, or life of structure. b)Grading of the slope is essential to the development intent and design. c)Slope disturbance will not result in substantial damage or alteration to major wildlife habitat or native vegetation areas. d)If the area proposed to be disturbed is predominated by steep slopes and is in excess of 10 acres, no more than one third of the total steep slope area shall be subject to major grade changes. e)If the area proposed to be disturbed is predominated by steep slopes and it less than 10 acres, complete grading may be allowed only if no interruption of significant wildlife corridors occur. Because north-facing slopes are generally more prone to stability problems and in many cases contain more extensive natural vegetation, no grading or removal of vegetation from these areas will be permitted unless all environmental impacts have been mitigated. Overriding circumstances are not considered adequate mitigation. 3)Required Runoff Control Plan: No development shall be permitted except pursuant to submittal of a runoff control plan prepared by a licensed engineer qualified in hydrology and hydraulics; such approved plans shall assure that there would be no increase in peak runoff rate from the developed site over the greatest discharge expected from the existing undeveloped site as a result of a 10-year frequency storm. Runoff control shall be accomplished by a variety of measures, including, but not limited to, onsite catchment basins, detention basins, siltation traps, and energy dissipators, and shall not be concentrated in one area. 4)Required Drainage or Erosion Control Facility Maintenance Arrangements: Development approvals shall include detailed maintenance arrangements for providing the on-going repair and maintenance for all approved drainage or erosion-control facilities. 5)Installation and Timing of Permanent Runoff and Erosion Control Devices: All permanent run-off control and erosion-control devices shall be developed and installed prior to or concurrent with any onsite grading activities. Page 8 March 16, 2021 Item #4 Page 96 of 193 Hillside Development and Design Guidelines 6) Required Open Space Easements on Undeveloped Slopes: All undevelopable slopes shall be placed in open space easements as a condition of development approval. Items 3-6 may be required of all development that requires grading. Carlsbad's Hillside Development Regulations recognize that the Hillside Conservation Policies of Carlsbad's LOP segments must be met in addition to the requirements of Chapter 21.95. B.Manufactured Slopes of Greater than 40% Gradient which are Greater than 15 in Height Manufactured slopes of greater than 40% gradient which are greater than 15 feet in height are regarded as important aesthetic (visual) resources in that they provide vertical open space separation between developed pads and developed pads and roadways (See Exhibit 7). For this reason, the development of buildings upon such downhill manufactured slopes which are visible from roadways or adjoining properties is prohibited. However, for residential and non-residential uses, limited development upon such uphill perimeter manufactured slopes would be permitted and for non- residential uses limited development upon downhill perimeter manufactured slopes would be permitted as shown on Exhibits 8 - 10. C.Contour Grading Contour grading creates manufactured slopes in a rounded, undulating pattern that blend into and mimic the surrounding natural hillside. Exhibits 11 and 12 illustrate an acceptable contour grading concept along with an unacceptable manmade slope. The emphasis of the contour grading standard is to create contour graded slopes in areas where they would be visible (i.e., along Circulation Element roadways, collector streets and useable open space areas). D.Screening Manufactured Slopes The screening of manufactured slopes is of considerable importance. Exhibits 13 and 14 illustrate the use of a variety of landscape materials to soften the appearance of the manufactured slope. Another way to accomplish this includes using the building itself as a screening devise. E.Hillside and Hilltop Architecture Hillside and hilltop architecture should be customized to specific hillside conditions. It is strongly recommended that the project architect begin conceptual design work only after becoming fully aware of both the specific hillside site and the Hillside Development Regulations. A preliminary review by staff of the conceptual design is also recommended before any final design is submitted. HAdmin\Report\Hillside Guidelines Page 9 March 16, 2021 Item #4 Page 97 of 193 7 Retaining walls, main buildings and accessory buildings may be constructed into an uphill slope to a maximum of 6 vertical feet from the toe of slope 14-1 CUT Permitted Residential And Non-Residential Development Of Uphill Perimeter Manufactured Slopes EXHIBIT 9 TaTKA 611R1 FEGA. DING RETANWG VW' y ATTACHMENT 6 t 1—.y 3,t, ItU'CIF the City of Callsbael, tic City IJ L1L&Jw axistitig rutailling wait located at the premises located at: 939 Begonia Court, Carlsbad, We live in the noighboritilud wheto the current retaining wall is located. It e.-IiharteeR the value of our propestyand does not pose a tin:eat to public sthty. It will be. over-bade-use= and disruptive to out neighborhood Wit is forded to be :moved by the Ci.. We therefore petition thal the wall be permitted. Allowing the petmittins of the existing wall will avoid a lengthy r,litiffmteo our voigbborb.4.1,od both noise and possible ingress and egress or our p.ropertios.Iti addit.011, it will avoid hetwY imelthiory and vast amounts of dirt and soil to be moved in, arid around our Stieet.,3and PrOPeAiie6- It will also avoid -the possible instability of tbe hill on which 0..)e retalping wall is Nitumed, if the wall is forced to be removed, Wc detpondtli at the Plotting and Zarling Comminns atim a permit of etc Ketaining-wall at 569 Begonia Court in our neigitbothood. We have listed ctlir address below to be notified &any-mid ail pfaiming and zoning Co/mission meetings as well as DICetirtgs with the City Couwel 1-9gaidin Ibis Matter_ itinmv Atlaress i Sittrqt.o.23 , .t"liteArlif- qb fNi4 bot-a.;,,,..* t 4„ 50, cos, Li 2„,t,s, .t fs,,,,,inteffit,e/FON4 _ S-1%.:) . A..1::: 1. Pik *frigh-- -e--) 0 1., ,..4.44,,e,..„ e4 ..9'.4104"/ _.a. a ....Kare,....;:: Ph 0 ,..t.2 ,,te.A.. ilitee 91.A. 0 /---- ar.6 - - . .-- A r .11 ...* f ile? 1 1 • FT ( in Jillit 4 PO' 7... erki / , /11-22.174C (?.;WU: _ 1, Pii.4,1464,- Ref.SS 1.941 tiltaa.i f-katfLIMA,7 OA 99.6 1 4 u. ') e-- • • nit . r 1 ..1 f? r i ( i` el-be / 1:13 W RIt kW e ".. 7 at I . A7 • erT..,. . (1,44,1 tle 41,6612 Isl'I ar,z., .. • March 16, 2021 Item #4 Page 99 of 193 W( U) ..1-0--a-g— Ake.-3> Iry-24 4C) t9a PIN March 16, 2021 Item #4 Page 100 of 193 Item #4 Page 101 of 193 March 16, 2021 rIngira ,.."•.4-T CURIVNT RETAINING WALL IN CITY OF Va-414-.'S.BATI We, - lc 4-gawks of the City Of Calisbed, peEition -Um City to allow the pewit " thc FientlY tirt g retainillg wait lomied at the memixls located at: 939 13 cgoziKi C:ourt, Carlsbad. — ' * 311 tht, netghborhoo-ti -whom the cocreat retHining Wall;,:; loe,Tted, h cnh-apce4 the ValtIC k)(11-1.71v.Perty and :does not pose a threat to public stiftly. II will be ovcr-thirtlensorne .41 0 0 41.52910” ottr neighborhood if it is forced to be removed by the Lt, Wc thordere be perrai A11,04Wi •%I, the penuittirig of the exi.itlitg wall will void a ienztily /3uisalve in our Ps-iShb both 'wise and possible iritv-ess and egress over our properties,in addition,. it vA11 'avoid Ilea Machinery and vast amour3ts of dire and soil to be mc...wed in and arourai Dar Sl=t$ aria.TircTeettieg- ift 'ill. also avoid the poAibia infitability of thehiII on which the retainiq ':-J''-)..'4ted; If the ORLI is :breed to be removed. We deuvul.4.that the Plarming and Zothtg COMMISSiMIS ailOW a permit of thceti Petr,onia Cim tinour neighborhood, We listed our atithtls btlew to be notified :5K Plaattirtg ofni4:40fling Conviissiop meetings as nizethigs with. the City this mallet, I 1 , Atleukrti*k_t1 4 t, ept,„Lic, March 16, 2021 Item #4 Page 102 of 193 Item #4 Page 103 of 193 March 16, 2021 o, the_ .titirana Of tile City of Catlfibed, petitiwi the City 'to allow th.o. ptrinfit, of the. eltistirEg 'Laski%wall locamt at the pm---nius rit; 939 Dego/lilt Cowl, Carighl,7_ We the titithborhood whefe the Oir..ectt. trii wUL sluqt-ct.t. II-t1016454, our FotePaliY,alid 4lOes That rkisti a &rent Pablie, gifttY, will cont-;tio'densa.A., i0.4111, .rionti if it ill/rood to be kiimoved by the City,`14ve14,-aorfole par.calqcd.. .. ,. . .A1101.Miikthc trEttitTigiliertiiT owl win 1t 'ia.0-,;(3.'irt.:•cfrio , th'tptst:attd. closaible9.4406a atid eta* ova or 0.OPtri*i; .ill-1?.ddttQ •-i.t.i,q4 4*,:,. . rn,;.1:0-4,064.,#4.vagt affotlii:t!adirt att4 i.toil to bc, *91416 q4:.0.40.. '.... uri.A .4.0,0 . g -voitty,O'tivoid the imsiiblio iottability a the hill ptii.70,4.i.;•;&:-. eTtilio:04-4.y.,,.' : -- 2, ..3 . • . . • . . I N 01 lo.::.tc*ed.to bc.4r.:niovild. WO clOr:patidgkiit the-Planning ZOni pg -Cotunitoio4s allow.5.0T4t L 1itflVW 01'1'4:939' Om* Oailjitt &it ncgbIwoQJ W have Listed our adtitio4:W6.w..i0e :otfe'za 66'4 a:4 4g 441.03titi)eetifigs ll b moiiii.ovviettfb - 7,Y if! March 16, 2021 Item #4 Page 104 of 193 N.nrap 0 04 irm 6z14, a 0114anek J 11 144 1:0.A.rA Simi= ce" cif.,,4 tau for ore.-4,4 ic Oynt,r1k-S 410 Ogre-W-10 OilkciLouiut 944 (3`itc!? / e 'r-17.2P1 m, ..„/1 `f1..p-1 S—z+, 90 0 vaiL-to 'Mk() 1,1PrY (EirV,Lv::e , . . 711M.N. REGARIA,UP CURRENT RETAINING Wit.EA.,111.CD _ isfaRE_SBAD uiti.e,t, a the City of Catisbat,' potition the ek,, malgsv the permit of the apirmtly tAistir3g ret gwL lomr.d at the pmraises located at: 839 ErsagGitaCiCliesbact. We Kt%jj the tit 'gum:thong] whve the Cuarent retaking wan is komed. trittmoa$ rbit vslise our proilmy md does got paao tin* to palic, seety. WI wit he crier -bturiamoit. disruoive -co oar ncighboximd .kf it is frc,..ed t bo rettovvi by the aty. We &wk.= potifAti the. the wail be pettvilvki. Mowing tig 11=1i/tin of the exist:am will avoid a kogiklY UtliSE,IiCt Giff Atii ivrhood ix)th noiw and pmfarple iogre-as al-td egft6S 42vt,r our proputies.fr 4tht. vW avaid heavy machinery owl vast aroma or din, witi, ELIA to be Dmved ir 4t141 ormod oar dreets and 1mo/241i:lies. It will also avoid the ponibIa Knability if the hill on MAO Oto waiting waD is simickt. tfs wall is femxi be. ratneved. We de-'1""d that glo Zoniug Cothrais4ints, alkw a permit of the wtstokting wa .t939 Begonia Court in. our neighT3orhopd. We have Wed ourOdre4s be.1,*-to be taifipd of Thi.;/ atid Planoing, and Zoning ComEn'ission meeting ax wel/ ae meetings with ibe City Cout this mar. March 16, 2021 Item 144 Page 105 of 193 ; Respectfully SubriVned, Advanced Geotechnical Solutions, Inc. AUL J. DER'S!, Vice President CEG 2536, Reg. -Exp. 5-31-21 N J. DO C VAN, Geotechnical Engineer E65051/ E 2790, Reg. Exp, 6-30-21 DiNttitvatias(t) Addrasce t ATTACHMENT 7 S• ADVANCED GEOTECHNI CAL SOLUTI ONS, I NC. . 48$ Corporate Drive. Suite B Escondido, California 92029 Telephone: (61)) 867-0487 Fax: (714) 409-3287 FUSION ENGINEERING & TECHNOLOGY October 9, 2019 4231 Balboa Avenue, Suite 619 P/W 1907-03 San Diego, CA 92117 Report No. 1907-03-B-3 Attention: John Rivera, PE Subject: Geotechnical Evaluation of Existing Mechanically Stabilized Earth Walls, 939 Begonia Court, City of Carlsbad, California References: Se l Appendix Gentlemen, Ptuluant to your request, Geotechnical Solutions, Inc., (AGS) has prepared this letter summarizing the results of our geotechnical evaluation of the existing mechanically stabilized earth (MSE) walls located in the rear yard of the existing- single-family residence located at 939 Begonia Court, City a Carlsbad, California. Also provided are recommendations • for remedittting the- current conditions. AGS appreciates the opportunity to provide you with geotechnical consulting services on this project. If you have questions concerning this report, please do not hesitate to contact the undersigned at (619) 867- 0487, ORANGE AND L.A. COUNTIES INLAND EMPIRE SAN DIEGO AND IMPERIAL COUNTIES (714) 786-5661 (619) 867-0487 (619) 867-0487 March 16, 2021 Item #4 Page 106 of 193 October 9, 2019 Page ii PAV 1907-03 Report No. 1907-03-13-3 TABLE OF CONTENTS Page 1.0 INTRODUCTION • 1 1.1. Scope of Study 1.2. Geotechnical Study Limitations 1 2.0 SITE LOCATION AND DESCRIPTION 2 3.0 SUBSURFACE INVESTIGATION.. 4.0 ENGINEERING GEOLOGY 4.1. Site Geology 9 4.1,1. Undocumented Artificial Fill 4.1.2. Very Old Paralic Deposits 3 4.2. Groundwater 3 5.0 GEOTECIINICA L ENGINEERING. 3 5.1. Expansion Potential 3 5.2. Shear Strength 3 53. Earthwork Adjustments 4 5.4. Relative Compaction of Artificial Fill Materials 4 5.5. Slope Stabi lity 4 6,0 CONCLUSIONS ... 5 7.0 Earthwork Recommendations 5 7.1. Site Preparation and Removals 6 7.2. Remediation Option Recommendations 6 7.2.1, OPTION 1- MSE Wall System,, 7 7.2.2. OPTION 2- Restore Slope with Reinforced Soil Slope 7 7.2,3. Temporary Buiccut Stability 7.3. Geologic Observation During Grading 9 7.4. Seepage 9 7.5. Earthwork Considerations., 9 7.5.1. Compaction Standards 9 7.5.2. Benching 9 7.5.3. Mixing and Moisture Control . to 7.5.4. Haul Roads I 0 7.5.5. Import Soils 10 7.5.6. Pill Slope Construction . 10 7.5.6.1. Overbuilding Fill Slopes I 0 7.5.6.2. Compacting the Slope Face 11 7.5.6.3. Reinforced Soil Slopes 11 8.0 DESIGN RECOMMENDATIONS 11 8.I. Mechanically Stabilized Earthen Wall Recommendations 11 8.1.1. Observation Durhig Construction 11 8.2. .Civil Design Recommendations 12 9.0 SLOPE AND LOT MAINTENANCE 12 9.1, Slope Planting 12 9.2, Lot Drainage 12 9.3. Slope irrigation 12 9 A. Burrowing Animals 13. ADVANCED GEOTECHNICAL SOLUTIONS, INC. March 16, 2021 Itern #4 Page 107 of 193 October 9, 2019 Page iii PAW 1907-03 Report No. 1907-03-B-3 10.0 CLOSURE 13 ATTACHMENTS: Figure 1 - Site Location Map Plate 1 - Boring Location Map Plate 2 - Geologic Cross Sections Appendix A - References Appendix B - Boring Logs Appendix C - Laboratory Test Results Appendix — Slope Stability Analysis Appendix E — Earthwork Specifications and Grading Details ADVANCED GEOTECHNICAL SOLUTIONS, INC. March 16, 2021 Item #4 Page 108 of 193 October 9, 2019 Page 1 P/W 1907-03 Report No. 1907-03-13-3 1.0 INTRODUCTION Advanced Geotechnical Solutions, Inc., (AGS) has prepared this report which presents the results of our subsurface exploration and geotechnical evaluation of existing mechanically stabilized earth (IVISE) walls located in the rear yard of the existing single-family residence located at 939 Begonia Court, City of Carlsbad, California, 1.1. Scope of Study The scope of this study included the following tasks: >Review of pertinent published and unpublished geologic and geotechnical literature, maps, and aerial photographs (Appendix A. References), "aa Geotechnical site reconnaissance to observe site conditions and select:exploratory locations. la Subsurface exploration consisting of four soil borings excavated with a tripod mounted 'limited access drill rig (Appendix. B). >Geotechnical laboratory testing'on selected soil samples (Appendix C), >Preparation of a plan (utilizing the 10-scale site plan as a bast) showing, the approximate locations of borings and geologic cross sections (Plate 1); •Prepare geologic cross sections depicting the existing site conditions and anticipated geologic contacts. (Plate 2). The proposed design is also shown; >Compile and analyze data collected from our site reconnaissance, subsurface evaluation, and laboratory testing. Specifically, our analyses included the following: ca Evaluation of general subsurface conditions and description of types, distribution, and engineeting characteristics of subsurface materials; O Perform slope stability analyses of the existing as-graded/as-built condition, >Provide recommendations on remediating the current conditions. •> Prepare this report describing the work performed, data acquired and our conclusions regarding the global stability of the existing tiered IVISE wall system as well as providing re.commendations on the repair of the existing slope and wall. 1.2, Geolechni cal Study Illanittions The conclusions and recommendations in this report are professional opinions based on information provided by involved parties and the data developed during this investigation. The conclusions presented herein are based on a limited geotechnical investigation. AGS did not provide. geotechnieal testing or observation services during site grading and wall construction, The materials immediately adjacent to or beneath those observed may have different characteristics than those observed. No representations are made as the quality or extent of material not observed. Any evaluation regarding the presence or absence of hazardous material is beyond the scope of this firm's Services, ADVANCED GEOTECNNICAL SOLUTIONS, INC. March 16, 2021 Item #4 Page 109 of 193 October 9, 2019 Page 2 P/W 1907-03 Report No, 1907-03-B-3 2.0 SITE LOCATION AND DESCRIPTION The subject site is located at 939 Begonia Court, City of Carlsbad. California and currently supports one single-family residence and associated improvements including an in-ground pool and Jacuzzi in the rear yard. The property is bounded on the west by Begonia Court and on the north, south, and east by existing single-family residences. Site topography ranges from flat to very gently sloping to the west in the lower building pad area and moderately sloping up to the east in the rear portion of the property. Elevations across the site range from approximately 165 feet above mean sea level (ams1) at the westerly property boundary to 200 feet amsl.at the easterly property boundary. A majerity of the rear slope has been graded to support the subject multi-tiered MSE wall system. Based on available information and review of hiStorie satellite imagery, construction of the subject retaining walls began in .2016 and continued until recent months.. The subject MSE walls were constructed with Keystonee Country Manor retaining wall blocks in a tiered manner with a maximum overall height of approximately 21 feet. Individual wall sections are approximately 5 feet in height and are horizontally separated by approximately I to 10 feet, Geogrid reinforcement (Miragridli) 2XT). appears to have been placed. at 1-‘foot vertical increments. Length of the geogrid reinforcement is reported to be 4 feet. The walls appear to be generally founded in formational materials with the exception of a portion of the lowest wall adjacent to the pool which is founded upon a pre-existing masonry well. At the time of our site exploration, the uppermost well was partially constructed. Groundwater seepage was obseived coming through the southerly portion of the uppermost wal L. 3.0 SUBSURFACE INVESTIGATION On Ally 18, 2019, AGS conducted subsurface exploration at the subject site. Four (4) exploratory borings (B-1 through B-4) were excavated with a tripod drill rig to depths ranging from. 5.5 to 16.5 feet below ground surface (bgs). The materials encountered in the borings were logged by our field pereonnel. The boring logs are presented in Appendix B. Upon completion, the borings were backfil lett with sail cuttings. The approximate boring locations are shown on Figure 2. Boring Location Map. Bulk and relatively undisturbed ring samples of the soils were obtained from the borings at various depths in an effort to evaluate lithologic changes and onsite geolou at the study site. Soil samples were transported to AGS' laboratory and tested for in-situ unit weight and moisture content, shear strength, and maximum density and optimum moisture content. Laboratory results are presented in Appendix C. 4,0 ENGINEERING GEOLOGY 4.1. Site Geoloev Cuteent published regional geologic maps indicate the site is underlain by Very Old Paralic Deposits (Kennedy, M.P., and Tan. S.S.. 2007). The following ,is a brief description of the geologic units encountered during our geotechnieal exploration. A geologic cross section showing approximate distribUtion of geologic units encountered +ensile is .presentedon Plate 2. 