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CT 13-02; COASTAL 10; SWMP; DWG 480-5, DWG 480-5A; 2013-11-21
, _ _j .. J i "j ' J ' ___ J 1.J I---;, ' I SWMP13-20 STORM WATER MANAGEMENT PLAN FOR COASTAL 10 C. T. 13-02 November 21, 2013 Prepared For: Coastal 10, LLC 7668 El Camino Real, Suite 104-108 Carlsbad, CA 92009 Prepared By: O'DAYCONSULTANTS, INC. 2710 Loker Avenue West, Suite 100 Carlsbad, CA 92010 J.N.131003 Nichole Fine RCE 70035 Registration Expires: 9/30/14 'r :J (""71 I I __ J ,-, 1__j ' __ ) Coastal 10 SWMP TABLE OF CONTENTS TABLE OF CONTENTS ...................................................................................................................................... i ATIACHMENTS: ............................................................................................................................................ ii 1. PROJECT SETTING ............................................................•...........•.......•.....................•...................... 1 2. APPLICABLE STORMWATER STANDARDS ....................................................................................... 3 2a. Storm Water Standards Questionnaire ..................................................................................... 3 2b. HMP Applicability Determination .............................................................................................. 3 3. IDENTIFY POLLUTANTS OF CONCERN .............................................................................................. 4 3a. Identify pollutants associated with type of project/use ........................................................... .4 3b. Identify watershed, hydrologic unit basin and receiving waters .............................................. .4 3c. List impaired water bodies ......................................................................................................... 5 3d. Beneficial uses of receiving water ............................................................................................. 5 3e. Summarize primary pollutants of concern ................................................................................ 7 4. SOURCE CONTROL MEASURES ........................................................................................................ 8 4a. Description of site activities and potential sources of pollutants ............................................. 8 4b. Stormwater Pollutant Sources and Source Controls ................................................................. 8 5. LOW IMPACT DEVELOPMENT (LID) DESIGN STRATEGIES ............................................................. 10 6. INTEGRATED MANAGEMENT PRACTICES (IMP's) ......................................................................... 11 6a. Selection process for IMP's ...................................................................................................... 11 6b. Sizing factors for IMP's ............................................................................................................. 11 6c. Geotechnical recommendation on soil infiltration rates ......................................................... 11 6d. Infiltration calculations ............................................................................................................ 11 7. TREATMENT CONTROL BMP's ....................................................................................................... 12 8. HYDROMODIFICATION .................................................................................................................. 13 Ba. Lower Flow Threshold Determination ..................................................................................... 13 Bb. Continuous Simulation Model ................................................................................................. 14 Be. Print-outs of Pond Sizing Criteria and Results Using BMP Sizing Calculator ............................ 14 Bd. Tabulation of Flow-control Facility Sizes and Design Criteria .................................................. 14 9. DOCUMENTATION OF STORMWATER DESIGN ............................................................................. 15 9a. Hydrology maps ....................................................................................................................... 15 9b. BMP Sizing Calculator .............................................................................................................. 15 9c. Tabulation ................................................................................................................................ 15 10. BMP FACILITY MAINTENANCE REQUIREMENTS ........................................................................... 16 10a. Ownership and responsibility of maintenance of BMP's ......................................................... 16 10b. Summary of maintenance requirements ................................................................................. 16 11. SWMP CERTIFICATION STATEMENTS ............................................................................................ 