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Home My WebLink AboutCUP 2021-0013; PARK DRIVE STREET AND DRAINAGE IMPROVEMENTS; Conditional Use Permit (CUP)(cityof Carlsbad LAND USE REVIEW APPLICATION P-1 Development Services Planning Division 1635 Faraday Avenue (760) 602--4610 www.carlsbadca.gov APPLICATIONS APPLIED FOR: (CHECK BOXES) Deyelopment ptnn/fs (FOR DEPT. use ONLY} Leqlshttlv• Permits 0 Coastal Development Pennlt D Minor f-~~~~=< ■ Condltlonal Use Pennlt ::-»'92011 -oo, ■ Mino, D Exlenskm 0 Day Care (Large) D Environmental Impact Ass ... ment ■ Habitat Managffllent Permit ■ Minor ~M..Plo-zo-000 ■ Hlllalde Development Pennlt ■ Minor l\t"vn ow-~ D Nonconforming Construction Pennlt D Planned Development Penntt D Minor 0 Reskfential O Non-Residential D Planning Commission Detennlnatlon 0 Reasonable Accommodation D Site Development Plan D Spoclal UH Ponnlt OMinor D Tentatiw Pare.I Map (Minor Subdivision) 0 Tentative Tract Map (Major Subdivision} 0 Variance 0Minor I------, 0 General Plan Amendment D Local CoHtal Program Amendment D Master Plan D Specific Plan 0 Z....Change □Amendment 0Amendment D Zona Code Amendment South Cftllbad CogtaJ BtrlfwAru Ptnnlts 0 RavtrM Pennlt D Administrative D Minor D Major YllllRt BtYilw Arn Permhs 0 Review Permit D Adminiatrative D Minor D Major (FOR DEPT. USE ONLY) B NOTE: A PROPOSED PROJECT REQUIRING APl'UCATION SLIIIIIITTAL MUST BE SUBMITTEO BY APPOINTIIENT'. PLEASE CONTACT THI!'. APPOINTIIENT SPl::CIAUST AT (780) I02-2'72) TO SCHEDULE AN APPOINTMINT. ,AM£ DAY APPOINTMENTS ARE NOT AVAIL.ABU: ASSESSOR PARCEL NO(S), Adjacent to 2071006700, 2071505700, and 2071005700 LOCATION OF PROJECT Park Drive near Bayshore and Marina Drive and adjacent to 4720 Park Drive NAME OF PROJECT: BRIEF DESCRIPTION OF PROJECT: 'PROJECT VALUE (STREET ADDRESS) Park Drive Street and Drainage Improvements, OP# 6611 Removal and replacement of an existing retaining wall adjacent to the wes;/north bound lanes of Plrk Odve between Bavshore and Marina PtiVe, (SITE IMPROVEMENTS) _:1.:;.B::.::m:::il:::lio::n.:_ ___ _ EsnMArEocOMPLET10N oATE-·spring·2023 FOR CITY USE ONLY Development No. ffl:BJD2D:::/l)\1_ Leed case No. evf2..02l -roB P-1 Parie 1 of 6 Revised 03/17 -·----------- ( City of Carlsbad LAND USE REVIEW APPLICATION P-1 Development Services Planning Division 1635 Faraday Avenue (760) 602-4610 www.carlsbadca.gov APPLICATIONS APPLIED FOR: (CHECK BOXES) Development Pe,mits ( I Coastal Development Permit D Conditional Use Permit 0 Minor D Extension D Day Care (Large) D Minor LI Environmental Impact Assessment Habitat Management Permit Hillside Development Permit ~Minor ~Minor 0 Nonconforming Construction Permit D Planned Development Permit D Minor D Residential D Non-Residential D Planning Commission Determination D Reasonable Accommodation 0 Site Development Plan D Special Use Permit D Minor D Tentative Parcel Map (Minor Subdivision) 0 Tentative Tract Map (Major Subdivision) D Variance D Minor (FOR DEPT. USE ON'_ Y) Legislative Permits I • U\t'Zo'l,()-«!)6 il0t'2-CW·CO.~ 0 General Plan Amendment 0 Local Coastal Program Amendment D Master Plan D Specific Plan D Zone Change □Amendment D Amendment 0 Zone Code Amendment South Carlsbad Coastal Review Area Permits D Review Permit D Administrative D Minor D Major Village Review Area Permits 0 Review Permit D Administrative O Minor D Major (FOR DEPT. USE ONLY) B NOTE; A PROPOSED PROJECT REQUIRING APPLICATION SUBMITTAL MUST BE SUBMITTED BY APPOINTMENT". PLEASE CONTACT THE APPOINlMENT SPECIALIST AT (760) 602-2723 TO SCHEDULE AN APPOINlMENT. "SAME DAY APPOINlMENTS ARE NOT AVAILABLE ASSESSOR PARCEL NO{S): N/A ---------------------------LOCATION OF PROJECT: Park Drive near Bayshore and Marina Drive and adjacent to 4720 Park Drive NAME OF PROJECT: BRIEF DESCRIPTION OF PROJECT: (STREET ADDRESS) Park Drive Street and Drainage Improvements, CIP# 6611 Removal and replacement of an existing retaining wall adjacent to the westjnorth bound lanes of Park Drive between Bayshore and Marina Drive. PROJECT VALUE ESTIMATED COMPLETION DATE (SITE IMPROVEMENTS) 2.8 million (cost estimate attached) Spring 2022 FOR CITY USE ONLY DevelopmentNo. A,\\3,JO?O-QQ\]-Lead Case No, l-}Ql:2.o2,0-DO0 3, P-1 Page 1 or 6 Revised 03/17 ( City of Carlsbad DISCLOSURE STATEMENT 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 other 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 applicant's 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 Daniel Zimny Corp/Part City of Carlsbad Title Associate Engineer Title Public Works ----~-~-------Address 1635 Faraday Avenue Address 1635 Faraday Avenue 2. OWNER (Not the owner's agent) P-1(A) 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 (i.e., 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 if necessary.) Person Daniel Zimny Corp/Part City of Carlsbad Title Associate Engineer Title Public Works --------------- Address 1635 Faraday Avenue Carlsbad CA 92008 Address 1635 Faraday Avenue Carlsbad CA 92008 Page 1 of2 Revised 07110 { City of Carlsbad PROJECT NAME: PROJECT DESCRIPTION P-1(8) Development Services Planning Division 1635 Faraday Avenue (760) 602-4610 www.carlsbadca.gov Park Drive Street and Drainage Improvements, GIP# 6611 Daniel Zimny, Associate Engineer City of Carlsbad Public Works APPLICANT NAME: _______________________ _ Please describe fully the proposed project by application type. Include any details necessary to adequately explain the scope and/or operation of the proposed project You may also include any background information and supporting statements regarding the reasons for, or appropriateness of, the application. Use an addendum sheet if necessary. Description/Explanation: See attached P-1{8) Page 1 of 1 Revised 07/10 6611 Park Drive Street and Drainage Improvements, CIP# 6611 Project Description Park Drive is a neighborhood connector street, per the City of Carlsbad's General Plan Mobility Element, that runs parallel to the Agua Hedionda lagoon in