4.1.1. Undocumented Artificial Fill Undocumented artificial fill materials were encotmtered extending to depths ranging from 3 feet to 7 feet onsite. These soils appear to be locally derived and generally consist of ADVANCED GEOTECHNICAL SOLUTIONS, INC. March 16, 2021 Item #4 Page 110 of 193 October 9, 201 9 Page 3 NW 1907-03 Report No. 1907-03-B-3 light yellow brown, silty sand with gravel and cobbles, The artificial fill is generally in a dry to slightly moist and loose Co moderately dense condition. 4.1.2. Very Old Penile Deposits Very old medic deposits were encountered beneath fill soils to the maximum depth explored. As encountered, these soils generally consist of dark yellow brown to orange brown, silty sand with trace clay in a slightly moist to moist and moderately dense to dense condition. 4.2. Groundwater Groundwater was not encountered during our subsurface investigation. No natural groundwater condition is known to exist at the site. However, seepage was observed coming through the uppermost wall near the southerly property boundary. Based on our observations, the seepage does not appear to be naturally occurring and is most likely related to drainage and/or irrigation water from the easterly superjacent residence. It should he noted that localized perched groundwater may develop at 41 later date, most. likely at or near fill/bedrock contacts, due to fluctuations in precipitation, irrigation practices, or factors not evident at the time of our field explorations: 5.4 GEOTECHNICAL ENGINEERING Presented herein is a general discussion of the geotechnical properties of the various soil types and the analytic methods used in this report. IL Expansion Potential Expansive soils are characterized by their ability to undergo significant volume changes (shrink or swell) due to variations in moisture content. Changes in soil moisture content can result from precipitation, landscape irrigation, utility leakage, roof drainage, perched groundwater, drought, or other factors and may result in unacceptable settlement or heave of structures or concrete slabs supported on grade. Based on our laboratory testing, it is anticipated that the expansion potential of the onsite materials wilt be "Very Low" to "Low". 5.2. Shear Streneth Based on our laboratory lest results and previous experience in the area with similar soils, the following shear strengths for undocumented artificial fill, engineered artificial fill, and very old mak deposits are presented on Table 5.2. ADVANCED GEOTECHNICAL SOLUTIONS. INC. March 16, 2021 Item #4 Page 111 of 193 Approximate Range Ceologie Unit Existing Pill [ Very Old Paralie DeEosits 15 to 25 percent shrinkace 0 to 10 .ereera hulk TABLE 5.3 Earthwork Adjustments October 9,2019 Page 4 P/W 1907-03 Report No. 1907-03,-B-3 TA HIE 5.2 FOR DESIGN RECOMMENDED SHEAR STRENGTHS Material Cohesion (POI Friction Angle (degrees) Total Unit Weight ' (KO Atli tieial Fill, Undocumented (Existing) 50 27 120 Artificial Fill, Engineered (Proposed) 50 . 3(1 125 Very Old Paralie Deposits i 50 31 125 53. Earthwork Adjustments The following average earthwork adjustment factors are presented for use in evaluating earthwork quantities. These numbers are considered approximate and should be refined during grading when actual conditions are better defined. Contingencies should be made to adjust the earthwork balance during grading if these numbers are adjusted. 5,4, Relative Comvaction of Artificial Fill .M*fe*iats Some of the fill materials were observed to be loose and dry to slightly moist. Test results indicated that some of the artificial fill materials have relative compactionS that are less than 90 percent when compared 0 the maximum dry density (ASTM 01557), L5. Skive Stability Slope .stability analyses were performed on representative cross-sections and considered both static and pseudo-static conditions to evaluate global stability. AGS evaluated the global stability of the tiered MSE retaining walls using GSTABL7. Geogrid reinforcement was added at a spacing schedtile that the owner provided AGS. Per the owner, Mira Miragrid 2XT was placed every 12 inches vertically and extended 48 inches beyond the wall. The Long Term Design Strength was used as provided by the geogid manufacturer. Searches were conducted in OSTAI31.3 to find the critical failure surface with the lowest factor of safety. The factor of safety was calculated using the Bishop method (circular failures), A pseudo-static analysis was used to evaluate the stability of slopes under seismic loading. A horizontal destabilizing seismic coefficient (kw or 0.15 was selected for the site, The ethical failure surface that was determined for the static analysis was also selected for the pseudo-static analysis, and the factor of safety was calculated using the Bishop method (circular failures), ADVANCED GEOTECHNICAL SOLUTIONS, INC. March 16, 2021 Item #4 Page 112 of 193 October 9, 2019 Page 5 PM 1907-03 Report No. I907.03-B-3 The results of the global stability analyses are presented in Appendix C. Based on the results of the analysis, the existing MSE retaining wall system has a slope stability Factor of Safety of less than I .5 for static conditions and less: than 1.0 for seismic conditions. The failure surfaces were shallow and indicate a potential for shallow or localized failures. Typically, the standard of practice in southern California, and has been adopted by most agencies, is to show that slopes have a slope stability factor of safety of 1.5 or greater for static conditions and 1.1 or greater for seismic conditions. AGS also conducted a stability analysis using a proposed design profile consisting of a new roe,, of-slope MSE wall, ascending slope and mid-slope MSE. wall. This design profile is considered preliminary since the civil engineer has net yet prepared grading plans for the site remediation. The proposed design has factor of safety is greater than 1.5 for static conditions and 1.1 for seismic conditions, which both meet the minimum recommended factors of safety. 6.0 CONCLUSIONS Based on the information gathered and the analyses performed, it is our professional opinion that the existing tiered MSE wall system will not meet current code standards as adopted by the City of Carlsbad. The following two items will need to be mitigated in order to meet the current standards. Si. The fill has not been compacted to a minimut of 90 percent of the relative compaction. Typically, fill should be compacted to a minimum of 90 percent of the relative compaction as determined by ASTM 01557, or as recommended by the geotechnical consultants. If settlement and material strength is not a concern, then perhaps a lesser relative compaction may be permissible. However, the shear strength of fill would eXpetted to improve with increased compaction. The tiered wall system does not possess an adequate factor of safety for long term global stability. Typically, a minimum factor Of safety of 1.3 is needed for long term stability and 1.1 for seismic stability. Mitigation may be needed to improve the stability of the system and demonstrate that the slope and wall system has an adequate factor of safety. The existing geogrid lengths are not adequate for the overall height of the system. 7.0 EARTHWORK RECOMINIENDATIONS it is recommended that the existing MSE wall system be remediated to meet current code standards. AGS considered three Options of remediation, described below. 1, NEW MSE WALL SYSTEM: Retrieve the existing MSE walls and undocumented fill. Replace with a new MSE wall system and slope. A five-foot wall can be constructed at the toe of the slope, with a proposed ascending fill slope located above the wall and a new MSE wall constructed near the top of the fill slope. Detailed recommendations are provided herein on constructing this option, 2. RESTORE SLOPE WITH REINFORCED SOIL SLOPE: Remove the existing MSE walls and undocumented fill. Restore the existing slope by constructing a keyway at the bottom and fill slope. Portions- of the new slope will need to be steeper than 2:1 (H: V), which is typically the steepest that is recommended without reinforcement. For the portion's that are steeper than 2:1, ADVANCED GEOTECHNICAL SOLUTIONS. INC. March 16, 2021 Item #4 Page 113 of 193 October 9, 20 I 9 Page 6 P/W 1907-03 Report No. 1907-03-B-3 reinforcement should be added consisting of primary and secondary geogrid layers. Reinforced soil slopes are typically more difficult to construct than unreinforeed slopes and are typically much more expensive, Due to the limited space for stockpiling, the reinforced soil slope will need to be constructed in sections. Difficulty should be expected when tying each section together, which will increase construction cOstS. They reinforced soil slopes should be constructed by an experienced contractor. Repair recommendations are provided herein. 3. REINFORCEMENT OF EXISTING SYSTEM: The existing tiered system can be left-inllace with a considerable reinforcement effort. AGS has met with a specialty geotechniced contractor to discuss possible repair options. Such an effort is expected to consist of building a reinforced shoterete wall in front of each MSE wall. The MSE wall will be cored and a tight spacing of anchors will be drilled through the walls into the formational materials. The MSE. walls will need to be cored at each anchor location. The anchor will be connected to the shoterete wall. The MSE walls will essentially be used as formwork for the sholcrete and anchor wall system. Due to the limited access, constructing the shotcrete wall and drilling will be completed with small equipment and is expected to take a considerable amount of time to complete. This system would need to be designed by a licensed engineer familiar with these systems. It is our understanding that additional information: is being gathered by homeowner in regard to this remediation option. If .the homeowner opts to rernediate the as-built/as-graded condition through reinforcement of the existing. wall system, additional geotechnical analyses should be performed and repair recommendations provided in a supplemental report. A possible configuration of repair option 1 is shown on the .attached geologic cross-sections. The •civil engineer will need to provide a grading plan if this option is selected, An MSE wail plan with supporting calculations may need to be prepared by a licensed engineer. It is possible that Kee/Stone may have standard wall plans that can be used in lieu of a she-specific design. 7.1. Site Preparation and Removals All grading shall be accomplished under the observation and testing of the project. Geotechnical Consuluun in acoordanco with the rcconuntatdatinos contained heroin, the current codes practiced by the City of Carlsbad and this firm's Earthwork Specifications (Appendix. E). Existing vegetation, trash, debris, and other deleterious materials should be removed and wasted •from the site prior to commencing removal of unsuitable soils and placement of compacted fill materials. The existing retaining walls on the slope should be removed. • Within the limits of grading, existing undocumented fill ineterials.and highly weathered Very Old Paralic Deposits should be removed until competent Very Old Paretic Deposits are encountered. In general, the removed materials are suitable to be reused as compacted fill provided deleterious materials are removed, 7./ Remediation Option Recommendations The following sections provide preliminary recommendations for Options I and 2, as discussed in Section 7.0 above, to reinediate the existing as-graded/as-built -condition. Recommendations for Option :4, if requested, can be provided in a supplemental geotechpical report. ADVANCED GEOTECHNICAL SOLUTIONS, INC. March 16, 2021 Item #4 Page 114 of 193 October 9, 2019 Page 7 PM 1907-03 Report No. I 907-03-B-3 7.2.1. OPTION 1- MSE Wall System WISE walls can be constructed near the toe of the slope. The wall should not be constructed atop or near the influence of the existing cantilever retaining walls. The lower MSE wall should have geogrid lengths of not less than 8 feet. The limits of the geogrid should be extended to the backcut, even if shorter geogrid lengths are shown on the wall plans. A minimum horizontal fall width of 8 feet should be maintained on the slope. The till slope can be constructed as described in Section 7.5.6. A minimum of I subdrain should he installed at the toe of the slope. A second drain may also be needed behind the upper MSE retaining wall. The MSE retaining walls should be embedded as recommended by the designer, but no less than 12 inches at the toe of the slope. MSE walls installed above descending slope should be embedded so that the daylight, distance from the. bottom of the wall to the slope face is at least 5 feet. 7.2.2. OPTION 2- Restore Slope with Reinforced Soil Slope A stabilization keyway should be constructed at the toe of the proposed. slope. The limits of this keyway should be based on the final slope design, but should be no less than 12 feet wide. Reinforced soil slopes (RSS) should be constructed on fill slopes steeper than 2:1. The grading contractor should have experience in the construetion of a RSS. There are several methods on constructing a RSS, such as using temporary wooden formwork or permanent wire mesh forms (See Figure 7.2.2, below), and the grading contractor should select the most economical method of construction. The construction method should allow for the fall to be compacted out to the slope face. without damaging the reinforcement. ADVANCED GEOTECHNICAL SOLUTIONS. INC. March 16, 2021 Item #4 Page 115 of 193 October 9, 2019 P/W 1907-03 Page 8 Report No. 1907-03-8-3 IMRE mEGH OR TEMPOI4AIRY FORNANORK N. -gC-+XhAlt,ARY A EINO0ACEmEnT ,t./AAR VEGETATION. MARY IMNFORaeMerif <;:e4•N„.ef: - •-GEO•l'EXritE VIAA0 "7 FACE twiRG SIEST-4 PAC:NG-az-TEMFORARv FORMWOAK VEG2IAT:cfN - '‘Zrs_Y_•<4 .s . _,---dtc;:anaAply AEI eAFCsICCAIC it WRAF' ..).-IJNAAAWY REINFOatttEMENT -44'"•</". f'":7K-0 /V *Z.k'/1./.././ rizure 7.2.2 Alternative Methods of RSS Construction (from TenCatt" 2010a) The primary reinforcement can include placing layers of Mirafi Miragid 3XT (or approved equivalent) every 4 feet vertically starting from the bottom of the keyway. The primary geogrid layers should extend from the slope face to the backcut. The primary geogrid should be oriented so that the primary strength is perpendicular to the slope tace. Splices in the primary direction should be avoided. A secondary layer of reinforcement consisting of 141irati Miramesh TR (or .approved equivalent) should be wrapped around the slope face and embedded a minimum of 5 feet with a maximum vertical spacing of 18 inches. The Miramesh vertical spacing can be reduced to every 2 to 4 feet if the primary geogrid layer is wrapped on the outside of the Miramesh and the primary geogrid is embedded a minimum of 8 fect as measured from the slope face. .0togrid reinforced slopes are expected to be globally and surficially stable to inclinations up to 1:1 (H:V). Splicing of the secondary layer shall not be conducted. 7.2,3. Temporary Bnekent Stability During grading operations, temporary backcuts will be required to accomplish removalt. and provide roam to place gnarl. Care should be taken during ba.ckcut construction and backlitl should be placed expeditiously in order to minimize risk of failure: Complete removal of the failed materials will be required should failure occur. ADVANCED GEOTECHNICAL SOLUTIONS. INC. March 16, 2021 Item #4 Page 116 of 193 October 9,2019 Page 9 P/W 1907-03 Report No. 1907-03-B-3 Baclocuts-exposing competent Very Old Pantile Deposits should be made no steeper than 1:1 to heights of up to 20 feet. Steeper backcuts may be possible for small sections but should be evaluated by AGS. Shallower backcuts are recommended below existing walls or within undocumented fill. Close geologic mapping of the stabilization and buttress key backcuts should be provided to document the exposed conditions. Revised recommendations may be necessary should areas of instability be encountered. In consideration of the inherent instability created by temporary construction of backcuis,. it is imperative that. grading schedules be coordinated to minimize the unsupported exposure time of these excavations. Once started these excavations and subsequent fill operations should be maintained to completion without intervening delays imposed by avoidable circumstances. In cases where five-day workweeks comprise a normal schedule, wading should be planned to avoid exposing at-grade or near-grade excavations through a non-work weekend. Where improvements may be affected by temporary instability, either on or offsite, further restrictions such as slot cutting, extending work days, implementing- weekend schedules, and/or other requirements considered critical to servingspecific circumstances may be imposed. 7.3. Geologic Observation Durine Grading All temporary slope excavations, including front, side and backcuts. and all cut slopes should be mapped to verify the geologic conditions that were modeled prior to grading. 7.4. Seepage Seepage, if encountered during grading, should be evaluated by the Geotechnical Consultant, If seepage is excessive, remedial measures such as horizontal drains or under drains may need to be installed. 7.5. Earthwork Considerations 7.5.1. Compaction standards All fills should be compacted at least 90 percent of the maximum dry density as determined by ASTM 01557. All loose and or deleterious soils should be removed to expose firm native soils or bedrock. Prior to the placement of fill, the upper 6 to inches of suitable material should be ripped, moisture conditioned to optimum moisture or slightly above optimum, and compacted to a minimum of 90 percent ate maximum dry density (ASTM DI557). Fill should be placed in thin (6 to 8-inch) lifts, moisture conditioned. to optimum moisture or slightly above, and compacted to at least 90 percent or the maximum dry density (ASTM D1557) until the desired grade is achieved. 7.5.2, Benching Where the natural slope is steeper than 5-horizontal to 1-vertical and where determined by the Geotechnical Consultant, compacted fill material shall be keyed and benched into competent materials, ADVANCED egOTECHNICAL SOLUTIONS. INC. March 16, 2021 Item #4 Page 117 of 193 October 9, 2019 Page 10 PM 1907-03 Report No. 1907-03-B-3 7.5.3. Mixing and Moisture Control In order to prevent layering of different sell types and/or different moisture contents, mixing and moisture control of materials will be necessary. The preparation of the earth materials through mixing and moisture control should be accomplished prior to and as part of the compaction of each fill lift. Water trucks or other. water delivery means may be necessary for mOiStlire control. Discing may be required when either excessively dry or wet materials are encountered. 7.5.4. Haul Roads All haul roads, ramp tills, and tailing areas shall be removed prior to engineered till placement. 7.5.5. Import Soils Import soils, if required, should consist of clean, structural quality, compactable materials similar to the on-site soils and should be free of trash, debris or other objectionable Materials. Import soils should be toted and approved vtl,.1.1nical Consultant prioro.,i_niorp_jiLgt., At least three working days should he allowed in order for the geotechnical consultant to sample and test the potential import material. Fill Slope Construction Fill slopes may be constructed by preferably overbuilding and cutting back to the compacted core or by back-rolling and compacting the slope face. The following recommendations should be incorporated into construction of the proposed fill slopes. Care should be taken to avoid spillage of loose materials down the face of any slopes during grading. Spill till wilt require complete removal before compaction, shaping and grid rolling. Seeding and planting of the slopes should follow as soon as prsintiCal tO inhibit erosion and deterioration of the slope. surfaces. Proper moisture control will enhance The long- term stability of the finish slope surface. 