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HomeMy WebLinkAboutCT 06-25; Robertson Ranch PA 21; Robertson Ranch PA 21; 2009-05-201 STORM WATER MANAGEMENT PLAN For ROBERTSON RANCH EAST VILLAGE PLANNING AREA 21 C.T 06-25 C.P. 06-17 A nOu o OSct .2'•*-> °5 Prepared: November 2007 Revised: February 2009 Revised: March 2009 J.N. 01-1014 MAY 212009 ENGINEER/NO DEPARTMENT Prepared for: CALAVERA HILLS II, LLC A California Limited Liability Company 12865 Pointe Del Mar, Suite 200 Del Mar, CA 92014 Prepared by: O'DAY CONSULTANTS 2710 Loker Avenue West, Suite 100 Carlsbad, C A 92010 Tim O. Carroll RCE 55381 CO a: Table of Contents Section 1.0 - Vicinity Map Section 2.0 - Project Description • Narrative of Project Activities • Introduction of Storm Water Pollution Prevention Section 3.0 - Site Map Section 4.0 - Pollutants and Conditions of Concern Pollutants of Concern • Name and Number of Carlsbad Watershed Hydrological Unit Impaired Water Bodies Downstream of the Project and Impairment • San Diego Region Hydrologic Units, Areas, and Subareas (Fig. 1-2) • 2006 CWA Section 303 (d) List of Water Quality Limited Segments (list) • Storm Water Requirements Applicability Checklist (Appendix A) • Construction Site Priority (Part D) • Standard Development Project & Priority Project Storm Water BMP Requirements Matrix (Table 1) Conditions of Concern Section 5.0 - Site Design BMPs Section 6.0 - Source Control BMPs Fact & Maintenance Requirement Sheets for: • Efficient Irrigation (SD-12) • Storm Drain Signage (SD-13) Section 6.0 - Source Control BMPs (cont.) • Spill Prevention, Control & Cleanup (SC-11) • Road and Street Maintenance (SD-70) • Landscape Maintenance (SC-73) • Drainage System Maintenance (SC-74) Section 7.0 - Structural Treatment BMPs • Anticipated and Potential Pollutants Generated by Land Use Type (Table 2) • Numeric Sizing Treatment Standards (Table 3) • Structural Treatment Control BMP Selection Matrix (Table 4) • Fact Sheets for BMPs - Including Inspection, Maintenance, Costs and Training for: • Multiple Systems (TC-60) • Vegetated Swale (TC-30) • Drainage Inserts with "Bio Clean" Grated Inlets with Hydrocarbon Absorption Booms (MP-52 & Manufacturer's Information) Section 8.0 - Post Construction BMPs Maintenance Cost Responsibilities Section 9.0 — Drainage Study for Robertson Ranch East Village - Summary Section 10.0 - Storm Drain Plans G:\ACCTS\011014\PA21 \SWMP\COVER&TOC.DOC SECTION 1.0 '-'SS&Y 5 \"-&:'2-;rf.->££SKJ! '^u^n.>X' - 17'30» SCALE 1:24 000 KILOMETERS '003 t'ETEBS 1000 2:00 MILES FEET 70-JC CA SECTION 2.0 Section 2.0 Project Description Planning Area 21 is a 9.20 acre site located at the northwest corner of Cannon Road and Hilltop Street. The project consists of 84 "courtyard" homes with private streets, sewer, water, storm drain and other utilities. The site has currently been mass graded per Drawing 433-6A. All exterior slopes have erosion control in place. Exterior streets and storm drains have been built per Drawing 433-6. All drainage from the project eventually drains to the 84-inch storm drain along Cannon Road where the low flows will outlet into the bio-filter vegetated swale located south of Cannon Road. The swale is designed to handle the flows from all the developed areas of Robertson Ranch East Village PA13, PA14, PA15, PA16, PA17, PA 18, PA 19, PA 21, PA22, and an open space area PA 23. Waters then flow into Agua Hedionda Creek and then into the lagoon downstream. 2006 CWA Section 303(d) lists Agua Hedionda Creek as an impaired body of water with pollutants of concern being manganese, selenium, sulfates, and total dissolved solids and lists Agua Hedionda Lagoon as impaired with pollutants of concern being indicator bacteria and sediment siltation. 2.1 INTRODUCTION Federal, state and local agencies have established goals and objectives for storm water quality in the region. The proposed project, prior to the start of construction activities, complied with all federal, state and local permits including the National Pollution Discharge Elimination System (NPDES) from the Regional Water Quality Control Board and the erosion control requirements from the City of Carlsbad grading ordinance. The applicant filed a Notice of Intent (NOI) with the State Water Quality Control Board (SWQCB), applied Best Management Practices (BMPs) and developed a storm water pollution prevention plan (SWPPP). The SWPPP is to be submitted as part of the first submittal of precise grading plans and improvement plans to the City of Carlsbad. The Storm Water Management Plan provides guidelines in developing and implementing best management practices (BMPs) for storm water quality. It includes both source control BMPs and treatment control BMPs. Source control BMPs prevent contact between the storm water and the pollution source. Treatment control BMPs are those that treat the storm water to remove the pollutant. 2.2 PROJECT BMP PLAN IMPLEMENTATION The proposed project can be broken down into two distinct phases: construction and post construction. Construction would be the period when the project is being graded and all improvements shown on the tentative map, the precise grading plans, and the improvement plans are being installed. These include graded lots, storm drain system, water and sewer systems, buildings, parking lots, landscaping and treatment control BMP's. Post construction would occur when all grading has been completed and improvements have been installed. These activities include, but shall not be limited to the reinstallation/continued maintenance of final treatment control NPDES facilities. 2.2.1 Construction BMP Options The greatest potential for short-term water quality impacts to the drainage basin would be expected during and immediately following the grading and construction phases of the project when cleared and graded areas are exposed to rain and storm water runoff. Improperly controlled runoff could result in erosion and sediment transportation into the existing drainage basin. During construction, the objectives for implementing BMP's as described in the "California Storm Water Best Management Practice Handbook", are for the following: practice good housekeeping, contain waste, minimize disturbed areas, stabilize disturbed areas, protect slopes and channels, control site perimeter and control internal erosion. To mitigate storm water pollution, mostly sediment, during construction, both BMP's for contractor activities and BMP's for erosion and sedimentation shall be used. •" BMP's for contractor activities include the following: Managing dewatering/paving operations and structure construction/painting. Management of material delivery, use and storage. Spill prevention and control. Waste management for solid, hazardous and sanitary waste, contaminated soil, liquid, concrete. Vehicle and equipment cleaning, fueling and maintenance. Contractor, employee and subcontractor training. BMP's for erosion and sedimentation control include the following: Vegetative stabilization such as hydroseeding or mulching. Physical stabilization such as dust control, geotextiles and mats, construction road stabilization and stabilized construction entrance. Diversion of run-off using earth dikes, temporary swales and drains. Velocity reduction using outlet control, check dams and slope roughening. Sediment trapping using silt fence, gravel bag barrier, inlet protection, sediment traps and basins. A storm water pollution prevention plan (SWPPP) dated February 2009 has been prepared by O'Day Consultants and will be approved prior to issuance of a grading permit. The approved SWPPP shall be implemented during the construction phase. The •«*»"• SWPPP will consist of the selected BMP's, guidelines and activities to carry out actions which will prevent the pollution of storm water runoff. The SWPPP will also include the monitoring and maintenance of the construction BMP's during the construction phase. 2.2.2 Post Construction BMP Options Of the two phases, the post construction phase should generate the least amount of urban pollutants, sediment and erosion. The pollutants most likely to be generated during this phase will be sediment, nutrients, heavy metals, organic compounds, trash and debris, oxygen demanding substances, oil and grease, bacteria and viruses, and pesticides.(See Section 7.0) The post construction phase begins when grading has been completed and the landscaping, irrigation, the storm drain system, buildings, parking lot and the water quality catch basin inserts have been installed. During this phase a combination of the following source and treatment control BMP's shall be implemented. Source Control BMP's Grounds maintenance (Street/Parking, Landscaping, Plazas/Sidewalks, etc.) Plaza and sidewalk cleaning Drainage system maintenance Waste handling and disposal Water and sewer utility maintenance Non-stormwater discharges to drains %*""" Over watering activities Outdoor storage of raw materials Storm Drain Outlet Controls Treatment Control BMP's Water quality catch basin inserts w/ biofilters/media filtration Vegetative swale At a minimum, all treatment control BMP's should be inspected and maintained annually as described in the Best Management Handbooks and this SWMP. (Section 7) 2.2.3 Sizing Criteria The sizing of the treatment control BMP's shall comply with the volume/flow based criteria per the California Regional Water Quality Control Board, San Diego Region Order No. 2001-01. As required by the RWQCB and the City of Carlsbad, the project, depending on the type of BMP, will use one or both of the following numeric sizing criteria: Volume based BMP is volume of runoff produced from a 0.6" storm event. Flow based BMP is volume of runoff produced from rainfall of 0.2 in./hr. Even for the entire proposed 9.20 acre development, the minimum size for a flow based structural BMP theoretically treating the entire Site would be: Area: 9.20 acre Storm event: 0.2 in/hr Runoff coefficient: 0.60 (MDR 10.9 DU/A or Less) Flow to be treated = 0.60(0.2 in/hr)(9.20 ac) = 1.10 cfs CONCLUSION This Storm Water Management Plan has been prepared to define potential Best Management Plan (BMP) options, or schemes, that satisfy the requirements identified in the following documents: 1) Carlsbad Municipal Code Stormwater Management and Discharge Control Ordinance. 2) Standard Specifications for Public Works Construction 3) NPDES General Permit for Storm Water Discharges Associated with Construction Activity issued by the State Water Resources Control Board, and 4) San Diego NPDES Municipal Storm Water Permit (Order Number 2001-01) and 5) the City of Carlsbad Standard Urban Storm Water Mitigation Plan (SUSMP) revised 6/4/2008. Specifically, this report includes the following 1) Specific Site Design, Source Control, and Structural BMP options for the Project, 2) BMP device information for the Project options, and 3) A listing of the Post-Construction BMP's maintenance cost responsibilities. SECTION 3.0 SECTION 4.0 Section 4.0 Pollutants of Concern Based upon the Water Quality Control Plan for the San Diego Basin (9), the site is located in the Hydrologic Unit 904.31. The stormwater runoff from the site enters the public storm drain, discharges into Agua Hedionda Creek and ultimately drains into Agua Hedionda Lagoon. According to the 2006 CWA 303(d) List of Water Quality Limited Segments for the San Diego Basin(9), this watershed is tagged by the San Diego Regional Water Quality Control Board as receiving storm water runoff with high levels of manganese, selenium, sulfates, total dissolved solids, indicator bacteria and sediment/siltation. See the attached Hydrologic Unit Map and List. Storm Water Requirements Applicability Checklist As part of the submittal for an application for a grading and improvement permit, the Stormwater Standards Questionnaire in Appendix A of the City of Carlsbad Standard Urban Storm Water Mitigation Plan (SUSMP), revised June 4, 2008, must be completed. The purpose of this checklist is to confirm/determine the priority of the proposed development based on several factors, including the type of on-site development proposed and the total area and location of such development. Once the priority of the project is determined, Table Nos. 1 and 2 of the City SUSMP must be completed in order to select which BMP's are to be considered and which pollutants are anticipated and which have the potential to be generated on site due to the future and continued use of the developed project. Region 7 - Colorado River " , *»>, -*^f -^ * * ^^ * HydK*ogfc Area Bqundaiy;(HAJ Hydrologfe Subsu-ea Bountfary (HS^ i > Figure 1-2. San Diego Region Hydrologic Unite, Areas and Subareas. 048 16 i Miles 1:760,000 Domed from an edied version of Cslwater 2.21 to comply with Itie 1994 Basin Ran Map OMIsdOetobei 2004Stats Water Resources Control Board INTRODUCTION OSED 2006 CWA SECTION 303(d) LIST o. ^ QUALITY LIMITED SEGMENTS ( SAN DIEGO REGIONAL BOARD SWRCB APPROVAL DATE: OCTOBER 25, 2006 REGION TYPE NAME CALWATER WATERSHED POLLUTANT/STRESSOR POTENTIAL SOURCES ESTIMATED PROPOSED TMDL SIZE AFFECTED COMPLETION R Agiu Hedionda Creek 9 £ Agua Hedioada Lagoon R Aiiso Creek 90431000 90431000 90113000 Manganese Selenium Suttates Total Dissolved Solids Indicator bacteria Source Unknown Source Unknown Source Unknown Urban Rnnofirstorm Sewers Unknown Nonpoint Source Unknown poiot source Nonpout/Poiut Source Nennoint/Point Source 7 Miles 7 Miles 7 Miles 7 Mites 2019 2019 2019 2019 Acres Acres 19 Miles 2006 2019 2005 This listing for indicator bacteria applies to the Aliso Creek mainstem and all the major tributaries of Aiiso Creek which are Sulphur Creek. Wood Canyon, Aliso Hills Canyon, Dairy Fork, and English Canyon. Urban RunoiBStann Sewers Unknown point source NonpointfPoint Source Phosphorus 19 M^ 2019 This listing for phosphorus applies to the Aliso Creek mainstem and all the major tributaries of Aliso Creek which are Sulphur Creek, Wood Canyon. Aliso HiUi Canyon, Dairy Fork, tout English Canyon. Urban RnnoO/Stonn Sewers Unknown Nonpoint Source Unknown poitt source Page 1 of 27 NEW DEVELOPMENT PRIORITY PROJECT TYPE Does you project meet one or more of the following criteria: 1. Home subdivision of 100 units or more. Includes SFD, MFD, Condominium and Apartments 2. Residential development of 10 units or more. Includes SFD, MFD, Condominium and Apartments 3. Commercial and industrial develooment Greater than 1 00. 000 sauare feet includina parkina areas. Any development on private land that is not for heavy industrial or residential uses. Example: Hospitals, Hotels, Recreational Facilities, Shopping Malls, etc. 4. Heaw Industrial / Industry areater than 1 acre (NEED SIC CODES FOR PERMIT BUSINESS TYPES) SIC codes 5013, 5014, 5541, 7532-7534, and 7536-7539 5. Automotive repair shop. SIC codes 5013, 5014. 5541, 7532-7534, and 7536-7539 6. A New Restaurant where the land area of development is 5,000 sauare feet or more includina parkina areas. SIC code 581 2 7. Hillside develooment (1) greater than 5,000 square feet of impervious surface area and (2) development will grade on any natural slope that is 25% or greater 8. Environmentally Sensitive Area {ESA}. Impervious surface of 2,500 square feet or more located within, "directly adjacent"2 to (within 200 feet), or "discharging directly to"3 receiving water within the ESA1 9. Parkina lot. Area of 5,000 square feet or more, or with 15 or more parking spaces, and potentially exposed to urban runoff 10. Retail Gasoline Outlets - servina more than 100 vehicles per dav Serving more than 100 vehicles per day and greater than 5,000 square feet 11. Streets, roads, driveways, hiahways, and freeways. Project would create a new paved surface that is 5,000 square feet or greater. 12. Coastal Development Zone. Within 200 feet of the Pacific Ocean and (1) creates more than 2500 square feet of impermeable surface or (2) increases impermeable surface on property by more than 10%. YES * X X NO X X X x X X X X 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 Quality Control Plan for the San Diego Basin (1994) and amendments); water bodies designated with the RARE beneficial use by the State Water Resources Control Board (Water Quality Control Plan for the San Diego Basin (1994) and amendments); areas designated as preserves or their equivalent under the Multi Species Conservation Program within the Cities and Count of San Diego; and any other equivalent environmentally sensitive areas which have been identified by the Copermittees. 2 "Directly adjacent" means situated within 200 feet of the environmentally sensitive area. 3 "Discharging directly to" means outflow 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. Section 1 Results: If you answered YES to ANY of the questions above you have a PRIORITY project and PRIORITY project requirements DO apply. A Storm Water Management Plan, prepared in accordance with City Storm Water Standards, must be submitted at time of application. Please check the "MEETS PRIORITY REQUIREMENTS" box in Section 3. If you answered NO to ALL of the questions above, then you are a NON-PRIORITY project and STANDARD requirements apply. Please check the "DOES NOT MEET PRIORITY Requirements" box in Section 3. SECTION 2 SIGNIFICANT REDEVELOPMENT: 1 . Is the project redeveloping an existing priority project type? (Priority projects are defined in Section 1 ) YES NO X If you answered YES, please proceed to question 2. If you answered NO, then you ARE NOT a significant redevelopment and you ARE NOT subject to PRIORITY project requirements, only STANDARD requirements. Please check the "DOES NOT MEET PRIORITY Requirements" box in Section 3 below. 2. Is the project solely limited to one of the following: a. Trenching and resurfacing associated with utility work? b. Resurfacing and reconfiguring existing surface parking lots? c. New sidewalk construction, pedestrian ramps, or bike lane on public and/or private existing roads? ••* Replacement of existing damaged pavement? If y.. >red NO to ALL of the questions, then proceed to Question 3. If Y u ,: ,-red YES to ONE OR MORE of the questions then you ARE NOT a significant redevelopment a,.-; yi %iiE NOT subject to PRIORITY project requirements, only STANDARD requirements. Please check 3 NOT MEET PRIORITY Requirements" box in Section 3 below. 3. vviii the development create, replace, or add at least 5,000 square feet of I impervious surfaces on an existing development or, be located within 200 of the Pacific Ocean and (1)create more than 2500 square feet of srmeable surface or (2) increases impermeable surface on property by more than 10%? if -'ou answered YES, you ARE a significant redevelopment, and you ARE subject to PRIORITY project jirements. Please check the "MEETS PRIORITY REQUIREMENTS" box in Section 3 below. If u answered NO, you ARE NOT a significant redevelopment, and you ARE NOT subject to PRIORITY project requirements, only STANDARD requirements. Please check the "DOES NOT MEET PRIORITY Requirements" box in Section 3 below. SECTION 3 Questionnaire Results: Q MY PROJECT MEETS PRIORITY REQUIREMENTS, MUST COMPLY WITH PRIORITY PROJECT STANDARDS AND MUST PREPARE A STORM WATER MANAGEMENT PLAN FOR SUBMITTAL AT TIME OF APPLICATION. MY PROJECT DOES NOT MEET PRIORITY REQUIREMENTS AND MUST ONLY COMPLY WITH STANDARD STORM WATER REQUIREMENTS. Applicant Information and Signature Box -02, 08 This Bus for i'ily L'.vf Only Address4 Assessors Parcel Numbcr(s): Applicant Name: D. Applicant Signature: Applicant Title:Vice, Date: City Concurrence:YES NO By: Date: Project ID: Standard Development Project & Priority Project Storm Water BMP Requirements Matrix Standard Projects LID Site Design BMPs'1' R Source Control BMPs121 R BMPs Applicable to Individual Priority Project Cateaories(3)a. Private RoadsR 10 <# £ & Si ga 5:1to > ifo> -n raa: a a. JO R c. Dock AreasR d. Maintenance BaysR e. Vehicle Wash AreasR w S •4— • 1Q. 01 1J 111 < *^ R g. Outdoor ProcessingAreasR O) 1 llCO < jf R toCO 1en "55 U_ R j. Hillside LandscapingR Treatment Control BMPs141 O Priority Projects: Detached Residential Development Attached Residential Development Commercial Development greater than 100,000ft2 Heavy industry /industrial Automotive Repair Shop Restaurants Steep Hillside Development greater than 5,000 ft2 Parking Lots Retail Gasoline Outlets Streets, Highways & Freeways CR) R R R R R R R R © (B) R R R R R R R R ® ® R R R © R R R R R R R R R R R R R R R R R R R(5) R R R (E) R © s s s s s s s s CD " R = Required; select one or more applicable and appropriate BMPs from the applicable steps in Section III.2.A-D, or equivalent as identified in Appendix B. O = Optional/ or may be required by City staff. As appropriate, applicants are encouraged to incorporate treatment control BMPs and BMPs applicable to individual priority project categories into the project design. C ty staff may require one or more of these BMPs, where appropriate. S = Select one or more applicable and appropriate treatment control BMPs from Appendix B. (1 ) Refer to Chapter 2.3.3.1 . LID = Low Impact Development. (2) Refer to Chapter 2.3.3.2. (3) Priority project categories must apply specific storm water BMP requirements, where applicable. Priority projects are subject to the requirements of all priority project categories that apply. Refer to Chapter 2.3.3.3 (4) Refer to Chapter 2.3.3.4 (5) Applies if the paved area totals >5,000 square feet or with >15 parking spaces and is potentially exposed to urban runoff. SWMP Rev 6/4/08 Conditions of Concern 1. See the hydrology/hydraulic study prepared specifically for this lot. This study includes calculations for the design of the storm drain conveyance system prior to the connection with the private storm drain in Planning Area 15 (SDP 06-04, DWG 450-6) and the public storm drain system designed as part of the Robertson Ranch East Village CT 02-16 (DWG 433.6). 