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CUP 12-05; Alps Innovation Staybridge Suites & Holiday Inn; Conditional Use Permit (CUP) (5)
storm Water Management Plan (SWMP) For ALPS Innovation Hotels (CUP 12-05, CUP 12-06; PUD 12-04; MS 12-02) Palomar Airport Road & Innovation Way Carlsbad, CA 92009 APN: 213-262-11-00 April 15% 2013 Prepared for: Prime Group Construction Inc. PO Box 800521 Santa Clarita, CA 91380 RECEIVED APR 1 8 2013 GITY OF CARLSBAD PLANNiNG DIVISION Prepared by: Andrew}. Kann, P.E. Omega Engineering Consultants, Inc. 9517 Grossmont Summit Dr. La Mesa Ca 91941 Ph: 619.741.9456 The selection, sizing, and preliminary design of storm-water treatment and other control measures in this plan have been prepared under the direction of the following Registered Civil Engineer and meet the requirements of Regional Water Quality Control Board Order R9-2007-0001 and subsequent amendments. Andrew J. Kann, R ALPS Innovation Hotels City of Carlsbad - Storm Water Management Plan The Storm Water Management Plan (SWMP) must be completed in its entirety and accompany applications to the City of Carlsbad for a permit or approval associated with certain types of development projects. See Completed Storm Water Standards Questionnaire in section II for project storm water classification. Project Name: ALPS Innovation Hotels Project Location: Palomar Airport rd & Innovation Way, 92009 Permit Number (Land Development Projects): Work Authorization Number (CIP only): AppHcant: Prime Group Construction Inc. Applicant's Address: PO Box 800521 Santa Clarita, CA 91380 Plan Prepared By: Andrew J. Kann, P.E. Omega Engineering Consultants, Inc. Preparer's Address: 9517 Grossmont Summit Dr. La Mesa, Ca 91941 Date: The purpose of the SWMP is to describe how the project wiU minimize the short and long-term impacts on receiving water quality. Projects that meet the criteria for a priority development project are required to prepare a SWMP. Since the SWMP is a living document, revisions may be necessary during various stages Project Stages Does the SWMP Need Revisions? If YES, Provide Revision Date Project Stages YES NO If YES, Provide Revision Date April 15*^ 2013 Bressi Ranch Hotels SWMP City of Carlsbad Storm Water Mitigation Plan TABLE OF CONTENTS I. Project Setting 1 a. Project Name, Location, Description, Vicinity Maps b. Existing Site Features and Conditions c. Proposed Land Use d. Storm Water Control and Treatment opportunities and Constraints e. Nearby Water Bodies and Existing Storm Drain systems II. Applicable Storm Water Standards 4 a. Completed Storm Water Questionnaire b. HMP Applicability Determination IIL Project Pollutants of Concem 7 a. Pollutants Associated with type of Project b. HMP Applicability Determination c. Identify Watershed and Hydrologic Unit and Receiving Waters d. Beneficial Uses of Receiving Water e. Summarize Primary Pollutants of Concern IV. Source Control Measures 10 a. Description of Site Activities and Potential Sources of Pollutants b. Complete Table Showing Sources and Controls V. Low Impact Development (LID) Design strategies 13 a. Optimization of Site Layout b. Layout and use of Permeable Pavement and Permeable Surfaces c. Dispersal of Runoff from Impervious to Pervious Surfaces VL Integrated Management Practices (IMPs) 15 a. Selection Process for IMP's targeting Project Pollutants of Concern b. Sizing Factors for IMP's c. Geotechnical Recommendation on Soil Infiltration Rates d. Drawdown Calculations & Infiltration Calculations April 15^ 2013 Bressi Ranch Hotels SWMP City of Carlsbad Storm Water Mitigation Plan VIL Treatment Control BMPs (TCBMP's) 16 a. Selection Process for TCBMP's targeting Project Pollutants of Concem b. Sizing Factors for TCBMP's c. Geotechnical Recommendation on Soil Infiltration Rates VIII. Hydromodification 18 a. Low Flow Threshold Determination b. Continuous Simulation Model c. Print-out of sizing Criteria and Results d. Tabulation of Flow-Control Facihties Sizes and Design Criteria IX. Documentation of Stormwater Water Design (IMP or TCBMP) .... 19 a. Hydrology Maps Tributary b. Print-out of BMP Sizing Calculator c. Tabulation of areas and Sizing X. BMP Facility Maintenance Requirements 20 a. Describe ownership & responsibiUty of maintenance of BMP's in perpetuity b. Summary of Maintenance requirements for each stormwater facihty XL SWMP Certification Statements 21 a. Preparer's Statement b. Owner's Statement April 15*^ 2013 ALPS Innovation Hotels City of Carlsbad - Storm Water Management Plan Figures 1 Vicinity Map 2 2 Aerial Photo of Drainage course 2 3 Existing Site Plan 3 4 Project BMP Location Plan See Map Pocket Appendices A. Bioretention Sizing Calculations, Details & Oudet Control B. Storm Water Standards Questionnaire C. Educational Materials D. Hydromodification Report April 15*^ 2013 ALPS Innovation Hotels City of Carlsbad - Storm Water Management Plan SECTION I - PROJECT SETTING A. Please provide a brief description ofthe project. The ALPS Innovation Hotel development proposes the development of two hotels with associated parking and common area improvements. Both hotels shall be 3 stories and will be built with a shared pool between the hotels. The project site is located at the southeast comer of the intersection of Palomar Airport Road and Innovation Way approximately 3.75 miles east of Interstate-5. The site coordinates are: Lat: 33.130° Long: -117.258° as iUustrated in Figures 1 and 2. B. Existing Site Features and Conditions The pre-project site is occupied by a mass graded pad sloping at y 2%-3% to the west. A cut slope mns along the north east boundary of the site. The existing site sheet-flows from the east side of the site to the southwest comer where the water is intercepted by a storm drain inlet and existing conduits. The mnoff is then conveyed via the existing pubUc storm drain system to San Marcos Creek. C. Proposed Land use and Anticipated Activities that could affect Storm Water The zoning of the site is P-C (Planned Community). The site is proposed to be used as commercial site with two separate hotels with shared common facilities. The potential activities that could affect storm water include presence of vehicles within parking areas and the trash and debris from presence of people in and around common areas and parking areas. D. Opportunities and Constraints for Storm Water Control and Treatment The site slopes from east to west, thus treatment along the west side of the site would be best so that all impervious surface may be conveyed to a natural surface before conveyance to the Carlsbad MS4. There is a requirement for landscaping buffer along Palomar Airport Rd and Innovation Way that we can use for storm water treatment as this is the low side of the site, the west side of the site. A constraint for control and treatment is the clayey soil that is not suitable for deep ground infiltration. The presence of a large area of landscaping along the Northwest side allows us to use a treatment facility that is capable of mitigating both water quality and quantity. Other treatment opportunities were implemented along long rows of parking providing a buffer from parking and also treatment of storm water. The site is not constrained by offsite run-on as the site wiU receive Uttie to no run-on from offsite areas as aU storm water presentiy being conveyed to our site from the East wUl be intercepted and conveyed via a separate private storm drain system. Nearby Water bodies and existing Storm Drain Systems Presendy the site has existing storm water facilities near the southwest corner of the site witii which the site can connect too. The area south of the project site has been developed and the existing storm drain improvements have been constmcted as part of this previous development. These facilities collect the site storm water at present conveying them into the Carlsbad MS4 within Innovation Way. The mnoff is then conveyed via the existing public storm drain system to the San Marcos Creek and the Batiquitos Lagoon. April 15'", 2013 Page j 1 ALPS Innovation Hotels City of Carlsbad - Storm Water Management Plan Figure 1 - Vicinity Map PALOMAR Project site. LA COSTA BLVD VICINITY MAP NOT TO SCALE INNOVATION WAY Figure 2 - Aerial Photo April 15^ 2013 Paee I 2 ALPS Innovation Hotels City of Carlsbad - Storm Water Management Plan Figure 3 - Existing Site Plan April 15^ 2013 Page I 3 ALPS Innovation Hotels City of Carlsbad - Storm Water Management Plan SECTION II - APPLICABLE STORMWATER STANDARDS A. Completed Storm Water Standards Questionnaire (SWSQ) (See Appendk B for SWSQ) April 15*^ 2013 Page j 4 ALPS Innovation Hotels City of Carlsbad - Storm Water Management Plan B. HMP Applicability Determination Re-<«sign &>«rgy Dissipatior> System n>TjrorroainC3iion uonrois requrrea Go:o HflUTB 2.2 OT Dewsion WaKnx April 15^ 2013 Page I 5 ALPS Innovation Hotels City of Carlsbad - Storm Water Management Plan HYDROMODIFICATION DETERMINATION No Questions Ye s No Information 1. Will the project reduce the pre-project impervious area and are the unmitigated post-project outflows (outflows without detention routing) to each outlet location less as compared to the pre-project condition? X If NO, continue to 2. IfYES,goto7. 2. Would the project site discharge mnoff directiy to an exempt receiving water, such as the Pacific Ocean, San Diego Bay, an exempt reservoir, or a tidaUy-influenced area? X If NO, continue to 3. IfYES,goto7. 3. Would the project site discharge to a stabilized conveyance system, which has the capacity for the ultimate Qio, and extends to the Pacific Ocean, San Diego Bay, a tidally influenced area, an exempt river reach or reservoir? X If NO, continue to 4. IfYES,goto7. 4. Does the contributing watershed area to which the project discharges have an impervious area percentage greater than 70 percent? X If NO, continue to 5. IfYES,goto7. 5. Is this an urban infiU project which discharges to an existing hardened or Rehabilitated conveyance system that extends beyond the "domain of analysis," where the potential for cumulative impacts in fhe watershed are low, and the ultimate receiving channel has a "Low" susceptibility to erosion as defined in the SCCWRP channel assessment tool? X If NO, continue to 6. IfYES,goto7. 6. Project is required to manage hydro-modification impacts. X Reference the approved "Hydromodification Management Plan" per the Appendix of Carlsbad SUSMP. April 15'", 2013 Page I 6 ALPS Innovation Hotels City of Carlsbad - Storm Water Management Plan SECTION III - IDENTIFY POLLUTANTS OF CONCERN This section of the Storm Water Management Plan identifies primary and secondary pollutants of concem. Pollutants of concem are those that are anticipated to be generated by the proposed project. Pollutants of concem are differentiated between primary and secondary priorities depending on the condition of downstream receiving waters. A. Identify Pollutants Associated with Type of Project and Use General Pollutant Categories Priority Project Categories Sediments Nutrients Heavy Metals Organic Compounds Trash & Debris Oxygen Demanding Substances Oil& Grease Bacteria & Viruses Pesticides Housing Development (> 10 dwelling X X X X(i) X(2) X X Commercial Development (>1 acre) P(i) P(i) P(2) X P(5) X P(3) P(5) Industrial development (>1 acre) X X X X X X P(i) Automotive Repair Shops X X(4)(5) X X Restaurants X X X X X Hillside Development >5,000 ft2 X X X X X X Parking Lots P(i) P(i) X P(4)(5) X P(l) X P(i) Streets, Highways & Freeways X P(i) X X(4) X P(5) X P(i) Retail Gasoline Outlets X X X X X X = anticipated P = potential (1) A potential pollutant if landscaping 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. April 15•^ 2013 Page I 7 ALPS Innovation Hotels City of Carlsbad - Storm Water Management Plan B. Identify Watershed and Hydraulic Unit Basin Number Number Name 904.00 Carlsbad Hydrologic Unit (HU) 904.50 San Marcos Hydrologic Area (HA) 904.51 Batiquitos Sub-Area (HAS) http://www. waterboards.