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Home My WebLink AboutCDP 2019-0015; SAUER RESIDENCE; GEOTECHNICAL UPDATE AND SITE/GRADING PLAN REVIEW - PROPOSED NEW BUILDING ADDITIONS AND REAR YARD SITE IMPROVEMENTS, 2465 JEFFERSON STREET, CARLSBAD, CALIFORNIA; 2020-04-30Project No. GI-17-09-139 April 30, 2020 Carefree Holdings, LLC Mr. Chris Sauer 2465 Jefferson Street Carlsbad, California 92008 §M§ GEOTECHNICAL SOLUTIONS, INC. Consulting Geotechnical Engineers 5931 Sea Lion Place, Suite 109 Carlsbad, California 92010 Office: 760-602-7815 smsgeosol.inc@gmail.com Geotechnical Update and Site/Grading Plan Review, Proposed New Building Additions and Rear Site Improvements, 2465 Jefferson Street, Carlsbad, California Project most current Site/Grading Plan And Cross Section, prepared by John Majocha, PE, dated November 21, 2019 for the proposed new building additions and rear site improvements were provided to us for review and comment. A copy of the project Site/Grading Plan And Cross Section (Sheet C-1 .0) is reproduced and included with this report as a Geotechnical Map, Figure 1. We are also in receipt of the City of Carlsbad "1st Review For CDP 2019-0015 (DEV2017-0054)-2465 Jefferson Street," dated July 2, 2019. A copy of the City of Carlsbad review letter is attached herein as Attachment A. Reference is also made to the following report prepared by this office in support of the proposed new building additions and rear site improvements: Limited Geotechnical Investigation Proposed New Building Additions And Rear Yard Site Improvement 2465 Jefferson Street Carlsbad, California Project No. GI-17-09-139, dated October 2, 2017 The referenced report is on file with our office and copies can be obtained upon request. The purpose of this effort was to review the most current Site/Grading Plan And Cross Section (Figure 1) from a geotechnical engineering viewpoint, and confirm its compatibility with the site indicated geotechnical conditions and recommendations given in the referenced report. Added and amended recommendations consistent withe current plans, and geotechnical information and clarifications to the City of Carlsbad review comments are also presented in the following sections. R18 C1077 D3740 E329 AASHI □ ACCR E CITEO Geotechnical Update and Site/Grading Plan Review, Proposed New Building Additions and Rear Site Improvements, 2465 Jefferson Street, Carlsbad, California I. GEOTECHNICAL CONDITIONS April 30, 2020 Page2 Topographic conditions and proposed development at the project property are shown on the enclosed Geotechnical Map, Figure 1. In general, site geotechnical conditions remain the same as discussed in the referenced report. The property is mostly characterized by a nearly level graded building surface terminated along the western perimeter by a relatively large descending graded slope developed over natural hillside terrain. Building pad surfaces were originally created by minor grading efforts with shallow filling primarily as wall backfills in the western reaches of the level building pad. Very dense to very tight Pleistocene Age Terrace Deposits (Old Paralic Deposits-Qop6-7) which are widely spread in coastal areas of Carlsbad underlie the property and western descending slope at or very shallow depths. Below, the Eocene Age Santiago Formation which is known to be present beneath the Terrace Deposits. Detailed descriptions of the underlying geologic units at the project property are provided in the Test Pit and Boring Logs, Figures 3, 4 and 5 of the referenced report. Approximate location of exploratory borings and hand-dug test pit, as well as distribution of the underlying geologic units, are transferred and depicted on the Figure 1. Pertinent geotechnical data including engineering properties of the underlying soils are provided in the referenced report. II. WESTERN SLOPE (BLUFF) ST ABILITY The rear western perimeter slope (bluff) is a graded cut over natural hillside embankment provided with nearly 6 feet wide drainage terraces at approximately 10-foot maximum vertical intervals. Cross-Section A-A, included in Figure 1, shows the bluff geometry based on surveyed topographic maps, was prepared by others. As shown, the slope descends nearly 60 vertical feet at variable gradients from the rear of the property to the Buena Vista Lagoon below. Slope gradients range from locally 2: 1 at its steepest to 5.5: 1 within the remainder more gentle portions. The rear slope (bluff) occurs at overall non-critical gradients (flatter than 2: 1) with well-established vegetation cover and drainage terraces provided at close vertical intervals underlain by dense to very dense formational deposits, thus rendering it very unlikely to geologic instability or significant erosion. Indications of significant erosion, or deep and/or surficial instability are currently not in evidence. A. Deep-Seated and Global Stability: In order to further evaluate the gross stability of the existing bluff, pertinent limits and areas were defined from the toe of the natural slope (bluff) inland to a line described on the slope top by the intersection of a plane inclined at a 20° angle from horizontal passing through the toe of the bluff, and 50 feet inland from the bluff edge, as shown on the attached Geotechnical Map and Cross Section A-A. The greater condition, which is defined by an area 50 feet inland from the bluff edge was then modeled for engineering analysis utilizing soil strength properties derived from laboratory testing performed on representative samples as a part of our original work (see referenced report). Geotechnical Update and Site/Grading Plan Review, Proposed New Building Additions and Rear Site Improvements, 2465 Jefferson