2. The existing Site drains into a branch of Agua Hedionda Creek, passing under El Camino Real and then on into Agua Hedionda Lagoon. SECTION 5.0 Site Design BMPs See Site Map (in Section 3.0) 1. Our site plan is utilizing the minimum widths required on-site. 2. All the slopes and landscape areas will have permanent landscaping consistent with the Carlsbad Landscape Manual. Existing hillside areas disturbed by the project development shall be landscaped deep- rooted drought tolerant plant species selected for erosion control, in accordance with Carlsbad Landscape Manual. 3. Impervious surfaces are disconnected by directing roof drains into landscaped areas prior to draining into private streets or storm drain. 4. This planning area was created concentrating development on the least environmentally sensitive portions on the East Village while leaving the remaining land in a natural undisturbed condition. SECTION 6.0 Section 6.0 Source Control BMPs 1. Hazardous materials with potential to contaminate urban runoff will not be stored on-site. 2. Spills of fuels and other hazardous materials on-site shall be prevented as much as possible by developing procedures to prevent/mitigate spills into the storm drain system. A Spill Prevention Control and Countermeasure (SPCC) Plan will be developed as part of the construction activities on-site (See Fact Sheet SC-11) 3. The project will use efficient irrigation systems and landscape design to include rain shut-off devices to prevent irrigation during precipitation, consistent with the Carlsbad Landscape Manual. Irrigation systems will be designed to each landscape area's specific water requirements consistent with the Carlsbad Landscape Manual. (See Fact Sheet SD- 12) 4. The storm drain inlets will be provided with signage of prohibitive language (e.g. "No Dumping - I Live Downstream") satisfactory to the City Engineer. (See Fact Sheet SD-13) 5. Street and parking areas to be maintained (SC-43 & SC-70). 6. Landscape areas have been incorporated into the drainage system design and are to be maintained (SC-73). 7. Storm drains to be maintained (SC-74). Design Objectives y Maximize Infiltration / Provide Retention / Slow Runoff Minimize Impervious Land Coverage Prohibit Dumping of Improper Maten'als Contain Pollutants Collect and Convey Description Irrigation water provided to landscaped areas may result in excess irrigation water being conveyed into stormwater drainage systems. Approach Project plan designs for development and redevelopment should include application methods of irrigation water that minimize runoff of excess irrigation water into the stormwater conveyance system. Suitable Applications Appropriate applications include residential, commercial and industrial areas planned for development or redevelopment. (Detached residential single-family homes are typically excluded from this requirement.) Design Considerations Designing New Installations The following methods to reduce excessive irrigation runoff should be considered, and incorporated and implemented where determined applicable and feasible by the Permittee: • Employ rain-triggered shutoff devices to prevent irrigation after precipitation. • Design irrigation systems to each landscape area's specific water requirements. • Include design featuring flow reducers or shutoff valves triggered by a pressure drop to control water loss in the event of broken sprinkler heads or lines. a Implement landscape plans consistent with County or City water conservation resolutions, which may include provision of water sensors, programmable irrigation times (for short cycles), etc. California . Stormwater QuaHty "i^' Association January 2003 V^X!rjmKKSi?B-K?^MMM*SU1 California Stormwater BMP Handbook 1 of 2 ( m Design timing and application methods of irrigation water to minimize the runoff of excess irrigation water into the storm water drainage system. a Group plants with similar water requirements in order to reduce excess irrigation runoff and promote surface filtration. Choose plants with low irrigation requirements (for example, native or drought tolerant species). Consider design features such as: Using mulches (such as wood chips or bar) in planter areas without ground cover to minimize sediment in runoff - Installing appropriate plant materials for the location, in accordance with amount of sunlight and climate, and use native plant materials where possible and/or as recommended by the landscape architect Leaving a vegetative barrier along the property boundary and interior watercourses, to act as a pollutant filter, where appropriate and feasible Choosing plants that minimize or eliminate the use of fertilizer or pesticides to sustain growth • Employ other comparable, equally effective methods to reduce irrigation water runoff. Redeveloping Existing Installations , ^^Various jurisdictional stormwater management and mitigation plans (SUSMP, WQMP, etc.) i i define "redevelopment" in terms of amounts of additional impervious area, increases in gross floor area and/or exterior construction, and land disturbing activities with structural or impervious surfaces. The definition of " redevelopment" must be consulted to determine whether or not the requirements for new development apply to areas intended for redevelopment. If the definition applies, the steps outlined under "designing new installations" above should be followed. Other Resources A Manual for the Standard Urban Stormwater Mitigation Plan (SUSMP), Los Angeles County Department of Public Works, May 2.002.. Model Standard Urban Storm Water Mitigation Plan (SUSMP) for San Diego County, Port of San Diego, and Cities in San Diego County, February 14, 2002. Model Water Quality Management Plan (WQMP) for County of Orange, Orange County Flood Control District, and the Incorporated Cities of Orange County, Draft February 2003. Ventura Countywide Technical Guidance Manual for Stormwater Quality Control Measures, July 2002. 2 of 2 California Stormwater BMP Handbook January ?nm Maximize Infiltration Provide Retention Slow Runoff Minimize Impervious Land Coverage Prohibit Dumping of Improper Materials Contain Pollutants Collect and Convey Description Waste materials dumped into storm drain inlets can have severe impacts on receiving and ground waters. Posting notices regarding discharge prohibitions at storm drain inlets can prevent waste dumping. Storm drain signs and stencils are highly visible source controls that are typically placed directly adjacent to storm drain inlets. Approach The stencil or affixed sign contains a brief statement that prohibits dumping of improper materials into the urban runoff conveyance system. Storm drain messages have become a popular method of alerting the public about the effects of and the prohibitions against waste disposal. Suitable Applications Stencils and signs alert the public to the destination of pollutants discharged to the storm drain. Signs are appropriate in residential, commercial, and industrial areas, as well as any other area where contributions or dumping to storm drains is likely. Design Considerations Storm drain message markers or placards are recommended at all storm drain inlets within the boundary of a development project. The marker should be placed in clear sight facing toward anyone approaching the inlet from either side. All storm drain inlet locations should be identified on the development site map. Designing New Installations The following methods should be considered for inclusion in the project design and show on project plans: a Provide stenciling or labeling of all storm drain inlets and catch basins, constructed or modified, within the project area with prohibitive language. Examples include "NO DUMPING - January 2003 California Stormwater BMP Handbook 1 nf 7 DRAINS TO OCEAN" and/or other graphical icons to discourage illegal dumping. m Post signs with prohibitive language and/or graphical icons, which prohibit illegal dumping at public access points along channels and creeks within the project area. Note - Some local agencies have approved specific signage and/or storm drain message placards for use. Consult local agency stormwater staff to determine specific requirements for placard types and methods of application. Redeveloping Existing Installations Various jurisdictional stormwater management and mitigation plans (SUSMP, WQMP, etc.) define "redevelopment" in terms of amounts of additional impervious area, increases in gross floor area and/or exterior construction, and land disturbing activities with structural or impervious surfaces. If the project meets the definition of "redevelopment", then the requirements stated under " designing new installations" above should be included in all project design plans. Additional Information Maintenance Considerations • Legibility of markers and signs should be maintained. If required by the agency with jurisdiction over the project, the owner/operator or homeowner's association should enter , into a maintenance agreement with the agency or record a deed restriction upon the i •«""•" property title to maintain the legibility of placards or signs. Placement m Signage on top of curbs tends to weather and fade. • Signage on face of curbs tends to be worn by contact with vehicle tires and sweeper brooms. Supplemental Information Examples m Most MS4 programs have storm drain signage programs. Some MS4 programs will provide stencils, or arrange for volunteers to stencil storm drains as part of their outreach program. Other Resources A Manual for the Standard Urban Stormwater Mitigation Plan (SUSMP), Los Angeles County Department of Public Works, May 2002. Model Standard Urban Storm Water Mitigation Plan (SUSMP) for San Diego County, Port of San Diego, and Cities in San Diego County, February 14, 2002. Model Water Quality Management Plan (WQMP) for County of Orange, Orange County Flood Control District, and the Incorporated Cities of Orange County, Draft February 2003. Ventura Countywide Technical Guidance Manual for Stormwater Quality Control Measures, uly 2002. 2 of 2 California Stormwater BMP Handbook Janua"ry~2003 Spill Prevention, Control & Cleanup SC-li Spills and leaks are one of the largest contributors of stormwater pollutants. Spin prevention and control plans are applicable to any site at which hazardous materials are stored or used. An effective plan should have spill prevention and response procedures that identify potential spin areas, specify material handling procedures, describe spin response procedures, and provide spill clean-up equipment The plan should take steps to identify and characterize potential spills, eliminate and reduce spiU potential, respond to spills when they occur in an effort to prevent pollutants from entering the stormwater drainage system, and tram personnel to prevent and control future spills. Approach Pollution Prevention m Develop procedures to prevent/mitigate spills to storm drain systems. Develop and standardize reporting procedures, containment, storage, and disposal activities, documentation, and follow-up procedures. • Develop a Spill Prevention Control and Countermeasure (SPCC) Plan. The plan should include: Objectives Cover Contain Educate Reduce/Minimize Product Substitution Description Many activities that occur at an uidustrial or commercial site have the potential to cause accidental or illegal spills. Sediment Preparation for accidental or illegal spills, with proper training Nutrients and reporting systems implemented, can minimize the discharge Trash of pollutants to the environment. Mgta)8 Targeted Constituents Bacteria Oil and Grease Organic* \ SO A California Stormwater Quality Association January 2003 California Sfcormwater BMP Handbook industrial and Commercial Iof9 SC-11 Spill Prevention, Control & Cleanup - Desci^lionofthefacilily.ownerandaddress.actmtiesandchemicalsptesent Facility map - Notification and evacuation procedures Cleanup instructions - Identification of responsible departments - Identity key spill response personnel process materials that are brought into the facility. Suggested Protocols (including equipment needs) Spitt. Prevention standardize reporting procedures, containment, storage, and disnosal activitiJidocumentation, and follow-up procedures. oisposai activities, , ... • If consistent illegal dumping is observed at the facility: (• - Post "No Dumping" sips wira a phone number for reporting illegaldu disposal. Signs should also indicate fines and penalties B^^tingand/orentrancebarriersmayalsobeneededtodiscourageaiegaldumping. ° Store and contain liquid materials in such a manner that if the tankflow' If JeUquWisoil.gas.orothermaterialthatseparatesfromandfloataonvrater install a sS?a"entSi S? Routine maintenance: . ..««««i« taps, and at all potentialdrip and spill locations during filling and unloading of tanks. Any collected liquids orsoiled absorbent materials mst_ — ——a v» uuuo. fuiy iKiiievuH absorbent materials must be reused/recycled or properly disposed. Store and maintain appropriate spill cleanup materials in a location known to all near the tank storage area; and ensure that employees are familiar with the site's spill control plan and/or proper spill cleanup procedures. Sweep and clean the storage area monthly if it is paved, do not hose down the area to astorm drain. 2 °f 9 California Stormwater BMP Handbook Jan 20Q, Industrial and CommarHsi Spill Prevention, Control ft Cleanup SC-11 areleaking, corroded, ^^^iS^^'S^^ all spilled liquids and properly dispose of them. "luumon. uwect • I*bel all containers according to their contents (e.g., solvent, gasoline). (corrosive, radioactive, *""*«* *•»*« "* t»»c materials (per US • Identify key spill response personnel. Spitt Control and Cleanup Activities • FoUowtheSpfflPreventionControlandCountermeasurePlan. • Clean up leaks and spills immediately. . Neverhosedownorburydrymaterialspuls. Sweep up the materiaUnd dispose of properly ' . For larger spills, a private spill cleanup company or Hazmat team may be necessary. Reporting . Report spilb to local agencies, such as the fire department; Ihey can assist in cleanup. 'or tracking incident Tlesystem should be designed ,o identify the Types and quantities (in some cases) of wastes Patterns in time of occurrence (time of day/night, month, or year) 3 of 9 \ SC-11 SPJI> Prevention, Control & Cleanup - Mode of dumping (abandoned containers, "midnight dumping" from moving vehicles, direct dumping of materials, accidents/spills) - Responsible parties Training m Educate employees about spill prevention and cleanup. • Well-trained employees can reduce human errors that lead to accidental releases or spills: - Ifce employee should have the tools and knowledge to immediately begin cleaning up aspill should one occur. ' * ^* F - Employeesshmddbefamaiarwifoto^ Jrl&Il* . Itoployewshouldbeeduratedabotf Employees raonnnaiRlo firtv ahsnramvnmil <•*•»___ *.__! J »« .m.. - ^ _ jf —_j~~.» familiar readily available. • Train employees to recognize and report illegal dumping incidents. Other Considerations (Limitations and Regulations) a storage ***** rf 10«000 Sanons or more ofPrevention Cortiol and Countermeasure (SPCQ Plan (Health & f h^doUS material8 (Healtl1 & Safe«y Code ^pter., and business plans for emergency response to thereleases or threatened releases. t~«c«*uw • Consider requiring smaller secondary containment areas (less than 200 sq. ft.) to be connected to the sanitary sewer, prohibiting any hard connections to the storm drain. Requirements Costs (including capital and operation & maintenance) • Will vary depending on the size of the facility and the necessary controls. Maintenance (including administrative and staffing) " ™^hMno™J<^ However, extra time isneeded to properly handle and dispose of spills, which results in increased labor costs. California Stormwater BMP Handbook January 2003 Spill Prevention, Control & Cleanup SO 11 i- Supplemental Information Further Detail of the BMP Reporting Record keeping and internal reporting represent good operating practices because they can increase the efficiency of thefacOity and the effectiveness of BMPs. A good record keeping system helps the facility minimize incident recurrence, correctly respond with appropriate cleanup activities, and comply with legal requirements. A record keeping and reporting system should be set up for documenting spills, leaks, and other discharges, including discharges of hazardous substances in reportable quantities. Incident records describe the quality and quantity of non-stormwater discharges to the storm sewer. These records should contain thefollowing information: • Date and time of the incident • Weather conditions • Duration of die spill/leak/discharge • Cause of the spin/leak/discharge • Response procedures implemented • Persons notified • Environmental problems associated with the spill/leak/discharge Separate record keeping systems should be established to document housekeeping and preventive maintenance inspections, and training activities. All housekeeping and preventive maintenance inspections should be documented. Inspection documentation should contain the following information: • The date and time the inspection was performed • Name of the inspector • Items inspected • Problems noted • Corrective action required • Date corrective action was taken Other means to document and record inspection results are field notes, timed and dated photographs, videotapes, and drawings and maps. Aboveground Tank Leak and Spill Control Accidental releases of materials from aboveground liquid storage tanks present the potential for contaminating stormwater with many different pollutants. Materials spilled, leaked, or lost from January 2003 California Stormwater BMP Handbook ~^ ™ ""'"" c",l# «" SOU Spill Prevention, Control & Cleanup tanks may accumulate in soils or on impervious surfaces and be carried away by stormwater runoff. The most common causes of unintentional releases are: • Installation problems • Failure of piping systems (pipes, pumps, flanges, couplings, hoses, and valves) • External corrosion and structural failure • Spills and overfills due to operator error • Leaks during pumping of liquids or gases from truck or rail car to a storage tank or vice versa Storage of reactive, ignitable, or flammable liquids should comply with the Uniform Fire Code and the National FJectric Code. Practices listed below should be employed to enhance the code requirements: • Tanks should be placed in a designated area. • Tanks located in areas where firearms are discharged should be encapsulated in concrete or the equivalent • Designated areas should be impervious and paved with Portland cement concrete, free of cracks and gaps, in order to contain leaks and spills. m. liquid materials should be stored in UL approved double walled tanks or surrounded by a curb or dike to provide the volume to contain 10 percent of the volume of all of the containers or no percent of the volume of the largest container, whichever is greater. The area inside the curb should slope to a drain. • For used oil or dangerous waste, a dead-end sump should be installed in the drain. • All other liquids should be drained to the sanitary sewer if available. The drain must have a positive control such as a lock, valve, or plug to prevent release of contaminated liquids. • Accumulated stormwater in petroleum storage areas should be passed through an oil/water separator. Maintenance is critical to preventing leaks and spills. Conduct routine inspections and: • Check for external corrosion and structural failure. • Check for spills and overfills due to operator error. • Check for failure of piping system (pipes, pumps, Hanger, coupling, hoses, and valves). * • Check for leaks or spills during pumping of liquids or gases from truck or rail car to a storage facility or vice versa. 