Carlsbad, California. Park Drive provides one lane of travel in each direction, parking, bike lanes, and sidewalks within the 60-foot-wide right-of-way (ROW) {Figure 1, Project location). Park Drive is the only connector road to Bayshore Drive, which has the only public boat launch for kayaks and other non-motorized vessels on Agua Hedionda lagoon. Bayshore Drive also provides beach access for fishing and other shoreline recreation. Currently, the hillside along the northeast side of Park Drive between Cove Drive and Bayshore Drive experiences significant erosion and drainage issues that affect the function of the roadway and sidewalk, and the safety of pedestrians, cyclists, and drivers, particularly during and after rain events. Road widening in the late 1980s cut the toe of the slope along the northeast side of the road, after which the slope began to show erosion issues, in turn prompting construction of the retaining wall several years later. Over the years, the deposition of sediment along the sidewalk and roadway has created a safety hazard, restricted public access to local public beach areas, and created a maintenance burden for the City of Carlsbad (City). In addition, the existing retaining wall shows signs of structural failure, likely due to ineffective drainage measures, which has affected its function and longevity (please refer to Figure 2, Existing Site Photos). The proposed Park Drive Slope and Drainage Improvement Project (Project) is needed to stabilize the slope along the north side of Park Drive, and to mitigate surface (surficial slaking, sloughing, and erosion) and deeper-seated instability. Weakly cemented to friable sandstone is exposed at the face of the slope, which is very prone to surface-water-induced erosion, as evidenced by the deep rills in the face of the slope. This erosion creates a large volume of sediment loss. Slope failure and sediment loss from the hillside repeatedly occurs during rain events, requiring the City to close the sidewalk and roadway on a regular basis to clean up large volumes of debris. Dating back to 2004, the City has recorded work orders and service requests every year to clean up debris within the Project site. Figure 2 depicts sediment deposition along Park Drive after a storm event in December 2018. The closure of the sidewalk, bicycle lane, and roadway caused by the sediment deposition impacts the public's beach access and presents continuous safety hazards. These closures occur multiple times a year after even small rain events. This erosion creates a large volume of sediment loss that was estimated to be an average of 35 cubic yards per year. In addition, slope stability analyses completed for the Alternatives Analysis indicated that portions of the slope do not meet generally accepted minimum standards. The analyses indicated that deep-seated stability of the slope should meet generally accepted minimum standards. In addition to the slope stability considerations, the existing retaining wall requires replacement because structural failure increases each year. Figure 2 depicts degradation of the existing retaining wall. Portions of the block wall are degrading to the point where the steel rebar is exposed, and portions of the retaining wall are beginning to lean toward the sidewalk. The failure of the retaining wall could result in additional slope instability issues and would be further exacerbated by storm events, and would require a long-term closure of the sidewalk, bicycle lane, and portions of the roadway until an emergency repair project could be constructed. To address public safety and coastal access issues associated with the failing hillside, the City proposes to remove the existing wall, install a new retaining wall, and repair portions of the failing slope. All wall improvements are contained within the City's ROW and the easement areas, including the open space easement, and no permanent impacts to the adjacent private property would occur. P-l(B) Construction impacts would occur within the private property to replace the slope to the existing condition due to the wall replacement. The proposed wall design includes several types of retaining walls based on the varying site conditions, easements, and access. For this analysis, the Project site has been sectioned into three improvement zones: Zone A, B, and C, which are shown on Figure 3, Proposed Improvement Zones, and described below. Zone A Zone A is located w·1thin the Park Or'1ve ROW {Assessor's Parcel Number 20-101-01) and private property {Assessor's Parcel Number 207-100-57) within the open space easement and 25-foot-wide storm drain easement (Doc. No. 85-207258). Zone A is located at the southeast end of the Project site and currently consists of about 1.5 to 1 {horizontal to vertical [1.5:1]) slope with a low retaining wall, approximately 2 to 5 feet high {please refer to Figure 4, Improvement Zone A). In most portions of this zone, the soil has eroded down to parent material, with little to no topsoil present. The overtopping of the sediment-laden flows, as well as the runoff from the hillside, is straining the existing wall in this area. Proposed Zone A improvements would include an approximately 330-linear-foot stepped planter block wall with geogrid reinforcement. The geogrid wall in Zone A would replace the existing wall at a maximum height of 12 feet. The geogrid-reinforced segmental retaining wall would consist of masonry facing blocks with proprietary means of vegetating the face, supported by a geogrid-reinforced soil mass behind the wall to create a gravity retaining wall. The slope behind the wall would be graded to a 2:1 slope (horizontal to vertical inclination). The wall would be constructed in incremental lifts consisting of stacked masonry facing blocks connected to geogrid reinforcing layers that are embedded in structural backfill behind the wall facing. The geogrid wall would be planted with native and