17 L_j Coastal 10 SWMP ATTACHMENTS: 1. Storm Water Standards Questionnaire 2. BMP Calculator Output & Orifice Calculations 3. BMP exhibit :__j ii G:\131003\SWMP\SWMP.docx , _ _J L __ J •l ,·, i.J \ .. J Coastal 10 SWMP 1. PROJECT SETIING The Coastal 10 project is located on the south side of Navarra Drive, west of Viejo Castilla Way in the City of Carlsbad, California (see Vicinity Map below). The Coastal 10 site is a multi-family residential development consisting 10 units, a rec area, pool and spa area. The entire site is approximately 0.49 acres and is located between a multi-family site on the east and on the west and adjacent to a golf course to the south. SIT£ VICINITY MAP NO SCALE 1 G:1131003\SWMPISWMP.docx ,, I (._j i , __ _j Coastal 10 SWMP The site is generally described as previously graded vacant land. The site is mostly flat or moderately sloped in the interior of the lot, with steep areas around the perimeter. The lot generally slopes toward the north towards Navarra Drive. From the Soil Hydrolgic Groups Map, it was determined that Soil Group D is the predominant soil on this site. Hydrologic Soils Group D soils have a very slow infiltration rate (high runoff potential) when thoroughly wet. These consist chiefly of clays that have a high shrink-swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission. The proposed land use is for 10 condominiums, a drive aisle, pool and rec area. Typical activities that could affect storm water include: landscape maintenance; pest control; refuse services; storage; fire sprinkler testing; and miscellaneous wash water. Stormwater control and treatment constraints include: poor soil type and permeability (soil type D); high intensity land use; steep terrain; restricted right-of-way; and safety concerns. Opportunities include landscape buffer areas, and elevation differences. All site drainage surface flows north to Navarra Drive. Once it enters the gutter, drainage from the site then combines with flows from the upper portion of Navarra Drive to the west and flows east. At the east cul-de-sac, the stormwater enters a ditch, which combines with a larger drainage area and then outlets into San Marcos Creek, which ultimately flows into Batiquitos Lagoon and finally the Pacific Ocean. 2 G:\131003\SWMP\SWMP.docx 'i u , _ _j Coastal 10 SWMP 2. APPLICABLE STORMWATER STANDARDS 2a. Storm Water Standards Questionnaire Results of the completed City of Carlsbad Storm Water Standards Questionnaire (SWSQ) indicate this project to be a Priority Development Project (PDP) and therefore must comply with additional stormwater criteria per the SUSMP. (See Attachment 1 for completed SWSQ) 2b. HMP Applicability Determination According to Figure 2-1, HMP Applicability determination flowchart below, Hydromodification controls are required. It was determined that field investigations would not be conducted pursuant to the SCCWRP channel screening tools. Therefore the site must mitigate peak flows and durations based on a pre-project condition lower flow threshold of 0.1Q2. G:\131003\SWMP\SWMP.docx Erd of Ooc1sion Matrix NO 11. D0tc11nh1u Oomuln ol Anulymo Sao HMP Sot.lkin !l.2 N() ftod,V1iUn E1wgy Uiia1µat1or1 :aystum N<> 14, Mydmmod1fcal Conlmls Ruquimd Go to Figuro 6~2 Qi 0.:-Ct$1M Mntrix FIGURE 2-1. HMP Applicability Determination 3 'r ·1 I LJ Coastal 10 SWMP 3. IDENTIFY POLLUTANTS OF CONCERN 3a. Identify pollutants associated with type of project/use Table 2-1 of the SUSMP (see below) identifies the pollutants anticipated from the Coastal 10 Development and associated improvements as indicated by the shaded categories. TABLE 2-1. ANTICIPATED AND POTENTIAL Pollutants Generated by Land Use Type. General Pollutant Categories Trash Oxygen Bacteria Priority Project Heavy Organic & Demanding Oil& & CateJ!.ories Sediment Nutrients Metals Compounds Debris Substances Grease Viruses Pesticides Detached Residential X X X X X X X Development Attat'hed Residential X X X P(1) P(2) p X De11e/o/J111e11t Commenial Development P(1) P(l) X P(2) X P(S) X P(3) P(S) >one acre Heavy Industry X X X X X X Automotive X X(4)(5) X X Repair Shops Restaurants X X X X P(l) Hillside Development X X X X X X >5,000 ft2 Parking Lots P(l) P(l) X X P(1) X P(1) Retail Gasoline X X X X X Outlets Streets, Highways & X 1'(1) X X(4) X 1'(5) X X 1'(1) Freeways X = anticipated P = potential (1) A potential pollutant iflandscaping exists on-site. (2) A potential pollutant if the project includes uncovered parking areas. (3) A potential pollutant if land use involves food or animal waste products. (4) Including petroleum hydrocarbons. (5) Including solvents. 3b. Identify watershed, hydrologic unit basin and receiving waters The project is located in the Batiquitos Lagoon Hydrologic Subarea (904.51) of the Carlsbad Hydro logic Unit in the San Diego Region As described in Section 1 above, site runoff enters Navarra Drive and combines with flows from surrounding developments before discharging to San Marcos Creek. San Marcos Creek then enters Batiquitos Lagoon. 4 01 G:1131003\SWMPISWMP.docx n ·'.---J ,_J Coastal 10 SWMP 3c. List impaired water bodies According to the California 2006 303(d) list of Water Quality limited Segments published by the RWQCB, there are currently no TMDLs established for Batiquitos Lagoon or Carlsbad. San Marcos Creek however is listed as Impaired with: ODE (Dichlorodiphenyldichloroethylene) from unknown sources Phosphorus, from unknown sources and urban runoff/stormsewers Sediment Toxicity from unknown sources and urban runoff/stormsewers Selenium from unknown sources The estimated size affected is 19 miles and it is unclear what reach of the creek is affected. 