( za.gov/sandiego/water issues/programs/basin plan/index, shtml The receiving waters that the project contributes to include: Unnamed Intermittent Streams San Marcos Creek Batiquitos Lagoon C. Listed 303d Impaired Water Bodies San Marcos Creek - Selenium, Phosphorus & Dichlorodiphenyldichloroethylene (DDE) D. Identify the Beneficial Uses of the Receiving Waters SURFACE WATERS (river, creek, stream, etc.) Hydrologic Unit Basin Number Impairment(s) Ested [303(d) listed waters or waters with established TMDLs ] Distance to Project Unnamed intermittent Streams 904.51 -300 ft Surface Waters Hydrologic Unit Basin Number MUN AGR IND PROC GWR FRESH POW REC 1 REC 2 BIOL WARM COLD WILD RARE SPWN 904.51 904.51 + • • • • • http://www.waterboards.ca.gov/water issues/programs/tmdl/docs/303dlists2006/epa/r9 06 303d reqtmdls.pdf + Excepted from Municipal • Existing Beneficial Use o Potential Beneficial Use GROUND WATERS Ground Waters Hydrologic Unit Basin Number MUN AGR IND PROC GWR FRESH POW RECl REC 2 BIOL WARM COLD WILD RARE 1 Batiquitos 904.51 • • • http://www.waterboards.ca.gov/sandiego/water issues/programs/basin plan/index, shtml + Excepted from Municipal • Existing Beneficial Use o Potential Beneficial Use April 15*^ 2013 Page I 8 ALPS Innovation Hotels City of Carlsbad - Storm Water Management Plan £. Summary of Primary Pollutants of Concern Please summarize the identified project pollutants-of-concem by checking the appropriate boxes in the table below and list any stirface water impairments identified. Pollutants anticipated to be generated by the project, which are also causing impairment of receiving waters, shall be considered the primary pollutants of concem. For projects where no primary pollutants of concem exist, those pollutants identified as anticipated shall be considered secondary pollutants of concem. Pollutant Category Anticipated (X) Potential (P) Surface Water Impairments Sediments The Receiving Water Bodies are not Usted on current 303d Ust for this poUutant. (Secondary Pollutants of Concem) Nutrients The Receiving Water Bodies are not Usted on current 303d Ust for this poUutant. (Secondary Pollutants of Concem) Heavy Metals San Marcos Creek-Phosphorus, Selenium (Primary Pollutants of Concem) Organic Compounds The Receiving Water Bodies are not Usted on current 303d Ust for this poUutant. (Secondary Pollutants of Concem) Trash & Debris The Receiving Water Bodies are not Usted on current 303d Ust for this poUutant. (Secondary Pollutants of Concem) Oxygen demanding Substances The Receiving Water Bodies are not Usted on current 303d Ust for this poUutant. (Secondary Pollutants of Concem) Oil & Grease The Receiving Water Bodies are not Usted on current 303d Ust for this poUutant. (Secondary Pollutants of Concern) Bacteria & Viruses The Receiving Water Bodies are not Usted on current 303d Ust for this poUutant. (Secondary Pollutants of Concem) Pesticides San Marcos Creek-DDE (Primary Pollutants of Concem) April 15 , 2013 Page I 9 ALPS Innovation Hotels City of Carlsbad - Storm Water Management Plan SECTION IV - SOURCE CONTROL MEASURES A. Site Activities and Potential Pollutants of Concem Site is the proposed location of two hotels and associated hardscape. Onsite activities that have the potential to contribute poUutants to runoff include paridng of vehicles, the storage of trash in designated areas and the use of pesticides, fertiliTiers or other chemicals for landscaping purposes. The buildings and associated improvements will be constructed with materials that shaU not create permanent or lasting sources of poUutants. B. Pollutants Sources and Control Measures Potential source of runoffpollutants Permanent source control BMPs Operational source control BMPs Landscaping Areas Landscape designed to rnininiize runoff. The minimum amount of pesticides necessary wUl be used on landscaping Refuse Areas Trash enclosure wUl have a sign that reads "NO DUMPING OF HAZARDOUS MATERIALS HERE" AU spills in or around the trash enclosure area will be cleaned immediately. Roofing & Gutters Copper and other unprotected metals that may leech into runoff wUl be avoided wherever possible - Sidewalks and Parking Areas - Parking areas will be swept regularly to prevent the accumulation of debris and other poUutants April 15'", 2013 Page I 10 ALPS Innovation Hotels City of Carlsbad - Storm Water Management Plan Number BMP and Objective Included Routine Non-Structural BMPs (numbers correspond to those in the County SWMP) Nl Education for Property Owners, Tenants and Occupants: Practical informational materials are provided to residents, occupants, or tenants to increase the pubUc's understanding of stormwater quality, sources of pollutants, and what they can do to reduce pollutants in stormwater. 'Explanation!Description: The property owner wiU review the educational materials included in Appendix B and also distribute these materials to appropriate grounds maintenance employees. Although the materials are not specific to the County of San Diego, the concepts are appropriate for the proposed use of the site. Y N3 N3 Common Area Landscape Management: Specific practices are followed and ongoing maintenance is conducted to minimize erosion and over-irrigation, conserve water, and reduce pesticide (Integrated Pest Management) and fertilizer applications. Explanation!Description: The property owner and landscape contractor shall inspect and maintain all landscaped areas and irrigation systems in a manner so as to rninirnize erosion and over-irrigation, conserve water use and reduce use of pesticides and fertilizers. Y N4 N4 BMP Maintenance: AU BMP inspection and maintenance activities shaU be conducted annually by October 1^', at a minimum. Details of responsible parties, maintenance activities, and schedules can be deferred to the O&M Plan to follow approval of this document. Explanation!Description: See O&M Plan for specific maintenance activities Y N7 N7 SpiU Contingency Plan: A SpiU Contingency Plan is implemented to ensure that spills are managed properly by requiring stockpiling of cleanup materials, notification of responsible agencies, disposal of cleanup materials, documentation, etc. Explanation!Description: A spiU contingency plan is included in the O&M Plan. Y NU Common Area Litter Control: Trash management and Utter control procedures are specified, including responsible parties, and implemented to reduce pollution of drainage water. Explanation!Description: The property owner is responsible for litter removal on this property.. Owner shall insure periodic observation, trash and Utter pick up, and disposal in appropriate trash receptacle. Y N12 Employee Training: Practical informational materials and/or training are provided to employees to increase their understanding of stormwater quahty, sources of pollutants, and their responsibiUty for reducing poUutants in stormwater - actual content shaU be included in the O&M Plan. Please note that employee training shaU be conducted annuaUy, at a minimum, and within one month of hire for new employees. Explanation!Description: Employees responsible for grounds maintenance wiU be trained with respect to stormwater quaUty requirements, sources of poUution, and their responsibilities to reduce potential poUutants and maintain proposed site BMPs. Y April 15^ 2013 Page I 11 ALPS Innovation Hotels City of Carlsbad - Storm Water Management Plan N13 Housekeeping of Loading Docks: Cleaning and clean up procedures are specified and implemented for loading dock areas to keep the area free for pollutants and reduce associated poUutant discharges. Explanation!Description: There are no loading docks proposed as part of this project. Y N14 Drainage Facility Inspection: AU drainage faciUty inspection and maintenance activities shaU be conducted annuaUy by October 1st, at a minimum. Details of responsible parties, maintenance activities, and schedules can be deferred to the O&M Plan to foUow approval of this document. Explanation!Description: Bioretention and drainage faciUties to be inspected as specified in O&M plan. Y N15 Street Sweeping Private Streets and Parking Lots: AU private streets and parking lots shaU include regular street sweeping practices. Details of street sweeping frequency, responsible parties, and regular sweeping scheduling can be included as part of the O&M Plan. Explanation!Description: The parking lots and drive aisles shaU be swept in accordance with the O&M plan. Y Number BMP and Objective Included Source Control Structural BMPs (numbers correspond to the Cahfornia BMP Handbook) Efficient Irrigation System: Project plans include appUcation methods to minimize irrigation water discharged into stormwater drainage systems. SD-12 Explanation!Description: The project will include or consider the foUowing components to be a part of the system: • Rain shutoff devices to prevent irrigation after precipitation • Designing irrigation systems to each landscape area's specific water requirements Y SD-13 Storm Drain System Signs: Stencils or affixed signs wiU be placed adjacent to storm drain inlets to prevent waste dumping at storm drain inlets. Explanation!Description: StencUs or affixed signs/tiles wiU be implemented at aU on-site grated inlets and curb inlets. Y SD-20 Pervious Pavements: Porous concrete or asphalt, blocks with pervious spaces or joints, or proprietary grass or gravel surfaces are employed to reduce mnoff volume and provides treatment. Explanation!Description: Pervious pavers wUl be used in areas near the entrance of each hotel. Y SD-32 Trash Enclosures: Trash storage areas are covered and enclosed to prevent introduction of trash and debris to site runoff (limited exclusion — detached residential homes) Explanation! Description: Trash enclosures wiU be covered and enclosed to prevent mnoff poUution. Y April 15 ,2013 Page I 12 ALPS Innovation Hotels City of Carlsbad - Storm Water Management Plan SECTION V - Low Impact Design Strategies The most effective means of avoiding or reducing water quaUty and hydrologic impacts is through incorporation of measures into the project design; also know as low impact development. These measures should be taken into consideration early in the planning of a project as they can affect the overaU design of a project. A. Optimization of Site Layout 1) Limitation ofthe design envelope: Designing to minimum widths necessary: The drive aisles, parking staUs, and sidewalk are designed to meet the minimum width required for the use whUe complying with ADA requirements and other Ufe safety requirements. The site parking staU layout is minimized to meet the site use. Reduced street widths: On-site drive aisles wiU be designed to meet minimum widths. 2) Preservation of natural drainage features This LID Site Design BMP is not appUcable to this project due to the developed condition of the area surrounding the site, and the high percentage of impermeable area of the proposed site. 3) Setbacks of creeks, wetlands and other riparian habitats: This LID site Design BMP is not appUcable to this project, as there are no creeks, wetiands or riparian habitats in adjacent to or near the site. 4) Minimization of imperviousness Minimizing impervious footprint: The project proposes the replacement of existing pervious area with buUding and associated hardscape. The site is designed to maximize the usefiilness of impervious area in order to minimize the amount of impervious area needed. This is accompUshed by having both proposed hotels share certain site improvements such as the courtyard area, rather than having a dedicated area for each hotel. Incorporation of landscaped buffers: This site is designed with a landscaped buffer around the site perimeter, on cut and fiU slopes, and also within the bioretention facilities located at the north west comer of the project site. April 15^ 2013 Page j 13 ALPS Innovation Hotels City of Carlsbad - Storm Water Management Plan 5) Using drainage as a design element Bioretention areas: The site wiU be constmcted with three bioretention areas that wiU provide landscape buffers while providing treatment for mnoff B. Use of Permeable Surfaces Use of permeable paving: Permeable paving wiU be used in several areas near the entrances of each hotel. Use of other permeable surfaces: The walking path that shaU mn along the north and west border of the site shaU be constructed of compacted decomposed granite. C. Drainage of Impervious Areas to Pervious Areas Draining rooftops into adjacent landscaping: The proposed development contains landscaping around the periphery of the buildings. The building roofs wUl drain to the proposed landscaped areas. These areas wiU be equipped with area drains. Draining hardscape into landscaping: AU proposed hardscape shaU drain to one of 3 bioretention areas for treatment before being discharged from the site. April 15 , 2013 Page | 14 ALPS Innovation Hotels City of Carlsbad - Storm Water Management Plan SECTION VI - INTEGRATED MANAGEMENT PRACICES TCBMP approach used. See Section VII, TREATMENT CONTROL BMPs April 15'", 2013 Page | 15 ALPS Innovation Hotels City of Carlsbad - Storm Water Management Plan SECTION VII - TREATMENT CONTROL BMP's A. Selection Process for Treatment Control BMP's Based on the General poUutant information provided in Section III, subsection A, the project is required to treat such poUutants present for commercial type developments. Bioretention faciUties were selected as the means of treating these poUutants of concem. These facilities fit within the site plan constraints and wiU blend with the site aesthetics. Below is the Table 2-3 from the Current City of Carlsbad SUSMP reflecting the effectiveness of each recognized treatment BMP. As shown below, bioretention faciUties are highly effective at removing coarse sediment and trash, poUutants fine particles poUutants and medium efficiency in removal of dissolved poUutants. Only infiltration trenches have a higher treatment efficiency of aU the treatment facilities on the Ust. TABLE 2-3. Groups of PoUutants and Relative Effectiveness of Treatment FaciUties. PoUutants of Concem Bioretention Facilities (LID) Settling Basins (Dry Ponds) Wet Ponds and