drought-tolerant species and would be maintained by the City. A brow ditch would be located at the top of the 2:1 slope and at the top of the wall to safely convey stormwater runoff to the existing storm drain system. Although erosion is expected to decrease substantially, the potential for erosion would not be eliminated entirely by removing the stormwater runoff from the face of the slope using the brow ditch at the top of the slope. Revegetation of coastal sage scrub along the hillside would commence once construction is complete. Mitigation efforts through revegetation would result in no-net-loss to coastal sage scrub. Zone B The majority of Zone Bis within private property, which limits options where the permanent impacts are contained within the existing ROW and easements (please refer to Figure 5, Improvement Zone B). Understanding that reduction of the current public access is unfavorable, options for this zone to replace the existing retaining wall in kind at its existing height are limited. Proposed improvements for Zone B include installation of an approximately 10-foot-tall solider pile and lagging type retaining wall to replace approximately 180 linear feet of the existing retaining wall in this area. The soldier piles would be drilled behind the existing wall along the majority of the alignment, and sections of the existing wall would be demolished from the top down to allow the lagging to be installed while maintaining the stability of the slope behind the wall. Once the lagging is installed, a finish would be installed on the face of the wall to mimic the existing block wall's look and color. The proposed retaining wall in Zone B would minimize the temporary construction impacts on the existing slope. At P·l(B) • I either end of the solider pile and lagging retaining wall in Zone B, the wall would tie into the proposed wall in Zone A to the southeast, and transition into the proposed wall in Zone C to the north. Zone C Zone C is located at the north end of the Project site (please refer to Figure 6, Improvement Zone C). Proposed improvements for Zone C would include installation of a 2-foot-tall block wall approximately 300 feet in length. Additionally, a drainage ditch and sediment trapping best management practice {BMP) is proposed to reduce the potential deposition of sediment from the slope on the sidewalk after storm events and to reduce the sediment that reaches the storm drain system and ultimately discharges into the Agua Hedionda Lagoon. The drainage ditch and screen wall would collect the eroded slope material until City crews are able to remove it. The proposed wall in Zone C would tie into the existing wall located at the north end of the Project site and is intended to be of similar color and type. The proposed 2-foot-tall wall in Zone C would transition into the proposed solider pile wall in Zone B. Similar to Zone B, the majority of Zone C is within private property, and the options are limited to improvements that can be made within the ROW. P-l(B) Per the California Environmental Protection Agency's website, ''While Government Code Section 65962.5 [referred to as the Cortese List] makes reference to the preparation of a "list," many changes have occurred related to web-based information access since [the amended statute's effective date in] 1992 and this information is now largely available on the Internet sites of the responsible organizations. Those requesting a copy of the Cortese "list" are now referred directly to the appropriate information resources contained on the Internet web sites of the boards or departments that are referenced in the statute." Below is a list of agencies that maintain information regarding hazardous waste and substances sites. Department of Toxic Substances Control www. ca lepa. ca. g ov/siteclean up/Cortese LisUdef auft. htm www.calepa.ca.gov/database/calsites www.envirostor.dtsc.ca.gov/public EnviroStor Help Desk (916) 323-3400 State Water Resources Control Board http://geotracker.waterboards.ca.gov/ County of San Diego Department of Environmental Health Services www.co.san-diego.ea.us/deh Hazardous Materials Division www.sdcounty.ca.gov/deh/hazmaUhazmat permits.html Mailing Address: County of San Diego Department of Environmental Health P.O. Box 129261 San Diego, CA 92112-9261 Call Duty Specialist for technical questions at (858) 505-6880, fax (858) 505-6868 (fax) Environmental Protection Agency National Priorities Sites ("Superfund" or "CERCLIS") www.epa.gov/superfund/sites/cursites (800) 424-9346 or (702) 284-8214 National Priorities List Sites in the United States www.epa.gov/superfund/sites/npl/npl.htm P-1{C} Page 2 of2 Revised 02/13 ENVIRONMENTAL INFORMATION FORM (To be Completed by Applicant) Date Filed: ____________ (To be completed by City) Application Number(s): __________________________ _ General Information 1. 2 3. 4. Park Drive Street and Drainage Improvements, CIP# 6611 Name of project: _________________________ _ City of Carlsbad Public Works Name of developer or project sponsor: __________________ _ 1635 Faraday Avenue Address: ____________________________ _ Carlsbad, CA, 92008 City, State, Zip Code: ________________________ _ 760-602-7551 Phone Number: __________________________ _ Daniel Zimny Name of person to be contacted concerning this project: ____________ _ 1635 Faraday Avenue Address: ____________________________ _ Carlsbad, CA, 92008 City, State, Zip Code: ________________________ _ 760-602-7551 Phone Number: -----~-----~--------~------N/A, Park Drive between Bayshore and Marina Drive Address of Project: N/A, Public ROW Assessor's Parcel Number: 5. Ust and describe any ottier related permits and other public approvals required for this project, including those required by city, regional, state and federal agencies: 6. 7. 