73.6.1. Overbuilding Fill Slope's Pill slopes should be overfilled to an extent determined by the contractor, but not less than 2 feet measured perpendicular to the slope face, so that when trimmed back to the compacted core, the compaction of the slope face meets the minimum project requirements for compaction. Compaction of each lift should extend out to the temporary slope face., The sloped should be back-rolled at fill intervals not exceeding 4 feet in height unless 'antore extensive overfilling is undertaken. ADVANCED GEOTECHNICAL SOLUTIONS, INC. March 16, 2021 Item #4 Page 118 of 193 October 5, 2019 Page 11 PM 1907-03 Report No. 1907-03-B-3 7.5.6.2. Compacting the Slope Face As an alternative to overbuilding the fill slopes, the slope faces may be back- rolled with a heavy-duty loaded sheepsfoot or vibratory roller at maximum 2-foot fill height intervals. Back-rolling at more frequent intervals may be required. Compaction of each fill should extend to the face of the slope. • 73_6.3. Reinforced Soil Slopes Reinforced sail slopes should be constructed by an experienced contractor. Compaction of the slope face is often achieved through the use of temporary or permanent forms. 8.0 DESIGN RECOMMENDATIONS 8.1. Mechanically Stabilized Earthen Wall Recommendations The base of the proposed MSE wall should be founded on compacted fill or on competent formational materials. The wall designer should provide specifications on the materials placed in the retained and reinforced zones. Assuming materials derived from onsite sources are used to backfill the MSE wall, the wall may be designed using the parameters presented in Table 8.1. More stringent criteria may be required by the wall designer. Testing should be conducted during grading to verify that the backfill materials meet the design criteria shown on the retaining wall plans. TABLE 8,1 MSE WALL DESIGN PARAMETERS' Zone Moist Unit Weight (Pa) Shear Strength Cohesion Ultimate i. qt./ Friction Angle Ultimate de rees) Rein rimed and Retained Soil Zones 125 50 30 Foundation Zono 12$ 50 30 Notc$: ' Assuming fill is &rival fRiEti onsite SNOCCS 8.1.1. Observation During Construction During construction of the MSE walls, the geotechnical consultants should observe the following operations: Grading to create wall foundation support and to verit, competency of foundation materials; Block type and size; Reinforcement type; > Placement of geogrid at design elevation, strength direction, and embedment; Drain placement; ADVANCED GEOTECHNICAL SOLUTIONS. INC. March 16, 2021 Item #4 Page 119 of 193 October 9, 2019 Page 12 PAV 1907-03 Report No. l907-03-11-3 •Gradation and placement of drainage rock; >e Gradation, shear strength, compaction, and moisture content of reinforced soils. Observations of operations not included above (including wall batter, connections, and block placement) are the responsibility of the wall designer and the contractor. The, geoteehnical consultant's observation of these operations in no way relieves the contractor of his obligation to construct the wall system in accordance with approved plans and specifications. 8.2. Civil Design Recommendations Final site grading should assure positive drainage away from structures. A concrete swale should be constructed at the top of the slope to capture offsite irrigation and rainfall n.tnciff. Planter areas should be provided with area drains to transmit irrigation and rain water away from structures. The use of gutters and down spouts to carry roof drainage well away from structures is recommended. Raised planters should be provided with a positive means to remove water through the face of the containment wall. 9.0 SLOPE AND LOT MAINTENANCE Maintenance of improvements is essential to the longterm performance of structures and slopes. Although the design and construction during mass grading created slopes that are considered both grossly and surficially stable, certain factors are beyond the control of the soil engineer and geologist. The homeowners must implement certain maintenance procedures. The following recommendations should be implemented, 9.1. Slope Planting Slope planting should consist of ground cover, shrubs and trees that possess deep, dense root structures and require a minimum of irrigation. The resident should be advised of their responsibility to maintain such planting. 9,2. Lt Drainage. Roof, pad and lot drainage should be collected and directed away from structures and slopes and toward approved disposal areas. Design fine-grade elevations should be maintained through the life of the structure, or if design tine grade elevations are altered, adequate area drains should be installed in order to provide rapid discharge of water away from structures and slopes. Residents should be made aware that they are responsible for maintenance and cleaning of all drainage' terraces, downdrains, and other devices that have been installed to promote structure and slope stability. 9.3. Slone Irrigation The resident homeowner and Homeowner Association should be advised of their responsibility to maintain irrigation systems. Leaks should be repaired immediately. Sprinklers should be adjusted to provide maximum uniform coverage with a minimum of water usage and overlap. ..Overwatering with consequent 1.vastehtl run-off and ground saturation should be avoided, If ADVANCED GEOTECHNICAL SOLUTIONS, INC. March 16, 2021 Item #4 Page 120 of 193 October 9, 2019 rage 13 PAV 1907-03 Report No. 1907-03-8-3 automatic sprinkler steins are installed, their use must be adjusted to account for natural rainfall conditions. 9,4, Burrowing Animals Residents or homeowners should undertake a program for the elimination of burrowing animals. This should be an ongoing program in order to maintain slope stability. 10.0 CLOSURE The findings and recommendations in this report are based on the specific excavations, observations, and tests results as noted herein. The findings are based on the review of the field and laboratory data combined with an interpolation and extrapolation of conditions between and beyond the exploratory excavations; The results reflect an interpretation of the direct evidence obtained. Services performed by AGS have been conducted in a manner consistent with that level of care and skill ordinarily exercised by members of the profession currently practicing in the same locality under similar conditions. No other representation, either expressed or implied, and no warranty or guarantee is included or intended. The recommendations presented in this report are based on the assumption that an appropriate level of field review will be provided .by geotechnical engineers and engineering geologists who are familiar with the design and she geologic conditions. That field review shall be sufficient to confirm that geotechnical and geologic conditions exposed during grading are consistent with the geologic representations and corresponding recommendations presented in this report. lf the project description varies from what is described in this report, AGS must be consulted regarding the applicability of, and the necessity for, any revisions to the recommendations presented herein. AGS should review structural plans to verify whether the recommendations presented herein are incorporated into the design. AGS accepts no liability for any use of its recommendations if the project description or final design varies and AGS is not consulted regarding the changes. The data, opinions, and recommendations of this report are applicable to the specific design of this project as discussed in this report. They have no applicability to any other project or to any other location, and any and all subacqucnt users a:cc:vpt any and all liability resulting from any use or reuse of the data, opinions, and recommendations without the prior written consent of AGS. AGS has no responsibility for construction means, methods, techniques, sequences, or procedures. or for safety precautions or programs in connection with the construction, for the acts or omissions of the CONTRACTOR, or any other person performing any of the construction, or for failure of any of them to carry out the construction in accordance .with the final design drawhigS and specifications. ADVANCED GEOTECHNICAL SOLUTIONS, INC. March 16, 2021 Item #4 Page 121 of 193 APPENDIX A REFERENCES ADVANCED GEOTECHNICAL SOLUTIONS, INC. March 16, 2021 Item #4 Page 122 of 193 October 9, 2019 Page A-1 PRAI 1907-03 Report No. 1907-03-B-3 REFERENCES Fusion Engineering and Technology, Preihninary Site Plan for Lichttnan Residence, 939 Begonia Court, City of Carlsbad, California, Map I of I, 10-Scale, undated. Kennedy, M.P., and Tan, S.S., 2007, Geologic Map of the Oceanside 30' x 60 Quadrangle, California Geological Survey: Scale t:100,000. ADVANCED GEOTECHNICAL SOLUTIONS, INC. March 16, 2021 Item #4 Page 123 of 193 APPENDIX B BORING LOGS ADVANCED GEOTECHNICAL SOLUTIONS, INC. March 16, 2021 Item #4 Page 124 of 193 BORING NUMBER B-1 PAGE 1 OF 1 AnvANctu Mincer:icon squatnIsS, INej CLIENT PROJECT NAME Begonia Court PROJECT NUMBER 1907-03 PROJECT LOCATION 939 Become Ct.. Carlsbad DATE STARTED 7/18119 COMPLETED 711W19 GROUND ELEVATION 186 ft HOLE SIZE 6 DRILLING CONTRACTOR Native Drilling GROUND WATER LEVELS: DRILLING METHOD Tr-Pod AT TIME OF DRILLING — LOGGED BY $8 CHECKED BY RID AT END OF DRILUNG — NOTES AFTER DRILLING — ur -•-•' 0 Ci :7 CI ro D MATERIAL DESCRIPTION SAMPLE TYPE NUMBER SLOW COUNTS (N VALUE) DRY UNIT WT. (Pd.) MOISTURE CONTENT (%) SATURATION (A OTHER TESTS A rfERBERG LIMITS I- LIQUID LIMIT PLASTIC LIMIT cix ,-• 0 0 z < - -1 ca. FINES CONTI (%) 10 : • Slvl SP SM • SM Artificial Fill - Undoetimented. (ata) 7.5 9.6 32 33 Max Shea SILTY SAND, tine- to coarse-grained. light yellow brown, thy to slightly most, meth= dense; with some sub-rounded gravel to cobble BU a 1.5 ft. Poorly graded SAND with (race CLAY. tine- to medium-grained. Slightly moist, medium dense 4-8-16 (18) 104 . • 11 a 3.0 ft, SILTY SAND, fine- to coarse-grained, slightly inerst to moist SWT 6-8-9 (17) . ft., CLAYEY SAND, fine- to coarse-grained, yellow I SPT 4-6-7 OS) .. •. -• , .. . . :. .. brown to orange brown, moist, medium dense Very Old Parallc Deposits, 10/450) SILTY SAND with trace CLAY, fine- to coarse-grained, red brown to orange brown, moist to very moist medium dense: micaceous SRI' 12-11-12 (23) 15 C,,,...., 14-14-12 ‘-‘w-, 94 a 15.0 ft„ dense mr, 11-16-17 Total Depth = 16.5 feet No grouldwater encountered Backftlfeci with soil cuttings March 16, 2021 Item #4 Page 125 of 193 Item #4 Page 126 of 193 March 16, 2021 SM Artificial Fill -Undocumented, (eu) SILTY SAND. fine- to medium-grained, light yellow brown, dry to slightly moist, medium dense; with some sfb-rttimded gravel to cobble 81 3-3-3 (6) BORING NUMBER B-2 PAGE 1 OF 1 PROJECT NAME Begonia Court PROJECT NUMBER 1907-03 _ DATE STARTED 7/18119 COMPLETED 7118/10 PROJECT LOCATION 939 Begonia Ct. Carlsbad GROUND ELEVATION 182 it HOLE SIZE 6 DRILLING CONTRACTOR Native DriIlino GROUND WATER LEVELS: AT TIME OF DRILLING — AT END OF DRILLING — AFTER DRILLING — LU Lu te (74 11 III Lu 0 ATTEREERG LIMITS N. Shea 10 9 Very Old Pantile DenosltS. (C3vota) SILTY SAND with trace CLAY. fine- to coarse-grained, dark yellow brown to orange brown, slightly ItOlSt to moist. medium dense, micaceous @ 6.0 ft., dense SM 8.8 15T MC L-16-33 (49) 9 Total Depth 7.5 feet No groundwater encountered Backtilled with soil cuttings 32 Shea DVANCED OCOIECHNICAL SOLullosis,NcJ CLIENT DRILLING METHOD Tri-Pod LOGGED BY SS CHECKED BY PJO NOTES MATERIAL DESCRIPTION MO 4-5-8 (13) Item #4 Page 127 of 193 March 16, 2021 )AGS I ,,f/Mcrn aolrcirocm. sournasis, tvo BORING NUMBER B.3 PAGE 1 OF I CLJENT PROJECT NAME Begonia Court LOGGED BY SS NOTES AT END OF DRILLING — AFTER DRILLING — CHECKED BY PJD AT TIME OF DRILLING — t5i19 10.35 - ZAPROJf. a BORING Ult.V2. GMT PROJECT NUMBER 1907-03 PROJECT LOCATION 939 Bectoeja Ct., Cedsbad DATE STARTED 7118119 COMPLETED 7118(19 GROUND ELEVATION 178 ft HOLE SIZE DRILLING CONTRACTOR Native Diiihrie GROUND WATER LEVELS: MATERIAL DESCRIPTION Artificial III - Undocunt faful SIL I Y SAND with trace CLAY7fine- to rnediorn.grgined, light yellow brown. dry to slightly olo;st, medium dense; with some sub-rounded gravel to cobble Very Old Fugue Deposits_JCIvop) SILTY SAND with trace CLAY. Vna-10 coarse-grained, orange brown, slightly nititat 10 moist, medium dense; micaceous 4.5 ft.. dense we- n _ tLi 8.0 32 Total Depth = 8.0 feel No groundwater encountered BacktiRed with soil cuttings ?e, - DRILLtNG METHOD Tri-Pnd 0 -‹ ATTERBERG LIMITS C-) C4' 7-; •- 05.t= •VA Sba: Item #4 Page 128 of 193 March 16, 2021 RAGS Auv.v4ctie ctIIIICAisicm. mincers, gyoi CLIENT PROJECT NUMBER 1907-03 BORING NUMBER 13-4 PAGE 1 OF I PROJECT NAME Begonia Court PROJECT LOCATION 939 Bg_gonle CI. Carlsbad GOT - NEM 11! 3 DATE STARTED 7118119 COMPLETED 7,118r19 GROUND ELEVATION 174 ft HOLE SIZE 6 DRILLING CONTRACTOR Native Drilling DRILLING METHOD Tri-Pod LOGGED BY SS NOTES GROUND WATER LEVELS: AT TIME OF DRILLING -- AT END OF DRILLING — AFTER DRILLING — CHECKED BY PJD MAtERIAL DESCRIPTION Artificial Fill - Undocumented, fefu) SILTY SAND, fine- to coarse-grained, gray Orriwn, dry 10 slightly moist, loose; with some sub-rounded gravel Very Old Paralic Deposita, (Qyoo) SILTY SAND with trace CLAY, me- to coare-grained, orange brown. moist, medium dense; micaceous ti) 4.0 ft,, dense Total Depth = 5.5 fact No groundwater encountered Backfilled with soil al:rings 'C-C) 4,t :r- s- D SM 10.5 SM ATTERBERG (1) LIMITS — z ci APPENDIX C LABORATORY TEST RESULTS ADVANCED GEOTTCHNICAL SOLUTIONS, INC. March 16, 2021 Item #4 Page 129 of 193 October 9, 2019 Page C-1 PM 1907-03 Report No. I907-03-B-3 APPENDIX LABORATORY TESTING Classification Soils were visually and texturally classified in accordance with the Unified Soil Classification System (USCS) in general accordance with ASTM 132488. Soil classifications are indicated on the boring logs in Appendix B. Modified Proctor Density The maximum dry density and optimum moisture content of a selected representative soil sample was evaluated using the Modified Proctor method in general accordance with ASTM D1557. The results of these tests are summarized herein. Direct Shear Direct shear tests were performed on relatively undisturbed samples in general accordance with ASTM D3080 to evaluate theshear strength characteristics of selected materials. The samples were inundated during shearing to represent adverse field conditions, The results are shown herein, ADVANCED GEOTECHNICAL SOLUTIONS, INC. March 16, 2021 Item #4 Page 130 of 193 3. „ 1 1 A \ NI S TesICUTW •Zwo Air Voids Osves SG=2.6 - - SO=2.7 - SG-2. i; , , .... 140.0 135.0 130.0 125.0 DRY DENSITY ipcf) 120.0 115.0 110.0 105.0 100.0 ADVANCED GEOTECHNICAL SOLUTIONS, INC. MAXIMUM DENSITY - ASTM D1557 AGS FORM E-8. Project Name: 939 Begonia Ct. Excavation. 13-1 Location: Carlsbad Depth: 0-3 ft PAN No.: 1907-03 Soil Type: afu Date: 7/212019 Tested by: FV Checked by: PJ Method: A Oversize Retained: 5.3 % Point No. 1 2 3 4 Dry Density (pot) 113.2 116,5 118.2 118.8 Moisture Content (%) 8.2 10.2 12.3 14.3 MAXIMUM DENSITY CURVE 00 so 10.0 15.0 20,0 25.0 30.0 MOISTURE (%) Corrected Max. Dry Density 120.1 pcf Corrected moisture 11.6 % Max. Dry Density 118.2 pcf Optimum Moisture 12.3 March 16, 2021 Item #4 Page 131 of 193 Depth: 2.5-3 It Tested by: FV Reviewed by: Location: Carlsbad Project No.: 1907-03 Date: 7/23/2019 March 16, 2021 Item #4 Page 132 of 193 ADVANCED GEOTECHNICAL SOLUTIONS, INC. DIRECT SHEAR - ASTM D3080 Project Name: 939 Begonia Ct. Excavation- B-1 Samples Tested 1 2 3 Intiat Moisture_()(0) 7.5 7.6 7.5 Initial Dry Density (pcf) 104,0 105.7 105.9 Normal Stress (lost) 500 1000 2000 Peak Shear Stress (psr) 455 816 1740 lilt. Shear Stress (psi') 456 744 1596 Soil Type: Yellow SC-Sh.1 Test Undisturbed method. Drained Consolidation: 'Yes Saturation: Yes Shear Rate (1r7miny, 0.01 Strength Parameters Peak Ultimate Friction Angle. phi (deg) 41 39 Cohesion (pst) 0 0 7500 2000 a 1500 tau' 40 01 1000 500 0 500 1000 1500 2000 2500 3000 3500 Normal Stress (psi) Shear Stress v. Displacement 0.04 -^ aces l 1010 I 0.05 Displacement On) •0.02 0.00 0.10 5,20 0.30 Diviacement f in) 2000 1800 1600 F. 1400 1200 Le 1000 yr .11500 , a GCO 4C0 200 0 0.00 Vertical Deformation v. Displacement 7.. .2 0.03 0.02 • • • o Peak -- peak ti loPtimate — Ultimate I. Am.% inn. Project ts.tame: 939 Begonia Ct. Location: Carlsbad Project No.: 1907-03 Date: 7123/2019 Samples Tested 1 2 3 Intia I Moisture (%) 4.1 4.1 41 Initial Dry Density (pcf) 80.6 81.7 83.8 Normal Stress (psi} 500 1000 2000 Peak Shear Stress (pst) 432 828 1358 Wit. Shear Stress cost) 408 816 1308 :41 I. 890 500 169) 1400 IMO 1003 OAP?, 0.02. 0.04 0.02 -5 0.9) .0.41 0.00 0.10 0 20 Displacement lin! 0,30 0.00 9,10 0,20 930 Displacement (in) Sheer Stress v. Displacement t •• MCC. I AtICO 1 Vertical befermation v. Displacement o.os ..... ---- --- -0.02 400 200 0 ADVANCED GEOTECHNICAL SOLUTIONS, INC. DIRECT SHEAR - ASTM D3080 Excavation: B-2 Depth: 3-3,5 ft Tested by: FA/ Reviewed by: $ell Type: Light ern SC Test: Undisturbed Method* Drained Consolidation: Yes Saturation: Yes Shear Rate (nlmin): 0.01 Strength Parameters Peak Ultimate Friction Angle, phi (deg) 32 32 Cohesion (psf) 125 75 2500 S. 2000 S. S. S. S. S. S. S. 1500 41J 1000 X te5 S. ; Jr 500 0 Peak P,-ak 1:1 Ultimate I ultImaN 0 500 1000 1500 2000 2500 3000 3500 Normal Stress 1pst) March 16, 2021 Item #4 Page 133 of 193 ADVANCED GEOTECHNICAL SOLUTIONS, INC. DIRECT SHEAR - ASTM 03080 Project Name: 939 Begonia CL Excavation: B-2 Location: Carlsbad Project No.: 1907-03 Date: 7/25/2019 Samples Tested 1 2 3 Intel Moisture (%) 8.8 8,8 8.8 Initial riry Density (peg 99_4 102.0 100.5 Normal Stress (psi) 500 1000 2000 Peak Shear Stress (psf) 432 708 1426 Lilt Shear Stress (psf) 408 684 1404 Depth: 7-7S ft Tested by FV Reviewed by: AB Sod Typo: Reddish ern. SC-SM Test: ljnchsturbed Method; Drained Consolidation: Yea Saturation: Yes Shear Rate (inirrm). 0.01 Strength Parameters Peak Ultimate Friction Angle, phi (deg) 34 34 Cohesion (psf) 75 25 2500 2000 500 4 0 Peal; Deg,. LI Ultimate Ulthnate 500 1000 1500 2000 2500 3000 3500 Normal Stress (psf) Shear Stress v. Displacement . ... . • ,,, • ----- ... .• , SGG 0. 0 0.20 030 Displacement Ork} Vertical Deformation v. Displacement ........ ---- , ..,....., •'4.'"--r•----- :-...,.....„...."..- t - i • ... —.-....---. 70imi woo Pa 0.10 0.20 0,30 Displacement On) 1600 1400 2C.9 1000 S110 ;44 600 400 0.05 104 0.03 0.02 0.00 0.00 -0,01 4102 200 0 0.00 March 16, 2021 Item #4 Page 134 of 193 9. 500 1000 1.500 2000 2500 Normal Stress (psf) o Peak Peak 11 Ultuiiate — — ultimme 3000 ,7,500 HOD 1403 120t1 ='!-• Woo 500 600 400 200 0 0.00 ,.. ... ... •• • :•:)..1:1 1033 i WO f. $hear Stress v. Displacement 010 0.20 displacement (m) 0.30 0.03 0,111 0.20 Displacement (10 t 0.03 ..9 0.02 .2 a 0.03. 0.03 -0.01 -0.02 0.05 0.04 Vertical Deformation v. Displacement ..... I • .. ...... - ,To ; _ - , . • lath) - j 0.30 ADVANCED GEOTECHNICAL SOLUTIONS, INC. DIRECT SHEAR - ASTM D3080 Project Name: 939 Begonia Ct, Location: Carlsbad Project No.: 1907-03 Date: 7/25/2019 Samples Tested 1 2 3 Intial Moisture {%) 8.0 8.0 8.0 Initial Dry Density (pet) 103.9 98,0 98.4 Normal Stress (pet) 600_ 1000 2000 Peak Shear Stress (est) 456 780 1416 Ult, Shear Stress (pst) 444 732 1344 Excavation: B-3 Depth: 5-5.6 ft Tested by: FV Reviewed by: Soil Type: Reddish Brn. SC-SM Test: Undisturbed Method: Drained Consolidation: Yes Saturation: Yes Shear Rate (l imn): 0.01 Strength Parameters Peak Ultimate Friction Angle, phi (deg) 32 31 Cohesion (psf) 150 150 2500 2000 a 1500 :71 ak 1000 tri 500 0 March 16, 2021 Item #4 Page 135 of 193 APPENDIX I) SLOPE STABILITY ANALYSIS ADVANCED GEOTECHNICAt SOLUTIONS, March 16, 2021 Item #4 Page 136 of 193 TZOZ `9T 1-10.1e1N E6T Jo LET aBed 1907-03 Section Ae-Ael - Static - Existing r..iproject tles‘1907-03 begonia cl wall evaluadontalcs & analysisk1907-03 secton ae static.pf2 Run By: AGS 10i8(2019 05:20PM # FS I ; Soil Soil 1 Total . Saturated CobesiOn Friction Pore Pressure Pim.. a 1.474 Dose. Type Unit Wt. Unit WI batmen( Angle Pressure Constant Surface b 1.492, No. (pcf) (pcf) (psi) (deg) Pararn. (psi) No. C afu 1 125,0 125.0 50.0 27.0 0.00 0.0 0 d 1.553: e 1.573; Ovop 2 .. 