6 of 9 California Stormwater BMP Handbook January 2003 Industrial and Spill Prevention, Control & Cleanup SC-11 • Visually inspect new tank or container installation for loose fittings, poor welding, and improper or poorly fitted gaskets. • Inspect tank foundations, connections, coatings, and tank walla and piping system. Look for corrosion, leaks, cracks, scratches, and other physical damage that may weaken the tank or container system. • Frequently relocate accumulated stormwater during the wet season. • Periodically conduct integrity testing by a qualified professional. Vehicle Leak and Spiff Control Major spills on roadways and other public areas are generally handled by highly trained Hazmat teams from local fire departments or environmental health departments. The measures listed below pertain to leaks and smaller spills at vehicle maintenance shops. In addition to implementing the spill prevention, control, and clean up practices above, use the following measures related to specific activities: Vehicle and Equipment Maintenance m Perform all vehicle fluid removal or changing inside or under cover to prevent the run-on of stormwater and the runoff of spills. • Regularly inspect vehicles and equipment for leaks, and repair immediately. • Check incoming vehicles and equipment (including delivery trucks, and employee and subcontractor vehicles) for leaking oil and fluids. Do not allow leaking vehicles or equipment onsite. • Always use secondary containment, such as a drain pan or drop cloth, to catch spills or leaks when removing or changing fluids. • Immediately drain all fluids from wrecked vehicles. • Store wrecked vehicles or damaged equipment under cover. • Place drip pans or absorbent materials under heavy equipment when not in use. • Use adsorbent materials on small spills rather than hosing down the spill. • Remove the adsorbent materials promptly and dispose of properly. • Promptly transfer used fluids to the proper waste or recycling drums. Don't leave full drip pans or other open containers lying around. • Oil filters disposed of in trashcans or dumpsters can leak oil and contaminate stormwater. Place the oil filter in a funnel over a waste oil recycling drum to drain excess oil before disposal. Oil filters can also be recycled. Ask your oil supplier or recycler about recycling oil filters. January 2003 California Stormwater BMP Handbook 7 of 9 SOU Spill Prevention, Control & Cleanup • Store cracked batteries in a non-leaking secondary container. Do this with all cracked batteries, even if you think all the acid has drained out If you drop a battery, treat it as if it is cracked. Put it into the containment area until you are sure it is not leaking. Vehicle and Equipment Fueling m Design the fueling area to prevent the run-on of stormwater and the runoff of spills: - Cover fueling area if possible. - Use a perimeter drain or slope pavement inward with drainage to a sump. - Pave fueling area with concrete rather than asphalt. • If dead-end sump is not used to collect spills, install an oil/water separator. • Install vapor recovery nozzles to help control drips as well as air pollution. • Discourage "topping-off of fuel tanks. • Use secondary containment when transferring fuel from the tank truck to the fuel tank. • Use adsorbent materials on small spills and general cleaning rather than hosing down the area. Remove the adsorbent materials promptly. • Carry out all Federal and State requirements regarding underground storage tanks, or install above ground tanks. • Do not use mobile fueling of mobile industrial equipment around the facility; rather, transport the equipment to designated fueling areas. • Keep your Spill Prevention Control and Counter-measure (SPCC) Plan up-to-date. • Train employees in proper fueling and cleanup procedures. Industrial Spill Prevention Response For the purposes of developing a spill prevention and response program to meet the stormwater regulations, facility managers should use information provided in this fact sheet and the spill prevention/response portions of the fact sheets in this handbook, for specific activities. The program should: • Integrate with existing emergency response/hazardous materials programs (e.g., Fire Department) • Develop procedures to prevent/mitigate spills to storm drain systems • Identify responsible departments • Develop and standardize reporting procedures, containment, storage, and disposal activities, documentation, and follow-up procedures i Address spills at municipal facilities, as well as public areas 8 of 9 California Stormwater BMP Handbook January 2003 Industrial and *Spill Prevention, Control & Cleanup SOU • Provide training concerning spill prevention, response and cleanup to all appropriate References and Resources California's Nonpoint Source Program Plan http://www.swrcb.ca.gov/nps/index.html Clark County Storm Water Pollution Control Manual ht^;//wronv.m.dark.wa.us/pubworks/bmpman.pdf King County Storm Water Pollution Control Manual http://dpr.fnp.tTnkc.gov/wlr/dsa/spcm.htni Santa Clara Valley Urban Runoff Pollution Prevention Program http://www.scvurppp.org The Stormwater Managers Resource Center http://www.atormwatercenter.net/ January 2003 California Stormwater BMP Handbook Industrial and Commercial 9 of 9 ( toad and Street Maintenance SC-70 ascription xeeta, roads, and highways an significant sources of pollutants a stonnwatef dtochargea, and operation and maintenance (OftM) practices, if not conducted properly, can contribute to the problem. Stomwaterponutionfom roadway and bridge maintenance should be addressed OQ a site-apedflcbasta. Use of toprowdiires outlraedbelow. that address street sweeping and repair, bridge and structure maintenance, and unpaved roads wffl reduce pollutants in stormwater. Approach Pollution Prevention paints, geU or sprays for graffiti removal) • Recycle paint and other materials whenever possible. • Enlist the help of citizens to keep yard waste, used oil, and other wastes out of the gutter. Suggested Protocols Street Sweeping and Cleaning • Maintain a consistent sweeping schedule. Provide minimum monthly sweeping of curbed streets. Perform street cleaning during dry weather if possible. Objectives • Cover • Contain • Educate • Reduce/Minimize • Product Substitution Targeted Constituents Sedbmnt Nutrients Trash Metals flnf tiiriii 01 and Grease Ofgantet Oxygen Demanding / / / / >\ Californ» \ Stormwatw . .; ^ Quality „/,' Ajsoelatlon January 2003 California Starmiwtalter BMP SC-70 Road and Street Maintenance • Avoid wet cleaning or flushing of street, and utilize dry methods where possible. • Consider increasing sweeping frequency based on factors such as traffic volume, land use, field observations of sediment and trash accumulation, proximity to watercourses, etc. For example: - Increase the sweeping frequency for streets with high pollutant loadings, especially in high traffic and industrial areas. . Increase the sweeping frequency just before the wet season to remove sediments accumulated during the summer. - Increase the sweeping frequency for streets in special problem areas such as special events, high Utter or erosion zones. • Maintain cleaning equipment in good working condition and purchase replacement equipment as needed. Old sweepers should be replaced with new technologically advanced sweepers (preferably regenerative air sweepers) that maximize pollutant removal. i Operate sweepers at manufacturer requested optimal speed levels to increase effectiveness. • To increase sweeping effectiveness consider the following: - Institute a parking policy to restrict parking in problematic areas during periods of street sweeping. - Post permanent street sweeping signs in problematic areas; use temporary signs if installation of permanent signs is not possible. - Develop and distribute flyers notifying residents of street sweeping schedules. • Regularly inspect vehicles and equipment for leaks, and repair immediately. • If available use vacuum or regenerative air sweepers in the high sediment and trash areas (typically industrial/commercial). • Keep accurate logs of the number of curb-miles swept and the amount of waste collected. • Dispose of street sweeping debris and dirt at a landfill. • Do not store swept material along the side of the street or near a storm drain inlet. • Keep debris storage to a minimum during the wet season or make sure debris piles are contained (e.g. by berming the area) or covered (e.g. with tarps or permanent covers). Street Repair and Maintenance Pavement marking m Schedule pavement marking activities for dry weather. c Road and Street Maintenance SC-70 • Develop paint handling procedures for proper use, storage, and disposal of paints. • Transfer and load paint and hot thermoplastic away from storm drain inlets. • Provide drop cloths and drip pana in paint mixing areas. • Properly maintain application equipment. • Street sweep thermoplastic grindings. Yellow thermoplastic grindings may require special handling as they may contain lead. • Paints containing lead or tributyltin are considered a hazardous waste and must be disposed of property. • Use water based paints whenever possible. If using water based paints, clean the application equipment hi a sink that is connected to the sanitary sewer. • Properly store leftover paints if they are to be kept for the next job, or dispose of properly. Concrete installation and repair'•**«>»*- (, m Schedule asphalt and concrete activities for dry weather. \ ( • Take measures to. protect any nearby storm drain inlets and adjacent watercourses, prior to breaking up asphalt or concrete (e.g. place san bags around inlets or work areas). • Limit the amount of fresh concrete or cement mortar mixed, mix only what is needed for the job. • Store concrete materials under cover, away from drainage areas. Secure bags of cement after they are open. Be sure to keep wind-blown cement powder away from streets, gutters, storm drains, rainfall, and runoff. • Return leftover materials to the transit mixer. Dispose of small amounts of hardened excess concrete, grout, and mortar in the trash. • Do not wash sweepings from exposed aggregate concrete into the street or storm drain. Collect and return sweepings to aggregate base stockpile, or dispose in the trash. • When making saw cuts in pavement, use as Uttle water as possible and perform during dry weather. Cover each storm drain inlet completely with filter fabric or plastic during the sawing operation and contain the slurry by placing straw bales, sandbags, or gravel dams around the inlets. After the liquid drains or evaporates, shovel or vacuum the slurry residue from, the pavement or gutter and remove from site. Alternatively, a small onsite vacuum may be used to pick up the slurry as this will prohibit slurry from reaching storm drain inlets. ••--if^'-' m Wash concrete trucks off site or in designated areas on site designed to preclude discharge of ' wash water to drainage system. 2003 ralilhmls Sbammwateir B.M9 SC-70 Road and Street Maintenance Patching, resurfacing, and surface sealing m Schedule patching, resurfacing and surface sealing for dry weather. • Stockpile materials away from streets, gutter areas, storm drain inlets or watercourses. During wet weather, cover stockpiles with plastic tarps or berm around them if necessary to prevent transport of materials in runoff. • Pre-heat, transfer or load hot bituminous material away from drainage systems or watercourses. • Where applicable, cover and seal nearby storm drain inlets (with waterproof material or mesh) and maintenance holes before applying seal coat, shiny seal, etc. Leave covers in place until job is complete and until all water from emulsified ofl sealants has drained or evaporated, dean any debris from covered maintenance holes and storm drain inlets when the job is complete. • Prevent excess material from exposed aggregate concrete or similar treatments from entering streets or storm drain iidets. Designate an area for clean up and proper disposal of excess materials. ***ev~ ) Use only as much water as necessary for dust control, to avoid runoff. • Sweep, never hose down streets to dean up tracked dirt. Use a street sweeper or vacuum truck. Do not dump vacuumed liquid in storm drains. • Catch drips from paving equipment mat is not in use with pans or absorbent material placed under the machines. Dispose of collected material and absorbents properly. Equipment cleaning maintenance and storage • Inspect equipment daily and repair any leaks. Place drip pans or absorbent materials under heavy equipment when not in use. • Perform major equipment repairs at the corporation yard, when practical. • If refueling or repairing vehicles and equipment must be done onsite, use a location away from storm drain inlets and watercourses. • Clean equipment including sprayers, sprayer paint supply lines, patch and paving equipment, and mud jacking equipment at the end of each day. Clean in a sink or other area (e.g. vehicle wash area) mat is connected to the sanitary sewer. Bridge and Structure Maintenance Paint and Paint Removal Transport paint and materials to and from job sites in containers with secure lids and tied down to the transport vehicle. Do not transfer or load paint near storm drain inlets or watercourses. 4 Of 9 raUfomla «hv*«i»«ih«» BMBI Road and Street Maintenance SC-70 • Test and inspect spray equipment prior to starting to paint. Tighten all hoses and connections and do not overfill paint container. • Plug nearby storm drain inlets prior to starting painting where there is significant risk of a spill reaching storm drains. Remove plugs when job is completed. • If sand blasting is used to remove paint, cover nearby storm drain inlets prior to starting work. • Perform work on a maintenance traveler or platform, or use suspended netting or tarps to capture paint, rust, paint removing agents, or other materials, to prevent discharge of materials to surface waters if the bridge crosses a watercourse. If sanding, use a sender with • Capture all clean-up water, and dispose of properly. • Recycle paint when possible (e.g. paint may be used for graffiti removal activities). Dispose of unused paint at an appropriate household hazardous waste facility. Graffiti Removal • Schedule graffiti removal activities for dry weather. • Protect nearby storm drain inlets prior to removing graffiti from walls, signs, sidewalks, or other structures needing graffiti abatement Clean up afterwards by sweeping or vacuuming thoroughly, and/or by using absorbent and property disposing of the absorbent. • When graffiti Is removed by painting over, implement the procedures under Painting and Paint Removal above. • Direct runoff from sand blasting and high pressure washing (with no cleaning agents) into a landscaped or dirt area. If such an area is not available, filter ranoff through an appropriate filtering device (e.g. filter fabric) to keep sand, particles, and debris out of storm drains. • If a graffiti abatement method generates wash water containing a cleaning compound (such as high pressure washing with a cleaning compound), plug nearby storm drains and Vacuum/pump wash water to the sanitary sewer. • Consider using a waterless and non-toxic chemical cleaning method for graffiti removal (e.g. gels or spray compounds). Repair Work • Prevent concrete, steel, wood, metal parts, tools, or other work materials from entering storm drains or watercourses. • Thoroughly clean up the job site when the repair work is completed. • When cleaning guardrails or fences follow the appropriate surface cleaning methods (depending on the type of surface) outlined in SC-71 Plaza & Sidewalk Cleaning fact sheet. SC-70 Road and Street Maintenance f • If painting is conducted, follow the painting and paint removal procedures above. • If graffiti removal is conducted, follow the graffiti removal procedures above. • If construction takes place, see the Construction Activity BMP Handbook. • Recycle materials whenever possible. Unpaved Roads and Trails m Stabilize exposed soil areas to prevent soil from eroding during rain events. This is particularly important on steep slopes. • For roadside areas with exposed soils, the most cost-effective choice is to vegetate the area, preferably with a mulch or binder that wfll hold the soils in place while the vegetation is establishing. Native vegetation should be used if possible. • If vegetation cannot be established immediateh/. apply temporary erosion control mats/blankets; a comma straw, or gravel as appropriate. "" If sediment ia already eroded and mobilized hi roadside areas, temporary controls should be installed. These may include: sediment control fences, fabric-covered triangular dikes, gravel-fflled burlap bags, biobags, or hay bales staked in place. Non-Stormwater Discharges Field crews should be aware of non-stormwater discharges as part of their ongoing street maintenance efforts. • Refer to SC-io Non-Stormwater Discharges • Identify location, time and estimated quantity of discharges. • Notify appropriate personnel. Training m Train employees regarding proper street sweeping operation and street repair and maintenance. • Instruct employees and subcontractors to ensure that measures to reduce the stormwater impacts of roadway/bridge maintenance are being followed. • Require engineering staff and/or consulting A/E firms to address stormwater quality in new bridge designs or existing bridge retrofits. Use a training log or similar method to document training. Train employees on proper spill containment and clean up, and in identifying non- stormwater discharges. Road and Street Maintenance SC-70 *• SpiU Response and Prevention m Refer to SC-ii, Spill Prevention, Control & Cleanup. • Keep your Spill Prevention Control and counterraeasure (SPCC) plan up-to-date, and implement accordingly. • Have spill cleanup materials readily available and in a known location. • Cleanup spills immediately and use dry methods if possible. • Properly dispose of spill cleanup material. Other Conrtderatton* m Densely populated areas or heavily used streets may require parking regulations to clear streets for cleaning. • No currently available conventional sweeper is effective at removing oil and grease. Mechanical sweepers are not effective at removing finer sediments. • Limitation* may arise in the location of new bridges. The availability and cost of land and other economic and political factors may dictate where the placement of a new bridge will occur. Better design of the bridge to control runoff is required if it is being placed near sensitive waters. Requirements Coats • The maintenance of local roads and bridges is already a consideration of most community public works or transportation departments. Therefore, die cost of pollutant reducing management practices will involve die training and equipment required to implement thesenew practices. • The largest expenditures for street sweeping programs are hi staffing and equipment The capital cost for a conventional street sweeper is between $60,000 and $120,000. Newer technologies might have prices approaching $180,000. The average useful life of a conventional sweeper is about four years, and programs must budget for equipment replacement Sweeping frequencies will determine equipment life, so programs that sweep more often should expect to have a higher cost of replacement. Sweeper operators, maintenance, supervisory, and administrative personnel arerequired. Traffic control officers may be required to enforce parking restrictions. Skillful design of cleaning routes is required for program to be productive. Arrangements must be made for disposal of collected wastes. SC-70 Road and Street Maintenance • If investing in newer technologies, training for operators must be included in operation and maintenance budgets. Costs for public education are small, and mostly deal with the need to obey parking restrictions and litter control Parking tickets are an effective reminder to obey parking rales, as well as being a source of revenue. Maintenance • Not applicable Supplemental Information Further Detail <tf the BMP There are advantages and disadvantages to the two comnun types of sweepers. The best choice depends on your specific conditions. Many communities find it useful to have a compliment of both type* in their fleet Mechanical Broom Sweepers - More effective at picking up large debris and cleaning wet streets. «ss costly to purchase and operate. Create mote airborne dust fej' Vacuum Sweepers - More effective at removing fine particles and associated heavy metals. Ineffective at cleaning wet streets. Noisier than mechanical broom sweepers which may restrict areas or times of operation. May require an advance vehicle to remove large debris. Street Rushers- Not affected by biggest interference to cleaning, parked cars. May remove finer sediments, moving them toward the gutter and stonnwater inlets. For this reason, flushing fell out of favor and is now used primarily after sweeping. Flushing may be effective for combined sewer systems. Presently street flushing is not allowed under most NPDES permits. Cross-Media Transfer of Pollutants The California Air Resources Board (ARB) has established state ambient air quality standards including a standard for respirable particulate matter (less than or equal to 10 microns in diameter, symbolized as PMio). In the effort to sweep up finer sediments to remove attached heavy metals, municipalities should be aware that fine dust, that cannot be captured by the sweeping equipment and becomes airborne, could lead to issues of worker and public safety. Bridges Bridges that carry vehicular traffic generate some of the more direct discharges of runoff to surface waters. Bridge scupper drains cause a direct discharge of stormwater into receiving waters and have been shown to cany relatively high concentrations of pollutants. Bridge maintenance also generates wastes that may be either directly deposited to the water below or carried to the receiving water by stormwater. The following steps will help reduce the stormwater impacts of bridge maintenance: • Site new bridges so that significant adverse impacts to wetlands, sensitive areas, critical habitat, and riparian vegetation are minimized. Road and Street Maintenance SC-70 • Design new bridges to avoid the use of scupper drains and route runoff to land for treatment control. Existing scupper drains should be cleaned on a regular basis to avoid sediment/debris accumulation, • Reduce the discharge of pollutants to surface waters during maintenance by using suspended traps, vacuums, or booms in the water to capture paint, rust, and paint removing agents. Many of these wastes may be hazardous. Properly dispose of this waste by referring to CA21 (Hazardous Waste Management) in the Construction Handbook. » • Train employees and subcontractors to reduce the discharge of wastes during bridge maintenance. De-tdng • Do not over-apply deidng salt and sand, and routinely calibrate spreaders. • Near reservoirs, restrict the application of deidng salt and redirect any runoff away from reservoirs. • Consider using alternative deidng agents Qess toxic, biodegradable, etc.). References and Resources) Model Urban Runoff Program: A How-To Guide for Developing Urban Runoff Programs for Small Municipalities. Preparedby City of Monterey, City of Santa Crux, California Coastal Commission, Monterey Bay National Marine Sanctuary, Association of Monterey Bay Area Governments, Woodward-Clyde, Central Coast Regional Water Quality Control Board. July. 1998. Orange County Stormwater Program hHpi//www.oewaterahedg.eont/atornawater/swp intmducrinn.asp Oregon Association of Clean Water Agencies. Oregon Municipal Stormwater Toolbox for Maintenance Practices. June 1998. Santa Clara Valley Urban Runoff Pollution Prevention Program. 