Constructed Wetlands Infiltration Facilities or Practices (LID) Media Filters Higher- rate biofilters Higher- rate media filters Trash Racks & Hydro- dynamic Devices Vegetated Swales Coarse Sediment and Trash High High High High High High High High High PoUutants that tend to associate with fine particles during treatment High High High High High Medium Medium Low Medium PoUutants that tend to be dissolved foUowing treatment Medium Low Medium High Low Low Low Low Low April 15*", 2013 Page I 16 ALPS Innovation Hotels City of Carlsbad - Storm Water Management Plan B. Sizing Factors for TCBMP's All Bioretention faciUties have been sized to provide adequate treatment for the volumes of water that wiU be generated by the development portion of the project. The sizing was done in accordance with the current City of Carlsbad SUSMP. Separate sizing calculations and design specifications have been provided for each individual treatment control BMP and each treatment control BMP location identified for use in a redevelopment project. • The BMPs have been sized to treat the 85* percentUe rainfaU volume or Stormwater QuaUty Design Volume (SQDV) based on the County of San Diego 85* percentile rainfaU map. • Bioretention areas have been sized according to City of Carlsbad SUSMP Section 4.: Tributary areas have been summed and multipUed by the mnoff factors Usted in Table 4-2 of the City SUSMP. The product of this was then multipUed by the sizing factor for bioretention areas from Table 4-6 of the City SUSMP. This provides the minimum area for each bioretention area. • BMP sizing calculations and particulars can be found in Appendix A of this report. For information regarding general Drainage see the Hydrology and HydrauUcs study, (submitted separately) C. Geotechnical Recommendations on Infiltration Rates This project does not propose BMP's that rely on infiltration into native soU for treatment, aU bioretention areas shaU have impermeable liners. April 15^ 2013 Page | 17 ALPS Innovation Hotels City of Carlsbad - Storm Water Management Plan SECTION VIII - HYDROMODIFICATION A. Lower Flow Threshold Determination Assumed high susceptibiUty, model utilizes 0.1 Q2 as lower threshold. 1. ) SCCWRP Analysis, if Chosen Not appUcable 2. ) HMP Decision Matrix See Section II B. Continuous Simulation Modeling See report in Appendix D C. Pond Sizing Criteria Not appUcable sizing provided through SDHM modeUng, not BMP sizing Calculator. D. Tabulation of Flow Control Facility See report in Appendix D April 15*^ 2013 Page | 18 ALPS Innovation Hotels City of Carlsbad - Storm Water Management Plan SECTION IX - STORM WATER DESIGN DOCUMENTATION A. Hydrology Map See Map Pocket for site map showing existing and proposed site with BMP's and tributary drainage basins delineated and numbered. B. BMP Sizing Calculations BMP Sizing Calculations have been provided in Appendix A of this report. C. Tabulation of BMP Data 1) Drainage Management Areas Areas have been delineated and summarized on the Site Hydrology Map 2) Tabulation of Drainage Management Areas Areas have been tabulated and summed on the Site Hydrology Map 3) DMA Descriptions DMA tabulations on the Site Hydrology Map include descriptions of individual DMA's 4) Listing of IMP's, TCBMP's and Flow Control FaciUties AU IMP'S, TCBMP'S and Flow Control FaciUties are shown on the Site Hydrology Map 5) Sizing Calculations BMP sizing calculations have been included in Appendix A April 15^ 2013 Page | 19 ALPS Innovation Hotels City of Carlsbad - Storm Water Management Plan SECTION X - BMP MAINTENANCE REQUIREMENTS A. Ownership and ResponsibiUty of Maintenance in Perpetuity 1) Commitments to Execute Necessary Agreements Owner shaU execute any agreements regarding the operation and maintenance of the site BMP's 2) ResponsibiUty for Operations and Maintenance The SWMP maintenance mechanism requires that the property owner implement the provisions of this SWMP, which includes on-going BMP maintenance as specified in the O&M Plan. The property owner is responsible to ensure that this SWMP and the O&M Plan are carried out and amended as appropriate to reflect up-to-date conditions on the site consistent with the current City of Carlsbad Jurisdictional Urban Runoff Management Program (}URMP)and SUSMP. Once the property owner transfers its interest in the property, its successors-in-interest shaU bear the aforementioned responsibiUty to implement and amend the SWMP. An appropriate number of approved and signed copies of this document shaU be avaUable on the subject site in perpettiity. Point of Contact: Company Name: Phone Number: Street Address: City/State/Zip: Email Address: 3) Summary of Maintenance Requirements Bioretention area maintenance requirements can be found in Figure 7, the CASQA informational packet for bioretention faciUties. April 15*^ 2013 Page I 20 ALPS Innovation Hotels City of Carlsbad - Storm Water Management Plan SECTION XI - SWMP CERTIFICATION STATEMENT City of Carlsbad Stonn Water Management Plan (SWMP) Project Name: ALPS Innovation Hotels. Bressi Ranch Carisbad. CA Tract / Parcel Number: 213-262-11-00 This Stonnwater Management Plan (SWMP) has been prepared for the above mentioned project. This SWMP is intended to comply with the requirements of the City of Carlsbad Jurisdictional Urban Runoff Management Plan (JURMP), Standard Urban Stonn Water Management Plan (SUSMP), Storni Water ordinance, and San Diego Regional Water QuaUty Control Board Order 2007-0001 (Permit). The undersigned, whUe it owns the subject property, is responsible for the implementation and maintenance of the provisions of the SWMP. The undersigned wiU ensure that this plan is carried out and any amendrnents are submitted to the City of Carlsbad for approval, as appropriate, to reflect up-to-date conditions on the site consistent with the current City of Carlsbad JURMP, SUSMP, and Permit. Once Undersigned transfers its interest in the property, its successors-in- interest shaU bear the aforementioned responsibiUty to implement and maintain the SWTSIP and receive approval by the Qty of Carlsbad for any amendments. An appropriate number of approved and signed copies of this document shaU be-available on the subject site in perpetuity. X- '"^ I. SIGNATURE: DATE: NAME: TITLE: COMPANY: ADDRESS: TELEPHONE: EMAIL: 5 [^^.j^^Jl ^^^^^Lc^^nXy^'^ . 1: April 15*, 2013 Page I 21 ALPS Innovation Hotels City of Carlsbad - Storm Water Management Plan APPENDIX A - TREATMENT BMP DESIGN CALCULATIONS April 15^ 2013 Page | 22 IMP-Area Sizing Calculations IMP -1, Bioretention DMA Name Area (sf) Surface Type Impervious % Runoff Factor Area * Runoff Factor DMA-1.1 19,300 mixed 70.0% 0.73 14,089 IMP Sizing Factor Min Area (sf) Prop. Area (sf) Total: 14,089 0.04 564 1,100 IMP -2, Bioretention DMA Name Area (sf) Surface Type Impervious % Runoff Factor Area * Runoff Factor DMA-2.1 22,337 mixed 86.0% 0.87 19,523 DMA-2.2 39,851 mixed 51.0% 0.56 22,277 DMA-2.3 46,391 mixed 23.0% 0.31 14,242 DMA-2.4 42,831 mixed 89.0% 0.90 38,591 DMA-2.5 30,637 mixed 74.0% 0.77 23,468 DMA-2.6 12,514 pervious 0.0% 0.10 1,251 IMP Sizing Factor Min Area (sf) Prop. Area (sf) Total: 119,351 0.04 4,774 9,350 IMP -3, Bioretention DMA Name Area (sf) Surface Type Impervious % Runoff Factor Area * Runoff Factor DMA-3.1 25,680 mixed 86.0% 0.87 22,444 IMP Sizing Factor Min Area (sf) Prop. Area (sf) Total: 22,444 0.04 898 1,260 IMP-Storage Volumes IMP Name Area (sf) Surface Storage depth (ft) Surface Storage Gravel Storage Layer Depth (ft) Gravel Storage Layer Volume(cf) Total Prop. Storage (cf) IMP Storage Volume IMP-1 1,100 0.75 825 3 1,320 2,145 IMP Storage Volume (*) IiVlP-2 9,350 0.7 6,545 4.5 16,830 23,375 IMP Storage Volume IMP-3 1,300 0.75 975 3 1,560 2,535 Notes: -Surface storage used to retain the required volume for 100-yr event to match existing 100-yr flow. Gravel storage layer used for hydromodification compUance. -Storage Volume = Area*Depth* Void ratio. Void ratio of 0.4 used for gravel layer calculations, 0 for surface layer. -Runoff Factor= (1.0*impervious %)+(0.1*(l-impervious %) (*) The surface storage layer is represented by the average height across the entire basin with a height varying between 1.4' and 0.0' Area Totals Area Name Area (sf) Area (ac) DMA-1.1 18,960 0.44 DMA-2.1 22,337 0.51 DMA-2.2 39,851 0.91 DMA-2.3 46,391 1.06 DMA-2.4 42,831 0.98 DMA-2.5 30,637 0.70 DMA-2.6 12,143 0.28 DMA-3.1 25,660 0.59 STA-1 2,270 0.05 STA-2 68,935 1.58 IMP-1 1,100 0.03 iMP-2 9,350 0.21 IMP-3 1,300 0.03 Pool 880 0.02 TOTAL 322,645 7.41 OUTLET CONTROL STRUCTURE DETAIL 389.75T0P OF BOX MANHOLE ACCESS 389.00 FREEBOARD MAX ELEVATION 388.40 - 100-YR PEAK STAGE 387.10 - 10-YR PEAK STAGE DEPTH 385.70 HNISH GRADE 380.00IE OF 6" SUBDRAIN HOLES DRILLED PER HNAL SDHM HYDROMODinCAWN REQUIREMENTS FOR 0.1Q2 TO QIO STORM EVENTS MODIFIED TYPE B INLET 2 CHAMBER W/ BAFFLE WALL BIORETENTION BASIN OUTLET CONTROL DETAIL ENGINEERING CONSULTANTG 9517 GROSSMONT SUMMIT DRIVE LA MESA, CALIFORNIA 91941 PH:(619) 741-9456 FAX: (619) 664-4291 BIORETENTION AREA CROSS SECTIONS WIDTH OF CALCULATED BIO RETENTION SURFACE AREA (VARIES) 10g^R_MAX^TAGE W-YR MAX STAGE BIORETENTION TYPICAL SECTION A-A (IMP-2) SD OUTLET 0-HEIGHT CURB PROPOSED PCC SIDEWALK SW UNDERDRAIN PROPOSED CURB & GUTTER BIORETENTION TYPICAL SECTION B-B (IMP-1) BIORETENTION TYPICAL SECTION C-C (IMP-3) ALPS Innovation Hotels City of Carlsbad - Storm Water Management Plan APPENDIX B - STORMWATER STANDARDS QUESTIONAIRE April 15*', 2013 Page j 23 ^ CITY O F CARLSBAD STORM WATER STANDARDS QUESTIONNAIRE E-34 Development Services Land Development Engineering 1535 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.qov/standards. 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 '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. 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 Section 1 and follow the instructions. When completed, sign the form at the end and submit this with your application to the city. SECTION 1 . . NEW DEVELOPMENT Does your project meet one or more of the following criteria: YES NO 1. Houslna subdivisions of 10 or more dwellina units. Examoles: sinale familv homes, multi-familv homes, condominium and apartments X 2. Commercial - areater than t-acre. Anv development other than heaw Industrv or residential. Examples: hospitals: laboratories and other medical facilities; educational Institutions; recreational facilities; municipal facilities; commercial nurseries; multl-aparlment buildings; car wash facilities; mini-malls and other business complexes; shopping malls; hotels; office buildings; public warehouses; automotive dealerships; airfields; and other light industrial facilifies. X 3. Heaw Industrial 1 Industrv- areater than 1 acre. Examoles: manufacturlna plants, food processino plants, metal working facilities, printing plants, and fleet storage areas (bus, truck, etc.). X 4. Automotive repair shoo. A facilitv cateoorized in anv one of Standard Industrial Classification fSICl codes 5013. 5014, 5541, 7532-7534, and 7536-7539 X 5. Restaurants. Anv facilitv that sells oreoared foods and drinks for consumotion. indudina stationan/ lunch counters and refreshment stands selling prepared foods and drinks for immediate consumption (SIC code 5812), where the land area for development is greater than 5,000 square feet. Restaurants where land development is less than 5,000 square feet shall meet all SUSMP requirements except for structural treatment BMP and numeric sizing criteria requirements and hydromodification requirements. X E-34 Page 1 of 3 REV 1/14/11 CiTY OF CARLSBAD STORM WATER STANDARDS QUESTIONNAIRE E-34 Development Services Land Devetopment Engineering 1635 Faraday Avenue 760-602-2750 www.carlsbadca.gov 6. Hillside development. Anv development that creates more than 5.000 sauare feet of imoervious surface and Is located in an area with known erosive soil conditions, where the development witl grade on any natural slope that Is twenty-five percent (25%) or greater. X 7. Environmentallv Sensitive Area (BSA)\ All develooment located within or directly adiacent^ to or discharaino directly* to an ESA (where discharges from the development or redevelopment will enter receiving waters within the ESA), which either creates 2,500 square feet or more of impervious surface on a proposed project site or increases the area of impen/iousness of a proposed project site 10% or more of its naturally occurring condition. X 8. Parkina lot Area of 5.000 sauare feet or more, orwith 15 or more oarkina soaces. and ootentialtv exoosed to urban runoff X 9. Streets, roads, hiahwavs. and freewavs. Anv oaved surface that Is 5.000 sauare feet or areater used for fhe transportation of automobiles, tmcks, motorcycles, and other vehicles X 10. Retail Gasoline Outlets. Servina more than 100 vehicles oer dav and areater than 5.000 souare feet X 11. Coastal Develooment Zone. Anv oroiect located within 200 feet of fhe Pacific Ocean and f1) creates more than 2500 square feet of impen/ious surface or (2) increases Impervious surface on property by more than 10%. X 12. Wore than 1-acre of disturbance. Proiect results in the disturbance of 1-acre or more of land and is considered a Pollutant-generating Development Project! X 1 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 Qualify Control Plan for the San Diego Basin (1994) and amendments); water bodies designated vni\) the RARE beneficial use by the State Water Resources Control Board (Water Quality Control Pian for the San Diego Basin (1994) and amendments); areas designated as preserves or their equivalent under the Multi Species Conservation Program wilhin the Cities and County of San Diego; and any other equivalent environmentally sensilive areas which have been identified by the Copermittees. 