Street, Carlsbad, California April 30, 2020 Page3 The bluff stability was evaluated using the ST ABL WV Patagonia program (Terra Wiz, LLC) for both static and pseudo-static (seismic) conditions utilizing selected method of analysis (Bishop). A 0.29g (65% of PGA=0.452) horizontal ground acceleration (ab) was assumed for pseudo-static (seismic condition). Global stability was evaluated by choosing selected limits which identify failure trail surfaces. Based on our assumptions and analysis, factors of safety greater than 1.5 and 1.1 were indicated for deep-seated global stability trail surfaces for static and pseudo-static (seismic) conditions, respectively. The minimum generally accepted safety factors for the static and pseudo-static (seismic) conditions are 1.5 and 1.1, respectively. Graphical illustration summary of the slope stability analysis results with the minimum factors of safety for the most critical failure plane are included with this report as Attachment B. Based on our analysis deep-seated and gross global slope stability will not be a factor in the planned project redevelopment as currently proposed. B. Surficial Stability: Surficial bluff stability was also evaluated for the most critical slope angle (2:1) considering seepage parallel to the slope and 3-feet deep depth of sliding mass to the surface of the slope. Based on our analysis, a factor of safety greater than 1.5 was indicated. The minimum generally accepted safety factors for surficial stability is 1.5. Based on our analysis surficial bluff stability will not be a factor in the planned project redevelopment, as currently proposed. Surficial stability analyses are also included in the enclosed Attachment B. III. WESTERN SLOPE (BLUFF) IMPACTS Based on our site study and engineering analyses, it is our professional opinion that the project can be designed or located so that it will neither be subject to nor contribute to significant geologic instability throughout the lifespan of the project. Our analyses are based on actual bluff geometry established from the topographic map (prepared by others) of the project areas. Soil parameters used were also obtained from actual sampling and testing. Consequently, the degree of uncertainty of analytical results due to assumptions and unknowns, and are considered well within acceptable engineering tolerances for this type of project, and are appropriate to the degree of potential risk presented by the site and proposed project. The site was found to be geologically stable and the project can be designed and constructed as proposed. It is our professional opinion that the proposed development will have no significant adverse effect on the stability of the rear slope (bluff) and will not endanger life or property, provided our development recommendations are considered in the project designs and implemented during the construction phase. Geotechnical Update and Site/Grading Plan Review, Proposed New Building Additions and Rear Site Improvements, 2465 Jefferson Street, Carlsbad, California IV. GRADING PLAN REVIEW April 30, 2020 Page 4 Based on our review, the project most current Site/Grading Plan And Cross Section (Figure 1) substantially proposes a similar development concept (from a geotechnical viewpoint), that was used as a basis for our original study. Minor architectural site redesigns and adjustments of site improvement locations, as shown on the project plans, will not impact the project development. The project Site/Grading Plan And Cross Section propose a feasible design, and is acceptable from a geotechnical viewpoint. All conclusions and recommendations provided in the reference report remain valid and should be incorporated onto the final plans and implemented during the construction phase. The following amended recommendations are also consistent with the current plans and should be considered where relevant and as appropriate: A. Shifting the pool east of the existing wall will further enhance development procedures and overall site stability, from our standpoint. A well-constructed and properly functioning wall back-drainage system shall be required behind the westerly pool trough retaining wall in substantial accordance with specifications provided in referenced report (see Figure 13 of October 2, 2017 report). Adequate foundation setback (minimum of 10 feet or % of the slope height, whichever is more, from the bottom outside edge of the footing to daylight shall also be maintained as specified. The swimming pool may also be constructed as proposed. However, a deepened pool wall footing shall be provided along the western pool perimeter to satisfy the minimum specified minimum 10 feet or % of the slope height to daylight setback requirement, but not less than 30 inches deep (measured from bottom of the pool) minimum. B. Permeable (pervious) pavers are incorporated into the project design, replacing the existing driveway and rear/sidewalk areas, in connection with the proposed stormwater BMPs. Actual in-situ testing for site infiltration feasibility conditions was not a part of the scope of our services. However, based on the geotechnical data collected during this work, underlying soil profile at site chiefly consists of sandy to silty sandy soils (SP/SM) which may be characterized as Group B hydrologic classification (based on San Diego Hydrology Manual classification). The planned permeable pavers should be designed and constructed considering the site indicated geotechnical conditions, and shall not adversely impact project onsite foundation bearing and subgrade soils or the nearby offsite improvements. The geotechnical considerations and recommendations should be considered in the project permeable