125.0 125.0 •150.0 31.0 0.00 0.0 G 1.584 g -1.614 i 1.623 70 60 50 Ii 9 tir koe PI Lit' • p of. i": 2 2 e •.2▪ .• 4 RS1,11;r1 ^ 40 - 30 r 20 .11- 10 0 160 170 180 190 200 210 220 230 240 250 GSTABL7 v.2 FSinin=1.474 Safety Factors Are Calculated By The Modified Bishop Method 260 270 1907-03 Section Ae-Ae Pseudostatic - Existing eproJect ffles11907.03 begonia ct %yell evalualiontalcs & analysist1S07-03 section ae static surface 1.p(t Run By: AGS 1018/2019 05:22PM _.. , —4 t .....r____ . Soil Soil Total Saturated Cohesion Fridion Pore %satire. Piez. Load Value 1 •Dest. Type Vnirm. Unit WI. Intercept Angle PivSsure Constant Surface Peak(A) CL470(0) i No. (pc?) (pot) (psi) (ceg) Pamir. (pat) No. Rh Cool. 0.150(g)‹ 1 Wu 1 125.0 «26.0 50.0 27.0 0.00 0.0 0 Lavap 2 125.0 126.0 150.0 31.0 0.00 0.0 0 _ _ . 40 - 2 2 160 170 180 190 200 210 220 230 240 250 260 270 GSTABLT v.2 FSmin=1.134 Factor Of Safety Is Calculated By The Modified Bishop Method 70 60 50 12;' 2 TZ0Z '9I 1-1DieVI •Ng rgfiSg. to: 2 1 30 Plier.extfattM.11 te...it SNOW 2 ' 1. IV 2 4.14,-.1«,,,,thbf 2 ;:"L:a 2 20 10 E6T lo 8ET aed TZOZ `9T LIDielAl E6T So 6ET a2ed ' Ayt,romttAKI ..r21 1.1Ai6 01, f . :`!i. :...11P1 • 2 113 - 1 iy 2 ' 2 1 42 1907-03 Section Be-Be - Static - Existing z.1/2”0,104t Cles+0907-03 begonia ct wail evaluation‘calcs & analysis%.1907-03 section statio,p12 Run By; AGS 10/812019 05:05PM 70 60 60 # FS Soil Soil Total Saturated Cohesion Friction Pore Pressure Piez, a 1,107. Oeso, Type Unit Wt. Unit Wt. tateropl Angle Pressure Constant Surface b 1,111; No, (pci) (pcf) (psi) (deg) Param. (psi) No. 1 125,0 125.0 50.0 27,0 0.00 0.0 2 125.0 125.0 150.0 31.0 0.00 0.0 C 1.112. afu d 1.117 Ovop 0 40 - 30 20 10 — 0 - 0 10 20 I 30 40 50 60 70 80 90 100 GSTABL7 v.2 FSmirt=1.107 Safety Factors Are Calculated By The Modified Bishop Method 110 1907-03 Section Be-Be' Pseudostatic - Existing 70 eproject fdest1907-03 begonia ot wal evaluationlcalos & analysisk1907-03 section be-be' static surface #1.plt Sol Soil Total Saturated Cohesion Fridion Pore Pressure Prez. Load Value Desc. Type Unit Wt. Unit Wt. letercept Angle Paassure Constant Surface No, iPef) (13Cf) (psf) (c.eg) Para m. (psi) No. aki 1 125.0 125.0 50.0 27.0 0.00 0.0 0 Peak(A) 0.470(g) kh Coef, 0.1•50(g)‹ (Noe 2 125.0 125.0 150.0 310 0.00 0.0 0 60 50 -* 13 40 10-------- 2 9 19/6—r 7 , 2 P., 44 • 'TV 2 30 • --e.o 2. S. L'• 20 2 2 10 Run By; AGS 10/8/2019 05:09Pkil IZOZ (9I (40-181A1 10 20 30 40 50 60 70 80 GSTABL7 v.2 FSrnin=0.895 Factor Of Safety Is Calculated By The Modified Bishop Method E6I Jo OVT aed 90 100 110 TZOZ '91 LIDJelAl E61 JO TV' aged a 7 , ! 2 1907-03 Section Ap-Ap' - Static a ft. Key - Proposed x Aproject files1.1907-03 begonia d wall evaluationicalcs & anatysis11907-03 section ap Bit key and grld.p12 0 FS I Soil Soil --4- • I Total Saturated Czhesion Friction Pore Pressure Piez, . 1 a 1.543 Desc, Type Unll VV1. Unit. VA htercept Angle Pressure Constant Surface b 1,576 No. (pci) (pcl) (psi) tdeg) Pararn. (psi) No. are 1 120.0 125.0 50.0 30.0 0.00 0.0 0 d 1.602 a 1 .503 Gyps 2 125.0 125.0 150.0 31.0 0.00 0,0 0 , 1.505 9 1.611i I) 1.6.2C Run By: AGS 101612019 04:47PM 70 60 50 40 30 20 ' 10 - 1 i i I , I J _./..._ 170 180 190 200 210 220 230 240 260 260 270 GSTABL7 v.2 FSmin=1.543 Safety Factors Are Calculated By The Modified Bishop Method 160 1907-03 Section Ap-Ap' - Pseudostatic 8 ft. Key - Proposed z:'proiect filen:1907-03 begonia ot wall evafuatioreicalcs & analysis11907-03 section ap 8ft key arid grid surface #1.plt Run Dy: AGS 1002010 04:48PM Soil Soil Total Saturated Cohesion Friction Pore Pressure Piez. ' Load Value Desc. Type Unit Wt. Unit Wt. Intercept Argle Pressure Constant Surface Peak(A) 0.47(1(g) No. (pct) afe 1 120.0 (pc) 125.0 (psf) (deg) Perarn. (psf) No. 50.0 30.4 0.00 0.0 0 kh Coe!. 0.150(g)-4 i Qvop 2 125.0 125.4 150.0 31.0 0.00 0.0 0 70 -HOZ `9T Lip-leiN 50 RP 7 40 piLac 2 2 hi/ 2 /2 2 30 hi' Fr. • re, •1 - .72 ;1-A i 2 2 ' 1_ 10 — 1 160 170 180 190 200 210 220 230 240 250 260 270 GSTABL7 v.2 F8mintl.166 Factor Of Safety Is Calculated By The Modified Bishop Method £6T 10 Zi7T aed 180 208 220 240 GSTABL7 v.2 FSrnin=1.589 Safety Factors Are Calculated By The Modified Bishop Method ztprojeot lifest1907-03 begonia ctwall evalualloneralcs & analysisk1907-03 section bp 8ft key and grid.p12 • FS a 1.669 b 1,572 Soil sa Total Saturatec Cohesion Friction Pore Pressure Plez. Dose, Type Unit Wt. Unit Wt_ Intercept Angle Pressure Constant Surfaoe No. (pcf) (poi) (psf) (deg) Param. (psq No. o 1.594 ate 1 125.0 125.0 50.0 30.0 0.00 0.0 0 d 1.613 Qvop .2 125,0 125.0 160.0 31.0 0.00 0.0 0 t..923] I '1.966 g 1.662 Ii 1.670 1907-03 Section Bp-Bp' - Static 8 ft. Key - Proposed Run By AGS 10/6/2019 0446PM . 9 xr 7 o fr) 0,744 52,5 CILOt 2 RAN 2 -HOZ `91 LlaielAl E6T Jo EVE aSed IZOZ `9T LipieVkl £6T 10 17t71 a2ed Soil Soil Total Saturated Cohesion Friction Pore Pressure Plea. Oesc. Type Unit Wt. Unit Wt. Intercept Angle Pressure Constant Surface No. (pert (pot) (psi) (deg) Peron (psi) No. ale Ovop 1 125.0 125.0 50.0 30.0 0.00 0.0 2 126,0 125.0 150.0 31.0 0.00 0.0 2 80 1901-03 Section Bp-Bp' - Pseudostatic 8 ft. Key - Proposed z:Vroject files41907-03 begonia cl wall evaluation%calcs & analysis).1907-03 section bp eft key and arid surface #1.plt Run By: AGS 10+8/2019 04:414PM I Load Value Peak(A) 0.470(0 th Coef. 0.16(m), 60 10.. 7 2 KAI—% - 2 40 - 2 0 160 180 ea a 4;4 Y - 2 200 220 240 260 G6TABL7 v.2 FSminr--1.210 Factor Of Safety Is Calculated By The Modified Bishop Method APPENDIX E GENERAL EARTHWORK SPECIFICATIONS AND GRADING DETAILS ADVANCED GEOTECHNICAL SOLUTIONS, INC. March 16, 2021. Item #4 Page 145 of 193 Cieneral Earthwork Specifications Page I GENERAL EARTHWORK S.PECIFICATIONS I. General A.General procedures and requirements for millwork and grading are presented herein. The earthwork and grading recommendations provided in the geotechnical report are considered part of these specifications, and where the general specifications provided herein conflict with those provided in the geotechnical report, the recommendations in the geotechnical report shall govern. Recommendations provided herein and in the geotechnical report. may need to be modified depending on the conditions encountered during grading. B.The contractor is responsible for the satisfactory completion of all earthwork in accordance with the project plans, specifications, applicable building codes, and local governing agency requirements. Where these requirements conflict, the stricter requirements shall govern. C.It is the contractor's responsibility to read and understand the guidelines presented herein and in the geotechnical report as well as the project plans and specifications. Information presented in the geotechnical report is subject to verification during grading. The information presented on the exploration logs depict conditions at the particular time of excavation and at the location of the excavation. Subsurface conditions present at other locations may differ, and the passage of time may result in different subsurface conditions being encountered at the locations of the exploratory excavations. The contractor shall perform an independent investigation and evaluate the nature of the surface and subsurface conditions to be encountered and the procedures and equipment to be used in performing his work. D.The contractor shall have the responsibility to provide adequate equipment and procedures to accomplish the earthwork in accordance with applicable requirements. When the quality of work is less than that required, the Geotechnical Consultant may reject the work and may recommend that the operations be suspended until the conditions are corrected. E.Prior to the start of grading, a qualified Geotechnical Consultant should be employed to observe grading procedures and provide testing of the fills for conformance with the project specifications, approved grading plan, and guidelines presented herein. All clearing and grubbing, remedial removals, clean-outs, removal bottoms. keyways. and subdrain installations should be observed and documented by the Geotechnical Consultant prior to placing fill. It is the contractor's responsibility to apprise the Geotechnical Consultant of their schedules and notify the Geotechnical Consultant when those areas are ready ibr observation. F.The contractor is responsible for providing a safe environment for the Geotechnical Consultant to observe grading and conduct tests. II. Site Preparation A. Clearing and Grubbing: Excessive vegetation and other deleterious material shall be sufficiently removed as required by the Geotechnical Consultant, and such materials shall be ADVANCED GEOTECHNICAL SOLUTIONS, INC. March 16, 2021 Item #4 Page 146 of 193 General Earthwork Specifications Page 2 properly disposed of offsite in a method acceptable to the owner and governing agencies. Where applicable, the contractor may obtain permission from the Geotechnical Consultant, owner, and governing agencies to dispose of vegetation and other deleterious materials in designated areas onsite. B.Unsuitable Soils Removals: Earth materials that are deemed unsuitable for the support of fill shall be removed as necessary to the satisfaction of the Geotechnical Consultant. C.Any underground structures such as cesspoles, cisterns, mining shells, tunnels, septic tanks, wells, pipelines, other utilities, or other structures located within the limits of grading shall be removed and/or abandoned in accordance with the requirements of the governing agency and to the satisfaction of the Geotechnical Consultant. Environmental evaluation of existing conditions is not the responsibility of the Geotechnical Consultant. D.Preparation of Areas to Receive Fill: After removals are completed, the exposed surfaces shall be processed or scarified to a depth of approximately 8 inches. watered or dried, as needed, to achieve a generally uniform moisture content that is at or near optimum moisture content. The scarified materials shall then be compacted to the project requirements and tested as specified. E.All areas receiving fill shall be observed and approved by the Geotechnical Consultant prior to the placement of fill. A licensed surveyor shall provide survey control for determining elevations of processed areas and keyways. III. Placement of Fill A.Suitability of fill materials: Any materials, derived onsite or imported, may be utilized as fill provided that the materials have been determined to be suitable by the Geotechnical Consultant. Such materials shall be essentially free of organic matter and other deleterious materials, and be of a gradation, expansion potential, and/or strength that is acceptable to the Geotechnical consultant. Fill materials shall be tested in a laboratory approved by the Geotechnical Consultant, and import materials shall be tested and approved prior to being imported. B.Generally, different fill materials shall be thoroughly mixed to provide a relatively uniform blend of materials and prevent abmpt changes in material type. Fill materials derived front benching should be dispersed throughout the fill area instead of placing the materials within only an equipment-width from the cut/fill contact C.Oversize Materials: Rocks greater than 12 inches in largest dimension shall be disposed of offsite or be placed in accordance with the recommendations by the Geotechnical Consultant in the areas that are designated as suitable for oversize rock placement. Rocks that are smaller than 8 inches in largest dimension may be utilized in the fill provided that they are riot nested and are their quantity and distribution are acceptable to the Geotechnical Consultant and do not inhibit the ability to properly compact fill materials. ADVANCED GEOTECHNICAL SOLUTIONS, INC. March 16, 2021 Item #4 Page 147 of 193 General Earthwork. Specifications Page 3 D.The fill materials shall be placed in thin, horizontal layers such that, when compacted, shall not exceed 6 inches. Each layer shall be spread evenly and shall be thoroughly mixed to obtain a near uniform moisture content and uniform blend of materials. E.Moisture Content: Fill materials shall he placed at or above the optimum moisture content or as recommended by the geotechnical report. Where the moisture content ofthe engineered fill is less than recommended, water shall be added. and the fill materials shall be blended so that a near uniform moisture content is achieved. If the moisture content is above the limits specified by the Geotechnical Consultant, the fill materials shall be aerated by cliscing, blading, or other methods until the moisture content is acceptable. F.Each layer of fill shall be compacted to the project standards in accordance to the project specifications and recommendations of the Geotechnical Consultant. Unless otherwise specified by the Geotechnical Consultant, the fill shall be compacted to a minimum of 90 percent of the maximum dry density as determined by ASTM Test Method: D1557. G.Benching: Where placing fill on a slope exceeding a ratio of 5 to I (horizontal to vertical), the ground should be keyed or benched. The keyways and benches shall extend through all unsuitable materials into suitable materials, such as firm materials or sound bedrock or as recommended by the Geotechaital Consultant. The minimum keyway width shall be 15 feet and extend into suitable materials, or as recommended by the geotechnical report and approved by the Geotechnical Consultant. The minimum. keyway width for ill/ over cut slopes is also 15 feet, or as recommended by the geotechnical report and approved by the Geotechnical Consultant. As a general rule, unless otherwise recommended by the Geotechnical Consultant, the minimum width of the keyway shall be equal to 1 /2 the height of the fill slope. IL Slope Face: The specified minimum relative compaction shall be maintained out to the finish face of fill and stabilization fill slopes. Generally, this may be achieved by overbuilding the slope and cutting back to the compacted core. The actual amount of overbuilding may vary as field conditions dictate. Alternately, this may be achieved by backrolling the slope face with suitable equipment or other methods that produce the. designated result. Loose soil should nor be allowed to build up on the slope face. If present, loose soils shall be trimmed to expose the compacted slope thee. I.Slope Ratio: Unless otherwise approved by the Geotechnical Consultant and governing agencies, permanent fill slopes shall be designed and constructed no steeper than 2 to 1 (horizontal to vertical). J.Natural Ground and Cut Areas: Design grades that are in natural ground or M. cuts should be evaluated by the Geotechnical Consultant to determine whether scarification and processing of the ground and/or overexcavation is needed. K.Fill materials shall not be placed, spread, or compacted during unfavorable weather conditions. When grading is interrupted by rain, filing operations shall not resume until the Geotechnical Consultant approves the moisture and density of the previously placed compacted fin. ADVANCED GEOTECHNICAL SOLUTIONS, INC. March 16, 2021 Item #4 Page 148 of 193 General Earthwork Specifications Page 4 IV. Cut Slopes A.The Geotechnical Consultant shall observe all cut slopes, including fill over cut slopes, and shall he notified by the contractor when cut slopes are started. B.If adverse or potentially adverse conditions are encountered during grading, the Geotechnical Consultant shall investigate, evaluate, and make recommendations to mitigate the adverse conditions. C.Unless otherwise stated in the geotechnical report, cut slopes shall not be excavated higher or steeper than the requirements of the local governing agencies. Short-term stability of the cut slopes and other excavations is the contraetor's responsibility. V, Drainage A.Backdrains and Subdrains: Backdrains and subdrains shall be provided in fill as recommended by the Geotechnical Consultant and shall be constructed in accordance with the governing agency and/or recommendations of the Geotechnical Consultant. The location of subdrains, especially outlets, shall be surveyed and recorded by the Civil Engineer. B.Top-of-slope Drainage: Positive drainage shall be established away from the top of slope. Site drainage shall not be permitted to flow over the tops of slopes. C.Drainage terraces shall be constructed in compliance with the governing agency requirements and/or in accordance with the recommendations of the Civil Engineer. D.Non-erodible interceptor swales shall be placed at the top of cut slopes that face the same direction as the prevailing drainage. VI. Erosion Control A.All finish cut and fill slopes shall be protected from erosion and/or planted in accordance with the project specifications and/or landscape architect's recorrunendations. Such measures to protect the slope face shall be undertaken as soon as practical Mier completion of grading. B.During construction, the contractor shall maintain proper drainage and prevent the ponding of water, The contractor shall take remedial measures to prevent the erosion of graded areas until permanent drainage and erosion control measures have been installed. VII. Trench Excavation and Backfill A. Safety: The contractor shall follow all OSHA requirements !iv safety of trench excavations. Knowing and following these requirements is the contractor's responsibility. All trench excavations or open cuts in excess of 5 feet in depth shall be shored or laid back. Trench excavations and open cuts exposing adverse geologic conditions may requite further evaluation ADVANCED GEOTECNNICAL SOLUTIONS, INC. March 16, 2021 Item #4 Page 149 of 193 G'eneral Earthwork Specifications Page 5 by the Geotechnical Consultant. If a contractor fails to provide safe access for compaction testing, backfill net tested due to safety coneems may be subject to removal. B.Bedding: Bedding materials shall be non-expansive and have a Sand Equivalent greater than 30. Where permitted by the Geotechnical Consultant, the bedding materials can be densified by jetting. C.Backlit!: Jetting of backfill materials to achieve compaction is generally not acceptable. Where permitted by the Geotechnical Consultant, the bedding materials can be densified by jetting provided the backfill materials are granular, free-draining and have a Sand Equivalent greater than 30. VIM Geotechnical Observation and Testing During Grading A.Compaction Testing: Fill will be tested and evaluated by the Geotechnical Consultant for evaluation of general compliance with the recommended compaction and moisture conditions, The tests shall be taken in the compacted soils beneath the surface if the surficial materials are disturbed, The contractor shall assist the Geotechnical Consultant by excavating suitable test pits for testing of compacted fill. B.Where tests indicate that the density of a layer of fill is less than required, or the moisture content is not within specifications, the Geotechnical Consultant shall notify the contractor of the unsatisfactory conditions of the fill. The portions of the fill that are not within specifications shall be reworked until the required density and/or moisture content has been attained. No additional fill shall be placed until the last lilt of fill is tested and fbund to meet the project specifications and approved by the Geotechnical Consultant, C.If, in the opinion of the Geotechnical Consultant, unsatisfactory conditions, such as adverse weather, excessive rock or deleterious materials being placed in the fill, insufficient eqnipment, excessive rate of fill placement, results in a quality of work that is unacceptable, the consultant shall notify the contractor, and the contractor shall rectify the conditions, and if necessary. stop work unti I conditions are satisfactory. D.Frequency of Compaction Testing: The location and frequency of tests shall be at the Geotechnical Consultant's discretion. Generally. compaction tests shall be taken at intervals approximately two feet in fill height. E.Compaction Test Locations: The Geotechnical Consultant shall document the approximate elevation and horizontal coordinates of the compaction test locations. The contractor shall coordinate with the surveyor to assure that sufficient grade stakes are established, so that the Geotechnical Consultant can determine the test locations. Alternately, the test locations can be surveyed and the results provided to the Geotechnical Consultant. F.Areas of fill that have not been observed or tested by the Geotechnical Consultant may have to be removed and recompacted at the contractor's expense. The depth and extent of removals will be determined by the Geotechnical Consultant, ADVANCED GEOTECHNICAL SOLUTIONS, INC. March 16, 2021 Item #4 Page 150 of 193 General Earthwork Specifications Page ti• G.Observation and testing by the Geotechnical Consultant shall be conducted during grading in order for the Geotechnical Consultant to state that. in his opinion, grading has been completed in accordance with the approved zeotechnical report and project specifications. H.Reporting of Test Results: After completion of grading operations, the Geotechnical Consultant shall submit reports documenting their observations during construction and test results. These reports may be subject to review by the local governing agencies. ADVANCED GEOTECHN1CAL SOLUTIONS, INC. March 16, 2021 Item #4 Page 151 of 193 MOIL. 13-04, twi-qa L•411,14A Nor Qvap 4,11.1..tomarrett..10 44...4-.41:4.z d4.44444. 