2 'Directly adjacent" means situated within 200 feet of the Environmentally Sensilive Area. 3 "Discharging directly to' means outfiow from a drainage conveyance system that is composed entirely of flows from the subject development or redevelopment site, and not commingled with flow from adjacent lands. 4 Pollutant-generating Development Projects are those projects that generate poiiutants at levels greater than background levels. In general, these Include all projects that contribute to an exceedance to an impaired water body or which create new Impervious surfaces greater than 5000 square feet and/or Introduce new landscaping areas that require routine use of fertilizers and pesticides. In most cases linear pathway projects that are for Infrequent vehicle use, such as emergency or maintenance access, or for pedestrian or bicycle use, are not considered Pollutant-generating Deveiopment Projects if they are built with pervious surfaces or if tfiey sheet flow to surrounding pen/lous surfaces. INSTRUCTIONS:: Section 1 Results: if you answered YES to ANY of the quesfions above, your project Is subject to Priority Development Project requirements. Skip Section 2 and please proceed to Section 3. Check the "meets PRIORITY DEVELOPMENT PROJECT requirements" box in Section 3. Additional storm water requirements wilt apply per the SUSI\^P. if you answered NO to ALL of the questions above, then please proceed to Section 2 and follow the instructions. E-34 Page 2 of 3 REV 1/14/11 CITY or STORM WATER STANDARDS QUESTIONNAIRE E-34 Development Services Land Development Engineering 163S Faraday Avenue 760-602-2750 www.carlsbadca.gov SECTION 2 SIGNIFICANT REDEVELOPMENT INSTRUCTIONS; Comploto the questions below regarding your project YES NO 1. Project results in the disturbance of 1 -acre or more of land and is considered a Pollutant-generating Development Projecl *? INSTRUCTIONS: If you answered NO, please proceed to question 2. If you ansv/ered YES. then you ARE a significant redeveiopmenl and you ARE subject lo PRIORITY DEVELOPMENT PROJECT requiremenis. Please check the "meets PRIORITY DEVELOPMENT PROJECT requirements" box in Section 3 below. 2. Is the projecl redeveloping an exisling priority project type? (Priorily projects are defined in Section 1) INSTRUCTIONS: tf you answered YES, please proceed to question 3. If you answered NO, then you ARE NOT a significant redevelopment and your project is subject to STANDARD STORMWATER REQUIREIWENTS. Please check the "does not meet PDP requirements" box in Seclion 3 below. 3, Is the v/ork limited lo trenching and resurfacing associated with utility work; resurfacing and reconfiguring surface parking lots and existing roadways; new sidev/alk; bike lane on exisling road and/or routine maintenance of damaged pavement such as polhole repair? Resurfacing/reconfiguring parking lots is v/here Ihe v/ork does not expose underiying soil during construction. INSTRUCTIONS: If you answered NO, fhen proceed to question 4. If you ansv/ered YES, then you ARE NOT a significant redevelopment and your projecl is subject to STANDARD STORMWATER REQUIREMENTS. Please check the "does not meet PDP requiremenis" box in Seclion 3 below. 4, VVill your redevelopment project create, replace, or add at least 5,000 square feet of impervious surfaces on existing developed property or v/ill your project be located v/ithin 200 feet of the Pacilic Ocean and (1) create 2500 square feel or more of Impervious surface or (2) increases impervious surface on the properly by more than 10%? Replacement of exisling impervious surfaces includes any activity lhal is nol part of routine maintenance v/here impervious material(s) are removed, exposing underlying soil during construction. INSTRUCTIONS: If you answered YES, you ARE a significant redeveiopmenl. and you ARE subject to PRIORITY DEVELOPMENT PROJECT requirements. Please check the "meets PRIORITY DEVELOPMENT PROJECT requirements' box in Section 3 below. Review SUSMP to find oul if SUSMP requirements apply lo your project envelope or the enfire project sile. If you answered NO, then you ARE NOT a significant redevelopment and your project is subject lo STANDARD STORMWATER REQUIREMENTS. Please check the 'does not meet PDP requiremenis" box in Section 3 below. •for definition see Footnote 4 on page 2 SECTION 3 : \i9UESTIpNNAlRE BeSULTS ® My project meets PRIORITY DEVELOPMENT PROJECT (PDP) requirements and musl comply wilh addllional stormwater criteria per the SUSMP and I understand I musl prepare a Slorm Water Management Plan for submitlal al time of application. I understand flow control (hydromodification) requirements may apply to my projecl. Refer to SUSMP for details. • My project does not meet PDP requirements and must only compiy with STANDARD STORMWATER REQUIREMENTS per the SUSMP. As part of these requiremenis. I will incorporate lov/ Impact development strategies throughout my projecl. Applicani Information and Signature Box This Box lor Qly Use Only Address: N/A Assessor's Parcel Number(s): 213-262-11-00 Applicant Name: ANDREW KANN Applicant Tille: CIVIL ENGINEER Applicant Signatures JJ^ Dale: 9/10/2012 City Concurrence: YES NO By. Date. Pro;«ct 10: E-34 Page 3 of 3 REV 1/14/11 ALPS Innovation Hotels City of Carlsbad - Storm Water Managennent Plan APPENDIX C - EDUCATIONAL MATERIALS April 15^ 2013 Page j 24 Under the Cily ol San Diego's Municipal Code §'13.03, Storm Water Management and Discharge Control, il is illegal to discharge construction delxis and materials, into tlie storm water conveyance system. Failure to prevent illegal discharges can result In fines up (a $10,000 a day per violation. De acuerdo con el Cddigo Municipal de San Diego, §43.03, Administracidn de aguas p/uwate.5 y control de descargas, se prohibe descargar desperdicios y basiira al sistenm de alejamiento de aguas pluviales. El Incumpliinienio de estas disposiciones podria muHarse con Iwsta $10,000 al dia porcada Infraccldn. i cinslnictlon siles are a source ol lllBitnl illscliarges inio Ihs stoim v/aler ^ conveyaiico system. As a condllion ot your iietinit, you aro requiied to jirevenl consliiiclion gciieialed or lelaleii potliitanls ftom cnteiing the system. Hei'ti ai'fj some Coiistmiitioii Pi!ii:;ti(;fis you f;aii ailopl: Follow the 3 Cs to Protecl Our Beaches, Bays S Rivers: Cotilral - The i3est line of defense is lo pievenl inaleitals and debris froin enlering the stoiin drain via procedural methods or "good housekeeping." Contain - Isolate your work area lo prevent discharges from leaving the site. Capture - Clean up the work area by sweeping or vacuuming up any residue pollutants that have the potential to be dis- cnarged. Properly dispose of the residue, and check with the t manufacturer for disposal lequirenients, Provltle erosion confrol to prevent sediment from leaving the site. Iphoto Al Cstat)lish and use an adequately sized concrete washout area to contain washout wastes on sile, Iphoto D} Sedlnieiil Control to provide a stabilized entrance and exit for vehicles to prevent tracking dirt off site. This may include using material such as gravel or corrugated steel panels/plates. Ipiioto B] Storm drain inlets around, construdion sites should be protected from pollutants.Do not allov/ concrete, paints, cliemicals, sediment, yard debris, etc. to enter the storm v/aler conveyance system (curb, gutter, sidewalk, street, drain and inlet), {photo C) Good Housekeeplny- Sweep-up surface areas regularly and place the v/aste in a dumpster. (photo f I Contain stored matertals in a secure place lo prevent seepage and spillage. "Sfofe these products where they will stay dry out of the rain iphoto [.T Think Blue and Help Clean up our Beaches anil Bays as obras iJe consUiiccldn iiiieden prodiiclr descaipas llegales al alcaiilailllailD da mjim ptiivlales. Coma cpadlclfiri de sit jiermtso de cdlllcaclfiii, estSn iisledes ofiilflados a Impedliqiib coiilamln^nles fleneiados por los liabajos o telaclonados con ia obra cnlien al alcanlariilado, Algunas praclicas (jus ustciJ piiede adoplar en la oljra: Localice las coladeras para atjua pluvial proximas a la obra yponoaenprapllca...las3C: Conjrole: La mejor Ifnea de delensa consisle en obseivar. biieiias pracltcas de limpieza a fin de impedir t|iie materiales :. yiscombros entren a la aloantarilla, Conlenfja: Aisle su area de trabajo para impedir que salgan descargas del lugai; Capte: Limpie elirea de trabajo, baiHendo o aspirando residuos de contaminantes que pudjeran descargaise a la alcafitarilla. Paraconocerla ftDrfn^ coriectadede^eohar los .' residuos, consulle con ol fabijcaote de Ips productos. i Conlrole la Erosidn para impedir que estos contaminantes salgan del area. (A folo} Eslablezca un drea de tamaflo adeciiado para el "avado de equipo titillzado con el coricrefo, a fin de relener los (qiiidos en el lugar. !P toto) c Conlrole la SelllmentQs eslablezca una entrada y salida estabilizada para Ips v^hfculos, a fin de Impedir que en las ruedas se lleven liena del l.ugar. -Esto podrfa requerir el uso dogravaoplarichas dejacero corfugado y la rejiosicibn de estos mateiriales con el paiso del tiempo, para contener los escoinbros y sedinientos en el area (Se trabajo. (B fol6] No permita que concreto, pinturas. sustaricias qufmlcas, sedimentos, ba^u'ra, etc. entren al sistenia de alejamiento. cie aguas pluviales {acera, cuneta, banquela, calle, coladera y alcantariiia). IC folol Tenya slempre aseatja el drea de trabajo barra las superficies per- Iddicamente y coloque la basura en un contenedor. 11- lotol Guarde los materiales en lugar seguro, para evitar ^r-, .,,-^i=r-M filtraciones y derrames. COI6QII8IOS donde se mantendr^n secbs. fuera de la lluvla. !E foioi Pionso en Azul y Ayude a f/lantener linipias iiuestras Playas y Balifas -•- torm Water Pollytion Pravention Program Impervious Surfaces; Cleaning Sidewalks, Pavements, Patios, Parking Lots & Drivewaye When it rains or wlven mim flovis ctil of yards or ov6f pavonieni, it flows dfroclly Into ^torr^t drains. Mariy peopte nilstakertty believe this water pts ''cle9ne<f before rea&tiirto waleiways. The smoi system and tho storm wgter conveyance system (dmlris, infels end c^ijqh basins) ore separate; tf'sy fife oa! cohfiecled. Sewer v/ofer gets treated. t)ul everythlnfl tiial washes irilo the storm drain ' goes (inlreated. direclty into our rivc^rs, creoks, bays and ocean, this cuusos beach closures and posliiiqs due lo contamirjialion, Think & Act Blue } ligli Pfessufo Wasriiiig or i losina Down of impervious areas cofitHbtites to ocean |>olliition by picking up contomlnanl? from these suffaces and carrying them to fscelvlntj waters via tlie slorm water convoyanco system, Dlscharae§ of washwater Into tho storm wator conveyance systam mo n violation of the Gity of San Djogo's Municipal Code (§43.0301) and subject to onforcomont action. C16ANINQ TIPS 'rifsi ?issess il water Is necessary to reniovo tho &ubstanb«(s) from the surfaces, •Uso dry clean-up moihods, such as a broom, mop or absorbent maioriaf for surface cleaning whenever possible. •If v/alor must bo used, use 11 eparingty. Delormino how you aro going tocapturo th© water end where you aro going lo dlschsroa it beforo slf^rting the wash job. •Avoid using cleaning produpls thai cpntoln hazardous substances that c^n create hozardous wasto, 'fvJover discharge washwater hito Ihe street, a dilcli. storm drain, or maffitenanco hole. Capture and collect the wnshwater and properly dispose of it. WHERe AND HOW TO DISt*0S6 OF WASHWATER 1. With the property owner's permission, washwater may be discharfled onto landscaped areas If privalo sower connections are not readily availablo and as long as (here Is no runoff and the v/ashwater does not contaminate soil with haiardous pollutants or,.. 2, Washwater may be disposed of Into the sanitary sewer system via a private connection located on Iho properly. Private connections such m an onslle sink, toilet, or laterel cleanout. This discharge musl be at a ftow rate that does not excoed 20 gallons per minute ond musl be tn compliance wilh the San Die^o IVlunicipal Code § 64,0512, For specific wasteslream advice related to (ho mmr system, call the City's Industriel wastewater Control Program al (856) 654-410D, Olher fact Sheets that msy pertain to your actfvltlesj BQ A C/oa/i Woi^r Loocfon Conttol, Contain & C&ptufe: Spills; Dun)pslor$, md F^osteutmts. Adopt these behaviors and help Clean up our beaches arid bays. Think Bfue. San Diego. For more Information, calf (619) 236-1000, or log on to: v^>thinkblufiBd.or^ iminmi •..