pavers design and construction: Geotechnical Update and Site/Grading Plan Review, Proposed New Building Additions and Rear Site Improvements, 2465 Jefferson Street, Carlsbad, California April 30, 2020 Pages I 1. Permeable (pervious) pavers pavement structural section (inclusive of driveway and rear/sidewalks) should consist of heavy/traffic rated 31/a-inch, PICP over a minimum of 2 inches of ASTM No. 8 bedding course/choke stone over a minimum 8 inches of ASTM No. 57 stone base course over natural undisturbed sandstone Terrace Deposits. Bedding course/choke stone and base course stone should also be well compacted, consolidated and interlocked (avoid crushing the underdrain pipes) with heavy construction equipment. ASTM No. 8, No. 9 or No. 89 should be used for joint materials depending on the joint size and per manufacturer recommendations. Gradation requirements for ASTM No. 57, No. 8, No. 89 and No. 9 are as follows: Sieve II Percent Passing I Size No.57 I No.8 I No.89 I No.9 1½" 100 1" 95 to 100 ½" 25 to 60 100 100 3/a" 85 to 100 90 to 100 100 No.4 0 to 10 10 to 30 20 to 55 85 to 100 No. 8 0 to 5 0 to 10 5 to 30 10 to 40 No. 16 0 to 5 0 to 10 0 to 10 No. 50 0 to 5 0 to 5 2. Suitable undisturbed ("uncompacted") subgrade soils considered for the permeable pavers should consist of undisturbed sandstone Terrace Deposits which occur beneath the property at depths ranging from approximately less than one foot in the front driveway portions to as much as 3 feet maximum in the western margins as wall backfills. For this purpose, pavement section ground preparation should consist of removal of the upper surficial soil section underneath the paver sections to expose the underlying undisturbed ("uncompacted") native Terrace Deposits, as approved in the field. An increased pavement base section (AS TM No. 57 stone base course) should then be placed over the exposed undisturbed ("uncompacted") native Terrace Deposits. The increased pavement base section, if and where necessary, will also provide a lager storage capacity for the planned BMP facility. Geotechnical Update and Site/Grading Plan Review, Proposed New Building Additions and Rear Site Improvements, 2465 Jefferson Street, Carlsbad, California April 30, 2020 Page 6 3. Finish paver subgrade sloped at a minimum 2% toward a minimum 12 inches wide by 12 inches deep collector trench at a low point provided with a 4-inch diameter (Sch. 40 or SDR 35) perforated underdrain pipe surrounded with ¾-inch crushed rocks is typically required for this type of construction. However, the paver subgrade may be flat and the collector trench/underdrain pipe eliminated, provided an adequate storage capacity ( with a minimum safety factor of 2) is considered in the design of the project pavers BMP facility. Additionally, all building and structural foundations shall penetrate the upper fills, and be adequately embedded into the underlying dense and competent undisturbed Terrace Deposits, as specified in the referenced report, or extended at least 18 inches below the pavers stone base course section, whichever is more. All deepened foundation trenches shall be confirmed/approved by the project geotechnical consultant. Elsewhere outside the paver areas, bearing and subgrade soils where they occur underneath the planned new improvement areas shall be compacted to minimum 95% compaction levels, unless otherwise specified or approved. 4 . All nearby site structures and improvements should also be protected from possible moisture intrusion and bearing/subgrade soil softening with a minimum 8 inches wide concrete slurry cut-off wall ( deepened edge restraints), extending a minimum of 18 inches into the underlying dense and competent undisturbed formational materials, as necessary and needed. C. Surface runoff drainage designs should consider and properly alleviate potential impacts on the western slope. Finish ground surfaces immediately adjacent to the building foundations shall be sloped away from the building at a minimum 5% for a minimum horizontal distance of 10 feet measured perpendicular to face of the building wall (CBC 1804.4 Site Grading). If physical obstructions or property lines prohibit 10 feet of horizontal distance, a 5% slope shall be provided with an alternative method for diverting water away from the foundations. Swales used for this purpose shall be sloped not less than 2% where located within 10 feet of the building foundations. hnpervious surfaces (concrete sidewalks) within 10 feet of the building foundation shall also be sloped at minimum 2% away from the building. D. The Limited Geotechnical Investigation report dated October 2, 2017 and this update report shall be referenced on, and considered a part of the project Site/Grading Plans. A note should also be provided on the plans indicating that "in the event discrepancies are noted between the project plans and soil reports, the most stringent recommendations/design shall govern." Geotechnical Update and Site/Grading Plan Review, Proposed New Building Additions and Rear Site Improvements, 2465 Jefferson Street, Carlsbad, California V . RESPONSE TO CITY OF CARLSBAD REVIEW COMMENTS April 30, 2020 Page 7 The following responses to the City of Carlsbad 1st review comments pertinent to the project geotechnical issues (see Attachment A) are appropriate: A. PLANNING: #8: The most current Site/Grading Plan And Cross Section plan showing the architectural site modifications and new pool location shifted east of the existing wall was reviewed and used a base map reproduced herein as a Geotechnical Map, Figure 1. #9: Detailed analyses and professional opinions are provided in Sections II and III of this report. In summary, it is our professional