1997 Urban Runoff Management Plan. September 1997, updated October 2000. Santa Clara Valley Urban Runoff Pollution Prevention Program. 2001. Fresh Concrete and Mortar Application Best Management Practices for the Construction Industry. June. Santa Clara Valley Urban Runoff Pollution Prevention Program. 2001. Roadwork and Paving Best Management Practices for the Construction Industry. June. United States Environmental Protection Agency (USEPA). 2002. Pollution Prevention/Good Housekeeping for Municipal Operations Roadway and Bridge Maintenance. On-line http!//www.eDa.gov/nDdes/menuQfbmPfl/poll .«• .J UL...I. Landscape Maintenance SC-73 Objectives • Contain • Educate • Reduce/MWmlza • Product Substitution Description Landscape maintenance activities include vegetation removal; herirfdde and insecticide application; fertilizer application; watering; and other gardening and lawn can practices. Vegetation control typically involve* a combination of chemical (herbk^)appHcation and mechanic^ methods. All of these maintenance practices have the potential to contribute pollutants to the atom drain system. The major objectives of this BMP are to minimize the discharge of pesticides, herbicides and fertilizers to the storm drain system and receiving waters; prevent the disposal of landscape waste into the storm drain system by collecting and properly disposing of clippings and cuttings, and educating employees and the public. Approach Pollution Prevention • Implement an integrated pest management (IPM) program. IPM to a sustainable approach to managing pests by combiningbiological, cultural, physical, and chemical tools. • Choose low water using flowers, trees, shrubs, and groundcover. • Consider alternative landscaping techniques such as naturescaping and xeriscaping. • Conduct appropriate maintenance (i.e. properly timed fertilizing, weeding, pest control, and pruning) to help preserve the landscapes water efficiency. Targeted Constituents Sedment 7" Nutria* / Trash / Bacteria OlandGieasa Organic* Oxygen Demanding / Californa Stormwater Quality /*• Association jC-73 Landscape Maintenance • Consi _ _ . _ _ . on the lawn when mowing. Grass dippings decompose quickly and release valuable nutrients back into the lawn). Suggested Protocols Mowing, Trimming, and Weeding • Whenever possible use mechanical methods of vegetation removal (e.g mowing with tractor- type or push mowers, hand cutting with gas or electric powered weed trimmers) rather than applying herbicides. Use hand weeding where practical. • Avoid loosening the soil when conducting mechanical or manual weed control, this could lead to erosion. Use mulch or other erosion control measures when soils are exposed. • Performing mowing at optimal times. Mowing should not be performed if significant rain events are predicted. Mulching mowers may be recommended for certain flat areas. Other techniques may be i employed to minimize mowing such as selective vegetative planting using low maintenance \ MSkjsj..-' » • • '( grasses and shrubs. « Collect lawn and garden clippings, pruning waste, tree trimmings, and weeds. Chip if • necessary, and compost or dispose of at a landfill (see waste management section of this fact sheet), • Place temporarily stockpiled material away from watercourses, and berm or cover stockpiles to prevent material releases to storm drains. Planting • Determine existing native vegetation features (location, species, size, function, importance) and consider the feasibility of protecting them. Consider elements such as their effect on drainage and erosion, hardiness, maintenance requirements, and possible conflicts between preserving vegetation and the resulting maintenance needs. • Retain and/or plant selected native vegetation whose features are determined to be beneficial, where feasible. Native vegetation usually requires less maintenance (e.g., irrigation, fertilizer) than planting new vegetation. • Consider using low water use groundcovers when planting or replanting. Waste Management • Compost leaves, sticks, or other collected vegetation or dispose of at a permitted landfill. Do not dispose of collected vegetation into waterways or storm drainage systems. Place temporarily stockpiled material away from watercourses and storm drain inlets, and : '""' berm or cover stockpiles to prevent material releases to the storm drain system. ; a Reduce the use of high nitrogen fertilizers that produce excess growth requiring more frequent mowing or trimming. Landscape Maintenance SC-73 f m Avoid landscape wastes in and around storm drain inlets by either using bagging equipment or by manually picking up the material. Irrigation n Where practical, use automatic timers to minimize runoff. • Use popup sprinkler heads in areas with a lot of activity or where there is a chance the pipes may he broken. Consider the use of mechanisms that reduce water flow to sprinkler heads if broken. • Ensure that there is no runoff from the landscaped area(s) if re-claimed water is used for . irrigation. • If bailing of muddy water is required (e.g. when repairing a water line leak), do not put it in the storm drain; pour over landscaped areas. • Irrigate slowly or pulse irrigate to prevent runoff and men only irrigate as much as is needed. • Apply water at rates that do not exceed the infiltration rate of the soil. Fertilizer and Featicfdc Management • Utilize a comprehensive management system that incorporates integrated pest management (IPM) techniques. There are many methods and types of IPM, including die following: - Mulching can be used to prevent weeds where turf is absent, fencing installed to keep rodents out, and netting used to keep birds and insects away from leaves and fruit. - Visible insects can be removed by hand (with gloves or tweezers) and placed in soapy water or vegetable ofl. Alternatively, insects can be sprayed off the plant with water or in some cases vacuumed off of larger plants. - Store-bought traps, such as species-specific, pheromone-based traps or colored sticky cards, can be used. - Slugs can be trapped in small cups filled with beer that are set in the ground so the slugs can get in easily. - In cases where microscopic parasites, such as bacteria and fungi, are causing damage to plants, the affected plant material can be removed and disposed of (pruning equipment should be disinfected with bleach to prevent spreading the disease organism). - Small mammals and birds can be excluded using fences, netting, tree trunk guards. • - Beneficial organisms, such as bats, birds, green lacewings, ladybugs, praying mantis, ground beetles, parasitic nematodes, trichogramma wasps, seed head weevils, and spiders that prey on detrimental pest species can be promoted. m Follow all federal, state, and local laws and regulations governing the use, storage, and disposal of fertilizers and pesticides and training of applicators and pest control advisors. ! &C-73 Landscape Maintenance .r • Use pesticides only if there is an actual pest problem (not on a regular preventative schedule). • Do not use pesticides if rain is expected. Apply pesticides only when wind speeds are low (leas than 5 mph). • Do not mix or prepare pesticides for application near storm drains. • Prepare the minimum amount of pesticide needed for the job and use the lowest rate that will effectively control the pest • Employ techniques to minimize off-target application (e.g. spray drift) of pesticides, includes consideration of alternative application techniques. • Fertilizers should be worked into the soil rather than dumped or broadcast onto the surface. • Calibrate fertilizer and pesticide application equipment to avoid excessive application. •> Periodically test sofls for determining proper fertilizer use. i ' Sweep pavement and sidewalk if fertilizer is spilled on these surfaces before applying ( irrigation water. • Puichase only the amount of pestidde that you can reasonably use in a given time period (month or year depending on the product). • Triple rinse containers, and use rinse water as product Dispose of unused pesticide as hazardous waste. • Dispose of empty pesticide containers according to the instructions on the container label. Inspection m Inspect irrigation system periodically to ensure that the right amount of water is being applied and that excessive runoff is not occurring. Minimize excess watering, and repair leaks in the irrigation system as soon as they are observed. • Inspect pesticide/fertilizer equipment and transportation vehicles daily. Training • Educate and train employees on use of pesticides and in pesticide application techniques to prevent pollution. Pesticide application must be under the supervision of a California qualified pesticide applicator. • Train/encourage municipal maintenance crews to use IPM techniques for managing public green areas. '•• VM^' ( • Annually train employees within departments responsible for pesticide application on the ! appropriate portions of the agency's IPM Policy, SOPs, and BMPs, and the latest IPM techniques. Landscape Maintenance _ SC-73 • Employees who are not authorized and trained to apply pesticides should be periodically (at least annually) informed that they cannot use over-the-counter pesticides in or around the workplace. • Use a training log or similar method to document training. Spill Response and Prevention m Refer to SC-n, Spin Prevention, Control & Cleanup • Have spin cleanup materials readily available and in a know in location • Cleanup spills immediately and use dry methods if possible. • Properly dispose of spill cleanup material; Othtf CoiutdBrottons • The Federal Pesticide, Fungicide, and Rodenticide Act and California Tide 3, Division 6, Pesticides and Pest Control Operations place strict controls over pesticide application and flnj specify training, pnQiial refresher, and tearing requirements. The regulations generally cover: a list of approved pesticides and selected uses, updated regularly; general application information; equipment use and maintenance procedures; and record keeping. The California Department of Pesticide Regulations and the County Agricultural Commission coordinate and maintain the licensing and certification programs. All public agency employees who apply pesticides and herbicides in "agricultural use" areas such as parks, golf courses, rights-of-way and recreation areas should be properly certified in accordance with state regulations. Contracts for landscape maintenance should include similar requirements. • All employees who handle pesticides should be familiar with the most recent material safely data sheet (MSDS) files. • Municipalities do not have the authority to regulate the use of pesticides by school districts, however the California Healthy Schools Act of 2000 (AB 2260) has imposed requirements on California school districts regarding pesticide use in schools. Posting of notification prior to the application of pesticides is now required, and IPM is stated as the preferred approach to pest management in schools. Requirements Cost* Additional training of municipal employees will be required to address IPM techniques and BMPs. IPM methods will likely increase labor cost for pest control which may be offset by lower chemical costs. Maintenance Not applicable 3C-73 Landscape Maintenance Supplemental Information Further Detail qf the BMP Waste Management Composting is one of die better disposal alternatives if locally available. Most municipalities either have or are planning yard waste composting facilities as a means of reducing the amount of waste going to tie landfill. Lawn clippings from municipal maintenance programs, as well as private sources would probably be compatible with most composting facilities Contractors and Other Pesticide Users Municipal agencies should develop and implement a process to ensure that any contractor employed to conduct pest control and pesticide application on municipal property engages in peat control methods consistent with me IPM Policy adopted by the agency. Specifically, municipalities should require contractors to follow the agency's IPM policy, SOPs, and BMPs; provide evidence to the agency of having received trahiing on current IPM techniques when feasible; provide documentation of pesticide use on agency properly to the agency hi a timely •nanner. f References and Resources (' >0ng County Stonnwater Pollution Control Manual. Best Management Practices for Businesses. ( 1995- King County Surface Water Management July. On-line: Los Angeles County Stormwater Quality Model Programs. Public Agency Activities Model Urban Runoff Program: A How-To Guide for Developing Urban Runoff Programs for Small Municipalities. Prepared by City of Monterey, City of Santa Cruz, California Coastal Commission, Monterey Bay National Marine Sanctuary, Association of Monterey Bay Area Governments, Woodward-Clyde, Central Coast Regional Water Quality Control Board. July. 1998. Orange County Stormwater Program http://www.oewfttfir9h6ds.com/StonnWatef/swp introduction, f\$p Santa Clara Valley Urban Runoff Pollution Prevention Program. 1997 Urban Runoff Management Plan. September 1997, updated October 2000. United States Environmental Protection Agency (USEPA). 2002. Pollution Prevention/Good Housekeeping for Municipal Operations Landscaping and Lawn Care. Office of Water. Office of Wastewater Management. On-line: http://www.epa.govynpdes/menuofbmpg/pnH Drainage System Maintenance SC-74 Description Aa • consequence of its function, th PhotoCn* o«*l Objectives Contain Educate Reduce/MlnJmiza t_~«~ «..».»«»»»«, UN oiormwater conveyance system collect* and transports urban runoff that may contain certain poUatants. Maintaining catch basins, stormwater inlets, and other stonnwater conveyance stnictures on a regular bask wffl remove pollutants, prevent clogging of the downstream conveyance system, restore catch basins'sediment trapping capacity, and ensure the system functions properly hydraulicalryto avoid flooding. Approach Suggested Protocol* Catch Basins/Inlet Structures m Municipal staff should regularly inspect facilities to ensurethe following: - Immediate repair of any deterioration threatening structural integrity. - Cleaning before the sump is 40% rail. Catch basins should be cleaned as frequently as needed to meet this standard. - Stenciling of catch basins and inlets (see SC-75 Waste Handling and Disposal). • Clean catch basins, storm drain inlets, and other conveyance structures in high pollutant load areas just before the wet season to remove sediments and debris accumulated during thesummer. Targeted Constituents Sedbnant « Nutrient! 4 Trash < Bacteria 01 and Grease Organlct Oxygen Demanding California Stormwatw Quality AiMciatien aC-74 Drainage System Maintenance sediment or trash accumulates more often. Clean and repair as needed. • Record the amount of waste collected. • Store wastes collected from cleaning activities of the drainage system in appropriate containers or temporary storage sites in a manner that prevents discharge to the storm drain. • Dewater the wastes with outflow into die sanitary sewer if permitted. Water should be treated with an appropriate filtering device prior to discharge to the sanitary sewer. If discharge to the sanitary sewer is not allowed, water should he pumped or vacuumed to a tank and properly disposed of. Do not dewater near a storm drain or stream. • Except for small communities with relatively few catch basins that may be cleaned manually, most municipalities will require mechanical cleaners such as eductors, vacuums, or bucket i loaders. orm Drain Conveyance System m Locate reaches of storm drain with deposit problems and develop a flushing schedule that keeps the pipe clear of excessive buildup. • Collect flushed effluent and pump to the sanitary sewer for treatment Pump Stations • Clean all storm drain pump stations prior to the wet season to remove silt and trash. • Do not allow discharge from cleaning a storm drain pump station or other facility to reach the storm drain system. • Conduct quarterly routine maintenance at each pump station. • Inspect, clean, and repair as necessary all outlet structures prior to the wet season. • Sample collected sediments to determine if landfill disposal is possible, or illegal discharges in the watershed are occurring. Open Channel m Consider modification of storm channel characteristics to improve channel hydraulics, to increase pollutant removals, and to enhance channel/creek aesthetic and habitat value. **«•«*-• Conduct channel modification/improvement in accordance with existing laws. Any person, government agency, or public utility proposing an activity that will change the natural (emphasis added) state of any river, stream, or lake in California, must enter into a steam or Lake Alteration Agreement with the Department of Fish and Game. The developer-applicant should also contact local governments (city, county, special districts), other state agencies Drainage System Maintenance SC-74 (SWRCB, RWQCB, Department of Forestry, Department of Water Resources), and Federal Corps of Engineers and USFWS Illicit Connections and Discharges • During routine maintenance of conveyance system and drainage structures field staff should look for evidence of illegal discharges or illicit connections: - Is there evidence of spills such as paints, discoloring, etc. - Are there any odors associated with the drainage system - Record locations of apparent illegal discharges/illidt connections - Track flows back to potential dischargers and conduct abovegraund inspections. This can he done through visual inspection of up gradient manholes or alternate techniques including zinc chloride smoke testing, fluorometric dye testing, physical inspection testing, or television camera inspection. ' - Once the origin of flow is established, i^uireilUcfe • Stencil storm drams, where applicable, to prevent illegal disposal of pollutants. Storm drain inlets should have messages such as "Dump No Waste Drains to Stream" stenciled next to them to warn against ignorant or intentional dumping of pollutants into the storm drainage system. • Refer to fact sheet SC-1O Non-Stormwater Discharges. Illegal Dumping m Regularly inspect and clean up hot spots and other storm drainage areas where illegal dumping and disposal occurs. • Establish a system for tracking incidents. The system should be designed to identify the following: - Illegal dumping hot spots - Types and quantities (in some cases) of wastes - Patterns in time of occurrence (time of day/night, month, or year) - Mode of dumping (abandoned containers, "midnight dumping" from moving vehicles, direct dumping of materials, accidents/spills) - Responsible parties • Post "No Dumping" signs in problem areas with a phone number for reporting dumping and disposal. Signs should also indicate fines and penalties for illegal dumping. a Refer to fact sheet SC°io Non-Stormwater Discharges. 