8. California Coastal Comission -Coastal Development Permit Neighborhood Collector Road Existing General Plan Land Use Designation: ________________ _ District 1 Existing zoning district Public Right of Way Existing land use(s): ------------~-~-----~~--- Road Improvement Project 9. Proposed use of site (Project for which this form is filed): Project Description 0.89 Acres (38,61 o square feet) 10. Site size: ____________________________ _ n/a 11. Proposed Building square footage: ____________________ _ n/a 12: Number of floors of construction: ____________________ _ 13. On street parking preserved Amount of off-street parking provided: __________________ _ NIA 14. Associated projects: ________________________ _ P-1(D) Page 2 of 4 Revised 07/10 { City of Carlsbad ------------'"">-----------~ EIA INFORMATION FORM P-1(0) INSTRUCTION SHEET FOR COMPLETING AN ENVIRONMENTAL IMPACT ASSESSMENT INFORMATION FORM Development Services Planning Division 1635 Faraday Avenue (760) 602-4610 www.carlsbadca.gov This Environmental Information Form will be used to assist staff in determining what type of environmental documentation (i.e., Environmental Impact Report, Mitigated Negative Declaration, Negative Declaration or Exemption) will be required to be prepared for your application, per the California Environmental Quality Act (CEQA) and Title 19 of Carlsbad's Municipal Code. The clarity and accuracy of the information you provide is critical for purposes of quickly determining the specific environmental effects of your project. Any environmental studies (i.e., biological, cultural resource, traffic, noise) that are necessary to substantiate a "no impact" or "yes impact" detennination should be submitted as an attachment to this Environmental lnfonnation Fonn. This is especially important when a Negative Dedaration is being sought. The more information provided in this form, the easier and quicker it will be for staff to complete the Environmental Impact Assessment Form -Initial Study. P-1{0) Page 1 of4 Revised 07/10 15. n/a If residential, include the number of units and schedule of unit sizes: _________ _ 16. If commercial, indicate the type, whether neighborhood, city or regionally oriented, square footage of sales area, and loading facilities: _0_1, ____________________ _ n/a 17. If industrial, indicate type, estimated employment per shift, and loading facilities: _____ _ 18. If institutional, indicate the major function, estimated employment per shift, estimated occupancy, loading facilities, and community benefits to be derived from the project _0_1, _______ _ 19. If the project involves a variance, conditional use or rezoning applications, state this and indicate clearly why the application is required: -'""/'=-------------------- P-1(□} Page 3of4 Revised 07110 Are the foflowing items applicable to the project or its effects? Discuss afl items checked yes (attach additional sheets as necessary). 20. Change in existing features of any bays, tidelands, beaches, or hills, or substantial alteration of ground contours. 21. Change in scenic views or vistas from existing residential areas or public lands or roads. 22. Change in pattern, scale or character of general area of project. 23. Significant amounts of solid waste or litter. 24. Change in dust, ash, smoke, fumes or odors in vicinity. 25. Change in ocean, bay, lake, stream or ground water quality or quantity, or alteration of existing drainage patterns. 26. Substantial change in existing noise or vibration levels in the vicinity. 27. Site on filled land or on slope of 10 percent or more. 28. Use of disposal of potentially hazardous materials, such as toxic substances, flammables or explosives. 29. Substantial change in demand for municipal services (police, fire, water, sewage, etc.). 30. Substantially increase fossil fuel consumption (electricity, oil, natural gas, etc.). 31. Relationship to a larger project or series of projects. Environmental Setting Attach sheets that include a response to the foflowing questions: Yes No 0 □ 0 □ 0 □ □ 0 □ 0 □ 0 □ 0 0 □ □ 0 □ 0 □ 0 □ 0 32. Describe the project site as it exists before the project, including information on topography, soil stability, plants and animals, and any cultural, historical or scenic aspects. Describe any existing structures on the site, and the use of the structures. Attach photographs of the site. Snapshots or Polaroid photos will be accepted. 33. Describe the surrounding properties, including information on plants and animals and any cultural, historical or scenic aspects. Indicate the type of land use (residential, commercial, etc.), intensity of land use (one-family, apartment houses, shops, department stores, etc.), and scale of development (height, frontage, set-back, rear yard, etc.). Attach photographs of the vicinity. Snapshots or polaroid photos will be accepted. Certification I hereby certify that the statements furnished above and in the attached exhibits present the data and information required for this initial evaluation to the best of my ability, and that the facts, statements, and information presented are true and correct to the best of my knowledge and belief. Date: 612212020 Signature: ~ ~ For: Daniel Zimny P-1(0) Page4of4 Revised 07/10 (city of Carlsbad DETERMINATION OF PROJECT'S SWPPP TIER LEVEL AND CONSTRUCTION THREAT LEVEL E-32 Development Services Land Development Engineering 1635 Faraday Avenue 760-602-2750 www.carlsbadca.gov I'm applying for: O Grading Permit D Building Permit D Right-of-way permit !Zl other Project Name: Park Drive Street and Drainage Improvements Project ID: 6611 DWG #/CB# _5_1_0~-•=~-- Address· Park Drive Between Bayshore and Marina Drive APN NIA Disturbed Area· 0.89 Ac . Section 1: Determination of Project's SWPPP Tier Level SWPPP Tier (Check applicable criteria and check the corresponding SWPPP Tier Level, then go to section 2) Level Exemgt-No Threat Project Assessment Criteria My project is in a category of permit types exempt from City Construction SWPPP requirements. Provided no significant grading proposed, pursuant to Table1, section 3.2.2 of Storm Water