3d. Beneficial uses of receiving water The beneficial uses for the hydro logic unit are indicated in Table 2-2 and 2-3 and described in detail below. This information comes from the Water Quality Control Plan for the San Diego Basin. Table 2-2. BENEFICIAL USES OF INLAND SURFACE WATERS BENEFICIAL USE Hydrologic M A I p G F p R R B w C w In land Surface Waters 1'2 Unit Basin R R E E I A 0 I Number u G N 0 w s 0 C C 0 R L L N R D C R H w 1 2 M D D L San Marcos Creek Watershed Batiquitos Lagoon 4.51 See Coast Water -Table 2-3 San Marcos Creek 4.52 + • • • • • unnamed intermittent streams 4.53 + • • • • • San Marcos Creek 4.51 + • • • • • Encinitas Creek 4.51 + • • • • • + Excepted from MUN 1 Waterbodies are listed multiple times if they cross hydrologic area or sub area boundaries. R s A p R w E N • Existing Beneficial Use 2 Beneficial use designations apply to all tributaries to the indicated waterbody, if not listed separately. Table 2-3. BENEFICIAL USES OF COASTAL WATERS BENEFICIAL USE R R C B w R A M s w Hydrologic I N E M E E 0 I I A Q I p A Coastal Waters Unit Basin N A s A Number D V C C M 0 T L R R u G w R 1 2 M L D E A R N M Batiquitos Lagoon • • • • • • • • • Beneficial Uses of Inland Surface Waters MUN -Municipal and Domestic Supply: Includes uses of water for community, military, or individual water supply systems including, but not limited to, drinking water supply. AGR -Aquaculture: Includes the uses of water for aquaculture or mariculture operations including, but not limited to, propagation, cultivation, maintenance, or harvesting of aquatic plants and animals for human consumption or bait purposes. s H E L L REC 1-Contact Recreation: Includes uses of water for recreational activities involving body contact with water, where ingestion of water is reasonably possible. These uses include, but are not limited to, 5 G:\131003\SWMP\SWMP.docx I__J LJ LJ ;_J 11 LJ Coastal 10 SWMP swimming, wading, water-skiing, skin and SCUBA diving, surfing, white water activities, fishing, or use of natural hot springs. REC 2 -Non-Contact Recreation: Includes the uses of water for recreational activities involving proximity to water, but not normally involving body contact with water, where ingestion of water is reasonably possible. These include, but are not limited to, picnicking, sunbathing, hiking, beachcombing, camping, boating, tide pool and marine life study, hunting, sightseeing, or aesthetic enjoyment in conjunction with the above activities. WARM -Warm Freshwater Habitat: Includes uses of water that support warm water ecosystems including, but not limited to, preservation or enhancement of aquatic habitats, vegetation, fish, or wildlife, including invertebrates. WILD -Wildlife Habitat: Includes uses of water that support terrestrial ecosystems including but not limited to, preservation and enhancement of terrestrial habitats, vegetation, wildlife, (e.g., mammals, birds, reptiles, amphibians, invertebrates), or wildlife water food and sources. Beneficial Uses of Coastal Waters REC 1-See Beneficial Uses of Inland Surface Waters above REC 2 -See Beneficial Uses of Inland Surface Waters above BIOL -Preservation of Biological Habitats of Special Significance: Includes uses of water that support designated areas or habitats, such as established refuges, parks, sanctuaries, ecological reserves, or Areas of Special Biological Significance (ASBS), where the preservation or enhancement of natural resources requires special protection. EST -Estuarine Habitat: Includes the uses of water that support estuarine ecosystems including, but not limited to, preservation or enhancement of estuarine habitats, vegetation, fish, or wildlife (e.g., estuarine mammals, waterfowl, shorebirds). WILD -See Beneficial Uses of Inland Surface Waters above RARE -Rare, Threatened, or Endangered Species: Includes uses of water that support habitats necessary, at least in part, for the survival and successful maintenance of plant or animal species established under state or federal law as rare, threatened or endangered. MAR -Marine Habitat: Includes uses of water that support marine ecosystems including, but not limited to, preservation or enhancement or marine habitats, vegetation such as kelp, fish, shellfish, or wildlife (e.g., marine mammals, shorebirds). MIGR -Migration of Aquatic Organisms: Includes uses of water that support habitats necessary for migration, acclimatization between fresh and salt water, or other temporary activities by aquatic organisms, such as anadromous fish. 6 G:1131003\SWMPISWMP.docx , __ J r ' i_J I ,_J -, i c..J _J - I I _J ·1 ~, Coastal 10 SWMP SPWN -Spawning, Reproduction, and/or Early Development: Includes uses of water that support high quality aquatic habitats suitable for reproduction and early development of fish. This use is applicable only for the protection of anadromous fish. 3e. Summarize primary pollutants of concern The primary pollutants of concern for this project are Sediment, Nutrients, Trash & Debris, Oxygen Demanding Substances, Oil and Grease, Bacteria and Viruses, and Pesticides. The extensive use of bioretention treatment control facilities throughout the site should be a highly effective method of treating Coarse Sediment and Trash, and Pollutants that tend to associate with fine particles during treatment. Bio retention facilities also show medium effectiveness for treatment of Pollutants that tend to be dissolved following treatment. 7 G:\131003\SWMP\SWMP.docx i ~ -J ' I '--~ _J 1_J i C. j -·1 Coastal 10 SWMP 4. SOURCE CONTROL MEASURES 4a. Description of site activities and potential sources of pollutants Activities and potential pollutant sources associated with this site include: • Landscape and outdoor pesticide use • Pools, spas, ponds, decorative fountains, and other water features • Miscellaneous Drain or Wash Water consisting of roofing, gutters, and trim • Plazas, sidewalks, and parking lots 4b. Stormwater Pollutant Sources and Source Controls The following table identifies permanent and operational source control measures for the project site as outlined in Appendix 1, Stormwater Pollutant Sources and Source Control checklist in the City's SUSMP: Potential Source of Runoff Pollutants Permanent Source Control BMPs Operational Source Control BMPs Landscape and Final landscape plans will accomplish all of the following: • Maintain landscaping using minimum Outdoor Pesticide Use • Preserve existing native trees, shrubs, and ground or no pesticides. cover to the maximum extent possible. • See applicable operational BMPs in • Design landscaping to minimize irrigation and runoff, Fact Sheet SC-41, "Building and Grounds Maintenance," in the CASQA to promote surface