1 SC-74 Drainage System Maintenance • The State Department of Fish and Game has a hotline for reporting violations called Cal TIP (1-800-952-5400). The phone number may be used to report any violation of a Fish and Game code (illegal dumping, poaching, etc.). • The California Department of Toxic Substances Control's Waste Alert Hotline, 1-800- 69.TOXIC, can be used to report hazardous waste violations. Training m Train crews in proper maintenance activities, including record keeping and disposal. • Only properly trained individuals are allowed to handle hazardous materials/wastes. • Train municipal employees from aU departments (public works, utilities, street cleaning, parka and recreation, industrial waste inspection, hazardous waste inspection, sewer maintenance) to recognize and report illegal dumping. • Train municipal employees and educate businesses, contractors, and the general public in proper and consistent methods for disposal. / a Train municipal staff regarding non-stormwater discharges (See SC-ioNon-Stormwater/1 Discharges). ( Spill Response and Prevention • Refer to SC-it, Prevention, Control ft Cleanup • Have spffl cleanup materials readily available and in a known location. • Cleanup spills immediately and use dry methods if possible. • Properly dispose of spfll cleanup material. Other Consideration* • Cleanup activities may create a slight disturbance for local aquatic species. Access to items and material on private property may be limited. Trade-on* may exist between channel hydraulics and water quality/riparian habitat If storm channels or basins are recognized as wetlands, many activities, including maintenance, may be subject to regulation andpermitting. . Storm drain flushing is most effective in small diameter pipes (36-inch diameter pipe or less, depending on water supply and sediment collection capacity). Other considerations associated with storm drain flushing may include the availability of a water source, finding a downstream area to collect sediments, liquid/sediment disposal, and disposal of flushed effluent to sanitary sewer may be prohibited in some areas • Municipal codes should include sections prohibiting the discharge of soil, debris, refuse hazardous wastes, and other pollutants into the storm drain system. • Private property access rights may be needed to track illegal discharges up gradient. Drainage System Maintenance SC-74 • Requirements of municipal ordinance authority for suspected source verification testing for illicit connections necessary for guaranteed rights of entry. Requirements Coat* u An aggressive catch basin cleaning program could require a significant capital and O&M budget A careful study of deaningeffecttveness should be undertaken before increased cleaning is implemented. Catch basin cleaning costs are less expensive if vacuum street sweepers are available; cleaning catch basins manually can cost approximately twice as much as cleaning the basins with a vacuum attached to a sweeper. • Methods used for illicit connection detection (smoke testing, dye testing, visual inspection, andflowmonitorhigjcanbecostiyandtime-consumhig. Site-specific factors, such as the level of impervious area, tine density and ages of buildings, and type of land use win determine the level of investigation necessary. Encouraging reporting of flUdt discharges by employees can offset costs by saving expense on inspectors and directing resources more efficiently. Some programs have used funds available from "environmental foes" or special assessment districts to fund their illicit connection elimination programs. Maintenance • Two-person, teams may be required to clean catch basins with vactor trucks. • Identifying illicit discharges requires teams of at least two people (volunteers can be used), plus administrative personnel, depending on the complexity of the storm sewer system. • Arrangements must be made for proper disposal of collected wastes. • Requires technical staff to detect and investigate illegal dumping violations, and to coordinate public education. Supplemental Information Further Detail qfthe BMP Storm Drainfushing Sanitary sewer flushing is a common maintenance activity used to improve pipe hydraulics and to remove pollutants in sanitary sewer systems. The same principles that make sanitary sewer flushing effective can be used to flush storm drains. Flushing may be designed to hydraulicaUy convey accumulated material to strategic locations, such as to an open channel, to another point where flushing will be initiated, or over to the sanitary sewer and on to the treatment facilities, thus preventing re-suspension and overflow of a portion of the solids during storm events. Flushing prevents "plug flow" discharges of concentrated pollutant loadings and sediments. The deposits can hinder the designed conveyance capacity of the storm drain system and potentially cause backwater conditions in severe cases of clogging. Storm drain flushing usually takes place along segments of pipe with grades that are too flat to maintain adequate velocity to keep particles in suspension. An upstream manhole is selected to place an inflatable device that temporarily plugs the pipe. Further upstream, water is pumped into the line to create a flushing wave. When the upstream reach of pipe is sufficiently full to -74 Drainage System Maintenance r ' cause a flushing wave, the inflated device is rapidly deflated with the assistance of a vacuum pump, releasing the backed up water and resulting hi the cleaning of the storm drain segment. To farther reduce the impacts of stormwater pollution, a second inflatable device, placed well downstream, may be used to re-collect the water after the force of the flushing wave has dissipated. A pump may Aen be used to transfer the water and accumulated material to the sanitary sewer for treatment In some cases, an interceptor structure may be more practical or required to re-collect the flushed waters. It has been found that cleansing efficiency of periodic flush waves is dependent upon flush volume, flush discharge rate, sewer slope, sewer length, sewer flow rate, sewer diameter, and population density. As a rale of thumb, me lengOi of m% to be flushed should not exceed 700 feet At IMS niaxtairarecoirniMnded length, ±ep 75 percent for organicsand 55-65 percent for dry weather grft/inorganic material. The percent removal efficiency drops rapidly beyond mat Water is commonly supplied by a water truck, but fire hydrants can also supply water. To make the best use of water, it is recommended that reclaimed water be used or that fire hydrant line flushing coincide with storm drain flushing. tw Management nw management haa bean one of the principal mnrivqrinn q fr>r dgdprfng urban stream Torridorsinthepast Such needs may or may not be compatible with the stormwater qualitygoals in me stream corridor. Downstream flood peaks can be suppressed by reducing through flow velocity. This can be accomplished by reducmg gradient with grade control structures or increasing roughness with boulders, dense vegetation, or complex banks forms. Reducing velocity correspondingly increases flood height, so afl such measures have a natural association with floodplain open space. Flood elevations laterally adjacent to the stream can be lowered by increasing through flow velocity. However, increasing velocity increases flooding downstream and inherently conflicts with channel stability and human safety. Where topography permits, another way to lower flood elevation is to lower the level of the floodway with drop structures into a large but subtly excavated bowl where flood flows we allowed to spread out. Stream Corridor Planning Urban streams receive and convey stormwater flows from developed or developing watersheds. Planning of stream corridors thus interacts with urban stormwater management programs. If local programs are intended to control or protect downstream environments by managing flows delivered to the channels, then it is logical that such programs should be supplemented by management of the materials, forms, and uses of the downstream riparian corridor. Any proposal for steam alteration or management should be investigated for its potential flow and ^.ability effects on upstream, downstream, and laterally adjacent areas. The timing and rate of low from various tributaries can combine in complex ways to alter flood hazards. Each section rf channel is unique, influenced by its own distribution of roughness elements, management activities, and stream responses. Drainage System Maintenance SC-74 Flexibility to adapt to stream features and behaviors as they evolve must be included hi stream reclamation planning. TTie amenity and ecology of streams may be enhanced through die landscape design options of i) corridor reservation, 2) bank treatment, 3) geomorphic restoration, and 4) grade control. Corridor reservation - Reserving stream corridors and valleys to accommodate natural stream meandering, aggradation, degradation, and over bank flows allows streams to find their own form and generate less ongoing erosion. In California, open stream corridors hi recent urban developments have produced recreational open space, irrigation of streamside plantings, and die aesthetic amenity of flowing water. Hank treatment - The use of armoring, vegetative cover, and flow deflection mav be used to influence a duumel's form, atabflity, and biotic habitat To prevent bank erosion, armoring can be done wHfc rigid construction materials, such as concrete, masonry, wood planks and logs, riprap, and gabions. Ooncnte linings have been criticized because of their kick of provision of biotic habitat In contract, riprap and gabions make relatively porous and flexible linings. Boulders, placed in the bed reduce velocity and erosfve power. Riparianvegetationcanstabulzetiiebanksofstreamstiiatareatornearaconditionof equilibrium. Binding networks of roots increase bank shear strength. During flood flows, resflient vegetation is forced wto erosion-inhibiting mats. The roughness of vegetation leads to lower velocity, furmer reducing erosive effects. Structural flow deflection can protect banks from erosion or alter fish habitat By concentrating flow, a deflector causes a pool to be scoured in the bed. fk-nmnrphlff reatoratioq - Restoration refers to alteration of disturbed streams so their form and behavior emulate those of undisturbed streams. Natural meanders are retained, with grading to gentle slopes on the inside of curves to allow point ban and riffle-pool sequences to develop. Trees are retained to provide scenic quality, biotic productivity, and roots for bank stabilization, supplemented by plantings where necessary. A restorative approach can be successful where the stream is already approaching equilibrium. However, if upstream urbanization continues new flow regimes will be generated that could disrupt the equilibrium of the treated system. grade Control - A grade control structure is a level shelf of a permanent material, such as stone, masonry, or concrete, over which stream water flows. A grade control structure is called a sill, wen*, or drop structure, depending on the relation of its invert elevation to upstream and downstream channels. A sill is installed at the preexisting channel bed elevation to prevent upstream migration of nick points. It establishes a firm base level below which the upstream channel can not erode. A weir or check dam is installed with invert above the preexisting bed elevation. A weir raises the local base level of the stream and causes aggradation upstream. The gradient, velocity, and erosive potential of the stream channel are reduced. A drop structure lowers the downstream invert below its preexisting elevation, reducing downstream gradient and velocity. Weirs and drop structure control erosion by dissipating energy and reducing slope velocity. 3C-74 Drainage System Maintenance e- When carefully applied, grade control structures can be highly versatile in establishing human and environmental benefits in stabilized channels. To be successful, application of grade control structures should be guided by analysis of the stream system bom upstream and downstream from the area to he reclaimed. JExamples The California Department of Water Resources began the Urban Stream Restoration Program in 1985. The program provides grant funds to municipalities and community groups to implement stream restoration projects. The projects reduce damages from streambank aid watershed instability arid floods while restoring streams' aesthetic, recreational, and fish and wildlife values. In Buena Vista Park, upper floodway slopes are gentle and grassed to achieve continuity of usable park land across the channel of small boulders at die base of the slopes. The San Diego River is a large, vegetative lined channel, which was planted in a variety of species to support riparian wildlife while stabilizing the steep banks of the floodway. _^ aferences and Resources 'erguson, B.K. 1991. Urban Stream Reclamation, p. 324-322, Journal of Sofl and Water Conservation. Los Angeles County Stormwater Quality. Public Agency Activities Model Program. On-line: /IftditW-org/vrnidnndegnublic TC.cftn Model Urban Runoff Program: A How-To Guide for Developing Urban Runoff Programs for Small Municipalities. Prepared by City of Monterey, City of Santa Cruz, California Coastal Commission, Monterey Bay National Marine Sanctuary, Association of Monterey Bay Area Governments, Woodward-Clyde, Central Coast Regional Water Quality Control Board. July. 1998. Orange County Stormwater Program htfT>://wvyw.Qcwaterahedfl.com/StQrmWater/swp introduction.aap Santa Clara Valley Urban Runoff Pollution Prevention Program. 1997 Urban Runoff Management Plan. September 1997, updated October 2000. San Diego Stormwater Co-permittees Jurisdictional Urban Runoff Management Program (URMP) Municipal Activities Model Program Guidance. 2001. Project Clean Water. November. United States Environmental Protection Agency (USEPA). 1999. Stormwater Management Fact Sheet Non-stormwater Discharges to Storm Sewers. EPA 832^-99-022. Office of Water, Washington, D.C. September. United States Environmental Protection Agency (USEPA). 1999. Stormwater O&M Fact Sheet Catch Basin Cleaning. EPA 832^-99-011. Office of Water, Washington, D.C. September. Drainage System Maintenance SC-74 United States Environmental Protection Agency (USEPA). 2002. Pollution Prevention/Good Housekeeping for Municipal Operations Storm Drain System Cleaning. On line: httD!//vyvfW-6pa.gov/npdea/nieniiofenip9/poU i6.htm SECTION 7.0 Section 7.0 Structural Treatment BMPs Based upon the categories in Table 2 - Anticipated and Potential Pollutants Generated by Land Use Type from the City of Carlsbad Standard Urban Storm Water Mitigation Plan (SUSMP), revised June 4, 2008, pollutants of concern for this project include: sediment, nutrients, heavy metals organic compounds, trash and debris, oxygen demanding substances, bacteria, oil and grease, and pesticides (See attached Table 2). To minimize pollutants of concern, we are using: Multiple Systems - BMPs using different removal processes will be combined to improve overall removal efficiency. (See Fact Sheet TC-60) The two selected, where possible, are the direction of polluted runoff through a vegetated swale prior to entering a storm drain with inlet baskets. Additionally, once inside the private storm drainage system the runoff is conveyed to the large Vegetated Swale located south of Cannon Road for final treatment. 1. Vegetated Swales (Pre-Treatment) - Grass-lined swales (See Fact Sheet TC-30) have been designed and incorporated into the landscaped areas immediately adjacent to the driveways in order to receive runoff from over 80% of the site prior to that storm water reaching the street. These short vegetated swales and gravel bottomed catch basins provide preliminary treatment to the runoff before treatment by items 2 and 3. 2. Storm drain inlet baskets (Pre-Treatment) - Storm drainage inserts have been used for Structural Treatment BMPs (See Fact Sheet MP-52). The drainage inserts will be catch basin baskets. As manufactured by Suntree Technologies Inc. products or BioClean Environmental Services, Inc. (See attached manufacturer's information in Section 7.0) Two drainage inserts are being used downstream of this project. These inserts are being installed in the Type 'B' Curb Inlets located in Summit Trail Court just inside Planning Area 15. These inserts will treat runoff from most of the new streets and from the driveways that drain into them. (See exhibit in Section 3.0) Based upon Table 3 - Numeric Sizing Treatment Standards from the City of Carlsbad SUSMP, we are using a flow-based BMP designed to mitigate, (infiltrate, filter or treat) the maximum flow rate or runoff produced from a rainfall intensity of 0.2 inches of rainfall per hour for each hour of a storm event. The following calculations show the maximum flow the insert will be required to treat. The curb inlet insert selected is capable of treating the maximum amount of flows produced. • Drainage Insert for Type 'B' Curb Inlets Max. Area (A) = 2.18 acre C = 0.90 lavg =0.2 in/hr Qavg = C*lavg*A Qavg = 0.90*0.2*2.18 = 0.39 cfs A Type 'B' Curb Inlet drainage insert is capable of treating up to 10.6 cfs of flow and will be adequate to treat a 0.39 cfs average peak runoff 3. Large Vegetated Swale - The Vegetated Swale located south of Cannon Road is designed to treat stormwater runoff from all of Robertson Ranch East Village. 10 Vegetated Swale South of Cannon Rd. (Flow-based BMP) Cavg= 0.56 1= 0.2 in/hr A= 108.78 AC. Q= CIA Q= (,56)(0.2)(108.78)= 12.18 cfs Tributary Area to Vegetated Swale Cavg Calculations Basin Subbasin B B-1 B-2 B-3 C C-1 C-2 D E E-1 E-2 E-3 F F-1 F-2 H Total Area (AC.) 3.59 16.21 38.05 2.63 3.68 28.58 1.41 1.61 0.5 2.99 5.9 3.63 108.78 c 0.71 0.35 0.57 0.57 0.63 0.57 0.87 0.87 0.87 0.71 0.63 0.57 Cavo= 0.56 O'Day Consultants Inc. 2710 Loker Avenue West, Suite 100 Carlsbad, CA 92008 Tel: (760) 931-7700 Fax: (760) 931-8680 Inside Diameter ( 24.00 in.) Water * * * * * * (15.16 in.) ( 1.264 ft.) I v Circular Channel Section Flowrate 12.180 CFS Velocity 5.823 fps Pipe Diameter 24.000 inches Depth of Flow 15.165 inches Depth of Flow 1.264 feet Critical Depth 1.259 feet Depth/Diameter (D/d) 0.632 Slope of Pipe 0.550 % X-Sectional Area 2.092 sq. ft. Wetted Perimeter 3.675 feet AR*(2/3) 1.437 Mannings 'n1 0.013 Min. Fric. Slope, 24 inch Pipe Flowing Full 0.290 % O'Day Consultants Inc. 2710 Loker Avenue West, Suite 100 Carlsbad, CA 92008 Tel: (760) 931-7700 Fax: (760) 931-8680 ****** *** *** *** *** *** *** *** ( 41.26') Water Depth ( 0.31') ****** *** *** *** - >| ***«**•*• *•«•*•*** *** ** * *** ***!< ( 40.00') >!*** ******************** Trapezoidal Channel Flowrate .................. 12 . 180 CFS Velocity .................. 0 . 953 f pa Depth of Flow ............. 0 . 314 feet Critical Depth ............ 0 .141 feet Freeboard ................. 0 .000 feet Total Depth ............... 0 .314 feet Width at Water Surface .... 41.257 feet Top Width ................. 41 . 257 feet Slope of Channel .......... 0 .400 % Left Side Slope ........... 2.000 : 1 Right Side Slope .......... 2 . 000 : 1 Base Width ................ 40 . 000 feet X-Sectional Area .......... 12.772 sq. ft. Wetted Perimeter .......... 41.406 feet ARA(2/3) .................. 5.831 Mannings 'n' .............. 0 .045 f— rff ' Table A-3 Average Manning Roughness Coefficients for Small Open Channels Conveying Less than 50 cfs4 Design Flow Depth Lining Type Concrete (Poured) Air Blown Concrete Grouted Riprap Stone Masonry Soil Cement Bare Soil Rock Cut Rock Riprap 0-0.5 ft 0.015 0.023 0.040 0.042 0.025 0.023 0.045 Based 0.5 -2.0 ft 0.013 0.019 0.030 0.032 0.022 0.020 0.035 on Rock Size (See Section > 2.0 ft 0.013 0.016 0.028 0.030 0.020 0.020 0.025 5.7.2) Table A-4 Table A-4 Average Manning Roughness Coefficients for Larger Open Channels Unlined Channels Clay Loam Sand 0.023 0.020 Lined Channels Grass Lined (Well-Maintained) 0.035 Grass Lined (Not Maintained) 0.045 Wetland-Bottom Channels (New Channel) 0.023 Wetland-Bottom Channels (Mature Channel) See Table A-5 Riprap-Lined Channels •. See Section 5.7.2 Concrete (Poured) 0.014 Air Blown Mortar (Gunite or Shotcrete)5 0.016 Asphaltic Concrete or Bituminous Plant Mix 0.018 For channels with revetments or multiple lining types, use composite Manning roughness coefficient based on component lining materials. 4 Based on materials and workmanship required by standard specifications. 5 For air-blown concrete, use M=0.012 (if troweled) and «=0.025 if purposely roughened. San Diego County Drainage Design Manual (May 2005) Page A-5 2.3 PERMANENT BEST MANAGEMENT PRACTICES SELECTION PROCEDURE 2.3.1 INTRODUCTION The following process should be followed to determine the permanent BMPs for the applicant's project. 2.3.2 IDENTIFY POLLUTANTS AND CONDITIONS OF CONCERN 2.3.2.1 Identify Pollutants from the Project Area Using Table 2 below, identify the project's anticipated pollutants. Pollutants associated with any hazardous material sites that have been remediated or are not threatened by the proposed project are not considered a pollutant of concern. Projects meeting the definition of more than one project category shall identify all general pollutant categories that apply. Descriptions of the general pollutant categories listed in Table 2 are defined in Appendix F under the definition of "pollutants of concern." Table 2 Anticipated and Potential Pollutants Generated by Land Use Type Project Categories Detached Residential Development Attached Residential Development Commercial Development > 100.000 ft2 Heavy industry /industrial development Automotive Repair Shops Restaurants Steep Hillside Development >5,000 ft2 Parking Lots Retail Gasoline Outlets Streets, Highways & Freeways General Pollutant Categories Sediments & X pO> X X p(1) (^•W*'' Nutrients © X p(i) X p(1) (3 Heavy Metals X X X X ® Organic Compounds p(2) X XH)(5) X & Trash & Debris (*) X X X X X X X X .ff-'. (& Oxygen Demanding Substances C*3 pd) p(5) X X X p(1) X ,-— -•& Oil& Grease (jD p(2) X X X X X X X (9 Bacteria & Viruses ® pd) p(3) X Pesticides © X p(5) X p(1) 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. SWMP Rev 6/4/08 Table 3 Numeric Sizing Treatment Standards Volume 1. i. iv. Flow 2. 3.0 4.0 5.0 Volume-based BMPs shall be designed to mitigate (infiltrate, filter, or treat) either: The volume of runoff produced from a 85th percentile storm event, as determined from isopluvial maps contained in the County of San Diego Hydrology Plan (0.6 inch approximate average for the San Diego County area) [Note: Applicants may calculate the 85th percentile storm event using local rain data, when available. See the County of San Diego's isopluvial map at http://www.sdcountv.ca.gov/dpw/engineer/flood.htm1: or The volume of runoff produced by the 85 percentile storm event, determined as the maximized capture urban runoff volume for the area, from the formula recommended in Urban Runoff Quality Management, WEF Plan of Practice No. 23/ASCE Plan of Practice No. 87, page 175 Equation 5.2; (1998); or The volume of annual runoff based on unit basin storage volume, to achieve 90 percent or more volume treatment by the method recommended in the latest edition of the California Stormwater Best Management Practices Handbook, or The volume of runoff, as determined from the local historical rainfall record, that achieves approximately the same reduction in pollutant loads and flows as achieved by mitigation of the 85th percentile 24-hour runoff event. OR Flow-based BMPs shall be designed to mitigate (infiltrate, filter, or treat) either: The maximum flow rate of runoff produced from a rainfall intensity of 0.2 inch of rainfall per hour for each hour of a storm event; or The maximum flow rate of runoff produced by the 85th percentile hourly rainfall intensity, as determined from the local historical rainfall record, multiplied by a factor of two; or The maximum flow rate of runoff, as determined from the local historical rainfall record, that achieves approximately the same reduction in pollutant loads and flows as achieved by mitigation of the 85th percentile hourly rainfall intensity multiplied by a factor of two. Notes on Structural Treatment Limited Exclusions Proposed restaurants, where the land area for development or redevelopment is less than 5,000 square feet, are excluded from the numerical sizing criteria requirements listed in Table 3. Where significant redevelopment results in an increase of less than 50 percent of the impervious surfaces of a previously existing development, and the existing development was not subject to priority project requirements, the numeric sizing criteria apply only to the addition, and not to the entire development. 