(:rn|-.- f-. 1 n. iif (1 if'-'i il ^-i";*? { !?Vi:i*! Vf i'Tl <5.-'S.>.!-'.I storm Water Pollutloit Preventibti Program Water Discharges froiii Prlvato Propetly When it liiins or \^\m wmi Hows oiti ol'j'iuds, over ivi-ivcin^i^i uiKi into $utm, ii flosvs tiiieclly inlo storni drains. Many pc^plo irilMsknly l^cltcvc [\}h walcr gel.* ck'iii'tcJ or utiitcd before a\iclilvig waicrways, T1H> vnjih i<i ilic scnvsf mi v\at«f syslemi !UL^ scp.niSlc ffoin die siomi mut c-tinYcyfirlcc syjicni. S<?\vc) wasff gels I irc^iijCif, bul everyiliiiig th.^t wasim into the storm sviiier ttvjivciymicy ^ysteirt tsc^js ri uinrcaicd *iirv*«tly itHo <m sWm, mcH, ba>'.s ami omm, Thh c-au^os Inmch ' iind pollings itue to toniamiiKtiton, lUirasiiig iHilltiiiiiil* inio ihc msm v,\\W( toltectioii sysk-irt is a violniipu of ihf Cily Ntujiiv-ipl Code, ), UiHtiafgcs fiotit wdlcr ptix-s do Imppcit, When ihi?y (k> occur ihe priiitnry mmm is mil the waicr ll-Hif, but lb* svitrttftiiffrj il cohics in coislact with itrnl cmki !o tmr Monii water conveynn<?c ^ysim polliuingoiir l>eadtfs m\i wAtcrwiiys. ll is iinpcirtiivf tlwn these potlutanls ^edimiiii, leaves, oilier organtv or chcutid»1 tiiijiier •iiio prevented trom eiMeiing ill? City's siorm walcr convcyaitec system, I why wlwn mkt occur, It's importani to cosiirol, coiiltiin w>i enphire Ihe iivi'f flow )t> prevem coiiiamliwilon of uur bciiobe^j, t?ays ftntl re-Huvoii*. 1 lm M)me sioriii ss Akt fk-st KtiinirKtmcftl Prrttlitts you can fjitopi (o kfi^p oiir \v.iicr-\vis)'s efe^sn atul Think •it ilye Wiiur I'Jpe UrmUi on yoiir properiy: # TUMI olY water As Soon A$ Po)i^ll:)lc (ASA£) to <«)j)if«:»l the """^ 6 Provlili! txvjil^iimittii (tjmvcl aiitl/or s{in4 hn^s., etc.) ilsni will prcvcDi flew twit distrhciiglng Into reptilr of the wfllcr pipes 5hc Stonn Water ConvcyanCv^ .Sy.s{cm. Vou my \\m{ io «)ll a jdumlnng piofcs&kViiit for I lopi'ify OJviitrs luc rt'sponsiltde for iliif propur nialnt<?nflnct untl tlittt extend ffoitt die City wairrmetei* on to your properly. • Otpturc iiiwl dispose of llw icfoaiiiirtg tld)tls {s\"<tijiw«t, le«vcs, brrtiiclici, iriisli, ttiv) itiiit intty l>e ill ths? cure, piitor and sircct. mt lo clean llw cuit).s and gulteis li^yoncl your projiv^rty' nil i)» wiiy lo tlie neftfcil stotnl ilfrrin irtlcl. Waltr f»lpe Breaks io ihe City RI}vhi.of.Way{ if yms [)t\i^ye n water main br^ak 1$ cffcciinii your propeny, or you ste wuteroivins giii ohJie grooncl tiirough tlw piiverncnl. please ti^ll rhe Wfiicr OepartmeiU emefjjem'y phone H« (fil')) 515.35^5. riujlitiig Writer riticsi Jii fliKshlng wnterlinc*, you rc^jwtsible to tOiilrol. contain niHl capUuo nil wniv-r arid debris teniliifig from the sclivily. 'I Ips; to help yon prepare for M overHoW' * I'fOViiU' rtHiiiiic mid icgular inaliiienimec of yrair water pipes « Locale m\ know how to operiiiic your water sl)iii-»ff valve « Coptiiiv exe*iss water lo uie on pUm, hwm md jilirilte « U.ic a broom aflil doisl pan to $we«p-«p le^duc Insied of witter « Dp\\'\ im "storm drains" on your property or in tfie Cily tUglil-of-Wuy lo dispose olMelxts Aiiopi iliesc behitvicirs mi help Clean up our beaelies and tiays, TItink DItie, san Diego, For more Infornjallon, tall (619) 235^1000, or log on (01 >vm>.djfri|l}|u^^ storm Water Pollution Prevention Program Standard Urban Storm Water Mitigation Plan The City of San Diego is committed to implementing corrective measures to mitigate the pollution problems associated with urban mnoff. In addition, the City is legally mandated to implement the provisions of the San Diego Municipal Storm Water Permit (Califomia Regional Water Quality Control Board - San Diego Region, Order No. 2001-01). The municipal permit requires development and implementation of a Standard Urban Storm Water Mitigation Plan (SUSMP) to reduce the negative impacts to receiving waters (e.g. our beaches and bays) from development mnoff. The SUSMP is one of many City-wide efforts to address •^^^.^^^s'^i surface waters contamination in the San Diego region and reduce by half the r,^^^^^^ current days of beach closures and postings by 2004. 1. Wliat is the Standard Urban Storm Water Mitigation Plan? The Standard Urban Stoim Water Mitigation Plan, or SUSMP (pronounced "su-sump"), identifies a number of permanent Best Management Practices (BMPs) requirements which apply to public and private new development or significant redevelopment projects in order to protect and enhance the water quality ofthe region's surface waters (note that constmction phase BMPs are addressed through other standards and guidelines). Permanent BMPs are site design features and storm water treatment devices that remain operational in a project once the site is in use. Think Act Blue 2. WIw developed the SUSMP? A model SUSMP was developed by the City of San Diego in cooperation with the 19 other local jurisdictions within the county (collectively refen-ed to as copermittees), mcluding the San Diego Unified Port District, in conformance with the requirements of the San Diego Municipal Storm Water Permit, The San Diego Regional Water Quality Control Board adopted the model SUSMP in June 12^^ of this year. The model SUSMP is available for download at the Regional Board website, litto://www.swrcb.ca.gov/rvvqcb9/Programs/Storm Water/stomi water.html. 3. City and other jurisdictions are in the process of developing and implementing their local regulations that are based on the model SUSMP developed cooperatively at the regional level, The City of San Diego's regulations, contained in what will be called the "Storm Water Standards" are currently being drafted. The Storm Water Standards will include information regarding the City's permanent BMP (i.e., SUSMP) and constmction BMP requirements, and detail the processes by with these requirements will be incorporated into private projects. storm Drain Stenciling Tips NOTE: You may clieck ouf the storni drain stencil and a stenciling Idf with the necessaiy paint, brushes, and other materials from: I Love A Clean San Diego, Inc. 4891 Pacific Highway, Suite 115 San Diego, CA 92110 (619)291-0103 Stencil Placement: The stencil needs to be painted above the storm drain. The stencil message should be readable fi-om the roadside. If the curb is red, paint directiy above the red area. -CNO DUMPING- 'KjMk GOES TO OCEAN NO TIRE NADA- LLEGAALMAR •Please remember not sit/stand in the sfreet while completing this project* Stenciling Steps: Wipe the street curb with cloth. The area to be painted should be as clean as possible so the paint will adhere properly. Place the stencil in the location you've selected. Use wide masking tape to tape only the perimeter of the fust stencil without taping down the inside ofthe stencil itself, (This will form the 8" x 32" rectangular background for you to paint white.) Open white paint only. Stir paint with mixing stick. Paint the rectangular area white. USE PAINT SPARINGLY!!! Remember, neatness is vei-y important. If your storm drains are relatively close together, paint all the white backgrounds first, then retum to paint the Think Blue stencil so the white paint has time to dry. Very Important: Make sure the paint is dry. Then tape the Think Blue stencil (illustrated above) on top ofthe white background. Open the blue paint, stir, and dab the blue pamt sparingly using the Think Blue stencil. TIPS: If painting a rough surface, finnly hold down the stencil and dab (don't brush) the letters and the figure, Be careful not to get paint underneath fhe stencil. The key to success is to USE AS LITTLE PAINT ON YOUR BRUSH AS POSSIBLE. When finished painting, wipe off any paint on the outside of the container and tightly replace the lid to the paint. Anytime you stop painting for more than a couple minutes, place the brush in its plastic bag to keep the brush from dr>'ing. storm Water Pollution Prevention Program Think 8t Acl Blue Construction Area Practices Constniction sites are a source of illegal discharges into the sloini water conveyance sy.steJii. The sewer systein and the stonn water conveyance systems (drains, streets, curbs, gutters, sidewalks, inlets, and calch basins) are separate; they are not connected. Sewer water gets treated, bul everything lhat washes into the storm water conveyance system goes untreated directly into our rivers, creeks, bays and ocean. This causes beach closures and postings due to contamination. The Cily I of San Diego has made water quality a top goal. Il impacts cvciy citizen and the environment. You can make a dilTerence by preventing illegal discharges and incorporating clean water behaviors into your daily routine. Under the City of San Diego's iM(tnicip.il Code §43,0301, Slorm Wafer Mauagciucut aiu! Discharge Control, if is illegal fo disclinrgc coustnicHon debris and mntcrinis, into the storni wafer conveynnce sysfenii or any body of wafer. Fnilurc to prevent illegnl discliargcs can result in fines up to $10,000 n day per violation. Here are some Construction Best Management Pr.ictices you can adopt: Identify the slorm drains near the construdion area. Reinenjber The 3 Cs: Control - The best line of defense is to prevent materials and debris fioin cnlcrtug the storm drain via procedural methods or "good housekeeping," Conlain - Isolate your woik area to pievenl discharges from leaving the site. Capture - Clean up the work area by s\veeping or vacuuming tip any icsidue j)ollulanls lhal have the polciilial to be discharged. Property dispose of Ihc residue, and check with the inainifnclurer for disposal requirements. Do nol allow concrete, paints, chemicals, sedunenl, yard debris, etc. lo enter the storm water conveyance system (curb, gutter, sidewalk, street, drain and inlet). And, store these products so they will stay diy out ofthe rain. Eslablisli and use an adequately sized concrete washout area lo contain all liquids on site. Provide erosion and sediment control to prevent these pollutants from leaving the site. Provide a stabilized entrance and exit for vehicles to prevent tracking dirt offsite. Sweep-up surface areas regularly and place the waste in a dumpster. Don't use waler lo clean. Conlain stored inaierials in a secure place to prevent seepage and spillage. Properly dispose of all materials. Do not dump unused or waste products on Ihc ground, where water can carry it to the conveyance system. When washing equipment on site, prevent wastewater from entering the stonn water conveyance system. Do not let the water leave the site. Adopt these behaviors and help Clean up our beaches and bays. Think Blue, San Dlcgo. For more information, call (619) 235-1000, or log ou fo; www.tlilnkbhicsd.oru storm Water Pollution Preyiinilidri Program Concrete Washout Think & Act Blue The sewer system and the stonn water conveyance systems (drains, inlets, and catch basins) are separate; they are not coiinecfed, Sewer water gels treated, btit everything that washes into the stonn water conveyance systein goes tinlreated directly into our rivers, creeks, bays and ocean. This causes beach closures and postings due to confamiuation. Whether you are at home, work, or play there are ways that residents and businesses alike can "Think Blue" and prevent pollutants from reaching our waterways FACT: Under the City of San Diego's Municipal Code §43.03, Storm Water Management anci Discharge Conlrol, it is illegal to wash out concrete, slurry, mortar, stucco, plaster and the like, into die slorm water conveyance system or any receiving waler. The penalties imposed for these violations typically ranged from $500 - $1,000 per uicidence. For gross negligence and/or repeat offenses, the fines can increase up to $ 10,000 per day per violation. Pleading ignorance does not proiect you from l)eing fined for iliegai discharges How can these penalties be avoided? Identify or locate the on-site concrete washout location. Homeowners, this means a washout area must be identified on your property before concrete arrives. An adequate washout area allows fools and equipment used in working the concrete to be cleaned without water or residue leaving your property. And, remember The 3 Cs; Control - The best line of defense is to prevent materials and debris from entering the storm drain via procedural methods or "good housekeeping." Contain - Isolate your work area fo prevent discharges from leaving die site. Capture - Clean up the work area by sweeping or vacuuming up any residue poUulants that have the potential to be discharged. Properly dispose of the residue , and check with Ihe manufacturer for disposal requirements. The Cily of San Diego has made water quality a top goal as il impacts eveiy citizen and the environment. You can make a difference by being aware of illegal discharges and incorporating water quality objectives into your daily routine. Otiier Fact sheets that may pertahi to your activities: Cleaning Jmpen'ious Surfaces (High Pressure Washing); Be A Clean Water Leader: Control, Contain & Capture. Think Blue, San Diego. For more