infiltration where appropriate, and Stormwater Quality Handbooks at to minimize the use of fertilizers and pesticides that www.cabmphandbooks.com can contribute to stormwater pollution. • Where landscaped areas are used to retain or detain • Provide 1PM information to new stormwater, specify plants that are tolerant of owners, lessees and operators. saturated soil conditions. • Consider using pest-resistant plants, especially adjacent to hardscape. • To insure successful establishment, select plants appropriate to site soils, slopes, climate, sun, wind, rain, land use, air movement, ecological consistency, and plant interactions. Pools, Spas, Ponds, • Water features to be plumbed to the sanitary sewer, • See applicable operational BMPs in Decorative Fountains, place a note on the plans and state in the narrative Fact Sheet SC-72, "Fountain and Pool and Other Water that this connection will be made according to local Maintenance," in the CASQA Features requirements Stormwater Quality Handbooks at www.cabmghandbooks.com Miscellaneous Drain • Avoid roofing, gutters, and trim made of copper or or Wash Water: other unprotected metals that may leach into runoff. • Roofing, gutters, and trim Plazas, Sidewalks, and • Plazas, sidewalks, and parking lots Parking Lots. shall be swept regularly to prevent the accumulation of litter and debris. Debris from pressure washing shall be collected to prevent entry into the storm drain system. Wash water 8 -1 G:\131003\SWMP\SWMP.docx _J Coastal 10 SWMP Potential Source of Runoff Pollutants Permanent Source Control BMPs Operational Source Control BMPs containing any cleaning agent or degreaser shall be collected and discharged to the sanitary sewer and not discharged to a storm drain. ' .I 9 G:\131003\SWMP\SWMP.docx ,j 1J --, I _ _j i_ j Coastal 10 SWMP s. LOW IMPACT DEVELOPMENT (LID) DESIGN STRATEGIES The LID strategies applicable to this residential development project include dispersing runoff to adjacent pervious surfaces and draining to Integrated Management Practices (I MPs). For planning purposes at the Tentative Map stage, bioretention facilities were considered for I MPs and sized to treat runoff from the roofs and impermeable surfaces. Bioretention facilities are also incorporated as a drainage design element. 10 G:1131003\SWMPISWMP.docx .--1 (_J (_j '· j Coastal 10 SWMP 6. INTEGRATED MANAGEMENT PRACTICES (IMP's) 6a. Selection process for IMP's According to Table 2-2 of the SUSMP, The majority of pollutants of concern for this project can be grouped in the category of Pollutants that tend to associate with fine particles during treatment. Nutrients also fall under the category of Pollutants that tend to be dissolved following treatment and Trash & Debris falls under the category of Coarse Sediment and Trash. According to Table 2-3, Infiltration Facilities provide the highest effectiveness for removal of pollutants in all three categories but our site is constrained by impermeable soils. Bioretention Facilities were chosen for the site for their high removal rates of Coarse Sediment and Trash and Pollutants that tend to associate with fine particles during treatment and their medium removal rates for Pollutants that tend to be dissolved following treatment. Bioretention facilities detain stormwater and filter it slowly through engineered soil or sand and are versatile in that they can be any shape and can be landscaped. The bioretention areas onsite were sized to treat stormwater as well as limit flow using control through hydromodification. 6b. Sizing factors for IMP's 1) Lower flow threshold determination Field investigations were not conducted pursuant to SCCWRP screening tools. Therefore, according to Figure 2-2 of the City's SUSMP, the site must mitigate peak flows and durations based on a pre-project condition lower flow threshold of 0.1Q2. 2) HMP Decision Matrix IMP facilities were sized using the Decision Matrices in Figures 2-2 in Section 8, Hydromodification, below. 6c. Geotechnical recommendation on soil infiltration rates IMP facilities were chosen that do not drain through native soil, as soil infiltration rates were anticipated to be low. 6d. Infiltration calculations Self-retaining areas were not utilized on this site, as soil infiltration rates were anticipated to be low. 11 G:\131003\SWMP\SWMP.docx i.J r, ,---, ~1 Coastal 10 SWMP 7. TREATMENT CONTROL BMP's Bioretention areas were sized for both treatment and hydromodification. Refer to Section 6, Integrated Management Practices, and Section 8, Hydromodification, for IMP and hydromodification discussion. 12 ,-1 G:1131003\SWMP\SWMP.docx :___l ,, :.~J u 8. Coastal 10 SWMP HYDROMODIFICATION Sa. Lower Flow Threshold Determination Field investigations were not conducted pursuant to SCCWRP screening tools. Therefore, according to Figure 2-2 below, the site must mitigate peak flows and durations based on a pre- project condition lower flow threshold of 0.1Q2. Consult with Geotechnlcal Engineer Redesign LID orBMP 4. Size LID and MP Facilities for Flow Range o 0.1 Q2 to 010? YES End of eclsion Matrix YES NO FIGURE 2-2. Mitigation Criteria and Implementation 13 G:\131003\SWMP\SWMP.docx ! _J <"l ,--, u LJ Coastal 10 SWMP Sb. Continuous Simulation Model A continuous simulation model was not considered for this project Sc. Print-outs of Pond Sizing Criteria and Results Using BMP Sizing Calculator Attachment 2 includes printout of sizing criteria and results for each bioretention facility proposed for this site. Sd. Tabulation of Flow-control Facility Sizes and Design Criteria See attachment 2 14 G:\131003\SWMP\SWMP.docx :I ' I c__J Coastal 10 SWMP 9. DOCUMENTATION OF STORMWATER DESIGN 9a. Hydrology maps Attachment 3, Single sheet Post-Construction BMP Exhibit, depicts tributary areas to each IMP, or Bioretention facility and displays DMA's by surface type. 9b. BMP Sizing Calculator Output from the BMP Sizing Calculator is included in Attachment 2. 