4/1•44.44•sa 444.4.4,41111•104414 C44444444.44444,444444.40( TO Z `9T LlileV\I 935 BEGOMA COURT LOT 138 PER MAP AIO 8453 APIV 4'3 913-23 rk4415::. 1 4441 2411*.? • IAA ri *-- Cg:Vtr; rr.r. afu (4:1 V 615:: ::i1-111 •».4s. t.. .3; 4 • 'SIO. r.:444.7. " t ' k ; r • .411,0 * .g11 : 1. :-. 74 13 fr :Tgiv •r"...t6f rj 44, C444 •"'tti.39'.4t4r - etiVA 44444 4444 440•41611.4444. PLATE I "C 101.\.: 1 mks. (248,•004.GicurwrekS pc IPZW'WAIelt 11.44444,14s.e.3 Oct UM PFcPAFED BY. 26110 ZST GOed F440 &q Teat 401 Mixe het Adti San rite:, CA CdS: r.10-10,9 PFELMNO SrtFtU - MI-MUM RESIDENCE 939 BEGONIA COURT SIV CAT ne -C4.infiVA Cbrep f 3 •.44..grt 113 "non. von Pnvesaii TZOZ '91 LIDieV\I TAWNY .7ogrocto Wnonnr1. v.v.. CROSS-SECTION AA =Ala 1,ou CROSS-SECTION Se otir144 E6T JO EST aed PLAIEI 4m.flinianaM11111 SAGS uvoitem rt MOW: PM HIM inr.ne., DeL6.11(1 ATTACHAAMT8 ( 16 -4°.it 44385VC"CEDoip o o , ra c te a GECRECHDriv 2 e 4 Suite "Ti MIS' INc A Telephone: (619) 867-0487 FUSION ENGINEERING & TECHNOLOGY September 10, 2020 4231 Balboa Avenue, Suite 619 P/W 1907-03 San Diego, CA 92117 Report No. 1907-03-B-4 Attention: John Rivera, PE Subject: Geotechnical Addendum, Response to City of Carlsbad Engineering Review Comments, Lichtman Residence, 939 Begonia Court, City of Carlsbad, California. References: Appendix Gentlemen: In accordance with your request and authorization, Advanced Geotechnical Solutions, Inc., has prepared this response to Engineering Review Comments provided by the City of Carlsbad Community Development Department regarding the existing Mechanically Stabilized Earth (MSE) retaining walls in the rear yard of the Lichtman Residence located at 939 Begonia Court, City of Carlsbad, California. More specifically, this letter has been prepared in response to Engineering review comments la through lg from the 1st Review for CDP 2020-0026/V 2020-0004 (DEV 2020-0134) - Begonia Court Retaining Wall dated June 29, 2020 and provided to AGS on September 9, 2020. Unless superseded in the text of this addendum report, the conclusions and recommendations presented in referenced geotechnical report (AGS 2019) remain valid and applicable and should be properly implemented. In preparing this response to cycle review comments we have first presented the review comment followed by our response. Cif)) of Carlsbad- Submit supplemental geotechnical report to the report dated October 9, 2019 by AGS expanding on analysis and recommendations of the third option chosen to reinforce the existing system. Include in the supplemental geotechnical report: la — Recommendations for anchor locations, lengths, spacing, etc. and speciA) which walls shall be anchored. AGS Response — It is our understanding that stabilization of the existing MSE retaining walls will be performed on a design.-build basis. The design-build contractor will provide the locations, lengths, spacing, etc. of the soil nails/tie-backs and detemiine which walls will be anchored. Any MSE retaining walls not stabilized with a shotcrete and soil nail/tie-back system should be evaluated by AGS and may require reconstruction using the appropriate geogrid type, length, and spacing and the reinforced and retained soils compacted to a minimum of 90 percent of the dry density per ASTM D- 1557. The shotcrete with soil nail/tie-back system should be designed by a licensed engineer familiar with these systems. The soil nail/tie-back capacity is dependent on the drilling and grouting methods and should be estimated by the design-build contractor. Testing should be conducted during construction. For preliminary estimating purposes, ultimate anchor capacities in the formational materials (sandstone) can be assumed to be 4,300 pounds per square foot (30 psi). Since the above friction capacities are considered ultimate, an appropriate factor of safety should be incorporated into the design. Soils nails should be embedded a minimum of 10 feet into competent formational ORANGE AND L.A. COUNTIES INLAND EMPIRE SAN DIEGO AND IMPERIAL COUNTIES (714) 786-5661 (619) 708-1649 (619) 867-0487 March 16, 2021 Item #4 Page 154 of 193 Page 2 September 10, 2020 Report 1907-03-B-4 P/W 1907-03 materials. The soil nail/tie-back reinforcement system should be designed to support an active pressure corresponding to an equivalent fluid weight of 40 pcf for level backfill and 60 pa' for sloping backfill, and should also consider the surcharges of the tiered walls. When a design is available, it should be reviewed by AGS and a global stability analysis performed. lb—installation methods and procedures. AGS Response — Installation methods and procedures should be provided by the design-build contractor. Typically, this type of reinforcement may first include coring through the MSE wall blocks at predetermined locations. Hand drills would be used to advance an inclined hole to the design length. The soil nail would be placed in the hole and possibly tubes for primary and post grouting. Testing of selected soil nails would be completed after grouting. Drain boards may be installed on the outside of the MSE wall blocks and a reinforcement mat may be installed. Bearing plates would be affixed to the end of the nails and possibly tied to the reinforcement mat on the outside of the MSE wall. Shotcrete would then be applied to complete the wall. Ic — Assess overall feasibility of the project. AGS Response — Stabilization of the existing MSE retaining wall system with soil nails/tie-back anchors is considered feasible from a geotechnical perspective. Plans for the stabilization of the existing retaining walls should be reviewed by AGS when they are available. id— Location Map. AGS Response — Figure 1- Site Location Plan is included herewith. le — Describe impacts on adjacent properties/improvements as a result of site grading and construction. AGS Response — It is anticipated that the impacts on adjacent properties/improvements as a result of site grading and construction will be negligible to favorable. It should be noted that depending on the final design length of the soil nails/tie-backs, they may encroach into the superjacent parcel(s) and require permission from the adjacent property owner(s). if— Reference applicable building/grading codes/ordinances. AGS Response — Applicable building/grading codes/ordinances should be provided by the design engineer and included on the project plans. le — Recompaction requirements as the fill has not been recompacted to a minimum of 90% of relative compaction per the conclusions in Section 6.0 of October 9, 2019 report. Is recompaction of slopes and level areas between wall required for this remediation option? Design engineer shall also estimate remediation quantities for recompaction in their grading quantity assessment. AGS Response — AGS is unaware of slopes between walls with the exception of the stairs. Provided that there are no structural or settlement sensitive improvements constructed in the project area and that some settlement of the retained soils is acceptable to the property owner, recompaction of the existing retained fill soils is not required. The recommended design active pressure for the ADVANCED GEOTECHNICAL SOLUTIONS, INC. March 16, 2021 Item #4 Page 155 of 193 GE 2790, Reg. Exp. 6-30-21 IN J. DO OVA_N CE 6505i, Distribution: (3) Addressee Attachments: References Figure 1 — Site Location Map PAUL J. DERISI CEG 2536, Reg. Exp. 5-31-21 otlAt_ 04(. r4 No. 2536 CERTIFIED * ENGINEERING * GEOLOGIST OF CAO Page 3 September 10, 2020 Report 1907-03-B-4 P/W 1907-03 reinforcement system and the shear strengths provided in the referenced report that should be used for the global.stability analysis have considered the current condition of the existing fill. Advanced Geotechnical Solutions, Inc. appreciates the opportunity to provide you with geotechnical consulting services and professional opinions. Should you have any questions, please contact the undersigned at (619) 867-0487. Respectfully Submitted, Advanced Geotechnical Solutions, Inc. ADVANCED GEOTECHNICAL SOLUTIONS, INC. March 16, 2021 Item #4 Page 156 of 193 Page 4 September 10, 2020 Report I 907-03-B-4 P/W 1907-03 REFERENCES Advanced Geotechnical Solutions, Inc. (2010). "Geotechnical Evaluation of Existing Mechanically Stabilized Earth Walls, 939 Begonia Court, City of Carlsbad, California," dated October 9, 2019, Report No. 1907-03-B-3. Fusion Engineering and Technology, Preliminary Site Plan for Lichtman Residence, 939 Begonia Court, City of Carlsbad, California, Map 1 of 1, 10-Scale, undated. Kennedy, M.P., and Tan, S.S., 2007, Geologic Map of the Oceanside 30' x 60' Quadrangle, California Geological Survey: Scale 1:100,000. ADVANCED GEOTECHNICAL SOLUTIONS, INC. March 16, 2021 Item #4 Page 157 of 193 SCALE I :43000 P/W 1907-03 FIGURE 1 SOURCE MAP - U.S.G.S. TOPOGRAPHIC MAP OF THE ENCINITAS 7.5 MINUTE QUADRANGLE, SAN DIEGO COUNTY, CALIFORNIA (2018) March 16, 2021 Page 158 of 193 Item #4 eAGS ADVANCED GEOTECHINICAL SOLUTIONS, INC. 485 Corporate Drive, SuiteH Escondido, CA 92029 Telephone: (619) 867-0487 Fax: (714) 409-3287 Batiquitos Lagoon SITE LOCATION MAP 939 BEGONIA COURT, CARLSBAD, CALIFORNIA ATTACHMENT 9 April E. Roberts, Esq. LAW OFFICE OF ALEC HARSHEY 901 S. State St., Suite 400 Hemet, CA 92543 Addendum to Variances P-4 Justification for Variance: 1.Explain what special circumstances are applicable to the subject property, including size, shape, topography, location or surroundings, whereby the strict application of the zoning ordinance deprives such property of privileges enjoyed by other property in the vicinity and under identical zoning classification: Special Circumstances: Location and size of the existing wall, topography of the area and accessability make approving the variance and issuing a permit of the current retaining wall with approved retrofitting the optimal alternative in remedying the code violation. Due to the location of the existing retaining wall as constructed, removing it would not only pose a threat of danger of destabilizing the slope/hill, removing the wall, which spans close to 100 feet long and 21 feet in height also poses extreme challenges regarding access to the wall. Such challenges would not only cause substantial nuisance to the neighborhood, but would also require considerable use and intrusion of and onto neighboring lots. Attached hereto is a petition with some 67 signatures of property owners in the neighborhood that not only support permitting the existing wall and allowing it to remain with retro-fitting, but that clearly shows that requiring the wall be removed will cause serious concerns of neighboring residents, and could possibly result in litigation. 2.Explain why the granting of the variance does not constitute a grant of special privileges inconsistent with the limitations upon other properties in the vicinity and zone in which the subject property is located and is subject to any conditions necessary to assure compliance with this finding: Granting of the variance would not constitute a grant of special privilege inconsistent any limitation upon other properties in the vicinity. On the contrary, granting of the variance would be absolutely consistent with the City's explicit or implicit approval of extremely similar retaining walls not only within the City of Carlsbad, but within the very neighborhood of the subject premises. To follow are several examples of retaining walls within the City's limits that do not comport with CMC 21.95.140. They are as follows: • The Karl Strauss complex with hotel near the Carlsbad Flower Fields. The combined wall heights are approximately 14 feet, perhaps higher. There are several areas of two walls staggered in a terrace fashion, similar to the walls constructed on my client's premises, each over 6 feet in height at the Karl Strauss complex. 1 March 16, 2021 Item #4 Page 159 of 193 I 4901 El Camino Real, Carlsbad (our closest approximation of address). The walls here are approximately 6 feet in height in areas, perhaps higher, and do not begin at the base of the hill. Here the hillside is quite steep, steeper even than the hill at my client's premises at issue. •On the comer of Salk Avenue and El Camino Real in Carlsbad at the Scripps Coastal Medical Center is a wall that may be as high as 40 feet. • At the corner of Kelly Drive and El Camino Real in Carlsbad (across the street from the Oasis Nursery at 4901 El Camino Real, Carlsbad) are walls that are as long as approximately 1000 feet. They are terraced and also do not begin at the base of the hill. The highest wall is approximately 20 feet in height. •The Robertson Ranch housing development at the beginning of the Robertson Ranch trail head, these load bearing walls are over six feet. •The Montecito Apartments at Carlsbad also exhibits walls in excess of 6 feet, including a single wall and two staggered terraced retaining walls. Across the street from the Montecito Apts. at the El Camino Estates also exhibits a long wall over 6 feet in height, which is load bearing. •The Crossings at Carlsbad off of Palomar Airport Road contains a wall that may be up to 30 feet in height and is perhaps 500 feet in length. •7214 Azalea Place, which is only one block from 939 Begonia Ct., the subject premises. On this wall are stairs following the side of a similar sized hillside as the existing wall of the subject premises. There is also a wooden deck approximately 20 feet up the side of the hill, above the wall. •907 Poppy Ln, two blocks from 939 Begonia Ct. At this address, according to its owner, permits were granted for additions to the house and an expansion of the driveway, wherein the hillside was cut away to make room for RV parking. The graded hillside has been cut almost vertically to over 8 ft to10 ft. These ten separate examples of hillside development retaining walls within the City of Carlsbad, which do not comport with the municipal code bear evidence to the City's allowance of variances of its Code and its selective enforcement thereof. As such, denying the permit would be inconsistent with the City's enforcement of its Code. In addition, granting the permit would not prejudice or harm any surrounding homeowners. Some such owners currently have hillside retaining walls of their own. In addition, the retaining wall, as constructed not only beautifies the subject property and substantially raises its property value, it does so for the neighborhood as a whole. 2 March 16, 2021 Item #4 Page 160 of 193 What is more, construction of the wall began sometime in 2016, and the wall was completed some time ago. Applicant is unaware of any complaints to the City regarding the wall, other than one specific disgruntled neighbor, with a history of making false claims, whose unfounded complaint had to do with noise rather than the existence of the wall itself. The wall, as constructed, does not impede any view of any surrounding property. It is placed upon an existing slope, both stabilizing the slope and making the slope attractive. 3.Explain why the granting of the variance does not authorize a use or activity which is not otherwise expressly authorized by the zone regulation governing the subject property: Granting of the variance does not authorize any use or activity unauthorized by the Code. Applicant does not seek a building permit in order to conduct some unauthorized activity, or to construct an object that is not there, the subject retaining wall has been already been constructed. The variance seeks permitting the existing wall after retrofitting. Further, no use or activity unauthorized by the zone regulations governing the subject property shall be conducted at the subject property if a permit is granted. The wall is to beautify the subject property, it is not for any other use or activity. 4.Explain why the granting of the variance is consistent with the general purpose and intent of the General Plan and any applicable specific or Master Plans: Granting the variance is consistent with the general purpose and intent of the General Plan as it protects and enhances natural resources. The retrofitted retaining wall will protect the integrity of the slope it is built upon, which protects the natural topography of the coastline. Forcing the removal of the retaining wall will do just the opposite, and will not only endanger the integrity of the slope but may cause the slope to become unreflective of its natural state prior to the wall being built, it may take away the height, slope, and size of the hillside. In addition, local vegetation and trees that were not a part of the hillside previously have been placed in and around the retaining wall. As part of granting the variance, Applicant is open to installing, introducing and placing additional natural vegetation and trees in and around the existing wall, which will enhance and restore the overall quality of the Coastal Zone environment and its natural and man-made resources, pursuant to the Coastal Act. 5.If located within the coastal zone, explain why the variance is consistent with and implements the requirements of the certified local coastal program and that the variance does not reduce or in any manner adversely affect the protection of coastal resources. The City is to take into consideration what will assure balanced utilization and conservation of Coastal Zone resources taking into account the social and economic needs of the people of the State. Applicant offers such a balance. By retrofitting the existing wall, it shall work to conserve the coastal zone, add natural resources, while benefitting both the social and economic needs of the community in that the wall brings value to surrounding properties. 