Standards, the following permits are exempt from SWPPP requirements: □ Exempt 0 Electrical □ Patio □ Mobile Home □ Plumbing □ Spa (Factory-Made) □ Fire Sprinkler D Mechanical □ Re-Roofing D Sign □ Roof-Mounted Solar Array Tier 3 -Significant Threat Assessment Criteria -(See Construction General Permit (CGP) Section LB)" O My project includes construction or demolition activity that results in a land disturbance of equal to or greater than one acre including but not limited to clearing, grading, grubbing or excavation; or, □ My project includes construction activity that results in land disturbance of less than one acre but the construction activity is part of a larger common plan of development or the sale of one or more acres of disturbed land surface; or, D My Project is associated with construction activity related to residential, commercial, or industrial □ Tier 3 development on lands currently used for agriculture; or □ My project is associated with construction activity associated with Linear Underground/Overhead Projects (LUP) including but not limited to those activities necessary for installation of underground and overhead linear facilities (e.g. conduits, substructures, pipelines, towers, poles, cables, wire, towers, poles, cables, wires, connectors, switching, regulating and transforming equipment and associated ancillary facilities) and include but not limited to underground utility mark out, potholing, concrete and asphalt cutting and removal, trenching, excavation, boring and drilling, access road, tower footings/foundation, pavement repair or replacement, stockpile/borrow locations. 0 other per CGP Tier 2 -Moderate Threat Assessment Criteria: My project does not meet any of the Significant Threat Assessment Criteria described above and meets one or more of the following criteria: i2I Project requires a grading plan pursuant to the Carlsbad Grading Ordinance (Chapter 15.16 of the Carlsbad Municipal Code); or, i2I Project wi\l result in 2,500 sq. ft or more of soils disturbance including any associated construction staging, stockpiling, pavement removal, equipment storage, refueling and maintenance areas and project meets one or more of the additional following criteria: 0 Tier 2 • located within 200 fl of an environmentally sensitive area or the Pacific Ocean; and/or, • disturbed area is located on a slope with a grade at or exceeding 5 horizontal to 1 vertical; and/or • disturbed area is located along or within 30 ft of a sto11T1 drain inlet, an open drainage channel or watercourse; and/or • construction will be initiated during the rainy season or will extend into the rainy season (Oct 1 -Aor. 30\ Tier 1 Low Threat Assessment Criteria □ My project does not meet any of the Significant or Moderate Threat criteria above, is not an exempt permit type per above and the prqect meets one or more of the following criteria: □ Tier 1 • results in some soil disturbance; and/or • includes outdoor construction activities (such as roof framing, saw cutting, equipment washing, material stockcilino, vehicle fuelina, waste stockoilin,.,1 . Items listed are excerpt from CGP. CGP governs crltena for tnggers for Tier 3 SWPPP_ Developer/owner shall confirm coverage under the current CGP and any amendments, revisions and reissuance thereof. E-32 Page1of2 REV. 02116 SWPPP Section 2: Detennination of Project's Construction Threat Level Construction Tier (Check applicable criteria under the Tier Level as determined in section 1, check the Threat Level corresponding Construction Threat Level, then complete the emergency contact and Level sianature block below) Exempt -Not Applicable -Exempt Tier 3 -High Construction Threat Assessment Criteria: Mt Project meets one or more of the following: □ Project site is 50 acres or more and grading will occur during the rainy season □ Project site is located within the Buena Vista or Agua Hedionda Lagoon watershed, inside or within 200 feet of an environmentally sensitive area {ESA) or discharges directly to an ESA □ High □ Soil at site is moderately to highly erosive (defined as having a predominance of soils with Tier3 USDA-NRCS Erosion factors k,greater than or equal to 0.4) □ Site slope is 5 to 1 or steeper □ Construction is initiated during the rainy season or will extend into the rainy season (Oct. 1 -April 30) □ Owner/contractor received a Storm Water Notice of Violation within past two years Tier 3 -Medium Construction Threat Assessment Criteria D Medium □ All projects not meeting Tier 3 High Construction Threat Assessment Criteria Tier 2 -High Construction Threat A§Sessment Criteria: M~ Project meets one or more of the following: 0 Project is located within the Buena Vista or Agua Hedionda Lagoon watershed, inside or within 200 feet of an environmentally sensitive area (ESA) or discharges directly to an ESA □ Soil at site is moderately to highly erosive (defined as having a predominance of soils with 0 High USDA-NRCS Erosion factors k, greater than or equal to 0.4) Tier2 □ Site slope is 5 to 1 or steeper O Construction is initiated during the rainy season or will extend into the rainy season (Oct. 1 -Apr. 30) □ Owner/contractor received a Storm Water Notice of Violation within past two years □ Srl:e results in 10,000 sa. fl. or more of soil disturbance Tier 2 -Medium Construction Threat Assessment Criteria D Medium □ My project does not meet Tier 2 High Threat Assessment Criteria listed above Tier 1 -Medium Construction Threat Assessment criteria: My Project meets one or more of the following: □ Owner/contractor received a Storm Water Notice of Violation within past two years □ Medium □ Site results in 500 sq. fl. or more of soil disturbance Tier 1 D Construction will be initiated during the rainy season or will extend into the rainy season {Ocl.1 -April 30) Tier 1 -Low Const[Yction Threat Assessment Criteria □Low D My project does not meet Tier 1 Medium Threat Assessment Criteria listed above I certify to the best of my