9c. Tabulation Attachment 2 tabulates areas draining to each IMP and includes sizing calculations printout from the BMP Sizing Calculator, and Attachment 3 illustrates DMAs and I MPs for the project site. 15 G:1131003\SWMPISWMP.docx ,, i~ :r I r ~ Coastal 10 SWMP 10. BMP FACILITY MAINTENANCE REQUIREMENTS 10a. Ownership and responsibility of maintenance of BMP's The Owner and Developer will be responsible for the maintenance of treatment facilities. Ongoing maintenance will be assured by executing a Permanent Stormwater Quality BMP Maintenance Agreement that "runs with the land." 10b. Summary of maintenance requirements Bio retention facilities remove pollutants primarily by filtering runoff slowly through aerobic, biologically active soil. Routine maintenance is needed to ensure that flow is unobstructed, that erosion is prevented, and that soils are held together by plant roots and are biologically active. Typical maintenance consists of the following: G:\131003\SWMP\SWMP.docx • Inspect inlets for channels, exposure of soils, or other evidence of erosion. Clear any obstructions and remove any accumulation of sediment. Examine rock or other material used as a splash pad and replenish if necessary. • Inspect outlets for erosion or plugging. • Inspect side slopes for evidence of instability or erosion and correct as necessary. • Observe the surface of bioretention facility soil for uniform percolation throughout. If portions of the bioretention facility do not drain within 24 hours after the end of a storm, the soil should be tilled and replanted. Remove any debris or accumulations of sediment. • Confirm that check dams and flow spreaders are in place and level and that rivulets and channelization are effectively prevented. • Examine the vegetation to ensure that it is healthy and dense enough to provide filtering and to protect soils from erosion. Replenish mulch as necessary, remove fallen leaves and debris, prune large shrubs or trees, and mow turf areas. When mowing, remove no more than 1/3 height of grasses. Confirm that irrigation is adequate and not excessive and that sprays do not directly enter overflow grates. Replace dead plants and remove noxious and invasive vegetation. • Abate any potential vectors by filling holes in the ground in and around the bioretention facility and by insuring that there are no areas where water stands longer than 48 hours following a storm. If mosquito larvae are present and persistent, contact the San Diego County Vector Control Program for information and advice. Mosquito larvicides should be applied only when absolutely necessary and then only by a licensed individual or contractor. 16 ;l -, LJ t _ _J u i_J i I LJ Coastal 10 SWMP 11. SWMP CERTIFICATION STATEMENTS 11a. Preparer's statement The selection, sizing, and preliminary design of stormwater treatment and other control measures in this plan meet the requirements of Regional Quality Control Board Order R9-2007-0001 and subsequent amendments. NAME DATE 11b. Owner's statement The selection, sizing, and preliminary design of stormwater treatment and other control measures in this plan meet the requirements of Regional Quality Control Board Order R9-2007-0001 and subsequent amendments. NAME DATE 17 G:\131003\SWMP\SWMP.docx ----. ~ «-~~ ~ CITY OF CARLSBAD STORM WATER STANDARDS QUESTIONNAIRE E-34 Development Services Land Development Engineering 1635 Faraday Avenue 760-602-2750 www.carlsbadca.gov To address post-development pollutants that may be generated from development projects, the City requires that new development and significant redevelopment priority projects incorporate Permanent Storm Water Best Management Practices (BMP's) into the project · , design per the City's Standard Urban Stormwater Management Plan (SUSMP). To view the SUSMP, refer to the Engineering Standards (Volume 4, Chapter 2) at www.carlsbadca.gov/standards . • _ __J Initially this questionnaire must be completed by the applicant in advance of submitting for a development application (subdivision, discretionary permits and/or construction permits). The results of the questionnaire determine the level of storm water standards that must be applied to a proposed development or redevelopment project. Depending on the outcome, your project will either be subject to LJ 'Standard Stormwater Requirements' or be subject to additional criteria called 'Priority Development Project Requirements'. Many aspects of project site design are dependent upon the storm water standards applied to a project. Your responses to the questionnaire represent an initial assessment of the proposed project conditions and impacts. City staff has responsibility for making the final assessment after submission of the development application. If staff determines that the questionnaire was incorrectly filled out and is subject to more stringent storm water standards than initially assessed by you, this will result in the return of the development application as incomplete. In this case, please make the changes to the questionnaire and resubmit to the City. ecJ If you are unsure about the meaning of a question or need help in determining how to respond to one or more of the questions, please seek assistance from Land Development Engineering staff. : A separate completed and signed questionnaire must be submitted for each new development application submission. Only one completed and signed questionnaire is required when multiple development applications for the same project are submitted concurrently. In addition to this questionnaire, you must also complete, sign and submit a Project Threat Assessment Form with construction permits for the project. Please start by completing Step 1 and follow the instructions. When completed, sign the form at the end and submit this with your application to the city. r , \ .