3 March 16, 2021 Item #4 Page 161 of 193 The City must also protect the rights of property owners. The City has allowed sirnilar retaining walls in size and scope within its limits, giving rise to the argument that such walls are desirable and in certain circumstances allowed by the City. Property owners should be allowed certain items on their property within reason. The scope of the wall, once retrofitted is reasonable and consistent with walls the City has allowed. If a permit is granted, the City will show its priority for coastal-dependent development over other development on the coast. The subject wall follows the hillside, it does not reduce or extend it, but was dependent upon its natural state when constructed. The wall merely covers what was there and stabilizes the hillside, but is not a development independent of the coast. The current wall also aids in erosion control. In addition, permitting the existing wall will further the City's policy regarding Maximum Density of Development. If the wall is permitted, its placement will disallow other development, which may not be coastal-dependant, and will create an area where further development cannot occur, minimizing the density of development. As stated, Applicant is willing to add further natural vegetation and trees, as well as features to slow runoff and maximize onsite infiltration of runoff. What is more, the retaining wall works to minimize the opportunity for toxic compounds, oil and grease, heavy metals, nutrients, suspended solids and other pollutants from entering the storm water conveyance system through the hillside. In all, granting the variance is consistent with the goals and policies of the City regarding its coastal zone and with other variances granted for similar retaining walls in the area. In contrast, denying the variance not only poses a risk to the hillside, but also a logistical nightmare that some 67 local residents object to. Removal of the wall will be oppressive to the surrounding neighborhood. Applicant has been a resident of the area for some time and is a proponent of coastal protection, and understands the City's interest in consistency and enforcement of its Code. However, Applicant hopes that the Code will not be arbitrarily enforced in a discriminatory and draconian manner that will thwart the City's efforts of coastal protection. Not only will granting the variance not cause harm, the wall's retrofitting shall work to protect the hillside. Applicant is willing to do all practicable to enhance and protect the coast's natural resources. In consideration of the above, allowing the variance shall not only be consistent with the City's enforcement of its Code, but also with the spirit and policies of its Master Plan. 4 March 16, 2021 Item #4 Page 162 of 193 ATTACHMENT 11 From: Linda Kranen To: Planning Subject: Begonia Ct retaining wall, CDP 2020-0026/V 2020-0004 Date: Friday, December 4, 2020 1:28:47 PM (...<4,002:5E tla,tlaGY,43,., Regarding the request for a permit and variance to allow an unpermifted retaining wall system at the site below and to the south of my property according to your map (you didn't provide an address), I see no reason why this request should not be approved, considering that there are a multitude of similar retaining walls throughout the old Spinnaker Hill neighborhood; it's likely that more downhill homes have them than not. Given the prevalence of these walls, I'm guessing that the city's involvement is the result of a complaint from a cantankerous neighbor. L. Kranen , Carlsbad CAUTION: Do not open attachments or click on links unless you recognize the sender and know the content is safe. March 16, 2021 Item #4 Page 163 of 193 From: g_n To: Planning Subject: Begonia Court Retaining Wail CDP 2020-00261V 2020-0004 Date: Tuesday, December 8, 2020 1:21:30 PM This property has been the OUTLAW of the neighborhood ! Non-stop party with blasting music and screaming children! Have you had child protective services there? ! Parties have gone ALL NIGHT on many occasions for over a year. The MASSIVE TERRACE cuts into the hillside, and from our view, has no rebar, mortar, drainage OR RAILINGS! It's amazing a kid hasn't fallen to his death already!. We are not using our name but we can see it and we have no doubt these scumbags will take retribution on us . On one weekend, they left a BLARING MEXICAN ( in Spanish) RADIO STATION ON! directed to the south, our way...We assumed it was because someone complained. CAUTION: Do not open attachments or click on links unless you recognize the sender and know the content is safe. March 16, 2021 Item #4 Page 164 of 193 From: YNmabev To: planning Subject: 939 Begonia Ct permit Date: Sunday, December 13, 2020 10:44:16 AM I and my other neighbors living near to the 939 Begonia Ct airbnb short term rental home, run by absentee business owners Puddle Escapers, agree completely with the planning dept enforcing the city building codes being violated by said business. We will not be disturbed enough by the removal process enough to to want it to stay there instead. That is silly idea. I also want to remain anonymous after read comments from his guests when they make any kind on negative comment he viciously attacks them making it look like they are the problem, not him. Go figure CAUTION: Do not oaLattachments or click on links unless you recognize the sender and know the content is safe. March 16; 2021 Item #4 Page 165 of 193 From: YNmabev To: planning Subject: 939 Begonia Ct wall permit Date: Monday, December 14, 2020 10:28:36 PM •• • . ,,, • • ,, „„ „ ,,,,, „, _• . ‘,„ This wall was build by workers paid under the table who had no workerscomp insurance coverage. The twisted 3rd world logic used by ABSENTEE airbnb business owner 'Puddle Escaper LLC'and their attorney, demanding they should be allowed to continue their multiple city code breaking, is just mind boggling. Constant cycling of noisy airbnb renters going up on the hill high on booze (or whatever) hootin & hollerin into the darkness at sunsets (and other times) lighting bottle rockets and small bonfires, pointing lazer lights at us, blasting outdoor amplified wall thumping music (provided free by the 'host'- how neighborly), even AFTER it was taped off by the city for its danger for their own safety (Absentee owners don't hear or see anything - doesn't bother them at all). This wall must come down and STVR license revoked CAUTION: Do not open attachments or click on links unless you recognize the sender and know the content is safe. March 16, 2021 Item #4 Page 166 of 193 From: )essica Bui To: Melissa Flores Subject: RN: Begonia Court Retaining Wall CDP 2020-0026/V 2020-0004 Date: Friday, December 11, 2020 4:45:03 PM Attachments: jrnage001.ong FYI — Begonia Ct. public comment follow up. (City of Carlsbad Jessica Bui, AICP Associate Planner Planning Division 1635 Faraday Ave. Carlsbad, CA 92008 760-602-46311 jessica.buiPcarlsbadca.gov DURING THE CURRENT PUBLIC HEALTH EMERGENCY: FOR ONGOING PROJECTS, PLEASE CONTACT YOUR PROJECT PLANNER TO SCHEDULE A RESUBMITTAL DROP-OFF APPOINTMENT. FOR NEW PROJECT SUBMITTALS AND LANDSCAPE SUBlvIITTALS/RESUBMITTALS/A$_BUILTS, PLEASE CALL OR EMAIL YOUR REQUEST FOR A SUBMITTAL DROP-OFF APPOINTMENT: Phone: 760-602-4610 planningPcarlsbadca.gov From: g n <gn7292186@gmail.com> Sent: Friday, December 11, 2020 4:22 PM To: Jessica Bui Klessica.Bui@carlsbadca.gov> Subject: Re: Begonia Court Retaining Wall CDP 2020-0026/V 2020-0004 Thanks for the update. We want to remain anonymous, because as I told you, the property has installed blaring spanish music radio boombox pointing our way, even though we have never made a complaint. We assume they LEFT FOR A WEEKEND, AND LEFT THIS BLARING MUSIC! It was for 2 days. They have built at least 20 feet of vertical block, and it looks like they are NOT DONE carving- out the slope, ( what does the resident above have to say about this? ! ...because we can see another 6-8 feet of columns indicating they are not done. On Wed, Dec 9, 2020 at 10:32 AM Jessica Bui clessica.BuiPcarlsbadca.gov> wrote: Hello, I am the project planner working on the Begonia Court project. I just wanted to reach out to you to let you know I have received your comment and it will be forwarded to the Planning Commission. March 16, 2021 Item #4 Page 167 of 193 Please feel free to contact me if you have any questions. (City of Carlsbad Jessica Bui, AICP Associate Planner Planning Division 1635 Faraday Ave. Carlsbad, CA 92008 760-602-46311 jessica.buiPcarlsbadca.gov DURING THE CURRENT PUBLIC HEALTH EMERGENCY: FOR c2LIGOING PROJECTS, PLEASE CONTACT YOUR PROJECT PLANNER TO SCHEDULE A RESUBMITTAL DROP-OFF APPOINTMENT. FOR NE i/ PROJECT SUBMITTALS AND CALL OR EMAIL YOUR REQUEST FOR A SUBMITTAL DROP-OFF APPOINTMENT: Phone: 760-602-4610 Email: planningP arlsbadca.gov LAND.accaL3LIBIEnULEF I. PLEASE CAUTIONi Do not open attachments or click on links unless you recognize the sender and know the content is safe. March 16, 2021 Item #4 Page 168 of 193 From: Jessica Bui To: Melissa Flores Subject: FW: Begonia Court Retaining Wall CDP 2020-0026/V 2020-0004 Date: Friday, December 11, 2020 4:44:49 PM Attachments: jmage001.ong FYI — Begonia Ct. public comment follow up. (city of Carlsbad Jessica Bui, AICP Associate Planner Planning Division 1635 Faraday Ave. Carlsbad, CA 92008 760-602-46311 jessica.buiPcarlsbadca.gov DURING THE CURRENT PUBLIC HEALTH EMERGENCY: FOR ONGOING PROJECTS, PLEASE CONTACT YOUR PROJECT PLANNER TO SCHEDULE A RESUBMITTAL DROP-OFF APPOINTMENT. FOR NEW PROJECT SUBMITTALS AND LANDSCAPE SUBMITTALS/RESUBMITTALS/ SBUILTS PLEASE CALL OR EMAIL YOUR REQUEST FOR A SUBMITTAL DROP-OFF APPOINTMENT: Phone: 760-602-4610 Emai!: planninsPcarlsbadca.gov From: g n <gn7292186@gmail.com> Sent: Friday, December 11, 2020 4:31 PM To: Jessica Bui <Jessica.Bui@carlsbadca.gov> Subject: Re: Begonia Court Retaining Wall CDP 2020-0026/V 2020-0004 Let me get this straight! !! You allowed them to build a dangerous terrace w/ wall without railing, mortar, rebar, wire, and they continue to build higher, judging by their unfinished columns... WE ALERTED YOU A YEAR AGO... You did NOTHING. Because the neighborhood doesn't have an active HOA they got away with this... So now, you are going to approve this CRAP? We live in Aviara HOA, if we tried this CRAP, they would have shut us down in a heartbeat. On Wed, Dec 9, 2020 at 10:32 AM Jessica Bui <Jessica.BuiPcarlsbadca.gov> wrote: Hello, I am the project planner working on the Begonia Court project. I just wanted to reach out to you to let you know I have received your comment and it will be forwarded to the Planning Commission. Please feel free to contact me if you have any questions. March 16, 2021 Item #4 Page 169 of 193 (City of Carlsbad Jessica BO, AICP Associate Planner Planning Division 1635 Faraday Ave. Carlsbad, CA 92008 760-602-46311 jessica.buiPcarlsbadca.gov DURING THE CURRENT PUBLIC HEALTH EMERGENCY: FOR ONGOING PROJECTS, PLEASE CONTACT YOUR PROJECT PLANNER TO SCHEDULE A RESUBMITTAL DROP-OFF APPOINTMENT. FOR NEW PROJECT SUBMITTALS AND LANDSCAPE SUBMITTALS/RESUBMITTALS/ASBUILTS„ PLEASE CALL OR EMAIL YOUR REQUEST FOR A SUBMITTAL DROP-OFF APPOINTMENT: Phone: 760-602-4610 planninOcarisbadca.gov CAUTION1 Do not open attachments or click on links unless you recognize the sender and know the content is safe. March 16, 2021 Item #4 Page 170 of 193 From: I ohelos To: planning Subject: Public Hearing Comment -- CDP 2020-0026/V 2020-0004 (DEV2020-0134) -- Begonia Court Retaining Wall Date: Tuesday, December 15, 2020 4:12:31 PM LACA-.• Subject: Public Hearing, Wednesday, December 16, 2020 CDP 2020-0026N 2020-0004 (DEV2020-0134) — Begonia Court Retaining Wall Dear Sirs: We received a letter from your office on the subject public hearing that invited us to comment via email. The subject property is to the rear of ours. While it is not contiguous, the topography is such that the subject property is very visible from the rear of our property. This notice inaccurately describes the non-permitted improvement as a retaining wall. Although it has a retaining wall as a feature, it includes a very large patio area that has been used to hold large gatherings of people. This non-permitted improvement has greatly degraded the character of the neighborhood through its unsightly aesthetics and, just as importantly, the very loud noise that comes from large parties that frequently run late in the night. The Planning Commission should order this eyesore and noise polluter removed immediately to restore the character of the neighborhood. Renee & Jack Phelps Carlsbad, CA 92011 December 15, 2020 CAUTION: Do not open attachments or click on links unless you recognize the sender and know the content is safe. March 16, 2021 Item #4 Page 171 of 193 From: YNmabey To: Planning Subject: RE: 939 Bebonia Ct wall permit Date: Monday, December 14, 2020 8:48:32 AM This wall was build by workers paid under the table who had no workerscomp insurance coverage. The twisted 3rd world logic used by ABSENTEE airbnb business owner 'Puddle Escaper LLC'and their attorney, demanding they should be allowed to continue their multiple city code breaking, is just mind boggling. Constant cycling of noisy airbnb renters going up on the hill high on booze (or whatever) hootin & hollerin into the darkness at sunsets (and other times) lighting bottle rockets and small bonfires, pointing lazer lights at us, blasting outdoor amplified wall thumping music (provided free by the 'host- how neighborly), even AFTER it was taped off by the city for its danger for their own safety (Absentee owners don't hear or see anything - doesn't bother them at all). This wall must come down and STVR license revoked. CAUTION: Do not open attachments or click on links unless you recognize the sender and know the content is safe. March 16, 2021 Item #4 Page 172 of 193 From: To: Cc: Subject: Date: tomtrihnte planning tomtribute440amail.corn RE: Begonia Ct retaining wall, CDP 2020-0026/V 2020-0004 Monday, December 14, 2020 5:37:26 PM •RE: Begonia Ct retaining wall, CDP 2020-0026/V 2020-0004 • •I am Thomas Ward and I live at Begonia Ct next to (South of) this property.1 am concerned about excess drainage coming onto my property from 939 Begonia during our first heavy rains last season since the drought years began, during which this wall project was constructed. Water was coming up very close to my framing level. 1 could also see a large visible stream pouring onto my side from the higher level of 939 close to my side gate. Will this be corrected by the repair plan, or will I be out of luck if this unpermitted wall is approved as is? Who will I go after for damage? The city? Another problem is that the storage shed in same area on 939 side appears to take a jog over the property line onto to my side in one spot. Maybe his recent survey would have detected this? My level is lower than 939 so water will always seek a lower level. Appreciate your help. How will I know you received this message? Thank You CAUTION: Do not open attachments or click on links unless you recognize the sender and know the content is safe. March 16, 2021 Item #4 Page 173 of 193 From: cm-de wail To: Planning Subject: Thank you :Begonia wall Date: Friday, December 11, 2020 8:02:44 PM Thank you to whom it may concern on the planning commission. This guy whos mother bought the house at 939 begonia court has made my family and I's Life a living hell for the past 5 years. Rene doesn't care about rules or laws or getting permission from our city to do anything and he's dangerous and has created a nuisance with his Spinnaker Gem Beach Villa Hotel/motel. Even in the midst of a pandemic the number of persons staying there only increased after March and these guests would have pool parties and birthday parties with different households obviously because no house has this many people living under it's roof, why else would they be renting this one and yelling and screaming outside at all hours of the day and night blasting music and never not once wearing any masks. They did this on the hill on top of the wall- which by the way this wall only adds to the deafening sounds of screaming and yelling because it's stone and the sound bounces everywhere ill think a lot of neighbors were hesitant to complain because of fear of the organized crime Rene is clearly involved in. He was arrested for possession with intent to sell meth in June of 2017 in san Diego county by the San Diegos sheriffs office . How that even ended up happening I don't know maybe he was on probation or maybe he's one of them which if so would be a huge relief to find out. Anyhow on behalf of me and my elderly folks thanks Carrie Ward 760 809-0078 CAUTION: Do not open attachments or click on links unless you recognize the sender and know the content is safe. March 16, 2021 Item #4 Page 174 of 193 EXHIBIT 8 PLANNING COMMISSION Minutes City Council Chamber 1200 Carlsbad Village Drive Carlsbad, CA 92008 DEC. 16, 2020 CALL TO ORDER: 3 p.m. ROLL CALL: Anderson, Geldner, Lafferty, Meenes, Merz, Luna, and Stine. APPROVAL OF MINUTES: Motion by Commissioner Lafferty, seconded by Commissioner Geldner, to approve the Nov. 18, 2020 meeting minutes, as amended. Motion carried 6/0/1 (Commissioner Merz abstained). PUBLIC COMMENTS ON ITEMS NOT LISTED ON THE AGENDA: Diane Nigard submitted comments stating that Covid-19 procedures are not adequately integrating public comments into discussion and encourages verbal comments be integrated into the meeting. PLANNING COMMISSION PUBLIC HEARING: Chair Anderson directed everyone's attention to the slide on the screen to review the procedures the Commission would be following for that evening's public hearing. Chair Anderson opened the public hearing for Item 1. 1. CDP 2020-0026/V 2020-0004 (DEV2020-0134) — BEGONIA COURT RETAINING WALL - Request for a Coastal Development Permit and a Variance to allow an unpermitted retaining wall system that exceeds standards on a manufactured uphill perimeter slope with a gradient greater than 40 percent and an elevation differential of greater than fifteen feet on property located at 939 Begonia Court within the Mello II Segment of the city's Local Coastal Program and Local Facilities Management Zone 4. The project site is not within the appealable area of the California Coastal Commission. The City Planner has determined pursuant to Sections 15061(b)(4) and 15270 of the state CEQA Guidelines that the project is exempt from CEQA because CEQA does not apply to projects which a public agency rejects or disapproves. Commissioner Merz disclosed that he will need to recuse himself from Agenda Item 1 due to a professional relationship that he has with the applicant. City Planner Neu introduced Agenda item 1 and stated Associate Planner Bui would make the staff presentation (on file in the Planning Division). DISCLOSURES: Commissioner Meenes stated that he drove by, walked up the driveway and looked over the gate into the backyard of the site. Commissioner Stine drove by and looked at the site aerially via Google maps. March 16, 2021 Item #4 Page 175 of 193 Planning Commission Minutes Dec. 16, 2020 Page 2 Commissioner Lafferty looked at the site via Google maps. PUBLIC COMMENTS: None APPLICANT QUESTIONS: Commissioner Stine asked why the applicant believes that special circumstance findings can be made on Agenda Item 1. April Roberts, attorney for the applicant stated that a continuance would allow time for plans to be presented regarding special circumstances. Mr. Lich man, applicant, referenced other properties within the city that have similar walls built. He states that while the property does not have special circumstances, removal of the wall will have negative effect to the existing neighborhood. COMMISSION DISCUSSION: Commissioner Luna stated that she has not seen any evidence supporting special circumstances or justification provided to go against the staff recommendation to deny the variance; Chair Anderson, Commissioners Lafferty, Geldner and Stine agreed. ACTION: Motion by Commissioner Stine, seconded by Commissioner Luna, to approve Resolution No. 7394 denying the requested permits. Motion carried, 6/0/1 (Commissioner Merz abstained). 