information, call (619) 235-1000, or log on to: wvvw.thinkblucsd.org ALPS Innovation Hotels City of Carlsbad - Storm Water Management Plan APPENDIX D -HYDROMODIFICATION REPORT April 15^ 2013 Page j 25 page 1 page 1 page 1 page 2 page 2 page 3-4 TABLE OF CONTENTS -SITE AND PROJECT DESCRIPTION -HYDROMODIFICATION MANAGEMENT METHODOLOGY -EXISTING PROJECT CONDITIONS AND ANALYSIS -DEVELOPED PROJECT CONDITIONS AND ANALYSIS -BMP MAINTENANCE -RESULTS AND CONCLUSIONS LIST OF FIGURES FIGURE 1: VICINITY MAP page 5 FIGURE 2: MITIGATED SURFACE EXHIBIT MAP page 6 FIGURE 3: PRE-PROJECT SURFACE EXHIBIT MAP page 7 LIST OF CALCULATIONS CALCULATION A: SDHM CALCULATIONS page 1-16 CALCULATION B: ORIFICE DRAWDOWN page 17 -26 SITE AND PROJECT DESCRIPTION This Hydro-modification Analysis has been prepared as part of the Discretionary Development Plan and for the development of two hotels. The project site is currently stabilized vacant and mass graded lot. The site is located at the southeast comer of intersection of irmovation way and Palomar Airport Road in the city of Carlsbad. See Figure No. 1 for a Vicinity Map. See Figure 2 for the proposed drainage limits. See Figure 3 for the existing drainage limits. This site currently drains to the public MS4 system within Innovation Way, which flows southwest to an unnamed creek which drains to the San Marcos Creek and the Batiquitos Lagoon. METHODOLOGY This Hydro-Modification Analysis was conducted in accordance with the recently adopted Hydromodification Management Plan, March 2011 for the County of San Diego. In lieu of using the County BMP sizing tools a continuous simulation model was conducted using an approved Proprietary Modeling Software. The following references have been used in preparation of this report: (1) San Diego Hvdrologv Model (SDHM^ Clear Creak Solutions (Version: 06/04/2012) • Inflitration will not be used in site modeling due to the high clay content of the in-situ soils. • No geomorphic assessment has been prepared as part of this project, thus it will be assumed that the receiving water body (Unnamed Stream) is at a high susceptibility for erosion impact. The modeling will thus utilize a low flow threshold of: 0.1Q-2yr EXISTING PREPROJECT CONDITIONS AND ANALYSIS; The existing project site consists of an imimproved vacant mass graded lot. There is minimal permanent landscaping on site, and the project area is nearly 100% pervious with a portion of the site at or above 10% slope. These steeper slope areas have been stabilized with seasonal grass etc. Runoff from the site currently flows to the storm system at the south west comer. For the analysis of the pre-project condition we have "D" type soil with three different surfaces parameters: Flat (0% - 5%) Grass Moderate (5% -10%) Grass Steep (10%- 15%) Grass The upper few feet of the site has a high clay content thus classifying as a type D soil. This is consistent with the NRCS Soil Survey, County of San Diego Soil Hydrologic Group Map, and the previously prepared Geotechnical Investigations. MITIGATED PROJECT CONDITIONS AND ANALYSIS; The proposed development includes re-grading and improvement of all of the site and in order to meet the proposed intent of the design. The site will be the future location of two separate hotels with common area drive aisles and parking. Nearly 100% of the site will be disturbed during constmction operations. The project proposes to slightly modify the on-site drainage pattems, and increase the total impervious surface, but maintain the same outfall points. For the analysis of the mitigated conditions we use the in-situ "D" type soil with three different surfaces parameters: Flat (0% - 5%) Grass / Turf Steep (10% - 20%) Grass / Turf Flat (0% - 5%) Impervious Self Retaining (Does not contribute to Storm Water runoff) The increase in impervious area will be mitigated with the use of bio-retention facilities with controlled outlet flows together with underground storage system. These site modifications will prevent any increase in the storm water discharge for the storm occurrences between the intervals of (0.1Q-2yr) through (Q-lOyr). BMP MAINTENANCE; The proposed development proposes the implementation of three separate Bio-retention facilities with ponding capability together with sub-siu-face storage volumes. These BMPs will serve as both Hydro-modification mitigation facilities as well as storm water quality treatment control BMP's. The proposed Hotel development and any future successors shall be responsible for on-going maintenance and fianctionality of these facilities. The proposed BMPs qualify as first category BMPs per San Diego SUSMP and are subject to maintenance mechanisms listed on table 5.2 ofthe San Diego County SUSMP. Party Responsible for Long-term Maintenance: Point of Contact: Company Name: Phone Number: Street Address: City/State/Zip: Email Address: See separately prepared Storm Water Management Plan (SWMP) for information outlining the mechanisms for on-going maintenance of such facilities; additionally an O&M plan will be prepared for the site. RESULTS AND CONCLUSIONS The SDHM Continuous Simulation Modeling results are attached hereto reflecting the compliance with the goveming threshold limits. Each bio-retention facility has been sized to mitigate the impacts of the site development. The bioretention facilities do not consider inflitration due to the in-situ soil parameters, thus each basin will be imderlain with an impermeable liner. The parameters input into the SDHM modeling software correspond to the design reflected on the proposed grading plans. The bio-retention facility parameters input into the software are as reflected on the following page. It is our opinion that the development of this project will decrease the mitigated storm water discharge intensities within the required Hydro-modification criteria compliance interval (Lower threshold 0.1Q2yr to the upper threshold QlOyr). The proposed Hydro-modification Management Practices are suitable in mitigating the site development to the standards set forth in the currently adopted County of San Diego SUSMP and Final Hydro-Modification Mitigation Plan. All maintenance detail for the Bio-retention areas are addressed within the main body of the Major Storm Water Management Plan. Bio-retention 1 - Parameters: First Soil layer: Treatment layer -18" Select material (Amended 3 in/hr infiltration rate) Second Soil Layer; Storage/conveyance layer - 3.00' Class II Perm Base / Gravel Under-drain: Proposed 6" Perforated under-drain with limiting outflow orifice 0.6" Length; 275 ft, Base Width: 4 ft (Total Bio-retention Surface area of 1,100 sf) Base Slope: 0.5 %, Side Slopes: 2:1 Freeboard; 0.5 ft Outflow information: Outflow Riser - 8" diameter pipe 8" above the finish surface (Riser pipe will be substituted with a curb inlet adequate to convey Q-lOOyr) Surface Drawdown: Less than 1 day (Peak stage 1.056 ft) Bio-retention 2 - Parameters: First Soil layer: Treatment layer -18" Select material (Amended 3 in/hr infiltration rate) Second Soil Layer; Storage/conveyance layer - 4.50' Class II Perm Base / Gravel Under-drain: Proposed 6" Perforated under-drain with limiting outflow orifice 1.1" Length: 250 ft, Base Width: 37.4ft (Total Bio-retention Surface area of 9,350 sf) Base Slope; 0.5 %, Side Slopes: 2:1 Freeboard; 2.05ft Outflow information: V-notched outflow Riser -18" diameter pipe 1.25' above the finish surface - Riser V-notch (H=l .0', Angle= 10°) (Riser pipe will be substituted with a modifies curb inlet adequate to convey Q-lOOyr) Surface Drawdown: Less than 1 day (Peak stage 1.40 ft) Bio-retention 3 - Parameters: First Soil layer: Treatment layer - 18" Select material (Amended 3 in/hr inflitration rate) Second Soil Layer; Storage/conveyance layer - 30" Class II Perm Base / Gravel Under-drain: Proposed 6" Perforated under-drain with limiting outflow orifice 0.6" Length: 325 ft, Base Width: 4 ft (Total Bio-retention Surface area of 1,300 sf) Base Slope: 0.5 %, Side Slopes: 2:1 Freeboard: 0.5 ft Outflow information: Outflow Riser - 8" diameter pipe 8" above the finish surface (Riser pipe will be substituted with a curb inlet adequate to convey Q-lOOyr) Surface Drawdown; Less than 1 day (Peak stage 1.056 ft) Site Vicinity Map PALOMAR Project site. LA COSTA BLVD VICINITY MAP NOT TO SCALE INNOVATION WAY RUNOFF DA TA BASIN BASIN AREA FLAT, IMPERVIOUS (D) FLA 1 GRASS (D) STEEP, GRASS SELF RETAINING BASIN (Sq. Ft.) (Acres) (Sq Ft.) (Acres) (Sq. Ft.) (Acres) (Sq. Ft.) (Acres) (Sq. Ft.) (Acres) M-1 20.400 04683 15.025 03449 1,904 0.0437 3,471 0.0797 0 0 M-2 205,220 4.7112 132.240 3.0358 43,725 1.0037 26.825 0.6158 1,520 00349 M-J 26.980 0.6194 21.670 0.4975 5,220 0.1198 0 0 0 0 M-4 68.775 1.5789 0 0 46,470 1.0668 22,305 0.5121 0 0 M-5 2.270 0.0521 0 0 2,270 0.0521 0 0 0 0 TOTAL: 322.735 7.4090 168.935 3.8782 99,589 2.2862 52,601 1.2076 1,520 00349 MITIGATED HYRDOMODIFICATION BRESSI RANCH HOTELS LEGEND: GRASS FLA T (0%-5% SLOPE) GRASS STEEP (>10% SLOPE) IMPERVIOUS FLAT (OZ-5% SLOPE) DIRT FLAT (0%-5% SLOPE) AREA BOUNDARY AREA NUMBER UNMITIGATED HYRDOMODIFICATION BRESSI RANCH HOTELS RUNOFF DA TA BASIN BASIN AREA (D) FLAT, GRASS (D) GRASS, MOD (D) STEEP, GRASS BASIN (Sq. Ft.) (Acres) (Sq. Ft.) (Acres) (Sq. Ft.) (Acres) (Sq. Ft.) (Acres) U-1 305,725 7.0164 233,790 5.3671 33,135 0.7607 38,800 0.8907 U-2 17,010 0.3905 17,010 03905 0 0 0 0 TOTAL: 322,735 74090 250,800 5.7576 33,135 0.7607 38,800 0.8807 LEGEND: GRASS FLAT (0%-5% SLOPE) GRASS STEEP (>10% SLOPE) GRASS MOD (5%-W% SLOPE) BASIN BOUNDARY BASIN NUMBER u-# ENGINEERING CONSULTANTS 9517 GROSSMONT SUMMIT DRIVE LA MESA, CALIFORNIA 91941 PH:(619) 741-9456 FAX:(619) 664-4291 CALCULATIONS SDHM Output & Drawdown Calculations Alps Innovation Hotels - Preliminary SWMP SDHM2011 PROJECT REPORT Project Name: Bressi (2013-04-15) Site Name: Bressi Hotel Site Address: Innovation Way City : Carlsbad, ca Report Date: 4/17/2013 Gage : OCEANSID Data Start : 10/01/1959 Data End : 09/30/2004 Precip Scale: 1.00 Version : 2012/06/02 Low Flow Threshold for POC 1 : 10 Percent of the 2 Year High Flow Threshold for POC 1: 10 year PREDEVELOPED LAND USE Name : U-l Bypass: No Groundwater: No Pervious Land Use D,Grass,FLAT(0-5%) D,Grass,MOD(5-10%) D,Grass,STEEP(10-20 Pervious Total Impervious Land Use Impervious Total Basin Total Acres 5.3671 .7607 .8907 7.0185 Acres 0 7.0185 Element Flows To: Surface Interflow Groundwater Name : U-2 Bypass: No Groundwater: No CALCULATIONS SDHM Output & Drawdown Calculations Alps Innovation Hotels - Preliminary SWMP SDHM2011 PROJECT REPORT Project Name: Bressi (2013-04-15) Site Name: Bressi Hotel Site Address: Innovation Way City : Carlsbad, ca Report Date: 4/17/2013 Gage : OCEANSID Data Start : 10/01/1959 Data End : 09/30/2004 Precip Scale: 1.00 Version : 2012/06/02 Low Flow Threshold for POC 1 : 10 Percent of the 2 Year High Flow Threshold for POC 1: 10 year PREDEVELOPED LAND USE Name : U-l Bypass: No Groundwater: No Pervious Land Use D,Grass,FLAT(0-5%) D,Grass,MOD(5-10%) D,Grass,STEEP(10-20 Pervious Total Impervious Land Use Impervious Total Basin Total Acres 5.3671 .7607 .8907 7.0185 Acres 0 7.0185 Element Flows To: Surface Interflow Groundwater Name : U-2 Bypass: No Groundwater: No Alps Innovation Hotels - Preliminary SWMP Pervious Land Use D,Grass,FLAT(0-5%) Pervious Total Impervious Land Use Impervious Total Basin Total Acres .3905 0.3905 Acres 0 0.3905 Element Flows To: Surface Interflow Groundwater MITIGATED LAND USE Name : M-1 Bypass: No Groundwater: No Pervious Land Use D,Grass,FLAT(0-5%) D,Grass,STEEP (10-20 Pervious Total Impervious Land Use IMPERVIOUS-FLAT Impervious Total Basin Total Acres .0437 .0797 0.1234 Acres 0.3449 0.3449 0.4683 Element Flows To: Surface Interflow BIORETENTI Surface 1 BIORETENTI Surface 1 Groundwater Name : M-5 Bypass: Yes Groundwater: No Pervious Land Use D,Grass,FLAT(0-5%) Acres ,0521 Alps Innovation Hotels - Preliminary SWMP Pervious Total Impervious Land Use Impervious Total Basin Total 0.0521 Acres 0 0.0521 Element Flows To: Surface Interflow Groundwater Name : M3 Bypass: No Groundwater: No Pervious Land Use D,Grass,FLAT(0-5%) Pervious Total Impervious Land Use IMPERVIOUS-FLAT Impervious Total Basin Total Acres .1198 0.1198 Acres 0.4975 0.4975 0.6173 Element Flows To: Surface Interflow BIORETENTI Surface#3 BIORETENTI Surface#3 Groundwater Name : M-2 Bypass: No Groundwater: No Pervious Land Use D,Grass,FLAT(0-5%) D,Grass,STEEP(10-20 Pervious Total Impervious Land Use IMPERVIOUS-FLAT Acres 1.0037 .6158 1.6195 Acres 3.0358 Alps Innovation Hotels - Preliminary SWMP Impervious Total Basin Total 3.0358 4.6553 Element Flows To: Surface Interflow BIORETENTI Surface#2 BIORETENTI Surface#2 Groundwater Name : M-4 Bypass: Yes Groundwater: No Pervious Land Use D,Grass,STEEP(10-20 D,Grass,FLAT(0-5%) Pervious Total Impervious Land Use Impervious Total Basin Total Acres .5121 1.0668 1.5789 Acres 0 1.5789 Element Flows To: Surface Interflow Groundwater Name : BIORETENTION # 1 Bottom Length: 275.00 ft. Bottom Width: 4.00 ft. Trench bottom slope 1: 0.005 To 1 Trench Left side slope 0: 0 To 1 Trench right side slope 2: 0 To 1 Material thickness of first layer: 1.5 Pour Space of material for first layer: Material thickness of second layer: 3 Pour Space of material for second layer: Material thickness of third layer: 0 Pour Space of material for third layer: Discharge Structure Riser Height: 0.7 5 ft. Riser Diameter: 8 in. 0.475 0.4 0.4 Element Flows To: Outlet 1 Outlet 2 Alps Innovation Hotels - Preliminary SWMP Landscape Swale Hydraulic Table stage(ft) Area(ac) Volume(ac-ft) Discharge(cfs) InfiltCcfs) 0 OOOO 0. 