• >'. '''f, ; '.}~;!'~''{;.,.: STEP 1F ,TO' B~COMPLETEO FOR ALL , __ J To determine if your project is a priority development project, please answer the following questions: -l L.J '_) ,-, 1. Is your project LIMITED TO constructing new or retrofitting paved sidewalks, bicycle lanes or trails that meet the following criteria: (1) Designed and constructed to direct storm water runoff to adjacent vegetated areas, or other non-erodible permeable areas; OR (2) designed and constructed to be hydraulically disconnected from paved streets or roads; OR (3) designed and constructed with permeable pavements or surfaces in accordance with USEPA Green Streets uidance? 2. Is your project LIMITED TO retrofitting or redeveloping existing paved alleys, streets, or roads that are designed and constructed in accordance with the USEPA Green Streets guidance? YES NO If you answered "yes" to one or more of the above questions, then your project is NOT a priority development project and therefore is NOT subject to the storm water criteria required for priority development projects. Go to step 4, mark the last box stating "my project does not meet POP requirements" and complete applicant information. If ou answered "no" to both questions, then o to Step 2. E-34 Page 1 of 3 Effective 6/27/13 ,.__.J l..J .·' Lj ,J -1 ;'I «~ ~ CITY OF CARLSBAD STORM WATER STANDARDS QUESTIONNAIRE E-34 Development Services Land Development Engineering 1635 Faraday Avenue 760-602-2750 www.carlsbadca.gov ,:'.:i?(r:}ttJ~cyt.,\«';-_. . : , :':_· ,·i\:/· .-". ·st.~.Ff~:f·~{;,'.{;-;: 1~~}.it~JiJ~::t~\ti~/r'~~:,\;~1~-<r· :t ~ ~ ,~-.. /(,: .TO BECOMPLETEDFOR1ALL NEW OR REDEVELOPMENT PROJEOTS;i!,· To determine if your project is a priority development project, please answer the following questions: 1. 2. 3. Is your project a new development that creates 10,000 square feet or more of impervious surfaces collectively over the entire project site? This includes commercial, industrial, residential, mixed-use, and public develo ment ro ·eels on ublic or rivate land. Is your project creating or replacing 5,000 square feet or more of impervious surface collectively over the entire project site on an existing site of 10,000 square feet or more of impervious surface? This includes commercial, industrial, residential, mixed-use, and ublic de veto ment ro ·ects on ublic or rivate land. Is your project a new or redevelopment project that creates 5,000 square feet or more of impervious surface collectively over the entire project site and supports a restaurant? A restaurant is a facility that sells prepared foods and drinks for consumption, including stationary lunch counters and refreshment stands selling prepared foods and drinks for immediate consum tion. 4. Is your project a new or redevelopment project that creates 5,000 square feet or more of impervious surface collectively over the entire project site and supports a hillside development project? A hillside development project includes development on any natural slope that is twenty-five percent or greater. 5. 6. 7. Is your project a new or redevelopment project that creates 5,000 square feet or more of impervious surface collectively over the entire project site and supports a parking lot. A parking lot is a land area or facility for the tem ora arkin or stora e of motor vehicles used ersonall for business or for commerce. Is your project a new or redevelopment project that creates 5,000 square feet or more of impervious surface collectively over the entire project site and supports a street, road, highway freeway or driveway? A street, road, highway, freeway or driveway is any paved impervious surface used for the transportation of automobiles, trucks, motorc cles, and other vehicles. Is your project a new or redevelopment project that creates or replaces 2,500 square feet or more of impervious surface collectively over the entire site, and discharges directly to an Environmentally Sensitive Area (ESA)? "Discharging Directly to" includes flow that is conveyed overland a distance of 200 feet or less from the project to the ESA, or conveyed in a pipe or open channel any distance as an isolated flow from the ro ·ect to the ESA i.e. not commin /es with flows from ad·acent lands . * 8. Is your project a new development that supports an automotive repair shop? An automotive repair shop is a facility that is categorized in any one of the following Standard Industrial Classification (SIC) codes: 5013, 5014, 5541, 7532-7534, or 7536-7539. 9. Is your project a new development that supports a retail gasoline outlet (RGO)? This category includes RGO's that meet the following criteria: (a) 5,000 square feet or more or (b) a project Average Daily Traffic (ADT) of 100 or more vehicles er da . 1 O. ls your project a new or redevelopment project that results in the disturbance of one or more acres of land and are expected to generate pollutants post construction? 