2. CT 2018-0002/SDP 2018-0002/CDP 2018-0005/HDP 2018-0001/HMP 2018-0001/EIR 2018- 0001 (DEV2017-0033) — AV1ARA APARTMENTS — Request for 1) certification of an Environmental Impact Report (EIR 2018-0001), including the approval of Candidate Findings' of Fact and a Mitigation Monitoring and Reporting Program; and 2) approval of a Tentative Tract Map, Site Development Plan, Coastal Development Permit, Hillside Development Permit and Habitat Management Plan Permit to demolish an agricultural packaging warehouse and construct 329 apartments (81 affordable units and 1 manager's unit), including development standards modifications, on an existing parcel that is bisected by Aviara Parkway, north of Laurel Tree Lane, currently addressed as 1205 Aviara Parkway, within the Mello ll Segment of the Local Coastal Program and within Local Facilities Management Zone 5. This project located within the appeal area of the California Coastal Commission. City Planner Neu introduced Agenda Item 2 and stated Associate Planner Garcia would make the staff presentation (on file in the Planning Division). DISCLOSURES: Commissioner Lafferty frequents the market at Aviara Farms monthly. March 16, 2021 Item #4 Page 176 of 193 Planning Commission Minutes Dec. 16, 2020 Page 3 Commissioner Meenes drove by the site and drove up the southwest bluff where he overlooked the site. Additionally, he stated has met the owner at community events but has not had any discussions with the applicant regarding Agenda Item 2. Commissioner Merz drove by the site. Commissioner Stine drove by and walked up the East and West parcels. Commissioner Geldner drove and walked around the site. She also spoke with a resident of the apartments across the street regarding street parking. Additionally, she read the TDM manual, the Mobility Element of the General Plan, the HEAC Report, several related ordinances, the LOS Guidelines and the detailed traffic comments received from the public. STAFF QUESTIONS: Commissioner Meenes asked if there are plans to excavate and remove hazardous soil from the site. Associate Planner Garcia responded that there are procedures in the Mitigation Monitoring and Reporting Program regarding hazardous materials that the applicant will need to submit and have a soil management plan approved by the County Department of Environmental Health. Chair Anderson asked if Laurel Tree Ln will be widened to accommodate parking on both sides of the street and if adequate recreational areas will be included on the property. Associate Planner Garcia responded that the north side of the street will be widened. Regarding recreation area, he responded that apartments don't have such requirements but as much recreation areas as possible will be provided. APPLICANT QUESTIONS: Kevin Dougherty of Summer Hill Apartment Communities gave a brief statement for the Planning Commission. Commissioner Geldner asked how the 60/40 split in traffic coming from the project was determined. Dawn Wilson, with Michael Baker International, responded that traffic was determined based on the location of schools, major employment opportunities and freeway access. Commissioner Stine asked for comment regarding the rationale behind parking spaces. Jeff Williams of Bridge Housing responded that parking is believed to be adequate per unit. Additionally, residents will be encouraged to use public transportation as well as guest parking will be provided. PUBLIC COMMENTS: Resident Chuck Collins submitted comments in opposition to agenda item 2 as the height of the development as planned will affect the views from his home. Residents Glen and Jennifer Domingo, and Mike Murton submitted comments in support of the project for affordable housing stating that the apartments will provide greater opportunity for low income residents and the Carlsbad workforce. March 16, 2021 Item #4 Page 177 of 193 Planning Commission Minutes Dec. 16, 2020 Page 4 Eva Aarons, General Manager of the Aviara Master Association commented to reject the use of the name Aviara Apartments due to its close proximity to the Aviara Master Community. She states there will be confusion between the two developments as there is no distinction. Resident Josh Cantor commented to support the project as it is in line with the needs and values of the community. Residents Mark Packard, Karen and Ray Pierson, Brian Colby commented in support of the project as it will provide housing for employees within the city, opportunity for those in need of assistance, balances different levels of housing needs, reduces net traffic congestion, and helps with needed infrastructure. Resident Jeff Segal commented in support of the project as it provides needed housing for workers. He adds that standards modification in parking recommended by staff should be supported. Steve Linke, Traffic and Mobility Commissioner commented as a private citizen that traffic studies for this project need to apply Carlsbad's Transportation Impact Analysis Guidelines. He adds not having the SANDAG Horizon Analysis and pedestrian and bike analysis within the E1R isn't consistent with HCM or the General Plan and doesn't meet TIA standard of adoption. He recommends redoing the traffic analysis in the EIR based on TIA guidelines and including a more comprehensive TOM plan. DeAnne Wiemer on behalf of the Friends of Aviara Board commented to encourage anti-poison protections as conditions for approval of the project. Lack of monitoring the removal of surface soils, hazardous materials and chemicals is addressed as a concern. Stated objections include an increase of unit density and the reduction of parking spaces. Christian Garcia on behalf of Californians for Home Ownership submitted a statement declaring that a letter was provided as part of their work monitoring local compliance with the housing accountability act. The city's approval of Agenda Item 2 is governed by the act, requiring the city to approve affordable housing projects without applying informal or subjective criteria. The city must only apply applicable and objective standards that can be uniformly verified by reference to external benchmarks of criterion available by the development applicant or proponent, and public officials. Violation of the act can expose the city to significant financial penalties. Having received the letter, the city can be sued if the project is denied. Associate Planner Garcia responded to comments that views will be obstructed for homes on Ebb Tide St. by clarifying that visual simulations of the project showed the project will not affect such views. Regarding the request not to have the name Aviara Apartments used, he states that the city does not get involved in the naming of projects but expects that the project will go by a different name. Kevin Dougherty responded that the site is not contaminated, and pesticides will not run down to Encinas Creek during construction. He notes an environmental study showed one area on site with motor oil and that is being addressed in the soil management plan. Karl Osmitson, Helix Environmental, comments that the Native Habitat Restoration Plan includes methods for dealing with potentially hazardous materials while maintaining sensitive habitats. He notes, it's a standard requirement not to use harsh chemicals. Also, the Preserve Management Plan dictates how open space will be managed and area specific management directives will be standards in how to handle specific pests. He confirms these standards must be implemented by the land manager. In response to comments about traffic analysis, Engineering Manager Jason Geldert states that the TIA guidelines are not applicable to CEQA determination of transportation impacts as the guidelines refer to March 16, 2021 Item #4 Page 178 of 193 Planning Commission Minutes Dec. 16, 2020 . Page 5 thresholds for use in transportation impacts. Under state requirements, to be adopted for general use, the guidelines must undergo a public review process, be supported by substantial evidence and be adopted by ordinance or resolution. The TIA guidelines did not go through these state requirements and could not be used for this project. It was legally determined to use historical thresholds. He notes that traffic studies were performed in accordance with the city's requirements. COMMISSION DISCUSSION: Commissioner Geldner, Lafferty, Luna, Meenes, Merz and Stine stated that the project is well located, complimented the collaboration and community outreach, support the mix of units available, the number of affordable housing units that will be provided and complimented the architectural design. They stated overall support for the project. ACTION: Motion by Commissioner Luna, seconded by Commissioner Meenes, to adopt Resolution No. 7398 and Resolution No. 7399. Motion carried, 7/0. 3. ELECTION OF OFFICERS • COMMISSION DISCUSSION: Chair Anderson opened nominations for the 2021 Planning Commission Chair. Commissioner Geldner nominated Commissioner Luna. Commissioner Stine nominated Commissioner Meenes. Chair Anderson opened nominations for the 2021 Planning Commission Vice Chair. Commissioners Stine and Merz nominated Commissioner Stine. Commissioner Lafferty nominated Commissioner Luna. ACTION: Motion to elect Commissioner Meenes as Planning Commission Chair carried, 5/2 (Commissioners Geldner and Lafferty no). Motion to elect Commissioner Stine as Planning Commission Vice Chair carried, 4/3 (Commissioners Geldner, Lafferty and Luna no). PLANNING COMMISSION REPORTS/COMMENTS: Commissioner Lafferty commented that the virtual SANDAG community chat discussed lowering the railroad tracks and the airport corridor. She stated that the community chats are open to the public in the following months. CITY ATTORNEY REPORTS: None March 16, 2021 Item #4 Page 179 of 193 Planning Commission Minutes Dec. 16, 2020 Page 6 CITY PLANNER REPORTS: None ADJOURNMENT: Chair Anderson adjourned the duly noticed meeting at 6:44 p.m. Corina Flores - Minutes Clerk March 16, 2021 Item #4 Page 180 of 193 EXHIBIT 9 Hillside Development and Design Guidelines a.The Planning Director to the Planning Commission. b.The Planning Commission to the City Council. H. HILLSIDE MAPPING PROCEDURES The Hillside Mapping Procedures are found in Section 21.95.110 of the Carlsbad Municipal Code. At least three major items are needed to appropriately map and identify a hillside: A.Slope Analysis Exhibit 1 illustrates how to show slope classifications. B.Slope Profiles: Exhibits 2 and 3 illustrate examples of slope profiles. C. Total Area of Grading and Grading Volumes The grading of hillside lands should be kept to a minimum. Exhibits 4 and 5 illustrate clear ways to show the total area of grading and grading volumes. D.Assurance of Accurate Hillside Mapping The assurance of accurate Hillside mapping is to be provided by either a registered landscape architect or civil engineer land surveyor. NIL HILLSIDE DEVELOPMENT AND DESIGN STANDARDS The Hillside Development and Design standards address the following development concepts. A.Coastal Zone Hillside Standards B.Development of Manufactured Slopes Greater than 40% Gradient C.Contour Grading D.Screening Manufactured Slopes E.Hillside and Hilltop Architecture HAAdmin\Report\Hillside Guidelines Page 5 March 16, 2021 Item #4 Page 181 of 193 -3PYZ., • •• •I •••••'/' • ••••1 • ••%. ••••.• •••• : •••• - - ' nr-• ' - EXHIBIT 'I' Slope Analysis: The following graphics illustrate ways to show slope classifications. SITE BOUNDARY SLOPE PERCENTAGE LEGEND AREA O 0-less.than 15% 18.2ac O 15-less than 25% 16.1ac 2540% 3.5ac •greater than 40% 2.7ac 40.5ac TOTAL SITE March 16, 2021 Item #4 Page 182 of 193 EXHIBIT 2. ft SIO 500 43Q 480 •ROF/LE LINE 1 SCALE • .41: 20 . f0/ 490 480 470 460 aid SOO 490 460 410 March 1r2021 Profile sr 41, Item #4 Page 183 of 193 •••., seiii I.:7 •••• .00 Olt •• L 0/ — 4.4)ao • "' 4,4 tir4 • Lin. - PROPOSED STRUCTURE BOUNDARY 5 EXiSTING TOPOGRAPHY (TYPICA.-) sursolvtaioN BOUNDARY .•••• I r• LI ar Tire. PROPOSED\ war ot.•="...E1 TOPOGRAPHY 240 PROPOSED STRUCTURE (TYFCAL) -740 —1.,0 .▪ 110' /50 —14.0 .24.0 220 —7C0 —ISO 160 SUBDIVISION BOUNDARY •••'••• /60 240 220 2X- 180 /60 ••• • SUBDIVISION BOUNDARY ZOO ••• f . /10 — PROFILE A EXISTING TOPOGRAPHY i 4 • -177 .5. PROPOSED TOPOGRAPHY PROFILE SUBDIVISION BOUNDARY fl 760 — 7.40 220 200 N.. 180 11.110.001 MAMMA' Ia PROFILE A PROFILE B XEY $0 a fit Item #4 Page 184 of 193 EXHIBIT 3; " EXISTING TOPOGRAPHY PROPOSED STRUCTURE (TYPICAL) •!r• I TOPOGRAPHY \ ' PROPOSED -PROFILE C SUBDIVISION BOUNDARY \J 7 .•'••••• 1:• • PROFILE C TO BE PREPARED AT SAME SCALE AS TENTATIVE MAP March 16, 2021 PROPOSED GRADING FILL .5ac 9100 Cy — CUT .4ac 8000 cy TOTAL SITE AREA: lac TOTAL GRADED AREA .92.0 -9100 cY .9ac 10,100 Cu yds/ac (1 ACRE LOT) (Larg•r of two) r/z ./ .4ac a000 cy cut .3 ac 2000 cy fill. OFFSITE GRADING INCLUDED IN CALCULATIONS oi•r• • 1 \ T•a•••• e•—•e—c••• .8ac 467 cu yd/ac FILL Aac 2800 cy 71 CUT 2a.c 2500 cy (Larger of two) TOTAL SITE AREA lac TOTAL GRADED AREA ..6ac. 2800 cy OFFSITE GRADING INCLUDED IN CALCULATIONS March 16 2021 EXHIBIT 4 NOT ACCEPTABLE - EXCEEDS 10,000 cy/ac ACCEPTABLE (1 ACRE LOT) PROPOSED GRADING TOTAL AREA OF GRADING Pik GRADING VOLUMES Item #4 Page 185 of 193 Ekicturarl Cu C Y0 3 AREA 10 24`J,J 87 18 —1— 30 ac, Fl 234,7'31 40 Enport 8,876 24,z.-0501 3Onc EXHIBIT 5 March 16k,121921cuyth'eaudOd Item #4 Page 186 of 193 Hillside Development and Design Guidelines F.Building Setbacks G.Roadway Design H.Hillside Drainage The following exhibits illustrate some of these concepts. These illustrations do not include all potential design solutions for meeting the Hillside Development Regulations, however they do show conceptual designs which fulfill the regulations intent. Land planners, site designers, engineers, and architects are encouraged to explore additional design solutions that fulfill the intent, purpose and specific requirements of Carlsbad's Hillside Development Regulations. A. Coastal Zone Hillside Standards Carlsbad's Local Coastal Program (LCP) and Chapters 21.38 and 21.201 - 21.203 of the Carlsbad Municipal Code implements the California Coastal Act. As shown on Exhibit 6, Carlsbad's Local Coastal Program is divided into six segments. Certain segments of Carlsbad's LCP require additional conservation of hillside areas. Wherever LCP hillside restrictions differ from Carlsbad's Hillside Development Regulations, the more restrictive aspect of each regulation shall be met. All segments except the Agua Hedionda segment and the Village Redevelopment segment have the same Hillside Development restrictions. The following regulations are taken directly from Carlsbad's Local Coastal Program. For Agua Hedionda segment the following special requirements must be met: Policy 4.4 Recognizing the unique environmental features of the lagoon and its environs and the sensitivity of the area to soil erodibility and sedimentation, development shall be regulated as follows: a.Development on existing subdivided lots having all of their area in slopes of 25% or greater shall be permitted, but grading shall be limited to minimal site preparation for pole-type footings. Driveway/parking areas shall be limited in size and shall be restricted to an area adjacent to the local streets. On-site vegetation shall not be disturbed beyond the minimal area needed to be cleared for the construction process, which shall be clearly delineated on approved site plans. b.Development, grading and landform alteration in steep slope areas (25%) shall be restricted. Exceptions may include encroachments by roadways and utilities necessary to reach developable area. The maximum allowable density shall be calculated on the total lot area, although this may be modified through setbacks, plan review, or other requirements of this plan and applicable city regulations_ c.Use of the Planned Development (PD) Ordinance and cluster development shall be required in areas containing environmentally sensitive resources, extensive steep slope areas and significant natural landform features. Page 6 March 16, 2021 Item #4 Page 187 of 193 1111111' SEGMENT MELLO 1 MELLO 11 REDEVELOPMENT AREA AGUA HED1ONDA LAGOON WEST BATIOUITOS LAGOON EAST BATIOU1TOS LAGOON CARLSBAD LOCAL COASTAL PROGRAM March 16, 2021 +++44 +++++ EXHIBIT 6 Item #4 Page 188 of 193 Hillside Development and Design Guidelines There are no Coastal Zone Hillside Standards within the Village Redevelopment Segment. For all other segments of Carlsbad's LCP the following policy regulates the development of hillsides: Any development proposal that affects steep slopes (25% inclination or greater) shall be required to prepare a slope map and analysis for the affected slopes. The slope mapping analysis shall be prepared during the CEQA environmental review on a project-by-project basis and shall be required as a condition of a coastal development permit. 1) Slopes Possessing Endangered Species and/or Coastal Sage Scrub and Chaparral Plant Communities: For those slopes mapped as possessing endangered plant/animal species and/or coastal sage scrub and chaparral plant communities, the following policy language would apply: a) Slopes of 25% grade and over shall be preserved in their natural state, unless the application of this policy would preclude any reasonable use of the property, in which case an encroachment not to exceed 10% of the steep slope area over 25% grade may be permitted. For existing legal parcels, with all or nearly all of their area in slope area over 25% grade, encroachment may be permitted; however, any such encroachment shall be limited so that at no time is more than 20% of the entire parcel (including areas under 25% slope) permitted to be disturbed from its natural state. This policy shall not apply to the construction of roads on the City's Circulation Element or the development of utility systems. Uses •of slopes over 25% may be made in order to provide access to flatter areas if there is no less environmentally damaging alternative available. b)No further subdivisions of land or utilization of Planned Unit Development shall occur on lots that have their total area in excess of 25% slope unless a planned Unit Development is proposed which limits grading and development to not more than 10% of the total site area. c)Slopes and areas remaining undisturbed as a result of the hillside review process, shall be placed in a permanent open space easement as a condition of development approval. The purpose of the open space easement shall be to reduce the potential for localized erosion and slide hazards, to prohibit the removal of native vegetation except for creating firebreaks and/or planting fire retardant vegetation and to protect visual resources of importance to the entire community. 2) All other Steep Slope Areas: I-1:1Admin\Report\Hillside Guidelines Page 7 March 16, 2021 Item #4 Page 189 of 193 Hillside Development and Design Guidelines For all other steep slope areas, the City Council may allow exceptions to the above grading provisions provided the following mandatory findings to allow exceptions are made: a)A soils investigation conducted by a licensed soils engineer has determined the subject slope area to be stable and grading and development impacts mitigatable for at least 75 years, or life of structure. b)Grading of the slope is essential to the development intent and design, c)Slope disturbance will not result in substantial damage or alteration to major wildlife habitat or native vegetation areas. d)If the area proposed to be disturbed is predominated by steep slopes and is in excess of 10 acres, no more than one third of the total steep slope area shall be subject to major grade changes. e)If the area proposed to be disturbed is predominated by steep slopes and it less than 10 acres, complete grading may be allowed only if no interruption of significant wildlife corridors occur. Because north-facing slopes are generally more prone to stability problems and in many cases contain more extensive natural vegetation, no grading or removal of vegetation from these areas will be permitted unless all environmental impacts have been mitigated. Overriding circumstances are not considered adequate mitigation. 3)Required Runoff Control Plan: No development shall be permitted except pursuant to submittal of a runoff control plan prepared by a licensed engineer qualified in hydrology and hydraulics; such approved plans shall assure that there would be no increase in peak runoff rate from the developed site over the greatest discharge expected from the existing undeveloped site as a result of a 10-year frequency storm. Runoff control shall be accomplished by a variety of measures, including, but not limited to, onsite catchment basins, detention basins, siltation traps, and energy dissipators, and shall not be concentrated in one area. 4)Required Drainage or Erosion Control Facility Maintenance Arrangements: Development approvals shall include detailed maintenance arrangements for providing the on-going repair and maintenance for all approved drainage or erosion-control facilities. 