15 SWMP Rev 6/4/08 2.3.3.5 Structural Treatment BMP Selection Procedure Priority projects shail select a single or combination of treatment BMPs from the categories in Table 4 that maximize pollutant removal for the particular pollutant(s) of concern. 1. Determine if the project would discharge to a Clean Water Act Section 303(d) impaired receiving water. If any receiving waters for the project are impaired, identify the specific type of pollutant(s) for which the receiving water(s) is/are impaired. 2. If the project is anticipated to generate a pollutant (per Table 2) for which the receiving water is impaired, select one or more BMPs from Table 4 that maximize the pollutant removal for that pollutant. Any pollutants the project is expected to generate that are also causing a Clean Water Act section 303(d) impairment of the downstream receiving waters of the project shall be given top priority in selecting treatment BMPs 3. If none of the project's receiving waters are listed as impaired, select one or more BMPs from Table 4 that maximize the removal of the pollutants the project is anticipated to generate. Alternative storm water BMPs not identified in Table 4 may be approved at the discretion of the City Engineer, provided the alternative BMP is as effective in removal of pollutants of concern as other feasible BMPs listed in Table 4. Table 4. Structural Treatment Control BMP Selection Matrix Pollutants of Concern Coarse Sediment and Trash Pollutants that tend to associate with fine particles Slicing treatment 3ollutants that ..and to be dissolved following treatment /SioretentionN Settling ( Facilities 7 Basins VJHPJ-^ (Dry Ponds) High High Medium High High Low Wet Ponds and Wetlands High High Medium Infiltration Facilities or Practices (LID) High High High Media Filters High High Low High-rate biofllters High Medium Low d \jh-rate\ ledia ) liters / High Medium Low Trash Racks & Hydro -dynamic Devices High Low Low 2.3.3.6 Notes on Pollutants of Concern In Table 4 above, Pollutants of Concern are grouped as gross pollutants, pollutants that tend to associate with fine particles, and pollutants that remain dissolved. The table below distinguishes the pollutant types associated with each of these three groupings. Pollutant Sediment Nutrients Heavy Metals Organic Compounds Trash & Debris Oxygen Demanding Bacteria Oil & Grease Pesticides Coarse Sediment and Trash X X Pollutants that tend to associate with fine particles during treatment X X X X X X X X Pollutants that tend to be dissolved following treatment X 16 SWMP Rev 6/4/08 General Description A multiple treatment system uses two or more BMPs in series. Some examples of multiple systems include: settling basin combined with a sand filter; settling basin or biofilter combined with an infiltration basin or trench; extended detention zone on a wet pond. Inspection/Maintenance Considerations Each of the separate treatment processes will require maintenance as described in the previous fact sheets. For example, multiple system comprises of a biofilter combined with an infiltration basin would require the inspection and maintenance considerations outlined on the fact sheet for each process. inspection Activities > -i'!?;^ *', _ - .,.' *• ->-• • • Refer to individual treatment control factsheets Maintenance Activities ", - :-' . i-,"-. • Refer to individual treatment control factsheets As needed As needed Maintenance Concerns^ Objectives, and Goals May include some of the following: • Accumulation of Metals • Aesthetics • Channelization of Flow • Clogged Outlet Structures • Endangered Species Habitat Creation • Erosion • Groundwater Contamination • Hazardous Waste • Hydraulic and Removal Efficiency • Invasive/exotic Plant Species • Mechanical Malfunction • Pollutant Breakthrough • Re-suspension of settled material • Sediment and Trash Removal • Sedimentation • Vector/Pest Control • Vegetation harvesting • Vegetation/Landscape Maintenance Targeted Constituents J Sediment "• S Nutrients • / Trash • / Metals • / Bacteria A / Oil and Grease • <f Organics • Legend (Removal Effectiveness) • Low • High A Medium CASQA ilfbrnla Stormwater Quality Association January 2003 California Stormwater BMP Handbook Industrial and Commercial 1 of 1 General Description Vegetated swales are open, shallow channels with vegetation covering the side slopes and bottom that collect and slowly convey runoff flow to downstream discharge points. They are designed to treat runoff through filtering by the vegetation in the channel, filtering through a subsoil matrix, and/or infiltration into the underlying soils. Swales can be natural or manmade. They trap particulate pollutants (suspended solids and trace metals), promote infiltration, and reduce the flow velocity of stormwater runoff. Vegetated swales can serve as part of a stormwater drainage system and can replace curbs, gutters and storm sewer systems. Therefore, swales are best suited for residential, industrial, and commercial areas with low flow and smaller populations. Inspection/Maintenance Considerations It is important to consider that a thick vegetative cover is needed for vegetated swales to function properly. Usually, swales require little more than normal landscape maintenance activities such as irrigation and mowing to maintain pollutant removal efficiency. Swales can become a nuisance due to mosquito breeding in standing water if obstructions develop (e.g., debris accumulation, invasive vegetation) and/or if proper drainage slopes are not implemented and maintained. The application of fertilizers and pesticides should be minimized. Maintenance Concerns, Objectives, and Goals • Channelization • Vegetation/Landscape Maintenance • Vector Control • Aesthetics • Hydraulic and Removal Efficacy Targeted Constituents / Sediment / Nutrients / Trash / Metals / Bacteria / Oil and Grease / Organics A • • A • A A Legend (Removal Effectiveness) • Low • High A Medium ASQA Ifornla Stormwater Quality January 2003 California Stormwater BMP Handbook Industrial and Commercial 1 of 3 Inspection Activities . "... .". ' .....•:.• .... _—..--.-j—.- .._--— ---. .- . ... -_. .„.__...-__-_ ._ _, t-__^_ m Inspect after seeding and after first major storms for any damages. I B Inspect for signs of erosion, damage to vegetation, channelization of flow, debris and | litter, and areas of sediment accumulation. Perform inspections at the beginning and end | of the wet season. Additional inspections after periods of heavy runoff are desirable. f -..Frequency Post construction Semi-annual Inspect level spreader for clogging, grass along side slopes for erosion and formation of rills or gullies, and sand/soil bed for erosion problems. Annual Mow grass to maintain a height of 3-4 inches, for safety, aesthetic, or other purposes. Litter should always be removed prior to mowing. Clippings should be composted. Irrigate swale during dry season (April through October) or when necessary to maintain the vegetation. Provide weed control, if necessary to control invasive species. Remove litter, branches, rocks blockages, and other debris and dispose of properly. Maintain inlet flow spreader (if applicable). Repair any damaged areas within a channel identified during inspections. Erosion rills or gullies should be corrected as needed. Bare areas should be replanted as necessary. As needed (frequent, seasonally) Semi-annual Declog the pea gravel diaphragm, if necessary. Correct erosion problems in the sand/soil bed of dry swales. Plant an alternative grass species if the original grass cover has not been successfully established. Reseed and apply mulch to damaged areas. Remove all accumulated sediment that may obstruct flow through the swale. Sediment accumulating near culverts and in channels should be removed when it builds up to 3 in. at any spot, or covers vegetation, or once it has accumulated to 10% of the original design volume. Replace the grass areas damaged in the process. Rototill or cultivate the surface of the sand/soil bed of dry swales if the swale does not draw down within 48 hours. Annual (as needed) As needed (infrequent) California Stormwater BMP Handbook Industrial and Commercial January 2003 Vegetated Additional Information Recent research (Colwell et al., 2000) indicates that grass height and mowing frequency have little impact on pollutant removal. Consequently, mowing may only be necessary once or twice a year for safety or aesthetics or to suppress weeds and woody vegetation. References Metropolitan Council, Urban Small Sites Best Management Practices Manual. Available at: http://www.metrocouncil.org/environment/Watershed/BMP/manual.htm .U.S. Environmental Protection Agency, Post-Construction Stormwater Management in New Development & Redevelopment BMP Factsheets. Available at: cfpub.epa.gov/npdes/stormwater/menuofbmps/bmp files.cfm Ventura Countywide Stormwater Quality Management Program, Technical Guidance Manual for Stormwater Quality Control Measures. July, 2002. January 2003 California Stormwater BMP Handbook Industrial and Commercial WWW.cabmDhandhnnkq.rnm 3 of 3 Description Drain inserts are manufactured filters or fabric placed in a drop inlet to remove sediment and debris. There are a multitude of inserts of various shapes and configurations, typically falling into one of three different groups: socks, boxes, and trays. The sock consists of a fabric, usually constructed of polypropylene. The fabric may be attached to a frame or the grate of the inlet holds the sock. Socks are meant for vertical (drop) inlets. Boxes are constructed of plastic or wire mesh. Typically a polypropylene "bag" is placed in the wire mesh box. The bag takes the form of the box. Most box products are one box; that is, the setting area and filtration through media occur in the same box. Some .products consist of one or more trays or mesh grates. The trays may hold different types of media. Filtration media vary by manufacturer. Types include polypropylene, porous polymer, treated cellulose, and activated carbon. California Experience The number of installations is unknown but likely exceeds a thousand. Some users have reported that these systems require considerable maintenance to prevent plugging and bypass. Advantages • Does not require additional space as inserts as the drain inlets are already a component of the standard drainage systems. • Easy access for inspection and maintenance. • As there is no standing water, there is little concern for mosquito breeding. • A relatively inexpensive retrofit option. Limitations Performance is likely significantly less than treatment systems that are located at the end of the drainage system such as ponds and vaults. Usually not suitable for large areas or areas with trash or leaves than can plug the insert. Design and Sizing Guidelines Refer to manufacturer's guidelines. Drain inserts come any many configurations but can be placed into three general groups: socks, boxes, and trays. The sock consists of a fabric, usually constructed of polypropylene. The fabric may be attached to a frame or the grate of the inlet holds the sock. Socks are meant for vertical (drop) inlets. Boxes are constructed of plastic or wire mesh. Typically a polypropylene "bag" is placed in the wire mesh box. The bag takes the form of the box. Most box products are Design Considerations • Use with other BMPs • Fit and Seal Capacity within Inlet Targeted Constituents / Sediment / Nutrients / Trash / Metals Bacteria / Oil and Grease / Organics Removal Effectiveness See New Development and Redevelopment Handbook-Section 5. ',--.. California Stormwater ,. Quality Association January 2003 California Stormwater BMP one box; that is, the setting area and filtration through media occurs in the same box. One manufacturer has a double-box. Stormwater enters the first box where setting occurs. The stormwater flows into the second box where the filter media is located. Some products consist of one or more trays or mesh grates. The trays can hold different types of media. Filtration media vary with the manufacturer: types include polypropylene, porous polymer, treated cellulose, and activated carbon. Construction/Inspection Considerations Be certain that installation is done in a manner that makes certain that the stormwater enters the unit and does not leak around the perimeter. Leakage between the frame of the insert and the frame of the drain inlet can easily occur with vertical (drop) inlets. Performance Few products have performance data collected under field conditions. Siting Criteria It is recommended that inserts be used only for retrofit situations or as pretreatment where other treatment BMPs presented in this section area used. Additional Design Guidelines ollow guidelines provided by individual manufacturers. , ••/. lalntenance Likely require frequent maintenance, on the order of several times per year. Cost • The initial cost of individual inserts ranges from less than $100 to about $2,000. The cost of using multiple units in curb inlet drains varies with the size of the inlet. • The low cost of inserts may tend to favor the use of these systems over other, more effective treatment BMPs. However, the low cost of each unit may be offset by the number of units that are required, more frequent maintenance, and the shorter structural life (and therefore replacement). References and Sources of Additional Information Hrachovec, R., and G. Minton, 2001, Field testing of a sock-type catch basin insert, Planet CPR, Seattle, Washington Interagency Catch Basin Insert Committee, Evaluation of Commercially-Available Catch Basin Inserts for the Treatment of Stormwater Runoff from Developed Sites, 1995 Larry Walker Associates, June 1998, NDMP Inlet/In-Line Control Measure Study Report Manufacturers literature ( •—-anta Monica (City), Santa Monica Bay Municipal Stormwater/Urban Runoff Project - i valuation of Potential Catch basin Retrofits, Woodward Clyde, September 24,1998 1 nf (( Woodward Clyde, June n, 1996, Parking Lot Monitoring Report, Santa Clara Valley Nonpoint Source Pollution Control Program. (•By: Suntree Technologies Inc. S ltnfQ Isny * (321) 637-7552 www.suntreetech.com Catch Basin Wall Details of Z-mold Figure 2 San Diego regional standard Curb Inlet - Type B Figure 1 * . V •* ''** • f ^' FLOW RATES per 3 ft BASKET Q = SO * cd*A,/2*g*n od =°SS55iol= .67 Top Front Bottom Front Bottom TOTAL SO .62 .56 68 A (ft2) 85.1 179.4 165.9 h(ft) 7.9 12.40 18.0 atf) 1.6 3.8 5.1 10.6 Figure 3 Patent Pending NOTES: 1. Shelf system provides for entire coverage of Inlet opening so to divert all flow to basket. 2. Shelf system manufactured from marine grade fiberglass, gel coated for UV protection. 3. Shelf system attched to catch basin with non corrosive hardware. 4. Filtration Basket structure manufactured of marine grade fiberglass, gel coated for UV protection. 5. Filtration Basket fine screen and coarse containment screen manufactured ' from stainless steel. 6. Filtration Basket holds boom of absorbent media to capture hydrocarbons. Boom Is easily replaced without removing mounting hardware. 7. Filtration Basket location Is directly under manhole access for easy maintenance. Distributed by: BIO CLEAN ENVIRONMENTAL SERVICES INC. PO BOX 869, OCEANSIDE, CA 92049 (760)433-7640 FAX (760) 433-3176 wfflyjbloolPJiOenvironmental.net By: Suntree Technologies Inc. The California Curb Shelf Basket Water Cleaning System Figure 1 | San Plego regional standard Curb Inlet - Type C Clean Water Out Figured Patent Pending (321) 637-7552 www.suntreetech.com Details of Shelf System (Dimensions will vary) Figure 2 FLOW RATES par 3 ft BASKET Q = SO*cd*A,/2*g*h cd«=cS£££*= .67 Top Front Bottom Front Bottom TOTAL SO .62 .56 .68 A (ft2) 85.1 179.4 165.9 h(fr) 7.9 12.40 18.0 atf-1) 1.6 ?.8 5.1 10.6 NOTES: 1. Shelf system provides tor entire coverage of Inlet opening so to divert all flow to basket. 2. Shelf system manufactured from marine grade fiberglass, gel coated for UV protection. 3. Shelf system attched to catch basin with non corrosive hardware. 4. Filtration Basket structure manufactured of marine grade fiberglass, gel coated for UV protection. 5. nitration Basket fine screen and coarse containment screen manufactured from stainless steel. 6. Filtration Basket holds boom of absorbent media to capture hydrocarbons. Boom is easily replaced without removing mounting hardware. 7. Filtration Basket location Is directly under grate for easy maintenance. Distributed by: BIO CLEAN ENVIRONMENTAL SERVICES INC. PO BOX 869, OCEANSIDE, CA 92049 (760)433-7640 FAX (760) 433-3176 nnt 1NTAL SERVIC! Grate Inlet Skimmer Box Curb Inlet Basket Nutrient Separating Baffle Box REPORTS & DATA Pollutant Loading Analysis for Stormwater Retrofitting in Melbourne Beach, Florida Pollutant Removal Testing for A Suntree Technologies Grate Inlet Skimmer Box Site Evaluation of Suntree Technologies, Inc. Grate Inlet Skimmer Boxes for Debris, Sediment And Oil & Grease Removal ENVIRONMENTAL SERVICES, INC. P O BOX 869, OCEANSIDE, CA 92049 CTS01 433.7640 FAX PollMtaist LoadiHg Analysis For Stormwater Retrolitting in Melbourne Beach, Florida By: Gordon England, P.E. Creech Engineers, Inc. 4450 W. Eau Gallic Blvd, #232 Melbourne, Fl. 32932 Introduction At Gemini Elementary School in Melbourne Beach, Florida, there has been a history of repeated flooding on the school grounds and in properties adjacent to the school. In 1999 Creech Engineers, Inc. (CEI) was chosen by Brevard County Storrmvater Utility to design drainage improvements to alleviate these flooding conditions, as well as to provide for stormwater treatment within this 20.06 hectare drainage basin. The project was divided into two phases. Phase 1 improvements were made in order to accelerate initial flood control measures for homes downstream of the school Phase 2 involved the design of more extensive flood and water quality control measures along Oak Street for further protection of school property and roadway flooding at nearby church property. This paper highlights the political challenges of retrofitting stormwater systems in developed areas, as well as demonstrates a methodology for performing a nonpoint source pollutant loading analysis. Existing Conditions Gemini Elementary School is located on a 8.02 hectare, triangular shaped property along the south side of Oak Street, a two lane collector road in Melbourne Beach, about one half mile from the Atlantic Ocean. See Exhibit 1. Residential properties lie downstream of the school, along its southeast and southwest borders. 