knowledge that the above statements are true and correct. I will prepare and submit an appropriate lier level SWPPP as determined above prepared in a=rdance with the City SWPPP Manual. I understand and ad<rowledge that I must adhere lo and comply with the storm water best management practices pursuant to Title 15 of the Carlsbad Municipal Code and to City Standards at all times during construction activities for the permit type(s) checked above. The City Engineer/Building Official may authorize minor variances from the Construction Threat Assessment Criteria in special circumstances where it can be shown that a lesser or higher SW PPP Tier Level Is warranted. Emergency Contact Name Daniel Zimny Telephone No: 760-602-7551 Owner/Owner's Authorized Agent Name Title: Daniel Zimny Associate Engineer Ow~er/Owner's A orized Agent Signature· Date: /h ' 6/22/2020 FOR CITY USE ONLY Yes No City Concurrence: By: Date: E-32 Page2of2 REV. 02/16 ',_/._", .. ".,, ';•,,.,"So'-•~~! ' "' ---·-, ",· ,.r.: , ,,,,. , ai,iill~' ' ' SC-4 Protect Materials Stored in Outdoor Work Areas from Rainfall. Run-On, Runoff, and □Yes □ No 1!1 NIA Wind Disoersal Discussion/justification if SC-4 not implemented: The project will not include any outdoor work areas for materials to be stored. SC-5 Protect Trash Storage Areas from Rainfall. Run-On, Runoff, and Wind Dispersal □Yes □No Iii NIA Discussion/justification if SC-5 not implemented: The project will not include any trash areas. SC-6 Additional BMPs based on Potential Sources of Runoff Pollutants must answer for each source listed below and identifv additional BMPs. (See Table in Annendix E.1 of BMP Manual for auidancel. II On-site storm drain inlets Iii Yes □No □ NIA D Interior floor drains and elevator shaft sump pumps □Yes □No !!I NIA □ Interior parking garages □Yes □No 111 NIA D Need for future indoor & structural pest control □Yes □No ■ NIA Iii Landscape/Outdoor Pesticide Use Iii Yes □No □NIA □ Pools, spas, ponds, decorative fountains, and other water features D Yes □ No 1!1 NIA □ Food service □Yes □No I!] NIA D Refuse areas □Yes □No Iii NIA D Industrial processes □Yes □No Ill NIA D Outdoor storage of equipment or materials □Yes □No Iii NIA D Vehicle and Equipment Cleaning □Yes □No Iii NIA D Vehicle/Equipment Repair and Maintenance □Yes □ No ii NIA D Fuel Dispensing Areas D Yes □No I!] NIA D Loading Docks D Yes □No Iii N/A D Fire Sprinkler Test Water □Yes □No Iii NIA D Miscellaneous Drain or Wash Water □Yes □No lilNIA □ Plazas, sidewalks, and oarkina lots □Yes □ No I!] NIA For "Yes" answers, identify the additional BMP per Appendix E.1. Provide justification for "No" answers. All storm drain inlets will be marked with the words "No Dumping Drains to Ocean" per City Standard No Dumping Detail. Landscaping will include protecting existing vegetation to the extent possible, planting native and drought tolerant species, and minimizing pesticide use. Pesticide use shall be in accordance with the latest version of the city's Integrated Pest Management Plan (IPM)" E-36 Page2of4 Revised 09116 Memorandum Subject: Alternatives Analysis Memorandum for Park Drive Slope and Drainage Improvement Project • Improvement to erosion control • Impacts to the environment and aesthetics • Impacts outside of the City's ROW on private property • Impacts to service level of Park Drive (vehicular impacts, parking. etc.) • Constructability • Costs • Long-term maintenance burden 3 Alternatives Analysis Methodology A wide range of retaining wall and slope stabilization options were reviewed and evaluated for the improvements along Park Drive in the Alternative Analysis report (Dudek, 2018). Potential alternatives are based on different slopes and retaining wall heights. All wall improvements are contained within the City's ROW and the easement areas, including the open space easement, and no permanent impacts to the adjacent private property would occur. Temporary construction impacts will occur within the private property to construct the replacement of the existing wall. The project area was broken into three zones in the Alternatives Analysis based on the varying site conditions to better differentiate the potential strategies for stabilization. The factors considered in the determination of the zones included the steepness of the slopes and relative stability of the existing slopes based on field observations and previous maintenance information, location of known jurisdictional waters, and easements. As shown on Agure 2, improvement zones within the project site are designated A through C, from south to north. Zone A is located at the southeast end of the project where the highly eroded hillside/slope is located. This zone begins at the brow ditch at the southeast end of the area and continues to the northwest to approximately the concrete brow ditch located near the intersection with Marina Drive. An existing retaining wall is located at the toe of slope and varies in height from 2 to 8 feet. This zone is located Within the Park Drive ROW and private property (APN 207-100-57) within the open space easement and 25-foot storm drain easement (Doc. No. 85-207258). Zone Bis the transition area between Zones A and C, within the center of the site. This zone begins on the southeast side at the end of Zone A, near Marina Drive, and continues to the northwest to the end of the existing retaining wall. There is also an existing, distressed 4 to 8-foot-high concrete masonry unit retaining wall at the toe of the slope. Outside of the Park Drive ROW, this zone is mainly in private property (APN 207-150-57), and a small portion of the zone is in the storm drain (Doc. No. 85-207258) and water (Map 5162) easements. Zone C begins at the end of the existing retaining wall, Zone B, and continues to the northwest towards Cove Drive and ends at the start of the approximately 2-foot-high retaining wall. There are small drainages down the slope that discharge sediment onto the sidewalk