5)Installation and Timing of Permanent Runoff and Erosion Control Devices: All permanent run-off control and erosion-control devices shall be developed and installed prior to or concurrent with any onsite grading activities. Page 8 March 16, 2021 Item #4 Page 190 of 193 Hillside Development and Design Guidelines 6) Required Open Space Easements on Undeveloped Slopes: All undevelopable slopes shall be placed in open space easements as a condition of development approval. Items 3-6 may be required of all development that requires grading. Carlsbad's Hillside Development Regulations recognize that the Hillside Conservation Policies of Carlsbad's LCP segments must be met in addition to the requirements of Chapter 21.95. B.Manufactured Slopes of Greater than 40% Gradient which are Greater than 15 in Height Manufactured slopes of greater than 40% gradient which are greater than 15 feet in height are regarded as important aesthetic (visual) resources in that they provide vertical open space separation between developed pads and developed pads and roadways (See Exhibit 7). For this reason, the development of buildings upon such downhill manufactured slopes which are visible from roadways or adjoining properties is prohibited. However, for residential and non-residential uses, limited development upon such uphill perimeter manufactured slopes would be permitted and for non- residential uses limited development upon downhill perimeter manufactured slopes would be permitted as shown on Exhibits 8 - 10. C.Contour Grading Contour grading creates manufactured slopes in a rounded, undulating pattern that blend into and mimic the surrounding natural hillside. Exhibits 11 and 12 illustrate an acceptable contour grading concept along with an unacceptable manmade slope. The emphasis of the contour grading standard is to create contour graded slopes in areas where they would be visible (i.e., along Circulation Element roadways, collector streets and useable open space areas). D.Screening Manufactured Slopes The screening of manufactured slopes is of considerable importance. Exhibits 13 and 14 illustrate the use of a variety of landscape materials to soften the appearance of the manufactured slope. Another way to accomplish this includes using the building itself as a screening devise. E.Hillside and Hilltop Architecture Hillside and hilltop architecture should be customized to specific hillside conditions. It is strongly recommended that the project architect begin conceptual design work only after becoming fully aware of both the specific hillside site and the Hillside Development Regulations. A preliminary review by staff of the conceptual design is also recommended before any final design is submitted. HAdmin\Report\Hillside Guidelines Page 9 March 16, 2021 Item #4 Page 191 of 193 Retaining walls, main buildings and accessory buildings may be constructed into an uphill slope to a maximum of 6 vertical feet from the toe of slope 14-1 2'-0-.1 Permitted Residential And Non-Residential Development Of Uphill Perimeter Manufactured Slopes EXHIBIT 9 neraugwz t --zzerz e-• - .,3MMUIP .11111•11110111 12111M.-11111111111r MILJNINbe -1111111110.— (0 0 (.0 BORHOOD CO UM L, R V NOTICE OF PUBLIC HEARING NOTICE IS HEREBY GIVEN to you, because your interest may be affected, that the City Council of the City of Carlsbad will hold a public hearing at the Council Chamber, 1200 Carlsbad Village Drive, Carlsbad, California, at 3:00 p.m. on Tues., March 16, 2021, to consider denying a Coastal Development Permit and a Variance for an unpermitted retaining wall system that exceeds standards on a manufactured uphill perimeter slope with a gradient greater than 40 percent and an elevation differential of greater than fifteen feet on property located at 939 Begonia Court within the Mello II Segment of the city's Local Coastal Program and Local Facilities Management Zone 4, and more particularly described as: Lot 138 of Carlsbad Tract No. 73-79, Spinnaker Hill Unit #3, in the City of Carlsbad, County of San Diego, State of California, according to map thereof no. 8453, filed in the Office of the County Recorder of San Diego County on Dec. 29, 1976 Whereas, on Dec. 16, 2020 the City of Carlsbad Planning Commission voted 6/0/1 to deny a Coastal Development Permit and a Variance for an unpermitted retaining wall system that exceeds standards on a manufactured uphill perimeter slope with a gradient greater than 40 percent and an elevation differential of greater than fifteen feet on property located at 939 Begonia Court within the Mello II Segment of the city's Local Coastal Program and Local Facilities Management Zone 4. The project site is not within the appealable area of the California Coastal Commission. The City Planner has determined pursuant to Sections 15061(b)(4) and 15270 of the state CEQA Guidelines that the project is exempt from CEQA because CEQA does not apply to projects which a public agency rejects or disapproves. Copies of the staff report will be available on and after March 12, 2021. If you have any questions, please contact Jessica Evans in the Planning Division at (760) 602-4631 or Jessica.Evans@carlsbadca.gov. Per California Executive Order N-29-20, and in the interest of public health and safety, we are temporarily taking actions to prevent and mitigate the effects of the COVID-19 pandemic by holding City Council and other public meetings online only. All public meetings will comply with public noticing requirements in the Brown Act and will be made accessible electronically to all members of the public seeking to observe and address the City Council. You may participate by phone or in writing. Participation by phone: sign up at https://www.carlsbadca.gov/cityhall/clerk/meetings/default.asp by 2 p.m. the day of the meeting to provide comments live by phone. You will receive a confirmation email with instructions about how to call in. Participation in writing: email comments to clerk@carlsbadca.gov. Comments received by 2 p.m. the day of the meeting will be shared with the City Council prior to the meeting. When e-mailing comments, please identify in the subject line the agenda item to which your comments relate. All comments received will be included as part of the official record. Written comments will not be read out loud. If you challenge the Coastal Development Permit and Variance in court, you may be limited to raising only those issues you or someone else raised at the public hearing described in this notice or in written correspondence delivered to the City of Carlsbad, Attn: City Clerk's Office, 1200 Carlsbad Village Drive, Carlsbad, CA 92008, at or prior to the public hearing. CASE FILE: CDP 2020-0026/V 2020-0004 (DEV2020-0134) CASE NAME: BEGONIA COURT RETAINING WALL PUBLISH: MARCH 5, 2021 CITY OF CARLSBAD CITY COUNCIL NOT TO SCALE SITE MAP Begonia Court Retaining Wall CDP 2020-0026/V 2020-0004 Easy Peel Address Labels Bend along line to expose Pop-up Edge Go to avery.com/templates Use Avery Template 5160 I AVERY 5160 AVIARA MASTER ASSOCIATION C/O A MCKIBBIN&CO 1921 PALOMAR OAKS WAY UNIT 104 CARLSBAD CA 92008 MAICHEN FAMILY TRUST 07-13-99 1000 WHIMBREL CT CARLSBAD CA 92011 CARTERETTE JOHN K AND CAROLYN J 1025 DAISY AVE CARLSBAD CA 92011 MARTIN AUDREY M TRUST 12-05-95 C/0 DAVID WHIDDON 1613 FAIRLEAD AVE CARLSBAD CA 92011 YASUKOCHI GEORGE 7204 WISTERIA WAY I CARLSBAD CA 92011 TURNER LIVING TRUST 0S-25-07 7208 WISTERIA WAY CARLSBAD CA 92011 ESCALLE ROGER LAND ISABEL 7210 WISTERIA WAY CARLSBAD CA 92011 STANTON JAMES AND SANDRA 2001 TRUST 12-31-01 7327 BOLERO ST CARLSBAD CA 92009 DUFFY FAMILY TRUST 10-23-03 1019 DAISY AVE CARLSBAD CA 92011 MCBRIDE JOHN B AND LAUREN J 1029 DAISY AVE CARLSBAD CA 92011 STEWART FAMILY TRUST 11-01-95 7202 WISTERIA WAY CARLSBAD CA 92011 HABIB FAMILY TRUST 02-06-01 7207 WISTERIA WAY CARLSBAD CA 92011 GIBSON MARYLOU G TRUST 03-24-15 7209 WISTERIA WAY CARLSBAD CA 92011 CASTNER JAMES J 7211 WISTERIA WAY CARLSBAD CA 92011 DAISY 1031 HOUSE LLC C/O SUSAN ALMOND 5308 DON RICARDO DR CARLSBAD CA 92010 MCDANIEL LIVING TRUST 03-12-03 1023 DAISY AVE CARLSBAD CA 92011 SHARMA GURU D AND RASHMI M 1577 CORTE ORCHIDIA CARLSBAD CA 92011 HASHIM GEORGE J JR AND MARIA G FAMILY TRUST 05-27-10 7203 WISTERIA WAY CARLSBAD CA 92011 , WEISSENBERGER ANDREW D AND JOYCE L 7208 AZALEA PL CARLSBAD CA 92011 WEST FAMILY REVOCABLE TRUST 09- 19-17 7210 AZALEA PL CARLSBAD CA 92011 BACHMAN BALDWIN FAMILY TRUST 10- 29-05 7212 AZALEA PL CARLSBAD CA 92011 DEGRUY FAMILY TRUST 08-15-12 C/O JUDITH DEGRUY 7214 AZALEA PL CARLSBAD CA 92011 LEVINE MICHAEL AND MAXINE FAMILY TRUST 2001 7216 WISTERIA WAY CARLSBAD CA 92011 JOSEPH FAMILY TRUST 09-23-10 C/O SUSAN JOSEPH 7219 WISTERIA WAY DAVISSON WILLIAM C AND CAROL J REVOCABLE LIVING TRUST 06-24-10 7214 WISTERIA WAY CARLSBAD CA 92011 MOSES DENNIS AND VICKI 7217 WISTERIA WAY CARLSBAD CA 92011 UHLJASON AND JANINE 7220 WISTERIA WAY CARLSBAD CA 92011 CARPENTER RICHARD L AND MARTHA A: INTERVIVOS TRUST 12-31-90 7215 WISTERIA WAY CARLSBAD CA 92011 QUINCE JOSEPH S AND JOYCE M 7218 WISI ERIA WAY CARLSBAD CA 92011 MASON ELBERT S AND VIVIAN J C M TRUST 03-10-15 7221 WISTERIA WAY CARLSBAD CA 92011 Etiquettes d'adresse Easy Peel' Allez a avery.ca/•abarits ' AVERY 5160' Easy Peel'Address Labels Bend along line to expose Pop-up Edge' Go to avery.com/templates Use Avery Template 5160 I PETERSON FRANCES M AND GERALD L REVOCABLE TRUST 03-16-07 7312 LILY PL CARLSBAD CA 92011 RU PERT WILLIAM AND JANICE Z FAMILY TRUST 06-14-95 7317 LILY PL WICHOWSKI FAMILY TRUST 11-01-16 7314 LILY PL CARLSBAD CA 92011 VARGAS RICHARD AND TERRA 7318 LILY PL CARLSBAD CA 92011 CARLSBAD CA 92011 WRIGHT BRADLEY B LIVING TRUST A KU MAR DAVE 10-06-99 917 BEGONIA CT 914 MYRTLE CT CARLSBAD CA 92011 CARLSBAD CA 92011 LEONARD FAMILY TRUST 03-03-93 LUCIUS FAMILY TRUST 05-31-94 919 BEGONIA CT 920 ANATRA CT ' CARLSBAD CA 92011 CARLSBAD CA 92011 DHILLON TRUST 10-09-96 7222 WISTERIA WAY CARLSBAD CA 92011 HANLY FAMILY TRUST 09-13-99 7227 WISTERIA WAY CARLSBAD CA 92011 PAUSE FAMILY TRUST 05-12-93 7305 LILY PL CARLSBAD CA 92011 LOFTIN FAMILY TRUST 06-25-01 920 POPPY LN CARLSBAD CA 92011 SCHULTZ MARK AND AUDREY 7223 WISTERIA WAY CARLSBAD CA 92011 THORP FAMILY 1993 TRUST 10-26-93 7303 LILY PL CARLSBAD CA 92011 OBERLE TRUST 05-08-01 7307 LILY PL CARLSBAD CA 92011 CONNORS FAMILY TRUST A 01-12-87 921 BEGONIA CT CARLSBAD CA 92011 SCOTT EDWARD W AND CAROL A 7225 WISTERIA WAY CARLSBAD CA 92011 BARNES J THOMAS AND JENETE FAMILY TRUST 06-02-11 7304 AZALEA PL CARLSBAD CA 92011 FERNANDES STEVE AND ERMA LIVING TRUST 05-11-06 7311 LILY PL CARLSBAD CA 92011 BURNS MICHAEL WAND JOANNE T 2017 TRUST 12-07-17 7315 LILY PL CARLSBAD CA 92011 SUTTON JANET L REVOCABLE TRUST 01-09-14 7319 LILY PL CARLSBAD CA 92011 LANDIS GREGG S AND KAREN W 917 POPPY LN CARLSBAD CA 92011 RAHN FAMILY TRUST 02-12-15 920 BEGONIA CT CARLSBAD CA 92011 KIEFFE RONALD V 921 POPPY IN CARLSBAD CA 92011 KOSKO JOHN AND PATRICIA REVOCABLE LIVING TRUST 06-27-08 922 BEGONIA CT CARLSBAD CA 92011 SCHRADER MICHAEL J AND ANN M 924 ANATRA CT CARLSBAD CA 92011 •P• FERRONE ROBERT T TRUST 06-25-14 922 POPPY LN CARLSBAD CA 92011 MARTIN DAVID G AND JUDITH A FAMILY TRUST 924 BEGONIA CT CARLSBAD CA 92011 Etiquettes d'adresse Easy Peer' ASBOCK STEFAN A AND AMY L1 923 BEGONIA CT CARLSBAD CA 92011 SMITH KAREN P LIFE TRUST 11-11-14 925 BEGONIA CT CARLSBAD CA 92011 Allez a aver .ca/•abarits ' Etiquettes d'adresse Easy Peel' AVERY 5160 SUGIURA FAMILY TRUST 09-11-15 •927 ANATRA CT CARLSBAD CA 92011 MCKAY FAMILY TRUST 09-20-17 929 BEGONIA CT CARLSBAD CA 92011 KRICKEL FRED RAND NANCY R 932 ANATRA CT CARLSBAD CA 92011 BAILEY CHRISTOPHER G AND NATALIE L 935 BEGONIA CT CARLSBAD CA 92011 CONGLETON FAMILY TRUST 940 ANATRA CT CARLSBAD CA 92011 STEWART CYNTHIA LIVING TRUST 02- 17-15 943 JASMINE CT CARLSBAD CA 920-11 DAQUILA DANIEL AND ANGELINA FAMILY TRUST 05-11-04 945 JASMINE CT CARLSBAD CA 92011 REDDY LALITHA 949 JASMINE CT CARLSBAD CA 92011 TRUJILLO ELAINE V 953 JASMINE CT CARLSBAD CA 92011 REDFIELD TIMOTHY S 955 JASMINE CT CARLSBAD CA 92011 Easy Peel 'Address Labels Bend along line to expose Pop-up Edge JOHNSON THOMAS KENT AND MARALIND TYLER FAMILY RESIDUARY TRUST 01-20-95 ETA 927 BEGONIA CT STEWART JOSHUA N AND LINDA M 930 BEGONIA CT CARLSBAD CA 92011 KENNEDY MICHAEL 932 BEGONIA CT CARLSBAD CA 92011 BALE CRAIG AND KENDLE 936 ANATRA CT CARLSBAD CA 92011 ROTH STUART G AND FILIPPO LORI A 941 BEGONIA CT CARLSBAD CA 92011 CANNON ANTOINE WAND CHEUNG DOROTHY 944 ANATRA CT CARLSBAD CA 92011 PAPAZOGLU VICTOR J AND PAULA A 947 JASMINE CT CARLSBAD CA 92011 HARDESTY J FAMILY REVOCABLE TRUST! 08-17-99 950 WHIMBREL CT CARLSBAD CA 92011 PARKFORD KENNETH A AND ANDREA L I FAMILY TRUST 08-31-04 953 WHIMBREL CT CARLSBAD CA 92011 PHELPS FAMILY 2015 TRUST 956 WHIMBREL CT CARLSBAD CA 92011 Go to avery.com/templates Use Avery Template 5160 ; HOLMES WILLIAM R AND PEARL E INTER VIVOS TRUST 06-12-98 928 BEGONIA CT CARLSBAD CA 92011 GIBBONS FAMILY REVOCABLE 1995 TRUST 07-28-95 931 BEGONIA CT CARLSBAD CA 92011 TURBEVILLE JOHN H JR 934 BEGONIA CT CARLSBAD CA 92011 WARD THOMAS R 937 BEGONIA CT CARLSBAD CA 92011 PITA BEATRICE M TRUST 01-19-04 943 BEGONIA CT CARLSBAD CA 92011 OLSEN DON AND BRENDA 944 BEGONIA CT CARLSBAD CA 92011 ANGUS PATRICK AND ALICE 948 ANATRA CT CARLSBAD CA 92011 VANSLYKE FAMILY TRUST 03-24-11 951 JASMINE CT CARLSBAD CA 9201.1 SCHAFFER ROBERT M FAMILY TRUST 07-29-03 954 MERGANSER LN CARLSBAD CA 92011 HOMA ROBERT AND NELLIE 957 JASMINE CT CARLSBAD CA 92011 Allez a aver .ca/•abarits ' Easy Peel Address Labels Bend along iinc to expose Pop-up Edge Go to avery.corn/templates Use Avery Template 3160 I AVE RY 5160 L---i WILLIAMS PERRY AND CHARLENE FAMILY TRUST 01-12-05 958 MERGANSER LN CARLSBAD CA 92011 WICKERN FAMILY REVOCABLE TRUST 02-18-92 960 WHIMBREL CT CARLSBAD CA 92011 ARKLE KEVIN AND LAUREN 969 WHIMBREL CT CARLSBAD CA 92011 SANDOVAL ARTHUR AND MICHELLE 974 MERGANSER LN CARLSBAD CA 92011 RAY JOHN RAND HOANG HUE T 980 WHIMBREL CT CARLSBAD CA 92011 WERNER REVOCABLE TRUST 07-19-00 989 WHIMBREL CT CARLSBAD CA 92011 OAKES CAROLINE A 7224 WISTERIA WAY CARLSBAD CA 92011-4848 OAKES BILL AND CAROLYN 962 MERGANSER LN CARLSBAD CA 92011-4861 BURNETT FAMILY TRUST 07-07-98 959 JASMINE CT CARLSBAD CA 92011 MARSHALL GREGORY LAND JANET 964 WHIMBREL CT CARLSBAD CA 92011 LUU HOA KIM 970 MERGANSER LN CARLSBAD CA 92011 LEHRMANN PATRICK AND RATIH FAMILY TRUST 05-04-17 976 WHIMBREL CT CARLSBAD CA 92011 MARR FAMILY TRUST 04-24-15 983 WHIMBREL CT CARLSBAD CA 92011 LAROCQUE MICHAEL A TRUST 995 WHIMBREL CT CARLSBAD CA 92011 AVAN DANIEL K AND WENDY S 970 WHIMBREL CT CARLSBAD CA 92011-4858 BRUGUERAZIRKLE MICHAEL 0 928 ANATRA CT CARLSBAD CA 92011-4876 I HANNA JOHN A AND HEATHER 959 WHIMBREL CT CARLSBAD CA 92011 NEIL FAMILY TRUST 05-23-01 966 MERGANSER LN CARLSBAD CA 92011 SPIESS NICOLAS SAND LIWAYWAY S 973 WHIMBREL CT CARLSBAD CA 92011 WHISNANT FAMILY TRUST 05-12-14 978 MERGANSER LN CARLSBAD CA 92011 MACKENZIE ANTOINE-FIT 984 WHIMBREL CT CARLSBAD CA 92011 CARVER CATHERINE 919 POPPY LN CARLSBAD CA 92011-4832 HIGGINS MATTHEW 990 WHIMBREL CT CARLSBAD CA 92011-4858 JENSEN JON A AND CAROL L PO BOX 130640 CARLSBAD CA 92013 WICK EISLER CAROL R 2058 N MILLS AVE # 521 CLAREMONT CA 91711-2812 MILLER ROBERT C AND BRENDA M 526 N 400 W N SALT LAKE UT 84054 Pat: aver .com .atents OCHOA HUMBERTO R 29027 BROOKINGS LN HIGHLAND CA 92346 WEIMER HAROLD H AND KIMBERLY J 34103 N 7TH ST PHOENIX AZ 85085 Etiquettes d'adresse Easy Peel' SHEDD RICHARD LIVING TRUST 02-26- 07 PO BOX 1581 MAMMOTH LAKES CA 93546 CASTANO FRANCISCO D AND SANCHEZ- CASTANO MARIA 15321 VIA MOLINERO POWAY CA 92064 Allez a avery.ca/gabarits Easy Peel' Address Labels Bend along line to expose Pop-up Edge' Go to avery.com/templates Use Avery Template 5160 i Allez avery.ca/gabarits JAVAMIMM...• AVE RY 5160' QIAN XIAO-JIANG AND FENG LI PO BOX 675594 RANCHO SANTA FE CA 92067 LICHTMAN VALERIE REVOCABLE TRUST 06-12-03 860 BERNARD WAY SN BERNRDNO CA 92404 DOMASZEWICZ CASIMIR J TRUST 673 AVE CORDOBA SAN MARCOS CA 92069 MENON SURESH M AND SANTHIRE V REVOCABLE TRUST 03-18-00 1574 PARROT AVE SUNNYVALE CA 94087 OBERMAN STEVEN REVOCABLE TRUST 04-21-06 2773 DOVE TAIL DR SAN MARCOS CA 92078 GUAN XIAOJUN AND HU JUNLIAN 565 MAR VISTA DR VISTA CA 92081 City of Carlsbad 1200 Carlsbad Village Drive Carlsbad, CA 92008 Pat: avery.com/patents Etiquettes d'adresse Easy Peel' Re•Ilez a la h. h - a •- - Etiquettes d'adresse Eas Peer Allez 0 . • . • AVE RY 5160 TENANT 7309 LILY PL Carlsbad, CA 92011-4828 Easy Peel' Address Labels Bend along line to expose Pop-up Edge TENANT 934 BEGONIA CT Carlsbad, CA 92011-4808 Go to avery.com/templates Use Avery Template 5160 111111111111111111••=111 Tammy Cloud-McMinn All Receive - Agenda Item # For the Information of the: CITY COUNCIL DateVit4ACA v CC CM iv- ACM ).----DCM (3) v From: Sent: To: Subject: Attachments: tomtribute <tomtribute44@gmail.com> Monday, March 15, 2021 9:18 PM City Clerk re: #4 item COASTAL DEVELOPMENT PERMIT AND VARIANCE FOR AN UNPERMITTED RETAINING WALL AT 939 BEGONIA COURT 939.pdf Included google maps photo pdf to show how large and disturbing to the neighbors this massive illegal slope project got before stopped, as it should have been. Obviously this STRV business was out to get higher income rent fees with this, and heck with us neighbors and city codes. Our builder's cc&r's forbid this also, which the owner got a copy of when she purchased this home in 2012, so they new it was illegal, and didn't apply for a permit, which would have been denied. CAUTION: Do not open attachments or click on links unless you recognize the sender and know the content is safe 1 Google Maps https://www.google.eom/maps/@33.0993496,-117.2996577,54m/data=!... Go gie Maps Map data 2021 , Map data (>2021 20 ft 1 of 3/15/2021. 9:03 PM March 12, 2021 924 Begonia Ct Carlsbad, CA 9201 1 City Council of the City of Carlsbad 1200 Carlsbad Village Drive Carlsbad, CA 92008 All IRmive - Agenda Item # q For the Information of the: CITY COUNCIL 06to 4/2/ CA CC ,.)c-ACM DCM (3)X RECEIVED MAR 1 6 2.021 CITY OF CARLSBAD CITY CLERK'S OFFICE Re: Public Hearing on Lot 138 of Carlsbad Tract No. 73 — 79, Spinnaker Hill Unit #3 To Whom It May Concern: I feel very strongly that "A Coastal Development Permit and a Variance for an unpermitted retaining wall system that exceeds standards on a manufactured uphill perimeter slope with a gradient greater than 40 percent and an elevation differential of greater than fifteen feet on the property located at 939 Begonia Court" should be DENIED. Most of the homes on Begonia Ct could reasonably be destroyed or severely damaged if that retaining wall fails due to forces of nature such as excessive rain or earthquake. Human lives could be at risk. Those of us who live on Begonia Ct should not have to live with the consequences because one homeowner desires permission to exceed city standards. Please enter my input into the decision making process regarding the approval of this Coastal Development Permit and Variance. Thank you for your consideration and opportunity to speak out regarding this matter. Sincerely, Judith A. Martin Begonia Court Retaining Wall Jessica Evans, Associate Planner March 16, 2021 2 Begonia Court Retaining Wall /~ CDP 2020-0026N 2020-0004 0 90 180 3REAR PROPERTY LINE.._ . ~ -- 0 (.) $ ~ 0 C, ~ olr,:q ; 939 BEGONIA COURT LOT 138 OF CT 73-39 PER MAP NO. 8453 APN 214-390-23' \ Dl>,'M; ~ ) I A .J.:Z 'B B 4 afterbefore 5 Project Request Request for a Coastal Development Permit (CDP) and Variance to allow an unpermitted retaining wall system that exceeds the standards on a manufactured uphill perimeter slope with a gradient greater than 40%and an elevation differential of greater than 15 ft. 6 PROJECT SITE Analysis 7 Variance Findings •Special circumstances: size, shape, topography, etc. •Does not grant special privilege •Does not authorize unpermitted activity •Consistent with General Plan •Consistent with Local Coastal Program Analysis 8 Coastal Development Permit Findings •Slope is stable and impacts mitigatable for 75 years •Grading is essential to development intent Recommendation That the City Council ADOPT the Resolution DENYING the Coastal Development Permit CDP 2020-0026 and Variance V 2020-0004 based upon the findings and subject to the condition contained therein. 9 J.C. 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