025 0. 000 0. 000 0. 000 0 0611 0. 025 0. 000 0. 000 0. 000 0 1222 0. 025 0. 001 0. 000 0. 000 0 1833 0. 025 0. 002 0. 000 0. 000 0 2444 0. 025 0. 002 0. 000 0. 000 0 3056 0. 025 0. 003 0. 000 0. 000 0 3667 0. 025 0. 004 0. 000 0. 000 0 4278 0. 025 0. 005 0. 000 0. 000 0 4889 0. 025 0. 005 0. 000 0. 000 0 5500 0. 025 0. 006 0. 000 0 000 0 6111 0. 025 0. 007 0. 000 0 000 0 6722 0. 025 0 008 0. 000 0 000 0 7333 0. 025 0 008 0. 000 0 000 0 7944 0. 025 0 009 0. 060 0 000 0 8556 0 025 0 010 0. 222 0 000 0 9167 0 025 0 Oil 0. 441 0 000 0 9778 0 025 0 Oil 0. 705 0 000 1 0389 0 025 0 012 1. 008 0 000 1 1000 0 025 0 013 1. 344 0 000 1 1611 0 025 0 013 1. 711 0 000 1 2222 0 025 0 014 2. 106 0 000 1 2833 0 025 0 015 2. 528 0 000 1 3444 0 025 0 016 2. 975 0 000 1 4056 0 025 0 016 3. 446 0 000 1 4667 0 025 0 017 3. 939 0 000 1 5278 0 025 0 018 4 . 453 0 000 1 5889 0 025 0 018 4 . 988 0 000 1 6500 0 025 0 019 5. 543 0 000 1 7111 0 025 0 020 6. 117 0 000 1 7722 0 025 0 020 6. 710 0 000 1 8333 0 025 0 021 7 . 320 0 000 1 8944 0 025 0 021 7 . 949 0 000 1 9556 0 025 0 022 8. 594 0 000 2 0167 0 025 0 023 9. 255 0 000 2 0778 0 025 0 023 9. 933 0 000 2 1389 0 025 0 024 10 . 62 0 000 2 2000 0 025 0 025 11 . 33 0 000 2 2611 0 025 0 025 12 .06 0 000 2 3222 0 025 0 026 12 .80 0 000 2 3833 0 025 0 026 13 . 55 0 000 2 4444 0 025 0 027 14 . 32 0 000 2 5056 0 025 0 028 15 . 10 0 000 2 5667 0 025 0 028 15 .89 0 000 2 6278 0 025 0 029 16 .70 0 000 2 6889 0 025 0 029 17 .52 0 000 2 7500 0 025 0 030 18 .36 0 000 2 8111 0 025 0 031 19 .21 0 000 2 8722 0 025 0 .031 20 .07 0 000 2 9333 0 025 0 .032 20 . 94 0 000 2 9944 0 025 0 .033 21 . 83 0 000 3 0556 0 025 0 .033 22 .72 0 000 Alps Innovation Hotels - Preliminary SWMP 3 1167 0 025 0 034 23 63 0 000 3 1778 0 025 0 034 24 56 0 000 3 2389 0 025 0 035 25 49 0 000 3 3000 0 025 0 036 26 43 0 000 3 3611 0 025 0 036 27 39 0 000 3 4222 0 025 0 037 28 36 0 000 3 4833 0 025 0 038 29 34 0 000 3 5444 0 025 0 038 30 33 0 000 3 6056 0 025 0 039 31 33 0 000 3 6667 0 025 0 039 32 34 0 000 3 7278 0 025 0 040 33 36 0 000 3 7889 0 025 0 041 34 39 0 000 3 8500 0 025 0 041 35 43 0 000 3 9111 0 025 0 042 36 49 0 000 3 9722 0 025 0 042 37 55 0 000 4 0333 0 025 0 043 38 62 0 000 4 0944 0 025 0 044 39 71 0 000 4 1556 0 025 0 044 40 80 0 000 4 2167 0 025 0 045 41 90 0 000 4 2778 0 025 0 046 43 02 0 000 4 3389 0 025 0 046 44 14 0 000 4 4000 0 025 0 047 45 27 0 000 4 4611 0 025 0 047 46 41 0 000 4 5222 0 025 0 049 47 56 0 000 4 5833 0 025 0 050 48 72 0 000 4 6444 0 025 0 052 49 89 0 000 4 7056 0 025 0 054 51 07 0 000 4 7667 0 025 0 055 52 26 0 000 4 8278 0 025 0 057 53 46 0 000 4 8889 0 025 0 058 54 67 0 000 4 9500 0 025 0 060 55 88 0 000 5 0111 0 025 0 061 57 10 0 000 5 0722 0 025 0 063 58 34 0 000 5 1333 0 025 0 064 59 58 0 000 5 1944 0 025 0 066 60 83 0 000 5 2556 0 025 0 067 62 09 0 000 5 3167 0 025 0 069 63 36 0 000 5 3778 0 025 0 071 64 63 0 000 5 4389 0 025 0 072 65 92 0 000 5 5000 0 025 0 074 67 21 0 000 5 5611 0 025 0 075 68 51 0 000 Name : BIORETENTI Surface 1 Bottom Length: 0.00 ft. Bottom Width: 0.00 ft. Material thickness of first layer: 0 Pour Space of material for first layer: Material thickness of second layer: 0 Pour Space of material for second layer: Material thickness of third layer: 0 Pour Space of material for third layer: Discharge Structure Riser Height: 0 ft. Riser Diameter: 0 in. Element Flows To: Alps Innovation Hotels - Preliminary SWMP Outlet 1 BIORETENTION # 1 Outlet 2 Name : BIORETENTION #3 Bottom Length: 325.00 ft. Bottom Width: 4.00 ft. Trench bottom slope 1: 0.005 To 1 Trench Left side slope 0: 0 To 1 Trench right side slope 2: 0 To 1 Material thickness of first layer: 1.5 Pour Space of material for first layer: Material thickness of second layer: 3 Pour Space of material for second layer: Material thickness of third layer: 0 Pour Space of material for third layer: Discharge Structure Riser Height: 0.75 ft. Riser Diameter: 8 in. 0.475 0.4 0.4 Element Flows To: Outlet 1 Outlet 2 stage(ft) Landscape Swale Area(ac) Volume (ac-ft) Hydraulic Table Discharge(cfs) Infilt(cfs) 0 OOOO 0 029 0. 000 0. 000 0. 000 0 0611 0 029 0. 000 0. 000 0. 000 0 1222 0 029 0. 001 0 000 0. 000 0 1833 0 029 0 002 0 000 0. 000 0 2444 0 029 0 003 0 000 0. 000 0 3056 0 029 0 004 0 000 0. 000 0 3667 0 029 0 005 0 000 0. 000 0 4278 0 029 0 006 0 000 0. 000 0 4889 0 029 0 006 0 000 0. 000 0 5500 0 029 0 007 0 000 0. 000 0 6111 0 029 0 008 0 000 0. 000 0 6722 0 029 0 009 0 000 0. 000 0 7333 0 029 0 010 0 000 0. 000 0 7944 0 029 0 Oil 0 060 0. 000 0 8556 0 029 0 012 0 222 0. 000 0 9167 0 029 0 013 0 441 0. 000 0 9778 0 029 0 013 0 705 0. 000 1 0389 0 029 0 014 1 008 0. 000 1 1000 0 029 0 015 1 344 0. 000 1 1611 0 029 0 016 1 711 0. 000 1 2222 0 029 0 017 2 106 0. 000 1 2833 0 029 0 018 2 528 0. 000 1 3444 0 029 0 019 2 975 0. 000 1 4056 0 029 0 019 3 446 0. 000 1 4667 0 029 0 020 3 939 0. 000 1 5278 0 029 0 021 4 453 0. 000 1 5889 0 029 0 022 4 988 0. 000 1 6500 0 029 0 023 5 543 0. 000 Alps Innovation Hotels - Preliminary SWMP 1.7111 0.029 0.023 6.117 0.000 1.7722 0.029 0.024 6.710 0.000 1.8333 0.029 0.025 7.320 0.000 1.8944 0.029 0.025 7.949 0.000 1.9556 0.029 0.026 8.594 0.000 2.0167 0.029 0.027 9.255 0.000 2.0778 0.029 0.028 9.933 0.000 2.1389 0.029 0.028 10.62 0.000 2.2000 0.029 0.029 11.33 0.000 2.2611 0.029 0.030 12.06 0.000 2.3222 0.029 0.031 12.80 0.000 2.3833 0.029 0.031 13.55 0.000 2.4444 0.029 0.032 14.32 0.000 2.5056 0.029 0.033 15.10 0.000 2.5667 0.029 0.033 15.89 0.000 2.6278 0.029 0.034 16.70 0.000 2.6889 0.029 0.035 17.52 0.000 2.7500 0.029 0.036 18.36 0.000 2.8111 0.029 0.036 19.21 0.000 2.8722 0.029 0.037 20.07 0.000 2.9333 0.029 0.038 20.94 0.000 2.9944 0.029 0.039 21.83 0.000 3.0556 0.029 0.039 22.72 0.000 3.1167 0.029 0.040 23.63 0.000 3.1778 0.029 0.041 24.56 0.000 3.2389 0.029 0.041 25.49 0.000 3.3000 0.029 0.042 26.43 0.000 3.3611 0.029 0.043 27.39 0.000 3.4222 0.029 0.044 28.36 0.000 3.4833 0.029 0.044 29.34 0.000 3.5444 0.029 0.045 30.33 0.000 3.6056 0.029 0.046 31.33 0.000 3.6667 0.029 0.047 32.34 0.000 3.7278 0.029 0.047 33.36 0.000 3.7889 0.029 0.048 34.39 0.000 3.8500 0.029 0.049 35.43 0.000 3.9111 0.029 0.050 36.49 0.000 3.9722 0.029 0.050 37.55 0.000 4.0333 0.029 0.051 38.62 0.000 4.0944 0.029 0.052 39.71 0.000 4.1556 0.029 0.052 40.80 0.000 4.2167 0.029 0.053 41.90 0.000 4.2778 0.029 0.054 43.02 0.000 4.3389 0.029 0.055 44.14 0.000 4.4000 0.029 0.055 45.27 0.000 4.4611 0.029 0.056 46.41 0.000 4.5222 0.029 0.058 47.56 0.000 4.5833 0.029 0.060 48.72 0.000 4.6444 0.029 0.062 49.89 0.000 4.7056 0.029 0.063 51.07 0.000 4.7667 0.029 0.065 52.26 0.000 4.8278 0.029 0.067 53.46 0.000 4.8889 0.029 0.069 54.67 0.000 4.9500 0.029 0.071 55.88 0.000 5.0111 0.029 0.073 57.10 0.000 5.0722 0.029 0.074 58.34 0.000 5.1333 0.029 0.076 59.58 0.000 Alps Innovation Hotels - Preliminary SWMP 5 1944 0.029 0 078 60 83 0 000 5 2556 0.029 0 080 62 09 0 000 5 3167 0.029 0 082 63 36 0 000 5 3778 0.029 0 083 64 63 0 000 5 4389 0.029 0 085 65 92 0 000 5 5000 0.029 0 087 67 21 0 000 5 5611 0.029 0 089 68 51 0 000 Name : BIORETENTI Surface#3 Bottom Length: 0.00 ft. Bottom Width: 0.00 ft. Material thickness of first layer: 0 Pour Space of material for first layer: Material thickness of second layer: 0 Pour Space of material for second layer: Material thickness of third layer: 0 Pour Space of material for third layer: Discharge Structure Riser Height: 0 ft. Riser Diameter: 0 in. Element Flows To: Outlet 1 BIORETENTION #3 Outlet 2 Name : BIORETENTION #2 Bottom Length: 250.00 ft. Bottom Width: 37.4 0 ft. Trench bottom slope 1: 0.005 To 1 Trench Left side slope 0: 2 To 1 Trench right side slope 2: 2 To 1 Material thickness of first layer: 1.5 Pour Space of material for first layer: Material thickness of second layer: 4.5 Pour Space of material for second layer: Material thickness of third layer: 0 Pour Space of material for third layer: Discharge Structure Riser Height: 1.25 ft. Riser Diameter: 18 in. Notch Type : V-notch Notch Angle: 10.000 Notch Height: 1.000 ft. 0.475 0.4 0.4 Element Flows To: Outlet 1 Outlet 2 Landscape Swale Hydraulic Table stage(ft) Area(ac) Volume(ac-ft) Discharge(cfs) Infilt(cfs) 0.0000 0.214 0.000 0.000 0.000 0.1033 0.217 0.010 0.000 0.000 Alps Innovation Hotels - Preliminary SWMP 0 2067 0 219 0 021 0. 000 0. 000 0 3100 0 221 0 032 0. 000 0. 000 0 4133 0 224 0 043 0. 002 0. 000 0 5167 0 226 0 054 0. 008 0. 000 0 6200 0 228 0 065 0. 018 0. 000 0 7233 0 231 0 076 0. 033 0. 000 0 8267 0 233 0 088 0. 055 0. 000 0 9300 0 236 0 099 0. 083 0. 000 1 0333 0 238 0 111 0. 118 0. 000 1 1367 0 240 0 122 0. 161 0 000 1 2400 0 243 0 134 0. 212 0 000 1 3433 0 245 0 146 0. 634 0 000 1 4467 0 247 0 158 1. 492 0 000 1 5500 0 250 0 169 2. 618 0 000 1 6533 0 252 0 179 3. 959 0 000 1 7567 0 255 0 190 5. 486 0 000 1 8600 0 257 0 200 7 . 177 0 000 1 9633 0 259 0 211 9. 019 0 000 2 0667 0 262 0 222 10 . 99 0 000 2 1700 0 264 0 233 13 . 10 0 000 2 2733 0 266 0 244 15 .34 0 000 2 3767 0 269 0 255 17 . 68 0 000 2 4800 0 271 0 266 20 . 14 0 000 2 5833 0 274 0 277 22 .70 0 000 2 6867 0 276 0 288 25 .37 0 000 2 7900 0 278 0 300 28 . 13 0 000 2 8933 0 281 0 312 30 . 99 0 000 2 9967 0 283 0 323 33 . 94 0 000 3 1000 0 285 0 335 36 .97 0 000 3 2033 0 288 0 347 40 .09 0 000 3 3067 0 290 0 359 43 . 30 0 000 3 4100 0 292 0 371 46 .59 0 000 3 5133 0 295 0 383 49 . 96 0 000 3 6167 0 297 0 395 53 .40 0 000 3 7200 0 300 0 408 56 . 92 0 000 3 8233 0 302 0 420 60 .52 0 000 3 9267 0 304 0 433 64 .19 0 000 4 0300 0 307 0 445 67 . 93 0 000 4 1333 0 309 0 458 71 .74 0 000 4 2367 0 311 0 471 75 . 62 0 000 4 3400 0 314 0 484 79 .56 0 000 4 4433 0 316 0 497 83 .58 0 000 4 5467 0 319 0 510 87 . 65 0 000 4 6500 0 321 0 523 91 . 80 0 000 4 7533 0 323 0 537 96 . 01 0 000 4 8567 0 326 0 550 100.2 0 000 4 9600 0 328 0 563 104 . 6 0 000 0633 0 330 0 577 109. 0 0 000 5 1667 0 333 0 591 113. 4 0 000 5 2700 0 335 0 605 117 . 9 0 000 5 3733 0 338 0 619 122.5 0 000 5 4767 0 340 0 633 127.1 0 000 5 5800 0 342 0 647 131.8 0 000 5 6833 0 345 0 661 136.5 0 000 5 7867 0 347 0 675 141.3 0 000 5 8900 0 349 0 690 146.2 0 000 5 9933 0 352 0 704 151.1 0 000 10 Alps Innovation Hotels - Preliminary SWMP 6 . 0967 0 354 0 741 156 0 0 000 6 .2000 0 357 0 777 161 1 0 000 6 .3033 0 359 0 814 166 1 0 000 6 4067 0 361 0 852 171 2 0 000 6 5100 0 364 0 889 176 4 0 000 6 6133 0 366 0 927 181 6 0 000 6 7167 0 368 0 965 186 9 0 000 6 8200 0 371 1 003 192 2 0 000 6 9233 0 373 1 042 197 6 0 000 7 0267 0 376 1 080 203 0 0 000 7 1300 0 378 1 119 208 5 0 000 7 2333 0 380 1 159 214 0 0 000 7 3367 0 383 1 198 219 5 0 000 7 4400 0 385 1 238 225 2 0 000 7 5433 0 387 1 278 230 8 0 000 7 6467 0 390 1 318 236 5 0 000 7 7500 0 392 1 358 242 3 0 000 7 8533 0 395 1 399 248 1 0 000 7 9567 0 397 1 440 253 9 0 000 8 0600 0 399 1 481 259 8 0 000 8 1633 0 402 1 523 265 7 0 000 8 2667 0 404 1 564 271 7 0 000 8. 3700 0 406 1 606 277 7 0 000 8. 4733 0 409 1 648 283 8 0 000 8 . 5767 0 411 1 691 289 9 0 000 8 . 6800 0 414 1 734 296 0 0 000 8. 7833 0 416 1. 776 302 2 0 000 8. 8867 0. 418 1. 820 308 5 0 000 8. 9900 0. 421 1. 863 314 7 0 000 9. 0933 0. 423 1. 907 321 1 0 000 9. 1967 0. 425 1. 950 327 4 0 000 9. 3000 0. 428 1. 995 333 8 0 000 Name : BIORETENTI Surface#2 Bottom Length: 0.00 ft. Bottom Width: 0.00 ft. Material thickness of first layer: 0 Pour Space of material for first layer: Material thickness of second layer: 0 Pour Space of material for second layer: Material thickness of third layer: 0 Pour Space of material for third layer: Discharge Structure Riser Height: 0 ft. Riser Diameter: 0 in. Element Flows To: Outlet 1 BIORETENTION #2 Outlet 2 ANALYSIS RESULTS 11 Alps Innovation Hotels - Preliminary SWMP Predeveloped Landuse Totals for POC #1 Total Pervious Area:7.409 Total Impervious Area:0 Mitigated Landuse Totals for POC #1 Total Pervious Area:3.4 937 Total Impervious Area:3.8782 Flow Frequency Return Periods for Predeveloped. POC #1 Return Period Flow(cfs) 2 year 1.258106 5 year 2.58128 10 year 3.319548 25 year 4.309238 Flow Frequency Return Periods for Mitigated. POC #1 Return Period 2 year 5 year 10 year 25 year Flow(cfs) 0.164929 0.615292 1.104709 1.213411 3.32 0.13 "10e-4 IOE-3 IOE-2 lOE-1 F*ercent Time 1 10 100 12 Alps Innovation Hotels - Preliminary SWMP 10.0 i LL 1.0 0.1 - 0.01 Cumulative Probability T 10.0 -: 1.0 6 0.5 1 2 10 20 30 50 70 80 90 95 98 9999.5160 POC #1 The Facility PASSED The Facility PASSED. 0 0 Flow(cfs) 0.1258 1581 0.1903 0.2226 0.2549 0.2871 0.3194 0.3516 0.3839 0.4162 0.4484 0.4807 5129 0.5452 0.5775 0.6097 0.6420 0.6742 0.7065 0.7388 0.7710 0.8033 0.8355 0.8678 0.9000 0.9323 0. 