opinion that the project can be designed or located so that it will neither be subject to, nor contribute to significant geologic instability throughout the lifespan of the project. It is further our professional opinion that the proposed development will have no significant adverse effect on the stability of the rear slope (bluff) and will not endanger life or property. Our analyses were based on actual bluff geometry established from a site surveyed topographic map and soil strength parameters obtained from actual sampling and testing with a degree of uncertainty of analytical results due to assumptions and unknowns considered well within acceptable engineering tolerances for this type of project, and are appropriate to the degree of potential risk presented by the site and proposed project. B. ENGINEERING: #1: We concur with the reviewer. Geotechnical drainage design requirements are provided in the referenced report and supplemented/amended in this update report, should be considered in the project designs and implemented during the construction phase, where appropriate and as applicable. #3: We concur with the reviewer. Detailed geotechnical recommendations for the proposed pavers and minimum site protection/design requirements are provided in this update report (see Section IV, B). Geotechnical Update and Site/Grading Plan Review, Proposed New Building Additions and Rear Site Improvements, 2465 Jefferson Street, Carlsbad, California April 30, 2020 Page8 If you have any questions or need clarification, please do not hesitate to contact this office. Reference to our Project No. GI-17-09-139 will help to expedite our response to your inquiries. SM§ Geotechnical Solutions, Inc. ~Ji--ifl~ Steven J. Melzer,c#2362 Engineering Geologist Enclosures: Figure 1 Geotechnical Map Attachment A City of Carlsbad l51 Review For CDP 2019-0015 (DEV2017-0054)-2465 Jefferson Street, dated July 2, 2019 Attachment B Bluff Stability Analysis Distribution: Addressee (1, email) Andrew Carlos, AIA (2, email) John Majocha, PE ( email) §.M§ GEOTECHNICAL SOLUTIONS. INC. ATTACHMENT A July 2, 2019 Andrew Carlos, AIA 3327 Adams Street Carlsbad,CA 92008 ~l-uJ , .s ·l'1 f:3 FILE COPY r·-City of Carlsbad SUBJECT: 1ST REVIEW FOR CDP 2019-0015 (DEV2017-0054}-2465 JEFFERSON STREET Thank you for applying for Land Use Permits in the City of Carlsbad. The Planning Division has reviewed your Coastal Development Permit, application no. CDP 2019-0015, as to its completeness for processing. The application is complete, as submitted. Although the initial processing of your application may have already begun, the technical acceptance date is acknowledged by the date of this communication. The city may, in the course of processing the application, request that you clarify, amplify, correct, or otherwise supplement the basic information required for the application. In addition, you should also be aware that various design issues may exist. These issues must be addressed before this application can be scheduled for a hearing. The Planning Division will begin processing your application as of the date of this communication. At this time, the city asks that you provide five (5) complete sets of the development plans so that the project can continue to be reviewed. In order to expedite the processing of your application, please contact me at 760-602-4622 to discuss or to schedule a meeting to discuss your application and to completely understand this letter. You may also contact each commenting department individually as follows: • land Development Engineering Division: Kyrenne Chua, Associate Engineer, at 760-602-2744 • Fire Department: Randy Metz, Fire Marshal, at 760-602-4661 Sincerely, /e -· ~; ~ CHRIS GARCIA Associate Planner CG:dh c: Chris Sauer, 755 Joy Lake Road, Reno, NV 89511 Carefree Holdings LLC, 44 Cook Street 11100, Denver, CO 80206 Kyrenne Chua, Project Engineer File Copy Community & Economic Development Planning Division I 1635 Faraday Avenue Carlsbad, CA 92008-73 l 4 I 760-602-4600 j 760-602-8560 f I www.carlsbadca.gov CDP 2019-0015 (DEV2017-0054)-2465 JEFFERSON STREET July 2, 2019 Pa e 2 ISSUES OF CONCERN Planning: 1. 2. Please comply with Part A of the public noticing requirements located online at: http://www.carlsbadca.gov/civicax/filebank/blobdload.aspx?BloblD=24117. On Sheet A-1.0, please make the following corrections: a. Move the "accessory stringline" label to the correct line on the plans. b. Correct the sheet numbers in the sheet index to be consistent with the sheet numbers shown. c. Delete the reference to "net usable". d. Identify the required parking and proposed parking as garaged spaces; not "covered". e. Add irrigated landscape area calculation. 3. The stringline shown is currently being evaluated by local staff at the California Coastal Commission. Additional changes based on their review may be required. Any comments or corrections will be passed along when received by city staff. 4. On Sheet A-1.1, please make the following corrections: a. Identify the height of the existing rolling gate. b. Identify the existing wall/fence along the north property line. c. Identify the existing fence on top of the existing front-yard plantar. d. Pursuant to Carlsbad Municipal Code (CMC) Section 21.46.130, walls, fences and hedges are limited to a maximum of 42" in the front yard setback. Please note this on the plans. The project will be conditioned to modify or remove any existing walls, fences, or hedges within the front yard setback that exceed 42". e. Identify the structure along the south property line that is shown with walls and gates and show the height. 