8.51 hectare Doug Ftotie Park is on the north side of Oak Street A soccer club uses the park and school grounds on a daily basis. There was no stormwater system at the park, along Oak Street, or on die school site. Stormwater flowed southward off Doug Fhrtie Park, across Oak Street, through the school site, and into the yards and homes south of the school These yards, and the roads dovrastream of them, are very flat and only a few feet above sea level Once water stages high enough in the yards, it gradually sheetflows down the adjacent roads a few hundred yards to the Indian River. The affected homeowners naturally blamed the school for allowing the school's water to flood them. West of the school, a few hundred yards along Oak Street, was a low point in the road where water ponded and flooded the road and an adjacent churchyard. Due to a thin clay lens at 26 cm deep causing a perched water table, water stood in die road for several days after even a nominal rainfall. This drainage basin was almost completely built out, with no easy path for developing outfalls to relieve flooding. This section of the Indian River is a Class 2 water body, with a Shellfish Harvesting classification bringing intense scrutiny from the St. Johns River Water Management District. Corp of Engineers permitting is required for new outfalls in the area due to seagrasses near the shoreline. The park, the school, and Oak Street lie in unincorporated Brevard County. The church, and properties west of the school are in Melbourne Beach. Being a collector road, all of the utility companies have major transmission lines in the road right-of-way. As can be seen, this challenging project involved Brevard County, Melbourne Beach, the School Board, Brevard County Parks and Recreation Department, Brevard County Road and Bridge Department, Brevard County Stormwater Utility, a church, three different Homeowners Associations, a soccer club, the Water Management District, the Corp of Engineers, and several utility companies. Stakeholder involvement and partnerships were going to be critical to weave a solution through the many players involved. Proposed Improvements The first priority was to alleviate flooding in the homes adjacent to the school As an interim measure,, a berm was designed and constructed by County personnel along the V "" south property lines of the school, with a swale behind the berm directing water to the ([' southernmost point of the school properly. At that location, an inlet and IB" outfall pipe were constructed in a utility easement through two heavily landscaped and fenced yards, toPompano Street, where it was tied into an existing storm drain pipe. A short time later, heavy rams overflowed the berms and swales and flooded homes adjacent to the school again. CEI was engaged at that point to provide more effective drainage improvements. Fortunately, Gemini Elementary School had a significant area of vacant land on their site. The school entered into agreements with Brevard County allowing the construction of three dry retention ponds totaling 2.95 hectare to reduce flows leaving the school site, as well as provide stormwater treatment where none existed. These dry ponds were wound around several soccer and baseball fields. The soccer field's locations had to remain in place due to previous agreements with the school and Parks and Recreation Dept. The ponds were only 26-40 cm (12"-18") deep and sodded, allowing the soccer teams to use the pond areas as practice fields when dry. When the ponds were excavated, the confining clay layer was removed to allow for infiltration though the beach sand at the site. Construction was scheduled during the summer when school was out. A control structure was designed at the outfall pipe location to provide protection for a 25 year storm. The temporary connection to the existing downstream pipe had overloaded -^the downstream system in a heavy rain event, so a new outfall to the Indian River was designed through a park adjacent to the River. The park was owned by a Homeowners Association, which reluctantly gave a drainage easement through the park. The County agreed to make several improvements to the park and its boat ramp in exchange for the easement The Corp of Engineers was concerned that the new outfall pipe discharges would impact the nearby seagrasses, so the new discharge pipe was not permitted to be constructed in the Indian River. A bubbleup box was designed ten feet back from the shoreline and rock riprap was placed between the bubbleup box and the mean high water line to prevent erosion. As mitigation for disturbing the shoreline, spartina and other plants were planted among the rocks to further buffer the shoreline from the stormwater discharges. This first phase of improvements was finished in September 2000 ait a cost of $124,000. The improvements implemented proved successful in preventing any flooding of adjacent homes in several large rainfalls in 2001. The second phase of the project addressed stormwater quantity and quality concerns along 1650 meters of Oak Street, from A1A to Cherry Street. To provide further flood protection at Gemini Elementary School, retention swales were designed along both sides of Oak Street and 625 meters of storm drain pipe was designed to intercept runoff and prevent it from crossing the road onto school property. The piping also provided an outfall for the low spot in the road by the church. This new pipe system discharged into a residential canal system, which was used by many of the adjacent residents for boating to the Indian River Lagoon (Bay). These canals were very politically sensitive since they were in need of dredging and the Town of Melbourne Beach does not dredge canals. The residents were concerned that the new stormwater system would lead to further sedimentation of the canals. The. first alternative for treatment was to use land at the church site for a pond for the road runoff The church was willing to donate the land where their septic tank fields were located if the County would provide a sewer connection. This scenario was designed, but when it came time for the church to give easements to die County, they balked and it was back to the drawing board. St. Johns River Water Management District, (District), criteria requires stormwater treatment for improvements which a) increase discharge rates b) which increase pollutant loadings, or c) which increase impervious areas. With this project, no new increased impervious areas were proposed, but there would be additional water flowing to the residential canal from the extension of the pipe system to the flood prone areas. These new flows create the potential for increased pollutant loadings to the canal Normal design methods would have used treatment ponds to offset these potential impacts. Due to lack of available land for ponds, alternative treatment methods were proposed for this project The District will consider alternative treatment methods if it can be demonstrated that all other possible alternatives have been exhausted. It would not be possible politically to use more school or park area for treatment ponds. For this project, ~~" showed that the only alternatives were to tear down houses for ponds, or use The treatment strategy involved maximizing treatment methods within the project basin with alternative BMPs, as well as retrofitting two adjacent watersheds as additional mitigation. A total of 1.67 acre feet of retention, storage was provided in Phase 2 in the roadside swales and small ponds. This was equivalent to 0.032 inches of retention from the drainage areas flowing to the retention areas. A treatment train along Oak Street was designed by using 9 Grated Inlet Skimmer Boxes, from Suntree Technologies, Inc., in the new inlets to trap debris entering the inlets, constructing berms to slow runoff from the ball fields, and installing one baffle box at the downstream end of the new pipe system along Oak Street. Baffle Boxes are in-line stormwater treatment devices which trap sediment, trash, and debris. They have been used by Brevard County successfully for the last 9 years. In ofisite Basin 4, which only had one existing baffle box to provide sediment removal, 16 Curb Inlet Skimmer Boxes were installed in all of the existing inlets to provide nutrient removal by trapping grass clippings, leaves, and yard debris. Nutrients were a concern in the canals since the nutrients promote a]gae blooms, which in turn increase muck build up in the canals. In offstte drainage Basin 5, there are 3 existing pipes which discharge directly to the canals. Three baffle boxes and 6 curb inlet skimmer boxes were designed to provide sediment and nutrient treatment for this drainage basin. Brevard County Stormwater Utility will implement this project and be responsible for all maintenance of the improvements. The baffle boxes will be inspected twice a year and cleaned as needed. The inlet traps will be cleaned twice a year. Brevard County has a vacuum truck dedicated to cleaning stormwater BMPs.. t Using numerous BMPs used on this project provided a high degree of treatment for the new piping system along Oak Street, and provided treatment for two ofisite basins where little treatment existed. The retrofitting of the ofisite areas was, in effect, mitigation for the new discharges to the canal See Exhibit 1 for a map of the improvements. Calculations In Phase 1 of the project, the dry ponds and outfall pipes were modeled hydraulically using the Interconnected Pond Routing program. Since the dry ponds in the Phase 2 project area were too small to provide effective attenuation, the predevelopment and post development runoff calculations were made using Hydraflow and the rational method. The only available storm drain pipe for Phase 2 was a 36" pipe in ofisite Basin 4. The new piping along Oak Street was connected to the existing 36" pipe, and the piping downstream of the connection was upgraded to a 42" pipe. The pipes were designed for a 25 year storm. Basins 1,2, and 3 were a much longer distance from the outfall man Basin 4. As a result of different times of concentration, the peak flows from Basin 4 passed sooner than Basins 1,2, and 3, giving only a slight increase in peak discharge, despite adding 12.25 hectares to the area flowing to the existing outfall. The potential for increased pollutant loadings in the canal system was a concern of local residents. These canals had a history of dredging operations every 8-10 years, and the residents did not want to increase the frequency of costly dredging. The main pollutants of concern leading to muck deposition in the canals were Total Suspended Solids (TSS), Total Nitrogen (TN), and Total Phosphorus (TP). Sediment build up at the end of the pipes was common. Nutrient loadings from grass clippings, leaves, and fertilizers leads to algae blooms and low dissolved oxygen in the canals, which in turn leads to muck build up from the eutrophication process. Most of the material dredged from residential canals is typically muck. To address this concern, a pollutant loading analysis of the existing and proposed stormwater discharges was performed. In the existing conditions, die only stormwater treatment for the canal system was a baffle box along Cherry Street for oflsite Basin 4 of 24.24 hectares. There were a total of 7 outfall pipes discharging into the canal system. In the first phase of this project stormwater treatment was provided for 8.02 hectares of the school grounds with 3 dry detention ponds. The discharge from these ponds was to the Indian River, rather than the canal system, so these pollutant bads were not included in the pollutant toad analysis for the canal outfall. The existing pollutant toad to the canal only came from the drainage Basins 4 and 5, totaling 31.2 hectares. The runoff from Oak Street did not drain to the canal in existing conditions, only in the post development conditions. The strategy for the pollutant analysis was to calculate the pollutant toads in the existing conditions, and then calculate the pollutant toads after the new pipes were added to the system and oflsite areas retrofitted for stormwater treatment. The pollutants used in this analysis were TSS, TP, and TN. Each drainage basin was categorized by land use. Area], annual, mass loading rates from "Stormwater Loading Rate Parameters for Central and South Florida", Harper, 1994, were multiplied by each basin's area to give existing and potential annual pollutant loadings. See Table 1. The next step was to calculate die pollutant removal rates for the different BMPs. Individual BMP removal efficiencies were take from "A Guide for BMP Selection in Urban Developed Areas", EWR1,2000. What was challenging with this analysis was the use of multiple BMPs in series for the treatment tram. Each BMP receives cleaner and cleaner water as the water moves down the train. At each BMP, the removal efficiency for each constituent was multiplied by the remaining percentage of the initial loading to give a weighted, cumulative, removal efficiency for each constituent See Table 2. These calculated removal efficiencies were then multiplied by the total calculated pollutant loads to give the reduced pollutant loadings after the BMPs were installed. See Table 3. Table 4 shows that the total toads to the canal were reduced as a result of the retrofitting of onsite and oflsite basins. The pollutant loading analysis below demonstrates that as a result of the numerous BMPs proposed, the total pollutant loadings entering the canals after project completion will actually be significantly reduced from the existing pollutant loadings entering the canals. The key to overall pollutant reduction is to provide additional treatment in offsite drainage basins. This will result in a net benefit of reduced pollutants entering the canals and a reduction of the severe flooding often seen along Oak Street. Table 1 Existing Pollutant Loading Basin 2A 2B 2C 2D 2E 2F ^G >--J*/ s (' J ' 2K 2L 3A 38 3C Subtotal 4** 5A SB 5C Subtotal Totals Area (acres) 9.23 1.15 0.77 1.45 2.63 1.87 0.75 1.29 0.08 0.8 0.57 0.34 2.19 3.02 4.02 30.26 59.0 5.9 8.62 2.68 77.1 107.36 Land Use Recreational Recreational Recreational Recreational Recreational Recreational Recreational DAfti^^^fawi^d ft*. _LBi_^_irftAgl_r»lRecreational Recreational Recreational Recreational Sinflte Family SUwteFamHv LowlntensNy Gonvneroial Single Family Single Famiy Single Famly QinnlA CT^nJKroinyle rcVnQr Loading Rate* (kg/ac-year) TSS 7.6 7.6 7.6 7.6 7,6 7.6 7.6 7.8 7.6 7.6 7.6 7.6 58.1 56.1 L343 56.1 58.1 56.1 56.1 Total pnosptiorus 0.046 0.048 0.046 0.046 0.048 0.046 0.046 0.046 0.046 a046 0.046 0.046 OJS94 0.594 0.65 • 0.594 0.594 0.594 0.594 Total Nitrogen 1.07 1.07 1.07 1.07 1.07 1.07 1.07 1.07 1.07 1.07 1.07 1.07 4.68 4.68 5.18 4.68 4.68 4.68 4.68 EV_.flu».«B*S«Bl B^.ll> lAjKM*Potential Pollutant (kg -year) TSS 70.15 8.74 5.85 11.02 19.99 14.97 5.70 9.80 0.61 6.08 4.33 2.58 122.86 189.42 1378,88 1830.97 672.00 330.99 483.58 150.35 1636.92 3467.89 Total Phosphorus 0.425 0.053 0.035 0.087 0.121 0.091 0.035 0.059 0.004 0.037 0.028 0.016 1.301 1.794 2.613 6.68 24.910 3.505 5.120 1.592 35.13 41.80 Loading Total Nitrogen 9.876 1.231 0.824 1.552 2.814 2.108 0.803 1.380 0.086 0.858 0.810 0.364 10.249 14.134 20.824 87.71 280.332 27.612 40.342 12.542 360.83 428.54 * From "Stormwater Loading Rate Parameters for Central and South Florida", 1994. Harper ** Basin 4 has an existing baffle box providing treatment. Basins 4 and 5 are the existing pollutant loadings to the canals. 6 Tafe!e2 BMP Pollutant Removals BMP POLLUTANT REMOVAL TABLE* BMP Type - 3ryPond Swale Baffle Box nlet Trap (grated) ntet Trap (euro) Swale + Met Trap to) + Baffle Box Dry Pond + Inlet Trap (a) * Baffle Box nlet Trap (cH- Baffle Box ntet Trap (a)+ Baffle Box 3MP Removal Efficiency TSS 85 80 80 73** 2*** 98.9 99.2 84 81.1 , Multiple BMP Pollutant Removal Calculations Swale* Inlet Trap to) + Baffle Box (%) TP 61 45 30 79** 11*** 91.9 94.3 37.7 85.3 TN 91 25 0 79** 10*** 84.2 98.1 10 79 TSS - 100x0.8 + (100r80)x0.7a + (100-80-14.6)x0.8 = 98.9% Removal TP - 100x0.45 + (1(XM5)x.79 + (1CKM&43.45) = 91.9% Removal TN - 100x25 + (100-25)x.79 = 84.2% Removal Diy Pond + lntet Trap (g) + Baffle Box TSS - 100x0.85 + (100-86)x0.73 + (100-65-10.95)x0.8 = 99.2% Removal TP - 100x0.61 + (100<1)x0.79 -«- (100H81-30.8)K.3 - 94.3% Removal TN - 100x91 + (100-91)x.79 = 98.1% Removal Inlet Trap (c) + Baffle Box TSS - 100-X0.2 + (100-20)x0.8 = 84% Removal TP - 100x0.11 + (100-1 1)x.3= 37.7% Removal TN - IOOx.10 ~ 10% Removal Inlet Trap (g) + Baffle Box TSS - 100x0.73 + (100-73)x0.30 = 81.1% Removal TP - 100x0.79 + (100-79)x0.3 = 85.3% Removal TN - 100X.79 - 79% Removal All removal values are from iGuide For Rent Mananomont DIB^HKO From Creech Engineers study "Pollutant Removal Testing For a Suntree Technologies Grate Inlet Skimmer Box", 2001 *From visual observation by Brevard County staff Table 3 Proposed Pollutant Loading Basin 2A 2B 2C 2D 2E 2F 26 2H 21 2J 2K 2L 3A 3B 3C 4 5A. 5B SC BBSPType swale + tntet trap (s) * baRte box swate* Intel »rap(g) + baffle box dw pond +Wet trap fa) + baffle box dry pond + Met trap £9) + baffle box <fty pond + Wrt trap (g) + baffle box swale + Met trap (0) + baffle box dry pond + Wet trap fa>+ baffle hoc dnri»rd+lnletlfapfg)+baHtebaK swate* Met tap (a) * baffle talc Met trao(fi)+ baffle box Wet traofa)* baffle box IMetfrajtfaD+bafltelxw Met bap fifl* baffle box WettoBpfcO+bafflebooc diy pood + MM. rap id) * Dene box WettraDfiA+bafflebox Wet trapfc) •«• baffle box Met trap fO+baflteboK Wetfrapfti+bafltebooc Removal Efficfensy From New B&IPs (%) TSS 88.9 98.9 9&.2 99^ 9ft2 9&9 9O2 saz 9BL9 81.1 81.1 81.1 81.1 81.1 9&2 81.1 84 84 "w TP 91.8 91.8 94.3 94.3 94.3 91.9 94.3 94.3 91.9 .85.3 85.3 85.3 85.3 8&3 94.3 85.3 37 37 37 TaM TN 84.2 64.2 98.1 98.1 98.1 04.2 98.1 98.1 84.2 79 79 79 79 79 96.1 79 10 10 10 PoOutentLoBd Reducifon From BRSPs (kg/year) TSS 69.38 8.64 5.81 10.93 19.83 14.81 5.65 9.73 O.60 4.93 3j51 2.10 99JB4 137.40 1387.83 544.99 278113 40621 126.29 230&77 TP 0.39 0.05 0-03 0.06 0.11 aos 0.03 aoe 0.00 0,03 0.02 0.01 1.11 1.53 246 2125 1^0 1.89 0.59 27.24 TN 8.32 1.04 0.81 1.52 2.76 1.77 0.79 1.35 0.07 aes O48 029 aio 11.17 20.43 221.48 2,76 403 125 281 JW Proposed Pollutant Loading {kgfyes?) TSS 0.77 0.10 0.05 tt09 0.16 0.16 0.05 008 0.01 1.15 0.82 0.49 23.22 32.02 11.03 127.01 52416 77.37 24.08 197.19 TP 0.03 0.00 0.00 0.00 0.01 0.01 0.00 0.00 0.00 0101 0,00 0.00 0,19 026 0.15 3.66 221 323 1.00 4.34 TN 1.58 0.19 0.02 0.03 0.05 0.33 0.02 0.03 0.01 ai8 0.13 0.08 2.15 2.97 0/40 58.87 24.85 36.31 11.29 67.01 Table 4 Net Pollutant Removals Predevelopment Postdevelopment Net Reduction TSSOo^D 3015.78 630.97 2384.81 (79%) TP(ks/yr) 35.13 21.95 13.18(37.52%) TN(kg/yr) 380.83 289.15 91.68(24.07%) Summary The days of solving flooding problems in communities with simple ditch and pipe solutions have disappeared. Environmental concerns now dictate that stormwater treatment techniques be integrated into these flood relief projects. By adding water quality components to water quantity projects, communities can help achieve pollution remediation goals being established for NPDES, TMDL, and PLRG programs. /Retrofitting existing stormwater systems to provide water quality treatment is more complicated, expensive, and time consuming than traditional stormwater designs for new development. The scarcity of available land and numerous existing utilities in older built out areas will tax an engineer's imagination to provide innovative BMPs in these locations. An carefully planned treatment train was designed consisting of swales, ponds, berms, baffle boxes, and inlet traps to provide overall stormwater pollution reduction. In order to address stormwater pollution concerns, treatment mitigation was designed in offsfte drainage basins. The pollutant loadings and removals were calculated using a simple but effective spreadsheet analysis incorporating the latest in BMP efficiency studies. While complicated stormwater modeling software can be used for pollutant analysis, this type of modeling is more cost effective on large basin studies than small basins and individual projects. The pollutant removal calculations showed an annual net reduction of 79% for TSS, 37% for Total Phosphorus, and 24% for Total Nitrogen in the Oak Street basin despite the creation of a new stormdrain system for a landlocked area. As this project demonstrates, there are typically numerous stakeholders that need to be brought into the project early in the process and kept in the process throughout the life of the project. Many meetings were held with city, county, and state officials, homeowners associations, schools, soccer clubs, churches, and utility companies. All it takes is one uncooperative stakeholder to set back or kill a project, as was demonstrated with the church backing out of the land acquisition process after many verbal indications of approval Using creative partnerships with other entities and agencies allowed the development of a unique strategy to solve flooding at several locations in the project area. References ASCE - "Guide For Best Management Practice Selection in Urban Developed Areas", 2001 Gordon England, P.E. "Pollutant Removal Testing For a Suntree Technologies Grate Inlet Skimmer Box", 2001 Harvey Harper, Ph. D, PJB., "Stormwater Loading Rate Parameters for Central and South Florida", 1994 POLLUTANT REMOVAL TESTING FOR A SBNTREE TECHNOLOGIES GRATE INLET SKIMMER BOX Prepared for Suntree Technologies, Inc. November 2001 CEI Project #21121.00 Prepared By: 4450 W. Eau Gallte Blvd., Ste. 232 Melbourne, FL 32934 (321) 255-5434 TABLE QF CONTENTS PAGE Background \ Methodology 2 Results 2 Table 1 - Sediment Sieve Analysis 3 Conclusions 3 APPENDIX A > Site Photos APPENDIX B > Universal Engineering Sciences Grate Inlet Skimmer Box Evaluation Report Pollutant Removal Testing for a Suntree Technologies by Creech Engineers, Inc. November 2001 With special thanks to Joanie Regan of the Cocoa Beach Storrawarer Utility Background; Over the last several years, a number of BMPs have been developed to provide storrawater treatment by trapping pollutants and debris in inlets. Inlet trap BMPs ate quasi source controls, being inexpensive, requiring no roadway construction or utility relocation, and keeping pollutants out of tte watw boclfcs, lather fhm fiyn^ the pollutants from the water once it is contaminated. Suntrec Technologies, of Cape Canaveral, Florida commissioned Creech Engineers, Inc. and Universal Enginceringto perform testing on a ^Grate Inlet Skimmer Box (CHSB) to detennine its pollutant removal 26, 2001. Attached are photographs from the test and the accompanying report byUmversal Engineering Sciences. The C3SB is designed to trap sediment, grass, leaves, organic debris, floating trash, and hydnxarboM as they enter a grated inlet, thereby prating AcsTp^Staiteirom entering me stormdram system where they -would cause detrimental impacts on most types of grated inlets. TtooveiflBWGapadlyoffliB<HSBfaae8«nedtob0g)teater than the curb grate capacity, thereby insuring that there wffl be no loss of hydraulic capacity due to the device being inside the mlet The bottom of the GISB is desimed to be above any pipes entering or leaving the inlet so that flow through me Wtetfai notblocked. . ^^ Water flowing through the grate first encountera a hydrocarbon ah^ This boom also saves to trap targe debris between the boom and the body of the (HSB At the f *•** of atainfess sted *_ *•** of atainfess sted *** ***** «wa*g 3^ inch videcutouts m the fiberglass body. These screens trap debris while aflowma water to nass'i"*!!