and require maintenance after most storm events. Approximately 20 feet from the end of the existing retaining wall, a larger drainage is located. Outside of the Park Drive ROW, this zone is located along two private parcels (APN 207-100-67 and APN 207-150-57). Methods of stabilization in the alternatives range from minimally impactful (reducing the street width to accommodate a sediment collection area) to major structural improvements (considering three types of retaining walls) with various additional measures to rebuild the slope remaining above the retaining wall. The types of retaining walls vary primarily in aesthetics, ease of construction, and cost of construction. The measures to rebuild DUDEK 3 11632 July 2019 Memorandum Subject: Alternatives Analysis Memorandum for Park Drive Slope and Drainage Improvement Project the slope above the retaining wall vary primarily in ease and cost of construction and long-term maintenance burden. Selection of a preferred mitigation measure requires careful and we·1ghted consideration of multiple considerations. A matrix analysis of the options under consideration was prepared to summarize and compare the alternatives and considered the following factors: • Improvement of deeper-seated slope stability • Improvement of erosion control • Impact to environment and aesthetics • Property boundary considerations • Design considerations • Construction considerations • Design and construction costs/duration of construction • Long-term maintenance burden • Stormwater BMP requirements The Alternatives Analysis selected a preferred alternative based on reviewing various combinations of stabilization options. The key considerations in selecting the preferred alternative focused on the improvement of the stability of the slope and a reduction of accumulated sediment impacts to the street and sidewalk to improve access to coastal resources and safety to pedestrians. In addition, the permitting constraints and aesthetics of the countermeasures were reviewed, including the extent of the work area into the open space easement, the critical habitat impacts, and the visual impact of each countermeasure. The analysis also included the fiscal impacts as well as an assumption on the level of reduction in long-term maintenance burden. In review·ing the retaining wall options, considering appropriate engineering, environmental, and public impact criteria, the City has selected the geogrid reinforced retaining wall with a 2:1 slope for its balance of higher aesthetic value and lower installation costs while meeting the goals of improve slope stability and reduce erosion potential within the open space easement. West of the open space easement, the retaining wall would be replaced in kind and a small screen wall and ditch would be added, within the City's ROW, to improve public safety along the sidewalk to the western terminus of the project. 4 Alternatives Summary This section presents a summarized version of the alternatives analyzed in the Alternatives Analysis and includes an additional alternative to increase the wall height in order to eliminate the need for a brow ditch at the top of slope. The wall heights discussed in the alternatives are the height of the face of the wall from the finished grade at the back of the sidewalk to the top of wall. 4.1 Zone A Three proposed alternatives are summarized in this section for Zone A. Figure 3, Zone A Alternatives, depicts cross sections and associated nm·1ts of grading for each proposed alternative within Zone A. DUDEK 4 11632 July 2019 Memorandum Subject: Alternatives Analysis Memorandum for Park Drive Slope and Drainage Improvement Project 4.1.1 Alternative 1 -10-Foot Retaining Wall -2:1 Slope (Preferred Alternative) This alternative is the preferred alternative and includes a 10-foot high vegetated retaining wall (geogrid reinforced) (Figure 4, Alternative 1 Biological Impacts (10-Foot Retaining Wall -2:1 Slope (Preferred Alternative)). The slope behind the wall would be graded to a 2:1 slope (horizontal to vertical inclination). A geogrid reinforced segmental retaining walls consist of masonry facing blocks with proprietary means of vegetating the face, supported by a geogrid reinforced soil mass behind the wall to create a gravity retaining wall. The wall is constructed in incremental lifts consisting of stacked masonry facing blocks connected to geogrid reinforcing layers that are embedded in structural backfill behind the wall facing. The proposed wall height increases the existing wall height up to 8 feet except at the ends where it matches the existing wall height. A brow ditch would be located at the top of the 2:1 slope as well as at the top of wall to safely convey storm water runoff to the existing storm drain system. Though erosion is expected to decrease substantially, the potential for erosion would not be eliminated entirely by removing the storm water runoff from the face of the slope using the brow ditch at the top of the slope. The considerations for this design include: • low to moderate environmental impact and aesthetics due to the large exposure of masonry block facing. Aesthetics can be improved by selecting a block system that allows for landscaping the face, although a relatively large near vertical face would remain. • Construction may require access outside of the City's ROW to install geogrids and to form the temporary slope needed to create horizontal space for the geogrids. It may also require excavation near or in the road to improve soils supporting the foundation of the retaining wall, although this wall system can tolerate higher settlement (relative to cast-in-place retaining wall), and therefore less excavation may be needed. Construction of slope above the wall would require access to adjacent properties. • Design requires specialist engineering. Design itself is not difficult relative to other retaining wall systems. Complexity of design depends on method