11. ls your project located within 200 feet of the Pacific Ocean and (1) creates 2,500 square feet or more of impervious surface or (2) increases impervious surface on the property by more than 10%? YES NO X X If you answered "yes" to one or more of the above questions, you ARE a priority development project and are therefore subject to implementing structural Best Management Practices (BMP's) in addition to implementing Standard Storm Water Requirements such as source control and low impact development BMP's. A Storm Water Management Plan (SWMP) must be submitted with your application(s) for development. Go to step 3 for redevelopment projects. For new projects, go to step 4 at the end of this questionnaire, check the "my project meets PDP requirements" box and complete applicant information. If you answered "no" to all of the above questions, you ARE NOT a priority development project and are therefore subject to implementing only Standard Storm Water Requirements such as source control and low impact development BMP's required for all development projects. A Storm Water Management Plan (SWMP) is not required with your application(s) for development. Go to step 4 at the end of this questionnaire, check the "my project does not meet PDP requirements" box and complete applicant information. E-34 Page 2 of 3 Effective 6/27/13 ·-J l_~_J t..._J ,----, ,.J ,-, 'c.J · .. ..J i.J ! I ~ «-~'» ~ CITY OF CARLSBAD STORM WATER STANDARDS QUESTIONNAIRE E-34 Development Services Land Development Engineering 1635 Faraday Avenue 760-602-2750 www.carlsbadca.gov Does the redevelopment project result in the creation or replacement of impervious surface in an amount of less than 50% of the surface area of the reviousl existin develo ment? If you answered "yes," the structural BMP's required for Priority Development Projects apply only to the creation or replacement of impervious surface and not the entire development. Go to step 4, check the "my project meets PDP requirements" box and complete applicant information. If you answered "no," the structural BMP's required for Priority Development Projects apply to the entire development. Go to step 4, check the "m ro·ect meets PDP re uirements" box and com lete a licant information. ¥l D My project meets PRIORITY DEVELOPMENT PROJECT (PDP) requirements and must comply with additional stormwater criteria per the SUSMP and I understand I must prepare a Storm Water Management Plan for submittal at time of application. I understand flow control (hydromodification) requirements may apply to my project. Refer to SUSMP for details. My project does not meet PDP requirements and must only comply with STANDARD STORMWATER REQUIREMENTS per the SUSMP. As part of these requirements, I will incorporate low impact development strategies throughout my project. • Applicant Information and Signature Box Accessor's Parcel Number~: {q 't(~-, o- Applicant Title: Hta:r~-r El\l.t1AfftL.. Date: (( {Z!J/Ulf. ?:> Appli~· This Box for City Use Only City Concurrence: I YES I NO I I By: Date: Project ID: * Environmentally Sensitive Areas include but are not limited to all Clean Water Act Section 303(d) impaired water bodies; areas designated as Areas of Special Biological Significance by the State Water Resources Control Board (Water Quality Control Plan for the San Diego Basin (1994) and amendments); water bodies designated with the RARE beneficial use by the State Water Resources Control Board (Water Quality Control Plan for the San Diego Basin ( 1994) and amendments); areas designated as preserves or their quivalent under the Multi Species Conservation Program within the Cities and County of San Diego; and any other equivalent environmentally sensitive areas which have been identified by the Copermittees. E-34 Page 3 of 3 Effective 6/27/13 :------;i ' ,~_j , _ _j ---, ' L__) ---1 -, :___J i _ _j ATTACHMENT #2 Calculations for Bioretention Facilities I ~ Hydromodification and Water Quality Calculations In order to meet Hydromodification requirements outlined in the Final Hydromodification Plan prepared for the County of San Diego on January 13, 2011 by Brown and Caldwell, an IMP r, sizing factor was determined. ~, Table 7-4 Sizing Factor for Flow-Through Planter . _ _\ ~1 u --, :--i l___j Lower Flow Threshold: 0.1Q2 Rain Gauge= Oceanside Soil Type: D Existing Slope: Flat Results: IMP sizing factor of0.16 Lower Flow Threshold: 0.1 Q2 Rain Gauge= Oceanside Soil Type: D Existing Slope: steep Results: IMP sizing factor of 0.105 There are 2 flow-through planter areas on the site along the east and west perimeter. See Attachment 3 for a typical section. Attached are excerpts from the BMP Calculator The treatment volumes required from the BMP Calculator are summarized in the table below. The depth of the gravel layer was adjusted to accommodate the smaller treatment areas. Flow-Through Planter Treatment Facilities at Coastal 10 Volume Reguired Per BMP IMP Facilitv Provided Calculator* Vl (cf} V2 (cf} Vtotal SF Vl (cf} Basin 1 609 439 1048 506 Basin 2 811 584 1395 625 *See attached results from BMP Calculator, LID Summary ** Depth of Gravel= V2/SF/0.40 assumes 40% porosity 506 520 V2 (cf} 542 875 Del!th of Gravel** 2.2' 3.5' . __ j In addition, the orifice size delineated by the BMP Calculator is based on a depth of 4.0 feet (1.5' ---. gravel+ l .5'soil/compost). Since we are adjusting the depth of the gravel, the size of the orifice based on the lower flow threshold is summarized in the table below. ,-·----i The Orifice Equation per San Diego Drainage Design Manual= Q=C* A(2gd)"0.5 C= 0.67 g= 32.2 d=head of water over orifice A= area of orifice Summarv of Orifice Sizin2: Calculations for Coastal 10 Lower Flow Depth of Head C*(2*g*d)"0.5 Diameter of Threshold* d** orifice (in) Basin 1 4.53 feet 11.45 0.2" 0.002 cfs r/ Basin 2 5.83 feet 12.98 0.2" 0.003 cfs "-i *See attached BMP Calculator Output _J **Depth of head equals depth of gravel layer+ 18" for soil/compost layer+ 1 O" ponded water __,_{epl~. J.esuf:.. i-J ' [_] J _J I . j [ ] r;ag! 1 &r 1 J i L.--L ,~ ___ J _J Project Summary Project Name Coastal 1 O Condos Project Applicant Coastal Living LLC Jurisdiction City of Carlsbad Parcel (APN) 216-170-19 Hydrologic Unit Carlsbad Compliance Basin Summary Basin Name: Basin 1-Units 1-5 Receiving Water: NW Cor of Site Rainfall Basin Oceanside Mean Annual Precipitation (inches) 13.3 Project Basin Area (acres): 0.13 Watershed Area (acres): 0.00 SCCWRP Lateral Channel Susceptiblity (H, M, L): SCCWRP Vertifical Channel Susceptiblity (H, M, L): Overall Channel Susceptibility (H, M, L): HIGH Lower Flow Threshold(% of 2-Year Flow): 0.1 Drainage Management Area Summary ID Type BMPID Description Area (ac) Pre-Project Cover Post Surface Type Drainage Soil Slope 32048 Drains to LID BMP 1 1-IS 0.04 Pervious (Pre) Roofs Type D (high runoff -clay Steep (greater 10%) soi... 32049 Drains to LID BMP 1 1-IF 0.08 Pervious (Pre) Roofs Type D (high runoff -clay Flat -slope (less ... soi. .. 