9646 0.9968 Predev Mit Percentage Pass/Fail 233 254 109 Pass 207 166 80 Pass 185 124 67 Pass 169 107 63 Pass 152 93 61 Pass 137 75 54 Pass 132 65 49 Pass 123 53 43 Pass 118 42 35 Pass 110 36 32 Pass 107 33 30 Pass 104 26 25 Pass 98 25 25 Pass 97 19 19 Pass 92 19 20 Pass 87 15 17 Pass 85 14 16 Pass 82 13 15 Pass 80 12 15 Pass 78 9 11 Pass 76 8 10 Pass 74 8 10 Pass 69 8 11 Pass 67 6 8 Pass 64 6 9 Pass 60 6 10 Pass 58 6 10 Pass 56 6 10 Pass 13 Alps Innovation Hotels - Preliminary SWMP 1 0291 55 6 10 Pass 1 0613 53 5 9 Pass 1 0936 53 5 9 Pass 1 1259 49 4 8 Pass 1 1581 48 4 8 Pass 1 1904 43 2 4 Pass 1 2226 42 2 4 Pass 1 2549 41 1 2 Pass 1 2872 38 1 2 Pass 1 3194 35 1 2 Pass 1 3517 33 1 3 Pass 1 3839 32 1 3 Pass 1 4162 31 1 3 Pass 1 4485 28 1 3 Pass 1 4807 27 1 3 Pass 1 5130 27 1 3 Pass 1 5452 27 1 3 Pass 1 5775 24 1 4 Pass 1 6098 23 1 4 Pass 1 6420 23 1 4 Pass 1 6743 22 1 4 Pass 1 7065 22 1 4 Pass 1 7388 21 1 4 Pass 1 7711 19 1 5 Pass 1 8033 18 1 5 Pass 1 8356 18 1 5 Pass 1 8678 17 1 5 Pass 1 9001 17 1 5 Pass 1 9324 17 1 5 Pass 1 9646 16 0 0 Pass 1 9969 15 0 0 Pass 2 0291 14 0 0 Pass 2 0614 14 0 0 Pass 2 0937 14 0 0 Pass 2 1259 13 0 0 Pass 2 1582 12 0 0 Pass 2 1904 12 0 0 Pass 2 2227 12 0 0 Pass 2 2550 12 0 0 Pass 2 2872 12 0 0 Pass 2 3195 11 0 0 Pass 2 3517 , 11 0 0 Pass 2 3840 11 0 0 Pass 2 4163 10 0 0 Pass 2 4485 10 0 0 Pass 2. 4808 10 0 0 Pass 2. 5130 10 0 0 Pass 2 5453 10 0 0 Pass 2 5776 9 0 0 Pass 2 6098 8 0 0 Pass 2 6421 7 0 0 Pass 2 6743 7 0 0 Pass 2 7066 7 0 0 Pass 2 7389 7 0 0 Pass 2 7711 7 0 0 Pass 2 8034 6 0 0 Pass 2 8356 5 0 0 Pass 14 Alps Innovation Hotels - Preliminary SWMP 2 8679 5 0 0 Pass 2 9002 5 0 0 Pass 2 9324 5 0 0 Pass 2 9647 5 0 0 Pass 2 9969 5 0 0 Pass 3 0292 5 0 0 Pass 3 0615 5 0 0 Pass 3 0937 5 0 0 Pass 3 1260 5 0 0 Pass 3 1582 5 0 0 Pass 3 1905 5 0 0 Pass 3 2228 5 0 0 Pass 3 2550 5 0 0 Pass 3 2873 4 0 0 Pass 3 3195 4 0 0 Pass Pond: BIORETENTION # 1 Days Stage(feet) Percent 1 5.438 0.0000 2 5.438 0.0000 3 5.438 0.0000 4 5.438 0.0000 5 5.438 0.0000 Maximum Stage: 1.056 Drawdovm Time: 05 00 00:10 Pond: BIORETENTI Surface#2 Days Stage(feet) Percent 1 0.463 0.0400 2 0.557 0.0311 3 0.112 0.0144 4 3.270 0.0000 5 3.270 0.0000 Maximum Stage: 1.400 Drawdown Time: 05 00:00:10 Pond: BIORETENTION #3 Days Stage(feet) Percent 1 5.438 0.0000 2 5.438 0.0000 3 5.438 0.0000 4 5.438 0.0000 5 5.438 0.0000 Maximum Stage: 1.056 Drawdown Time: 05 00:00:10 15 Alps Innovation Hotels - Preliminary SWMP Perlnd and Implnd Changes No changes have been made. This program and accompanying documentation is provided 'as-is' without warranty of any kind. The entire risk regarding the performance and results of this program is assumed by the user. Clear Creek Solutions, Inc. disclaims all warranties, either expressed or implied, including but not limited to implied warranties of program and accompanying documentation. In no event shall Clear Creek Solutions, Inc. be liable for any damages whatsoever (including without limitation to damages for loss of business profits, loss of business information, business interruption, and the like) arising out of the use of, or inability to use this program even if Clear Creek Solutions, Inc. has been advised of the possibility of such damages. 16 ALPS Iimovation Hotels, Carlsbad, Califomia Hydraulic Analysis of basin outlet structures BIO-RETENTION BASIN #1 ORIFICE EQUATION Weir Formula for Orifices and Short Tubes (free & submerged) = Ca (2gHf^; ( Eq. 4-10, Brater & King, Handbook of Hydraulics) Where: Qyv = the flow rate, ft /sec C = the orifice coefficient of discharge a = the open area of the orifice g = the acceleration due to gravity H = head on the horizontal centeriine of the orifice Qy, = Ca((2*32.2)H/^ = Ca(64.4Hy^ ; (C = 0.6, Table 4-3 & 4-6, Brater & King, Handbook of Hydraulics) Q^ = 4.812a(Hy^ Orifice Outflow Calc: Given: Surface: H = L056ft (Max surface stage Q-lOyrfrom SDHM) a = 0.00196 sq. ft (0.6" diameter orifice) Surface Drawdown 5.556ft<H< 4.5ft • Designed with a surface infiltration rate of 3.0 in/hr • Anticipate a long term surface infiltration rate of 2.0 in/hr) Assume: Ho = 1.056' max surface stage +1.5'filter layer + 3.0' class IIperm layer HI =1.5'filter layer + 3.0' class 2 perm layer H2 =3.0' class 2perm layer Then Orifice limited outflow: Qwo = 0.022 cfs - Max Surface Stage (assumes infiltration is not limiting factor) Qwi =0.020 cfs - Zero Surface Stage (assumes infiltration is not limiting factor) Qw2 =0.016 cfs - Storage Stage (assumes only head from bottom rock course) 17 ALPS Irmovation Hotels, Carlsbad, Califomia Hydraulic Analysis of basin outlet stmctures INFILTRATION EQUATION Qi=AxI Where: QI = the flow rate, ft^/sec A = Basin Surface area Inflitration Outflow Calc: Given: k = 1,100 sf Assume: I = long term rate of infiltration Io = 3 in/hr Ii=2 in/hr (Anticipated stabilized long term infiltration rate) Then: Qio = 0.076 cfs Qn =0.051 cfs Infiltration inflow: 0.051 cfs <Qi< 0.076 cfs The water surface elevation of the bioretention Area (IMP 1) will be governed by Qw2. If the stabilized rate of infiltration were to be reduced by a factor of 3 to 1 in/hr then the surface outflow would still be govemed by the orifice control. For the drawdown calculations we will assume that the lose rate is limited to the rate of outflow from only Qw2 as this is a more conservative scenario. 18 ALPS Innovation Hotels, Carlsbad, Califomia Hydraulic Analysis of basin outlet stmctures BASIN DRAWDOWN TIME DISCHARGE EQUATION T=V/Q V=hsxA T=(hsXA)/Q where T = time duration of discharge in seconds V = volume of detained water ft^ Q = the flow rate, ft /sec hs = height of maximum surface stage from SDHM analysis A = surface area of the bioretention basin Drawdown Calc. Assume: The most conservative Q (lowest rate of inflitration) will be used to calculate the drawdown for the basin. Should it be determined in the field that the basin takes longer to drain then reflected in the calculations, then the basin surface shall require maintenance. Given: Then: hs = 1.056ft A=l,100sf Q = 0.016 cfs T = 72,600 secT = 1,210 min-^ T = 20.2 hrs Check: Is T (20.2 hrs) < Tmax (72hrs) YES Thus under the highest stage of surface inundation and the lowest rate of infiltration the bioretention facility will drain within 20.2 hours. 19 ALPS Innovation Hotels, Carlsbad, Califomia Hydraulic Analysis of basin outlet stmctures BIO-RETENTION BASIN #2 ORIFICE EQUATION Weir Formula for Orifices and Short Tubes (free & submerged) Qw = Ca (2gH)'^; ( Eq. 4-10, Brater & King, Handbook of Hydraulics) Where: Qw = the flow rate, ft /sec C = the orifice coefficient of discharge a = the open area of the orifice g = the acceleration due to gravity H = head on the horizontal centeriine of the orifice Q^ = Ca((2*32.2)H)^^^ Qw = Ca(64.4H)'^ ; (C = 0.6, Table 4-3 & 4-6, Brater & King, Handbook of Hydraulics) Qw = 4.812a(H)'^ Orifice Outflow Calc: Given: Surface: H = 1.40 ft (Max surface stage Q-lOyrfrom SDHM) a = 0.0066 sq. ft (1.1" diameter orifice) Surface Drawdown 7.4ft <H< 6.0ft • Designed with a surface infiltration rate of 3.0 in/hr • Anticipate a long term surface infiltration rate of 2.0 in/hr) Assume: Ho = 1.4' max surface stage +1.5'filter layer + 4.5' class IIperm layer HI =1.5'filter layer + 4.5' class 2perm layer H2 =4.5' class 2 perm layer Then Orifice limited outflow: Qwo = 0.086 cfs - Max Surface Stage (assumes infiltration is not limiting factor) Qwi =0.078 cfs - Zero Surface Stage (assumes infiltration is not limiting factor) Qw2 =0.067 cfs - Storage Stage (assumes only headfrom bottom rock course) 20 ALPS Innovation Hotels, Carlsbad, Califomia Hydraulic Analysis of basin outlet stmctures INFILTRATION EQUATION Qi=AxI Where: Ql = the flow rate, ft /sec A = Basin Surface area Infiltration Outflow Calc: I = long term rate of inflitration Given: K = 9,350 sf Assume: Io = 3 in/ hr Ii=2 in/hr (Anticipated stabilized long term infiltration rate) Then: Qio = 0.649 cfs Qn =0.433 cfs Infiltration inflow: 0.649 cfs <Qi< 0.433 cfs The water surface elevation of the bioretention Area (IMP 1) will be governed by Qw2. If the stabilized rate of infiltration were to be reduced by a factor of 6 to 0.5 in/hr then the surface outflow would still be govemed by the orifice control. For the drawdown calculations we will assume that the lose rate is limited to the rate of outflow from only Qw2 as this is a more conservative scenario. 21 ALPS Innovation Hotels, Carlsbad, Califomia Hydraulic Analysis of basin outlet stmctures BASIN DRAWDOWN TIME DISCHARGE EQUATION T=V/Q V=hsxA T=(hsxA)/Q where T = time duration of discharge in seconds V = volume of detained water ft^ Q = the flow rate, ft'^/sec hs = height of maximum surface stage from SDHM analysis A = surface area of the bioretention basin Drawdovm Calc. Assume: The most conservative Q (lowest rate of inflitration) will be used to calculate the drawdown for the basin. Should it be determined in the field that the basin takes longer to drain then reflected in the calculations, then the basin surface shall require maintenance. Given: hs = 1.40 ft A=9,350sf Then: Q = 0.067 cfs T = 195,373 sec T = 3,256 min-^ T = 54.3 hrs Check: Is T (54.3 hrs) < Tmax (72hrs) YES Thus under the highest stage of surface inundation and the lowest rate of infiltration the bioretention facility will drain within 54.3 hours. 22 ALPS Innovation Hotels, Carlsbad, Califomia Hydraulic Analysis of basin outlet stmctures BIO-RETENTION BASIN #3 ORIFICE EQUATION Weir Formula for Orifices and Short Tubes (free & submerged) Qw = Ca (2gHy^; ( Eq. 4-10, Brater & King, Handbook of Hydraulics) Where: Qw = the flow rate, ft /sec C = the orifice coefficient of discharge a = the open area ofthe orifice g = the acceleration due to gravity H = head on the horizontal centeriine of the orifice Qw = Ca((2*32.2)H)^^^ Qw = Ca(64.4Hf^ ; ( C = 0.6, Table 4-3 & 4-6, Brater & King, Handbook of Hydraulics) Qw = 4.812a(H)'^ Orifice Outflow Calc: Given: Surface: H=L056ft (Max surface stage Q-IOyrfrom SDHM) a = 0.00196 sq. ft (0.6" diameter orifice) Surface Drawdown 5.556ft < H < 4.5ft • Designed with a surface infiltration rate of 3.0 in/hr • Anticipate a long term surface infiltration rate of 2.0 in/hr) Assume: Ho = 1.056' max surface stage +1.5'filter layer + 3.0' class IIperm layer HI =1.5'filter layer + 3.0' class 2 perm layer H2 =3.0' class 2perm layer Then Orifice limited outflow: Qwo = 0.022 cfs - Max Surface Stage (assumes infiltration is not limiting factor) Qwi =0.020 cfs - Zero Surface Stage (assumes infiltration is not limiting factor) Qw2 =0.016 cfs - Storage Stage (assumes only headfrom bottom rock course) 23 ALPS Innovation Hotels, Carlsbad, Califomia Hydraulic Analysis of basin outlet stmctures INFILTRATION EQUATION Qi=AxI Where: QI = the flow rate, ft /sec A = Basin Surface area I = long term rate of inflitration Infiltration Outflow Calc: Given: A = 1,300 sf Assume: Io = 3 in/hr Ii=2 in/hr (Anticipated stabilized long term infiltration rate) Then: QIO = 0.090 cfs Qn =0.060 cfs Infiltration inflow: 0.090 cfs <Qi< 0.060 cfs The water surface elevation of the bioretention Area (IMP 1) will be governed by Qiy2. If the stabilized rate of infiltration were to be reduced by a factor of 3 to 1 in/hr then the surface outflow would still be govemed by the orifice control. For the drawdown calculations we will assume that the lose rate is limited to the rate of outflow from only Qfy2 as this is a more conservative scenario. 24 ALPS Innovation Hotels, Carlsbad, Califomia Hydraulic Analysis of basin outlet stmctures BASIN DRAWDOWN TIME DISCHARGE EQUATION T=V/Q V=hsxA T=(hsxA)/Q where T = time duration of discharge in seconds V = volume of detained water ft^ Q = the flow rate, ft /sec hs = height of maximum surface stage from SDHM analysis A = surface area of the bioretention basin Drawdown Calc. Assume: The most conservative Q (lowest rate of infiltration) will be used to calculate the drawdown for the basin. Should it be determined in the field that the basin takes longer to drain then reflected in the calculations, then the basin surface shall require maintenance. Given: Then: hs = 1.056ft A = I,300sf Q = 0.016 cfs T = 85,800 sec T= 1,430 min-^ T = 23.8 hrs Check: Is T(23.8 hrs) < Tmax (72hrs) YES Thus under the highest stage of surface inundation and the lowest rate of infiltration the bioretention facility will drain within 23.8 hours. 25 ALPS Innovation Hotels, Carlsbad, Califomia Hydraulic Analysis of basin outlet stmctures BASIN DRAWDOWN All basins will adequately drain within the 72 hr window. All surface storm water that exceeds that which is reflected in these calculations is assumed to be conveyed by the overflow orifice within a relatively short manner of time. These drawdown calculation times may seem excessively high, however they use the most conservative measures and are only considering losses due to infiltration and sub-drain system not the riser outlets. The SDHM model reflects the surface stage for bioretention facilities 1 & 2 to draw down in less than a single day and bioretention facility 3 to be less than 3 days. This matches relatively close to the drawdown calculations that were conducted above. 26