5. On Sheet A-2.1, please make the following corrections: a. Remove the stairs shown in front of the entrance to Bedroom #3. b. Delete the reference to the "look through" fireplace in the master bedroom. 6. On Sheet 1 of the Topography Survey, show the closest outline of the existing residential building on the upper/eastern portion of the site to the south. 7. On the elevations, please make the following cor,rections: a. Update the scale from 1/4" to 3/16". b. Clearly show the existing grade and finished grade. c. Provide tallest building height measurements on all elevations. This should be shown from existing grade or finished grade, whichever is lower. A higher grade may be established with this CDP. If requesting to establish a higher grade for building height purposes, please note on the elevations. d. The roof pitch on the tower feature is labeled as 3.5:12 whereas the roof plans show 3:12. Please correct to make consistent. 8. The Geotechnical Report shall be updated or have a supplemental letter showing the location of the pool shifted to the east of the existing wall. CDP 2019-0015 (DEV2017-0ps4f :_ 2465 JEFFERSON STREET July 2, 2019 ', Pa e 3 9. The Geotechnical Report shall also express a professional opinion as to whether the project can be designed or located so that it will neither be subject to nor contribute to significant geologic instability throughout the lifespan of the project. The report shall use a currently acceptable engineering stability analysis method, shall describe the degree of uncertainty of analytical results due to assumptions and unknowns, and at a minimum, shall cover an area from the toe of the bluff inland to a line dese:ribed on the bluff top by the intersection of a plane inclined at a twenty- degree angle from horizontal passing through the toe of the bluff or fifty feet inland from the bluff edge, whichever is greater. The degree of analysis required shall be appropriate to the degree of potential risk presented by the site and the proposed project. If the report does not conclude that the project can be designed, and the site be found to be geologically stable, no coastal shoreline development permit shall be issued. Engineering: 1. Per the geotechnical report dated 10/02/2017, it states that the current site drainage is considered poor to adequate. Provide on the site plan the proposed method of drainage including but not limited to drainage improvements to address the site drainage issues including drainage patterns, stormwater clean-outs, landscape dispersion, etc. All proposed drainage improvements shall be shown and labeled on the site plan. 2. Provide on the title sheet of the plans under 'Project Data', the Assessor's Parcel Number and short legal description of the property. 3. Currently, the site plan shows pervious pavers are proposed to replace existing driveway. The geotechnical report does not include recommendations on the proposed pervious pavers and whether infiltration is allowed on-site. Provide a geotechnical letter or update to address the proposed pervious pavers including geotechnical recommendations. Also, the site plan proposes the use of pervious or impervious pave rs in the rear yard. If pervious is being proposed for the rear yard, it should be addressed in the geotechnical recommendations for pervious pavers. 4. Provide on the title sheet the earthwork quantities of cut, fill, import, export, and remedial in cubic yards. Per the geotechnical report and site plan, cuts and minor backfill within existing rear retaining wall are proposed and expected and the soil is unsuitable for proposed scope of work which will require remedial and/or cut and import of soil. 5. Provide two copies of the corrected city's Standard Project Requirement Checklist addressing the redline comments on the form. 6. The exhibits 'A' and 'B' provided for the proposed access easement will not be formally reviewed at this time. However, if the applicant/owner would like a formal review of the easement, they can submit a formal easement application with the city's Land Development Engineering division. The easement application shall comply with the city's easement submittal checklist, Form E-5, which is _available on the city's website. 7. Address the redline comments of the site plan and E-36 Form and return with the re-submittal to facilitate the next review. CDP 2019-0015 {DEV2017-0054}-2465 JEFFERSON STREET July 2, 2019 Pa e4 Landscape: Numbers below are referenced on the red line plans where appropriate for ease in locating the area of the comment concern. 1. This project is subject to the requirements of the City of Carlsbad Landscape Manual. However, the project may have less than 2,500 square feet of landscaping, and therefore may qualify for the option of only satisfying the requirements of "Appendix D Prescriptive Compliance Option" of the Landscape Manual. To make this determination, please provide a calculation showing the total amount of landscape area. Include the water swimming pool, spa and any increased areas of planting caused by other comments in this review letter. For the purpose of the calculation, the City Landscape Manual defines Landscape Area in the following way: Landscape Area means an area w_ith plants, turfgrass and/or other vegetation. A landscaped area includes a water feature either in an area with vegetation or that stands alone. A landscaped area may also include non-vegetated design features adjacent to an area with vegetation, provided that the features are integrated into the design of the landscape area and the primary purpose of the features are decorative. A landscaped area does not include the footprint of a building, decks, patio, sidewalk, curbs, driveway, parking lot or other hardscape. A landscaped area also does not include an area without irrigation designated for non-development such as designated open space or area with existing native vegetation. The landscaped area refers to the area to be landscaped as part of the work for which the current approval by the city is being sought. 