32050 Drains to LID BMP1 1-LS 0.01 Pervious (Pre) Landscaping Type D (high runoff -clay Steep (greater 10%) soi. .. LID Facility Summary BMPID Type Description Plan Area (sqft) Volume 1(cft) Volume 2(cft) Orifice Flow (cfs) Orifice Size (inch) BMP 1 Flow-Through Planter Flow-Through Planter on West Side 731 609 439 0.002 0.2 http://uknow.brwncald.com/wastewater/Toolkits/Watershed/SiteToolkit/ReportResult.aspx?pid= 13 8617&bid=SDC-0001 ... 11/21/2013 JKep=i. JestL. J [ J L j Project Summary Project Name Project Applicant Jurisdiction Parcel (APN) Hydrologic Unit Compliance Basin Summary Basin Name: Receiving Water: Rainfall Basin Mean Annual Precipitation (inches) Project Basin Area (acres): Watershed Area (acres): SCCWRP Lateral Channel Susceptiblity (H, M, L): SCCWRP Vertifical Channel Susceptiblity (H, M, L): Overall Channel Susceptibility (H, M, L): Lower Flow Threshold (% of 2-Year Flow): ,-I L. _J I L_ J L -· J Coastal 10 Condos Coastal Living LLC City of Carlsbad 216-170-19 Carlsbad Basin 2-Units 6-10 Southeast Comer of Site Oceanside 13.3 0.17 0.00 HIGH 0,1 Drainage Management Area Summary ID Type BMPID Description 32055 Drains to LID BMP2 2-IS 32056 Drains to LID BMP2 2-IF 32057 Drains to LID BMP2 2-LF LID Facility Summary BMPID Type Description BMP 2 Flow-Through Planter Flow-Through Planter for Units 6-10 j Area (ac) 0.04 0.11 0.02 L I .a Pre-Project Cover Pervious (Pre) Pervious (Pre) Pervious (Pre) Plan Area (sqft) 973 J .J L_ -I ,.- Lr ag-e 1 br 1 Post Surface Type Drainage Soil Slope Roofs Type D (high runoff -clay Steep (greater 10%) soi. .. Roofs Type D (high runoff -clay Flat -slope (less , .. soi. .. Landscaping Type D (high runoff -clay Flat -slope (less ... soi... Volume 1(cft) Volume 2(cft) Orifice Flow (cfs) Orifice Size (inch) 811 584 0.003 0.3 http://uknow. brwncald.corn/wastewater/Toolkits/Watershed/SiteToolkit/ReportResult.aspx?pid= 13 8617&bid=SDC-0001 ... 11/20/2013 L J I I r I o· . -------,, SL :d~?( 10' .. 5 - : 1" =· 10' I 20' "' ;·) i : --, . " .. f ( ' .. j \ 'ii' ' \ 'SJ: ----' ' /_,/ . ';,( .·. ; \ ' ' , \ ! _t~""~:.1· ~~ EE> SL -; -s+-~ -i+---+--J .. -3>- EI)-I .. -.'. , .. / 1/350 / \. i ,,,-Ci\ TREATMENT CONTROL I HYDROMODIFICATION BMPID# BMPTYPE SYMBOL CASQA NO. QUANTITY 00 FLOW THROUGH [:~:::] TC-32 1230 SF PLANTER -»-----~---·- LOW IMPACT DESIGN (L.1.D.) BMPTYPE SYMBOL CASQA NO. QUANTITY ROOF DRAIN TO BMP SD-11 ' SOURCE CONTROL . i BMPID# BMPTYPE SYMBOL CASQA NO. QUANTITY ' 0 EFFICIENT SD-11 I IRRIGATION ' PERVIOUS © I I SD-20 5180 SF PAVEMENT ©2012 O'Day Consultants, Inc. .. / .... '. ..... , .... °"", '. • / BMP TABLE DRAWING NO. SHEET NO. 480-5A 3-5 DRAWING NO. SHEET NO. BLDG PLANS - DRAWING NO. SHEET NO. 480-SL - 480-SA 3-5 ---·-·-·--·--------··--- / / ....... ,,. .. / /~ ' . / ;" ,' ,' .· ·- . .. Ii ' . ,..-~---\,_ -----------------------------·. Ji ====--· 1 .st ,+···/···=·····====~=·=····=····=··\:::;::;::==;=··----···· -· --····· =···=·+=\ ==;=::J \' ---~ ., .. ,/, ,/ /·-( . ,., .... UNIT 10 s s / UNIT I \ INSPECTION FREQUENCY 81-MONTHL Y & AFTER MAJOR STORM EVENTS ACTiON ' . ~ ------SBD'--=--• • • • • • / .., ·.·'./ .,-~ \i \.' ' UNIT 9 '· s UNIT 2 MAINTENANCE CONSTRUCTION FREQUENCY SIGN OFF SEMI-ANNUALLY OR IF REQUIRE AFTER INSPECTION ROOF DOWNSOUTS & OTHER IMPERVIOUS AREA TO BE DIRECTED TO BIORETENTION AREAS INSPECTION MAINTENANCE CONSTRUCTION FREQUENCY FREQUENCY SIGN OFF SEMI-ANNUALLY & AFTER MONTHLY MAJOR STORM EVENTS ANNUALLY 2-3 TIMES PER YEAR • • • • • • ' i' \ .. UNITiS ' \ s "\ ____ : -·-·- s : UNIT 4 / . . / / SCALE: I• = 10' C9./~T s 2710 Loker Avenue West Civil Engineering Suite 100 Planning Carlsbad, California 92010 Processing 760-9.31-7700 Surveying Fax: 760-931-8680 /' .... . POOL . ' ' \ -· __ .., 1 • D / ,/ . •' s / / \ UNIT 5 ----~----~ .. -····----·-·---._, ___ J ~-· ... :A\ . • ! . DESIGNED BY: A.M. DATE: MARCH 2013 DRAWN BY: J.S. SCALE: 111 = 101 PROJECT MGR.· K.W.H. JOB NO.: 131003 ENGINEER OF WORK DATE: KEITH W. HANSEN RCE: 60223 \ .I / .... ) i; f • I I ii/ I NIT 7 I I ®! / \:. __ ,,,,, -----'.'/ / DA TE OF PREPARA T/ON: NOltfl.fBER 20, 2013 /1\ DATE INITIAL ENGINEER OF WORK REVISION DESCRIPTION / / , • / I I I DATE INITIAL OlttER APPROVAL DATE \ SWMP NO. 13-20 ' MAINTENANCE AGREEMENT DOCUMENT: RE'CORDA /ION NO. __ _ PARTY RESPONSIBLE FOR MAINTENANCE: NAME': COASTAL 10, UC AODRE'SS· 7668 EL CAMNO REAL, Slf 104-108 CARLSBAD, CA 9~009 PHONE' N0.:(619) 995-6044 PLAN PREPARED BY: COMPANY.· O'DAY CONSULTANTS, INC. ADDRE'SS· 2710 LOKER A \!£NU£ 1,E'ST SU/If 100 CARLSBAD, CA 92010 PHONE' NO.: 760-931-7700 BMP NOTES: YE'S_X_ NO __ _ 1. THESE BMPS ARE MANDA TORY TO BE INSTALLED PER MANUFACTURER'S RECOMMENDATIONS OR THESE PLANS .. 2. NO CHANGES TO THE PROPOSED BMPS ON THIS SHEU f\lTHOUT PRIOR APPROVAL FROM LAND DEVELOPMENT ENGINEER/NG. 3.. NO SUBSTITUTIONS TO THE MATERIAL OR TYPES OR PLANTING TYPES f\lTHOUT PRIOR APPROVAL FROM LAND DEVELOPMENT ENGINEERING. 4. NO OCCUPANCY f\lLL BE GRANTED UNTIL THE CITY INSPECTION STAFF HAS INSPECTED THIS PROJECT FOR APPROPRIATE BMP CONSTRUCTION AND INSTALLATION. VERIFIED BY: INSPECTOR DATE I SH1ET I CITY OF CARLSBAD I SH1ETS I ENGINEERING DEPARTMENT SS BJIP SIT£ PLAN FON: COASTAL 10 APPROVED BY: GLEN K. VAN PESKI CITY ENGINEER PE 41204 EXP. 03/31/15 DATE OWN BY: PROJECT NO. DRAWING NO. INITIAL CHKD BY: CITY APPROVAL RVWD BY: I CT 13-02 I 480-5SW G:\131003\SWMP\BMP-Exhibit.dwg Feb 18, 2014 1:34pm Xrefs: 1303ASITE; 1303TOPO; 1 JOJAMAP; 1303VIC; 1303agrd; 1303autl; 13037utl