used to rebuild the slope above the retaining wall. • Requires various construction activities with somewhat labor-intensive handling to place geogrid reinforcement and compact soils. Requires select import soils in reinforced zone. May require some local dewatering for the excavation needed to improve soils supporting the foundation of the retaining wall, although this wa\l system can tolerate higher settlement (relative to cast-in-place retaining wall), and therefore less excavation below groundwater may be needed. Construction equipment used to reconstruct the slope above the retaining wall can also be used to construct the segmental retaining wall. Complexity of construction depends on method used to rebuild the slope above the retaining wall. • Low construction cost ($25 to $30 per square foot of wall space) and moderate duration for completion. Soil nail stabilization of slope above the retaining wall would increase cost and duration. • Should have typical long-term maintenance burden. The potential for erosion is not eliminated entirely, however, by removing the storm water runoff from the face of the slope, though erosion is expected to be decreased significantly. 4.1.2 Alternative 2 -20-Foot Retaining Wall -3:1 Slope An additional alternative was analyzed to eliminate the brow ditch at the top of slope and to reduce habitat impacts. To eliminate the brow ditch at the top of slope, the slope grade was reduce to reduce potential erosion. Based on the review of stable slope grades near the residential development, a grade of 3:1 (horizontal to vertical inclination) was used in the design. The resulting wall height was determine to be a maximum of a 20-foot-ta II retaining wall for this alternative {Figure DUDEK 5 11632 July 2019 Memorandum Subject: Alternatives Analysis Memorandum for Park Drive Slope and Drainage Improvement Project 5, Alternative 2 Biological Impacts (20-Foot Retaining Wall -3:1 Slope)). This alternative assumed the vegetated retaining wall {geogrid reinforced) would be used. The proposed wall height increases the existing wall height up to 16 feet except at the ends where it matches the existing wall height. A brow ditch would be located at the top of the retaining wall. The reduction of the slope angle is expect to reduce the amount of erosion compared to the existing condition; however, the stormwater would still be conveyed over the slope face. Therefore, this alternative would not eliminate erosion of the slope. The design consideration for this wall are similar to Alternative 1 and include: • Improvement for the potential for erosion is reduced compared to Alternative 1 with the removal of the brow ditch at the top of slope. The slope is expected to be more stable than the current condition with the 3:1 slope once vegetation is established but moderate erosion is still anticipated. • Environmental impacts are fess than the Alternative 1 as less hab"ltat will be impacted. • The impact to aesthetics will be greater than Alternative 1 as there is 45% increase in the amount of wan face. ln addition, the wall in this alternative will significantly vary in height • The construction access, activities and duration, specialized engineering, and the cost per square foot are similar to the discussion for Alternative 1, • The long-term maintenance burden is expected to be moderate and higher than Alternative 1 as the potential for erosion on the slope is greater since the storm water runoff will not be removed from the face of the slope. 4.1.3 Alternative 3 -Stepped Slope and No Wall The stepped cut slope only option includes removing loose surface soils, reforming the slope at 2 on 1 (horizontal to vertical inclination), and excavating small benches in the slope to mitigate erosion (Figure 6, Alternative 3 Biological Impacts (Stepped Slope and No Wall)). Revegetation of the graded slope face with erosion resistant planting could be considered to further mitigate erosion and surficial slope stability. This design improves resistance to erosion, but does not eliminate it entirely. Erosion control is further improved using: a) fl/I or reinforced fill slopes with careful selection of the import fill (cohesive fines) needed for construction and b) typical surface drainage and landscaping treatments on the face of the slope. Additional considerations for this design include: • Environmental impact related to minimal site grading. Aesthetics remain relatively similar to the existing conditions, although more sandstone is exposed at the face of the slope. Aesthetics are similar to other nearby roads and freeways. • Requires off-site grading. • Requires min·1mal design effort. • Requires very few construction activities and does not require substantial or multiple types of construction equipment. • Low design and construction cost with relatively short duration for completiOn. • Maintenance would be required since the alternative does not eliminate the potential for erosion. • Requires native revegetat1on treatments appropriate to the existing native vegetation communities present adjacent to the project. DUDEK 6 11632 July 2019 Memorandum Subject: Alternatives Analysis Memorandum for Park Drive Slope and Drainage Improvement Project by non-native species. Additionally, this alternative would result in the removal of approximately nine individuals of California adolphia, a California Rare Plant Rank 28.1 plant.1 Given the siting and design alternatives, the proposed project has been designed to be the least environmentally damaging alternative. It also accomplishes the need to stabilize and repair the unstable slope, and is consistent with Section 30233 of the Coastal Act regarding alternatives. 1 CNPS (California Native Plant Society). 2019. Inventory of Rare and Endangered Plants (on line edition, version 8-03 0.39). Sacramento, California: California Native Plant Society. Accessed April 2019. www.rareplants.cnps.org. DUDEK 10 11632 July 2019