2. For the purpose of this project review, it is presumed that the landscape area will exceed 2,500 square feet and will not qualify for the Prescriptive Compliance Option review. If the Applicant can demonstrate that the total landscape area is less than 2,500 square feet, the project can be re-evaluated with the next submittal. 3. Please show and identify the Proposed 25' Access Easement as shown on the architectural plans. 4. Plans should generally be drawn on a 50% screen of the civil engineering grading plan in order that all utilities, easements, property lines, grading, etc. can be identified. Please add all utility lines and easements as appropriate to the landscape plans. 5. Please provide the following note on the plan regarding drainage: All landscape areas shall have positive drainage (2% grade in planting areas) away from all structures and terminating in an approved drainage system. 6. Please show and identify all existing walls and fences on the property lines that are proposed to remain and/or be removed. Show wall/fence materials and heights. Also show any proposed property line walls or fences and identify their height and materials. 7. Please label the street by name. 8. From the extent of the new construction being proposed, it seems as if all or most existing landscaping (exclusive of the slope to the west of the existing wall) will be disturbed and removed in favor of new landscaping. Please show all proposed landscaping on the site. If there is existing landscaping proposed to remain, please identify these areas and provide a general description of the plant material to remain. CDP 2019-0015 (DEV2017-0054)-2465 JEFFERSON STREET July 2, 2019 Pa e 5 9. If there are any existing trees on site, please identify them and specify if they are to remain or be removed. 10. Plans are too conceptual to provide an appropriate review. Plantings are not identified as to what they are. Please provide a separate symbol for each type of shrub (i.e. large evergreen shrub, medium size shrub, small flowering accent shrub, etc.) and ground covers. Please provide a planting legend. Final comments are reserved pending receipt of more complete plans. 11. It is assumed that all maintenance for the project will be provided the property owner. If so, please add a note to the plan indicating that all landscape maintenance will be provided by the property owner. 12. Please coordinate with the architect/engineer for the project to determine if there are any bio- retention basins on the project. If there are, please include them on the landscape plan and provide appropriate planting per the Appendix E: BMP Design Fact Sheet. 13. The layout of hardscape elements for the project is not consistent between the landscape plan, architectural plan and surveyor's plan. Please see areas noted on the plan, and coordinate for all plans to be consistent. 14. The plan shall demonstrate that plants, when installed and at maturity, will be positioned to avoid obstructing motorists' views of pedestrian crossings, driveways, roadways and other ·vehicular travel ways. On collector streets and larger, landscape elements over 30 inches in height (including planting measured at maturity) as measured from adjacent str~et grade are not permitted at street corners within a triangular zone drawn from two points, 25 feet outward from the beginning of curves. At medium to high use driveways, the 30-inch height limitation applies at driveways 25 feet from the edge of the apron outward along the curb, then 45 degrees ln toward the property. Landscape features (shrubs, trees, fencing, etc.) shall be selected to ensure that no visual impairments or obstructions are located within the CalTrans sight distance lines. Please coordinate with the civil engineer and show and label all vehicular sight lines and sight triangles on the plans per above and insure no conflicts. 15. The Landscape Manual indicates that landscape plans are to feature ground cover, shrubs, and trees to screen elements of unsightliness and screen/soften new improvements. The landscape Manual also indicates that landscaping shall be used to accentuate and enhance architecture. Please provide additional taller planting in the front and on side yards to provide softening of the architecture. 16. . Please add a note to the plan to indicate that all utilities are to be screened. landscape construction drawings will be required to show and label all utilities and provide appropriate screening. 17. Please provide a Water Conservation Plan in conjunction with the Landscape Concept Plan. This plan shall demonstrate to the city how the proposed development will use all practical means available to conserve water in the landscape. Please provide/address the following; a. Please indicate the proposed type of water to be used for irrigation (i.e. potable, recycled, graywater, etc.). CDP 2019-0015 (DEV2017-0054)-2465 JEFfERSON STREET July 2, 2019 Pa e 6 b. Please provide a note on the plan to indicate that all irrigation water will be potable water. c. Please provide written descriptions of water conservation features including addressing xeriscape principles (see Appendix A of the Landscape Manual) within the project. d. Hydrozone Diagram: Please include one "Hydrozone Diagram" which identifies grouping of plants within the individual hydrozones (high, moderate, low, very low or special landscape areas) and which indicates the square footage and irrigation method of each area. e. Concept plans shall include calculations which document the maximum allowed annual water use for the landscaped area or maximum applied Water allowance (MAWA) and estimated total water use (ETWU). A landscape project shall not exceed the MAWA. The MAWA for a landscape project shall be determined by the following calculation as defined in the City ordinance: MAWA = (ETo)(0.62)((0.55 x LA)+ (0.45 x SLA)]. The ETWU shall be determined by the following calculation as defined in the Landscape Manual: ETWU = (ETo)(0.62{ PF:.eHA + SLA) Please provide calculations and worksheets on city forms as found in the Landscape Manual. In addition to the calculations, include a statement on the plans signed under penalty of perjury by the person who prepared the plan that provides: "I am familiar with the requirements for landscape and irrigation plans contained in the City of Carlsbad's Landscape Manual and Water Efficient Landscape Regulations. I have prepared this plan in compliance with those regulations and the landscape manual. I certify that the plan implements those regulations to provide efficient use of water." Please provide a line. beneath this statement for signature and date. 18. The surface area of a water feature, including swimming pools, shall be included in a high water use hydrozone. 19. The p_lan shall provide that only subsurface irrigation shall be used to irrigate any vegetation within twenty-four inches of an-impermeable surface unless the adjacent impermeable surfaces are designed and constructed to cause water to drain entirely into a landscaped area. Please· add a note to this effect. 20. Please add the following notes to the plans and insure all requirements are met: Slopes 6:1 or steeper requiring erosion control measures as specified herein shall be treated with one or more of the following planting standards: a. Standard 1-Cover Crop/ And Erosion Control Matting: Cover crop shall be a seed mix typically made up of quick germinating and fast covering grasses, clovers, and/or wild flowers. Submit the specific seed mix for city approval prior to application. The cover crop shall be applied at a rate sufficient to provide 90% coverage within thirty (30) days. The type of erosion control matting shall be as approved by the city and affixed to the slope as recommended by the manufacturer. CDP 2019-0015 (DEV2017-0054) -2465 JEFFERSON STREET July 2, 2019 Pa e 7 On slopes 3 feet or less in vertical height where adjacent to public walks or streets: When planting occurs between August 15 and April 15, erosion control matting shall be required. During the remainder of the year, the cover crop and/or erosion control matting may be used. On slopes greater than 3 feet in height, erosion control matting shall be required and a cover crop shall not be used, unless otherwise approved by the city. b. Standard #2 -Ground Cover One hundred (100%) percent of the area shall be planted with a ground cover known to have excellent soil binding characteristics (planted from a minimum size of flatted material and spaced to provide full coverage within one year). c. Standard #3 -Low Shrubs Low spreading woody shrubs (planted from a minimum of 1-gallon containers) shall cover a minimum of seventy (70%) percent of the slope face (at mature size). d. Standard #4-Trees and/or Large Shrubs Trees and/or large shrubs shall be (planted from a minimum of 1-gallon containers) shall be installed at a minimum rate of one (1) plant per two hundred (200) square fee_t. Slopes -6:1 or steeper and: a. 3' or less in vertical height and adjacent to public walks or streets require at a minimum Standard #1 (cover crop or erosion control matting). b. 3' to 8' in vertical height require Standards #1 (erosion control matting shall be installed in lieu of a cover crop), #2 and #3. c. In excess of 8' in vertical height require Standards #1 (erosion control matting shall be installed in lieu of a cover crop), #2, #3, and #4. Areas graded flatter than 6:1 require a cover crop per Standard #1 with temporary irrigation when they have one or more of the following conditions: a. Sheet graded pads not scheduled for improvements within 6 months of completion of rough grading. b. A potential erosion problem as determined by the city. c. Identified by the city as highly visible areas to the public or have special conditions that warrant immediate treatment. 21. Please verify if fire suppression zones are required for this project. Review plans with the Fire Marshal to confirm fire suppression zone locations and requirements and provide documentation of findings. Address fire suppression as appropriate.· 22. RETURN REDLIN ES and provide 2 copies of all plans (concept, water conservation, fire protection, and colored water use plan) for the next submittal. The submittal must be made to a Planning Division staff member at the Planning counter along with a transmittal clearly indicating what the submittal is for (i.e. Conceptual Plan re-submittal}. Please provide a written response to all comments clearly indicating where and how each comment was addressed. ATTACHMENT B Bluff Stability Analysis -Static Condition Project Name: Carefree Holdings, LLC Project Location: 2465 Jefferson Street, Carlsbad, CA Minimum factor of safety= 2 .8699 65 60 1n I 55 50 111 I Soil 1 : c = 273; phi -38 45 111 I 40 ti I I II I 35 30 I / 25 20 15 I ASL 10 - 5 l 0 10 20 30 40 50 60 70 / I ~ //II / ~ ~ 80 90 100 110 120 130 140 SMS GEOTECHNICAL SOLUTIONS, INC. Consulting Geotechnical Engineers 593 J Sea Lion Place, Suite I 09 Carlsbad, California 920 I 0 150 160 L Boundary 1 r Boundary 2 L Boundary 3 I C Boundary 4 ' Boundary 5 L Boundary 6 C: Boundary 7 r-Boundary 8 I I Boundary 9 '-Boundary 10 [ Boundary 11 r Boundary 12 ,___ Boundary 13 [ Boundary 14 r Boundary 15 L_ Boundary 16 [ Boundary 17 r Boundary 18 L Boundary 19 r-Boundary 20 170 180 L Boundary 21 Blu(fStability Analvsis -Pseudo-Static {Seismic) Condition . Project Name: Carefree Holdings, LLC Project Location: 2465 Jefferson Street, Carlsbad, CA Minimum factor of safety= 1.4876 65 60 1n -i 55 50 11 1 I I SoH ;~ o -m, e» -,a I I / /I ' I 45 111 I 40 llf=J II / d 35 30 I 25 20 I / 15 10 I ~ 5 I 0 10 20 30 40 50 / ~ ~ ~ 60 70 80 90 100 llO 120 130 140 SMS GEOTECHNICAL SOLUTIONS, INC. Consulting Gcotechnical Engineers 5931 Sea Lion Place, Suite I 09 Carlsbad, California 920 I 0 150 160 170 L Boundary 1 r Boundary 2 L Boundary 3 [ Boundary 4 • Boundary 5 L Boundary 6 C Boundary 7 r Boundary 8 L Boundary 9 [ Boundary 10 • Boundary 11 L Boundary 12 C Boundary 13 r-Boundary 14 L Boundary 15 C Boundary 16 ' Boundary 17 I I Boundary 18 I ~ Boundary 19 ' Boundary 20 180 I Boundary 21 1-C 'i 21-f( Zo'2o G\ofe S-b.b\ld-y AV?dlyo;s e: Q. Ass urn ~+-i'ons ~ ~ = 12'7 per; ¢> = 38° C :=. c. 73 PSr S l..trGce &c.fX"je E.,xis4 1 ~ &lu~f T =X -:3 F-t-. Conf ,.B = 2 ( Mo5i Gr,'-t,•ea.D Tan /J -= 0,$0 Cos f3 = o.BC\ Ta.n ~ =-o, 78 ('l) =-X YL,.) c~2p =-.2_ X 02,'-¼ xCAs2'2(o,~ =-o.3'3 1 Y. J ,21 Fro'f'Y) per+;ne.nt Stc:3b;\;1j c"1~l.s: A.. -=-o, s·e 5 -= 2, so SF =-A Tan<P -;-5 c ( To+-I s+res.s) Ta-n/3 ~ = 6 ,S:2 'j..0.7$ e.,So)!_ Z.13 0. 50 +-!27X3.~ -=-O, 61 + /. 58 =-2. 33 ) /,so lo Ok SM f z Ii' .. I I I I I I 4 I I / 1/ I I I I I I ',-/=------- G -__,I - [ GEOTECHNI CAL MAP l 65.58 TG 64.24 IE 65.71 FS 65.87 FS -~=:,'>'(---=. -"''""-' -~~ N ""'l<J'JT f ZXl,1'7 116.or I 66.62 TW G 61.00 TG 62.3 62.40 FG FG 62.80 FG I , FG 1-st~-~_, 65.45 FG 2 67.62 TW 65.45 FG 67.58 TG 63.85 IE 67.62 FS 66.56 TG 64.08 IE 67.70 61f:IO 67.6 FS 61.75 67.70 FS 67.55 TG 63.44 IE ' EXISnNG "'"',,,.-I---FS RESIDENCE Ff=61.81 67.5 're 67.4 FS 67.35 FS ' I I 67.76 FS ' ':-,c--t----c:', Qt ' ' 7.50 '-':-6'[€-'".:.. r--'fa'.ffe FSO .15 0 ◊ ,' ,-,-<-<-< ' ' I I --Hl"OCj""W 2<9.3;' , 67.05 ' FS 2 65.45 TG 64.07 IE ---- 66.3 FL PLAN VIEW 1 "=20' 67.71 G ' ' TP-1 ' ' ' ' , EXISJ. BOJ~RY~ FS 67.81 FS PAVER SUBGRADE B] =65.91 ~ 67.81 FS 67.60 §.6Z,1.2~81,--']"7 5FS~ 67.81 r'--¾L'.JFS 67;ff5 67.49 67.25 FS 67.16 FS i \."f-->..!26~1.g.8.!II FS FS s--3 67.55 4 67.61 FS FS 67.00 FS 66.9 FL ~ • I FL I 67.00 FL tu w Cl:'. ,_ V) z 0 V) Cl:'. w LL LL w -,+ I PERMEABLE CHIPS IN JOINTS 3" PERMEABLE INTERLOCKING PAVER 2" BEDDING COURSE ASTM/8 AGGREGATE (OR SIMILAR) CURB/EDGE RESTRAINT EXTENDS TO BOTTOM OF ASTM #57 ROCK BASE OR 1 • BELOW ADJOINING PAVEMENT CLASS II BASE SECnON MINIMUM. WASHED FRACTURED STONE ASTM /8 4 • BASE COURSE ASTM /57 ROCK • 6" SECnoN OF -------~ ADJOINING CONCRETE DRIVEWAY SECnON 3/4"CRUSHED ROCK SUBGRADE -GRADE AT FLAT ELEVAnON TO FACILITATE INFILTRA noN NOTES: PERMEABLE PAVER SECTION NOT TO SCALE 1. IMPORT FILL WILL NOT BE PLACED UNDER THE PERMEABLE PAVERS WITHOUT CONSULTING AND APPROVAL FROM THE GEOTECHNICAL ENGINEER. 2. SUB-GRADE SOIL UNDER PAVER AREAS SHALL REMAIN UNCOMPACTED AFTER INITIAL EXCAVAnON. 3. ALL AGGREGATE MUST BE CLEAN/WASHED AND FREE OF ANES (SAND, SILT, ETC.) 4. THE PAVERS SHALL NOT BE SEALED ONCE THE VOID FILLER HAS BEEN ADDED 5. EACH COURSE SHALL BE VIBRATORY COMPACTED BEFORE PLACEMENT OF NEXT COURSE 6. NO IMPERVIOUS LINER IS TO BE USED 7. FOLLOW MANUFACTURER'S RECOMMENDAnONS. WHERE DISCREPANCY OR CONFLICTS ARE PRESENT, CONTACT THE DOR FOR GUIDANCE PRIOR TO PROCEEDING. [j] EXISnNG PAINTED STEEL ROLLING GA TE [Ij EXISnNG 42" CMU PLANTER WALL l1] EXISnNG 72" HIGH METAL FENCE AND GATE [±] 42" HIGH WALL AND GATED ENTRANCE @] 72" HIGH WALL AT GATED COURTYARD ~ EXISnNG CONCRETE CURB AND GUTTER [I] EXISnNG CONCRETE WALK/PAVING/STAIRS ~ EXISTING GAS METER [g] EXISnNG 200 AMP ELECTRICAL SERVICE [Qj EXISnNG WATER METER [jJ] EXISTING SEWER CLEANOUT B] EXISTING 30' CONCRETE APRON r;,i REPLACE EXISTING CONCRETE DRIVEWAY l'.:cl WITH PERMEABLE PAVERS [j] EXISnNG AIR CONDlnONING CONDENSING UNIT [ill EXISTING RETAINING WALL TO REMAIN ij] PAVER PATIO jj] VANISHING EDGE POOL OVERFLOW !ill UNDEVELOPED BLUFF fill PERMEABLE PAVER SIDEWALK ~ AREA DRAIN @J DRAINAGE SWALE ~ 4 • PVC STORM DRAIN @ 2% SLOPE ~ RETAINING WALL ~ PROPOSED GATE MOTOR ~ FLUSH CONCRETE CURB 9 o .--------,-------,-----,----,--------,--------.----,------,------,--------.-----,------.-----.-I --,-I ----.1----,--------,-----,-----, 90 80 70 60 50 40 30 l:: 20 II--~----\ .-;;: - 10 10+00 10 +50 -----~ I POOL I _..,,._. __-B--WALL BA K-DRAIN PER R~ORT _--L--L □ -=---l-----1-- TERR ,CE DEPOSITS (Qt) 11 +00 SECTI ON 1"=10' H A-A AN D V SAN TIAGO FORMATION (Tsa)? 11 +50 CROSS SECTION Pf OPOSED SING~E FAMILY DWflLING c., I ~. ~I "'' <31 ' I i ' I ' I ,. ' I ~AVERS 12 +00 ~ ~l---~ " ;:; .; ~ ~ <>: :;i 80 ~ <'5 / 70 . ' 60 50 40 30 20 10 12+30 GEOTECHNICALLEGEND ··• s--2 Approximate Location of Test Boring ~ TP-1 Approximate Location of Hand-Dug Test Pit 4 ~ 4 Cross-Section 10° Line Intersection of 20° Inclined Plane From Toe of Bluff 50' Line Line 50' Inland From Bluff Edge af Fill (Primarily Wall Backfill) Qt Terrace Deposits Tsa Santiago Formation Project No. Gl-17-09-139 [ FIGURE 1 ] NORTH E 8 t5 QJ -.c u .... ro en 0 -.:::: ro u :s: ~ carlos architects inc \J C ro John Majocha , PE CIVIL ENGINEER (760) 707-4972 Cf) 00 t-o Z C) w N :'.2: 0, w c3 6 0 0::: <( 0.. D'.l :'.2: Cf) ---' w 0::: t- <( Cf) 0 t-0 wZ w <( 0::: ---' t-w W Cf) 0 ~z~ w 0 w 0 Cf) 0::: -0::: Cf) w 0::: W LL 0 0::: LL -, 0::: ~ <( W lO :'.2: :::::> co z <( -=::t' 0 Cf) N '"Cf)t-0 Cf) 9:: w w 0::: -, 0::: 0 0 0 Cf) 0::: 0 W 0.. <( 0 REVISIONS COP PRELIM REVIEW: 3/10/2017 COP I REVIEW: 5/24/2019 ISSUE DATE: 11/21/2019 SITE/GRADING PLAN AND CROSS SECTION SHEET NUMBER