*^*^*"**^floo^firstv^rowoftteCHSBarefi^ii^ The second vertical row of screens are medium mesh and the highest row are coarse mesh. On the outside of the cutouts the screens are Wnilgi -stainless dianwnd plate to provide support ^ heavy toads of debns build up in the box. If the flow rate through the inlet exceeds the capacity of the filter screens there is another row of overflow holes cut out with no S!3i4?~i2SfT JJ"^. *** to *** tht°l*h ^QISB ™i if it becomesfoil of debns The level of the holes is above the bottom of the top tray, enabfiiig the tray to act as a skimmer to prevent floating trash ftom escapiog tlirough the oveSw holes. About halfway down the box is a diffuser plate to minimize resuspension of trapped sediment. Inlet traps such as these are generally designed to capture hydrocarbons, sediment, and floating debris. There is generally a large build up of grass, leaves, and yard debris in the GISBs; which represent a source of nutrients, which do not enter the waterbodies. Royal and England, 1999, determined that leaves and grass leach most of their nutrients into the water within 24-72 hours after being submerged in water. GISBs are designed to keep captured debris in a dry state, off the bottom of the inlet, thus preventing phosphates and nitrates from teaching into the stormdram system, where much more expensive BMPs would be required to remove the dissolved nutrients. Methodology; A test was designed to simulate a rainfall event and measure the ability of a GISB to remove sediment and grass leaves from a typical grated inlet at 600 South Brevard Ave., Cocoa Beach, Florida. Joanie Regan of the Cocoa Beach Stormwater Utility provided this location for the test, as well as a water track to flush the curbs. Universal Engineering Sciences performed the testing, measurements, and sediment sampling. Creech Engineering, Inc. observed the testing. The City has installed a number of these devices and Joanie indicated this location was typical of a normal installation. The grate, curb, and gutter around and upstream of the inlet were brushed and washed clean. A new, clean GISB was placed inside the inlet. A water truck with a pump discharged reuse water into the gutter upstream of the inlet at a rate of 500 gpm (1.1 eft). Dry, green St. Augustine grass cuppings from a yard mat had been recently fertilized were slowly fed into the glitter and mished into the mtet. It was observed that the cast iron grate trapped a sjgoi£baitf amount of grass around the edges of the grate. The grate was removed for att tests to enable all of the grass and sediment to enter the box. After all of a measured sample of grass bad been washed into the inlet, the grass was removed from the inlet, dried, and weighed. Samples of grass before and after the test were sent to PC&B laboratories in Oviodo, Florida. Laboratory analysis was performed to determine the Total Phosphorus and TKN content of the grass. Next, a sediment sample was washed through the GISB using the same methodology. Universal Engineering ran a sieve size analysis, using ASTM D 422 procedures, before and after the test The sediment was classified as a poorly graded gravely sand. The sediment was removed from the GISB, dried, and weighed. During both of the tests, all water leaving the GISB passed through the filter screens. The water levels in the box only rose a few inches, with no water passing through the overflow holes or coarse screens, even though the bottom screens were completely covered with grass or sediment. There was a small amount of grass and sediment that ;of the inlet. This situation Is fairly common in most inlets due to loose tolerances in construction techniques. In the grass test, 6.58 Ibs. of grass were washed into the inlet and 5.22 Ibs. were captured, resulting in 1.36 Ibs. of grass passing through the GISB. This represents a removal efficiency of 79.3%. The pretest grass sample had a Total Phosphorus content of 950 mg/kg and a TKN content of 510 mg/kg. The grass sample removed from the GISB had a Total Phosphorus content of 2,270 mg/kg and TKN content of 905 mg/kg. The sediment test was a little more complex. The initial results showed that of the 57.87 Ibs. of sediment introduced to the GISB, 42.41 Ibs. were captured, giving a total mass removal efficiency of 73.3%. Universal Engineering indicates that the Pretest sample had 10.7 % gravel 88.0% sand, and 1.4% day. The Post test sample had 25.9% gravel, 14.7% sand, and 1.7% day. Gravel is considered to be particles No.4 and larger. Silt and clay is defined as particles passing the No. 200 sieve. Table 1 Sediment Sieve Analysis Sieve Size PreTest % Passing Post Test % Passing jLjpiiilE'PBBUPfi 3/8" 94.3 88.8 5.5 No.4 89.3 74.1 15.2 No. 10 81.8 62.6 19.2 No. 40 64.8 44.2 20.6 No. 60 50.3 31.8 18.5 No. 100 25.5 14.7 10.8 No. 200 1.4 1.7 -0.3 Conclusions; At the flow rate tested, the GISB removed 79.3% of the grass clippings washed into it. The abiHty of the GISB to remove grass during large flows when water passes through the bypass holes was not tested. In Florida, 90% of the storms ace low lainM events of 1" or less, resulting in low flows similar to the test conditions. This makes the GISB a very effective BMP for Low flow events. It is unknown how effectively the GISB works in large storm events. By keeping grass and other trapped organic debris in a dry state, the nutrients in the debris do not leach out and become dissolved nitrates and phosphates. The GISB is a very effective BMP for preventing nutrients from organic debris from entering waterbodies. The significant increase in nutrient concentration after the test is probably attributed to die use of wastewater reuse water during the test. The grass matted several inches thick in the bottom of the box. This thick layer could have acted as a filter to remove nutrients from the water source. At the flow rate of 1.1 cfs, the GISB had a sediment removal efficiency of 73.3%. As would be expected, most of the trapped sediment was gravel and sand, with little fine material collected. The GISB has sediment removal capabilities rivaling those found in many structural BMPs, at a fraction of the cost, and without disruptive construction. UNIVERSAL ENGINEERING SCIENCES Constants fcrGecfedimcal Engineering • Environmertaf Sesnss • Conslructioo Materials Testing • Threshold Inspection 820 Brevard Avenue • Rockledge, Florida 32955 (321.) 638-0808 Fax (321) 638-0978 November 2,2001 Mr. Gordon England, P.E. Creech Engineers, Inc. 4450 West Eau Gallie Boulevard Melbourne, Florida 32934 Reference: Grate Inlet Skimmer Box Evaluation Northwest Comer of South Brevard Avenue and South 8"1 Street Cocoa Beach, Brevard County, Florida Universal Project No. 33186-002-01 Universal Report No. 51479 Dear Mr. England: Universal Engineering Sciences, Inc. (Universal) has completed an evaluation of a Grate Inlet Skimmer Box (GISB) in accordance with Universal Proposal No. P01-0781. The evaluation was conducted to document the pollutant removal effectiveness at the above-referenced site. A Location Map, Site Map and Site Photographs are presented as Attachments 1, 2 and 3, respectively. Sediment Testing Universal supplied the sediment sample for the GISB evaluation. The sediment sample consisted of fine sands, coarse grain sands with crushed sheds, and gravel. A gradation analysis of the sediment sample (S-1) was performed, prior to GISB performance testing. The * percentages of soil grains, by weight retained on each sieve warn measured and a grain size distribution curve generated, to determine the textural nature of the sample and provide a control (baseline) prior to fieldwork. A sediment sample of known weight (57.87 IDS.) was placed on the pavement upstream of the GISB and washed into the GISB with a portable water source simulating a storm event. The captured sediment was then removed from the GISB. dried and weighed. The captured sediment weighed 42.41 Ibs. resulting in a loss of 15.46 IDS. from the GISB testing. A gradation analysis of the captured sediment sample (S-2) was performed. Universal completed particle size analyses on the two representative sediment samples (S-1 and S-2). The samples were tested according to the procedures for mechanical sieving of ASTM D 422 (Standard Method for Particle Size Analysis of Soils). In part, ASTM 0 422 requires passing each specimen over a standard set of nested sieves (% inch, No. 4, No. 10, 'o. 40, No. 60, No. 100, No. 200). The percentage of the soil grains retained on each sieve size re determined to provide the grain size distribution of the sample. The distribution determines he textural nature of the soil sample and aids in evaluating its engineering characteristics. Mr. Gordon England Project No. 33186-002-01 November 2, 2001 Report No. 51479 Page2 . S-1 consisted of 10.7 percent grave! (grain size larger than 4.75 mm), 88.0 percent sand (grain size between 0.075 mm and 4.75 mm), and 1.4 percent fines (grain size less than 0.075 mm). S-2 consisted of 25.9 percent gravel, 72.4 percent sand, and 1.7 percent fines. The grain size distribution curves are presented as Attachment 4. According to the Unified Soil Classification System (USCS), S-1 and S-2 were classified as poorly-graded gravely sand [SPJ. Based on the gradation analysis, the major portion of the lost sediment was the fine sand component. Grass Clippings Test The grass clippings were supplied by Suntree Technologies. A grab sample of grass (G-1) was collected and submitted for laboratory analysis to determine the TKN (EPA Method 351.2) and Total Phosphorus (EPA Method 365.3) content A grass sample of known weight (6.58 Ibs.) was placed on the pavement upstream of the GISB. The grass dippings were washed into the GISB in the same manner as the sediment sample. The captured grass clippings were then removed from the GISB, dried and weighed. The captured grass clippings weighed 5.22 Ibs. resulting in a loss of 1.36 Ibs. A second grab sample (G-2) was collected from the captured grass dippings and submitted for laboratory analysis to determine the removal efficiency for TKN and Total Phosphorus. The samples were shipped to PC&B Laboratories, Inc. in Oviedo. Florida. Laboratory analysis documented 950 milligrams per Kilogram (mg/Kg) of Total Phosphorus and 510 mg/Kg of TKN for G-1. Laboratory analysis documented 2,270 mg/Kg of Total Phosphorus and 905 mg/Kg of TKN for G-2. Laboratory Analytical Results and Chain-of-Custody Documentation are presented as Attachment 5. Universal appreciates the opportunity to provide environmental services as part of your project team. Should you have any questions, please do not hesitate to contact the undersigned at (321) 638-0808. Respectfully submitted, Universal Engineering Sciences, Inc. James E. Adams" Robert Alan Speed Staff Scientist II Regional Manager Rockledge Branch Office (2) Addressee Attachments Attachment 1: Site Location Map Attachment 2: Site Map Mtachment 3: Site Photographs 'Attachment 4: Soil Gradation Curves Attachment 5: Laboratory Analytical Results and Chain-of-Custody Documentation ATTACHMENT 1 SITE LOCATION MAP Grate Inlet Skimmer Box Evaluation South Brevard Boulevard Cocoa Beach, Brevard County, Florida SITE LOCATION MAP OHAWMBY: SBJEIT A ADAMS IGfSQfOI A ADAMS ATTACHMENT 2 SITE MAP RESIDENTIAL CONDOMINIUMS CONDOMINIUM DRIVEWAY LANDSCAPED MEDIUM RESIDENTIAL CONDOMINIUMS CO >'' RESIDENTIAL CONCRETE DRAINAGE SWALE SOUTH 8™ STREET ui RESIDENTIAL Grate Inlet Skimmer Box Evaluation South Brevard Boulevard Cocoa Beach, Brevard County, Florida S!TE MAP J. ADAMS [PASS WO: ATTACHMENT 3 SITE PHOTOGRAPHS Grate Intet at 600 South Brevard Avenue, Cocoa Beach Grate Inlet Skimmer Box FeaturesFlorida Type C Intet Flange is reinforced with knitted 1808 ±45° biaxial fiberglass Pollutant Removal Testing for a Suntree Technologies Grate Inlet Skimmer Box SITE PHOTOGRAPHS Sedunent Bnteribg GISB Sediment Trapped in GISB Pollutant Removal Testing for a Suntree Technologies Grate Inlet Skimmer Box SITE PHOTOGRAPHS GISB Inserted into Inlet Grass campings Entering GISB Sediment Testing ^^K'' !*"'" '•***''' ' ^-Kl"^'"^"•''•""'• '"•"-PoButant Removal Testing for a Suntree Technologfes Grate Met Skimmer Box SITE PHOTOGRAPHS Photo No. i: (Pre-Test) Installation of new G1SB. Photo No. 2: Start of the grass dippings test Grate Inlet Skimmer Box Evaluation NWC of South Brevard Avenue and South 8th Street Cocoa Beach, Brevard County, Florida SITE PHOTOGRAPHS N/A IW30NH 'KCWelJIBK S^r.r-^u • — OHECKSBBV: 1080/01 sS|j^5>^f£i*???-*fc^^^ :•*-•:•• -•-••v Photo NO. a: storm simulation for the grass dp teat Photo No. 4: Completion of grass dippirip removed for Grate Intet Skimmer Box EvaJuatkm N WC of South Brevard Avenue and South 8th Street Cocoa Beach, Brevard County, Florida SITE PHOTOGRAPHS N/A 2 ^fliiii.'iB.i'iAaj Photo No. 6: Sediment test to progress. Grate Inlet Shkwner Box Evaluation NWC of South Brevacd Avenue and South 8th Street Cocoa Beach, Brevard County. Florida SITE PHOTOGRAPHS msmr M/A sacsr 1WW01 hHUfcUINU 3KHT Photo No. 7: Compfetkwi Of Photo No. 8: Storm water catch basin alter testing! Grata Inlet Skimmer Box Evaluation NWC of South Brevard Avenue and South 8lh street Cocoa Beach, Brevard County, Florida • SITE PHOTOGRAPHS mmmr 1W30/(hooEcrmr SSS" 10/30/01 ATTACHMENT 4 SOIL GRADATION CURVES y.S. SIEVE OPENING IN INCHES U.S. SIEVE NUMBERS t.6 t MO 71oo 90 85 T 80 75 \ 70 60 55I N E50 45B Y40 30 28H 15 10 5 0 1 ! Ill 111SI _ . i i 100 10 1 GRAIN Size IN MHJJMETERS COBBLES Spedme 1 GRAVEL1 eoMM i me nMenfificafon • 31 SEDIMENT 1 Spedme ...... «n ktenuncBuon • SI 3/4"W 944 «*w»1 \ 1' |l I II 1 | . 0.1 0.01 O.O01 m CfaMHfcaflan D100 ItAO NO. 4 89.3 D60 0.38 030 0.164 NO. 10 £>10 0.0961 NO. 40 814 644 CKent CREECH ENGINEERING 4450 W. EAU OALUE BOULEVARD MELBOURNE FLORIDA 32934 Project: GRATE INLET SKIMMER Rrnr EVALUATION MCK SILT OR CLAY LL SGraval 10.7 NO. 60 50.3 PL, SSand 88.0 Pi Cc 0,79 %sm Cu 3.T %Clay 1.4 NO. 100 25.5 NO. 200 1.4 Client No: 33186-002-01 . Report No: 51479 Date: 10/9/01 BREVARD COUNTY, FLORIDA SOIL GRADATION CURVES U.S. SIEVE OPENING 8N INCHES S « 9 * U * «J« 8(8 U.S. SIEVE NUMBERS HYDROMETER 140•ni H 90 85 80 E75 R__CTO ^65 T60 FI 55 NE50 R 45 B Y40 ?» 30 25 5 , _ f. . . r. 1 100 1 COBBLES h-sssF*! • 82 SEDIMENT 2 Specimen Identification •1- 3/4" 3/8" 88.0 ,; 10 1 GRAIN SIZE IN Ml ^Tiar .* COM W 1 ffiMM • LLMETBRS fl»T — 1 s n • 0.1 O.01 m — f^JnpplllJ^JAtlgigk • D100 12,50 D60 1^1 NO. 4 74.1 D30 OJE37 NO. 10 62.6 DID 9.1169 NO. 40 442 4460 W. EAU OALUE BOULEVARD MELBOURNE FLORIDA 32934 Project: GRATE INLET SKIMMER nrat CVAI lunnu -j SILTORCIAY MC%LL %Gravel 2S3 NO. 60 314 PL KSand 724 PI O.OO1 Cc 0.30 %Sift Cu 13.7 %Clay . 1.7 NO. 100 14.7 NO. 200 1.7 Client No: 33186-002-01 Report No: 51479 Data: 10/9/01 BREVARD COUNTY, FLORIDA Ann ATTACHMENT 5 LABORATORY ANALYTICAL RESULTS AND CHAIN-OF-CUSTODY DOCUMENTATION 210 Park Road, Oviedo, Florida 32765 Phone: 407-359-7194 Fax: 407-359-7197 Client: Universal Engineering Sciences 820 Brevard Avenue Rockledge, FL 32955- Laboratory Reference Number: 201090199 Project Name: Inlet Skimmer Box Evaluation Project Number: Laboratory ID Matrix Client ID Contact: James Adams Phone: (321) 638-0808 Chain of Custody: 24025 Status Date/Time Sampled 201090189-1 Solid G-1 RUN 09/26/2001 14:20 Number Parameter Description EPA 6010 EPA 9200/3513. Phosphorus by ICAP Total Nitrogen 210 Park Road QViedo, FL 32765-8801 407-3S9-7194 - (FAX) 407-359-7197 Case Narrative James Adams Universal Engineering Sciences 820 Brevard Avenue RocMedge, FL 32955- CA8E NARRATIVE for Work Order: 201090199 Project Number: Project Name: Inlet Skimmer Box Evaluation This Case Narrative te a summary of events and/or problems encountered with this Work Order. lysis for TKN was performed by Environmental Science Corporation (E87487) J UQT V VMue,vaknnotaoourate. tvatetegraaterthanvriuagtan.Samitowalyi^tayoodtheacovtedhohfctgttnw. VMkMneaMfetowttanltolBbMtftyimirtAnriytownboHi detected hi the method bbnfc and sampfe. f Environment! laboratories. Inc. ark Roado, FL 32765-6801 CLIENT NAME: Universal Engineering Setenees PROJECT NAME: Inlet Skimmer BOK Evaluation) PROJECT NUMBER. PATE RECEIVED: 09/26/2001 Lab Reference Number Client Sample ID Date/Time Sampled Sample Maftfe fas Received) 201090199^1 6-1 09/26/2001 1420 Solid EPA 6010 EPA 9200/351.2 Phosphorus, Total Total Nitrogen mg/kg mg/kg 950 510 'ndetected. The value preceedlng the'If tei the RL for the t. FDEP CompQAPP #! Reviewed by: INORGANICS Spike Percent Rasutt Lower Upper Control Control Unit Limit OT—*l$tOClMTAX)407-3S9-7t97 SAMPLE RECBIPT Total* of Cpntainers Chain of Custody Seals RecVd in Good Condition SAMPLE Total* of Containers I Environmental Laboratories, too. 0, FL 32765-8801 AE-. 4Q7-358-7194 CLIENT MAME: Universal Engineering Seiencas PROJECTNAME: PROJECT NUMBER: DATE RECP|VPCV-iQ/18/2001Lab Reference Number Date/Time Sampled 201100168-1 G-2 10/10^0010:00: EPA 6010 Phosphorus, Total mg/kg 2270 EPA 9200/351.2 Total Nitrogen mg/kg 905 Detected. The value i l the V Is the RL for the analyte. Results i Reviewed by:Ltm 210 Park Road, Ovbdo, Florida 32765 Phone: 407-359=7194 Fax: 407-359-7187 Client: Universal Engineering Sciences 020 Brevard Avenue Roekledge, FL 32955- Laboratoiy Reference Number: 20110016B Project Name: Project Number: Contact: Bob Speed Phone: (321)638-0808 Chain of Custody: 20344 Laboratory ID Matrix Cll 201100168-1 Solid < Number Parameter 1 EPA 6010 4 . BDA mniuwM o ' lent ID 3-2 Description Phosphorus by ICAP TWtot kHh»».._ Status RUN Date/Time Sampled 10/10/2001 INORGANICS Lower Upper Percent Control Control Um!L_ Lta* SITE EVALUATION OF SIWTREI TECHNOLOGY, DfC GRATE INLET SKIMMER BOXES FOR DEBRIS, SEDIMENT, AND OIL & GREASE REMOVAL Reedy Creek Improvement District Planning ft Engmeeriqg Department Eddie Snell, Compliance Specialist Stonnwater is now recognized as the leading source of pollution to our remaining natural water bodies in the United States. Development and urbanization have removed most of the natural filtration and sediment trapping systems provided by the environment Ciment development must address mis need through the implementation of stonnwater treatments systems in the project design. Most of these systems perform reasonably well, if properly designed, constructed, and maintained. Retrofit of older urban areas lacking these modem steonwater systems is a continually expensive challenge. The Downtown Disney complex, formerly the Lake Buena Vista Shopping Village, has several drainage basins with 1970'g stonnwater systems. These older systems discharge dkectty into the adjacent drainage canal with no pollutant treatment Over tune die accumulation of sediments, nutrients, intensive development, and recreational/entertainment pressures are contributing to water quality degradation. Whenever new development or redevelopment occurs, the stonnwater system is brought to current coo^pennk requirements. In the interim, several areas are in need fix- rapid, effective, and economical improvement in the qualify of its stonnwater discharge. Suntree Technologies Incorporated, located in Gape Canaveral, FL, manufactures stonnwater grate inlet skimmer boxes. They are nude of a high quality fiberglass frame, with stainless steel filter screens backed by heavy-duty aluminum grating. Each unit is custom made to accommodate various inlet sizes. A hydrocarbon absorption boom is attached to the top of the skimmer box for petroleum, ofl, and grease removal. These devices fit below the grate and catch sediment, debris, and petroleums, oils ft greases. Clean-out, maintenance, and performance reporting is provided by Suntree on a scheduled basis. Picture of Grate Inlet Skimmer Box The Reedy Creek Improvement District (ROD) selected six (6) test sites in the Lake Buena Vista area to evaluate (he performance of these units. One unit was placed in a cub inlet along Hotel Plaza Boulevard to trap landscape leaf litter, sediment, and oil & grease from a high use roadway. Three (3) units were placed in the backstage service area of nie Rain Forest Cafe. Two (2) units were placed in the backstage service area of theMcDonald's restaurant and Legos merchandise shop. After several field meetings, during which Suntree took extensive measurements, photos, and other documentation of each stormwater drain, the Grate inlet Skimmer Boxes were manufactured and delivered for installation. Afl units were installed without mishap approximately two weeks before the 1999 Christmas holiday season. Hie target time period lor particle catchment was one month. Mr. Henry and Tom Happel, Suntree Technologies, visited each site several times during the month to ensure that debris wouldnot fill the units too soon. On January 25,2000, Suntree serviced me six units. At each she, the material captured in the skimmer boxes was removed, measured, weighed, visually identified, photographed, and recorded Some units were slightly field modified for optimum performance. All units performed as expected removing, on average, 20 pounds of debris from each of the six sites. The composition of debris varied considerably. The Hotel Plaza (roadway) site was 90% leaf litter and 10% sediment The Rain Forest Cafe sites ran in opposition as you got dose b the lake. First inlet was about 50% leaf litter and cigarette butts and 50% sediment, The middle inlet was 60 % sediment and 30 % leaf litter (10% miscellaneous). The inlet closest to the lake was 95% sediment and 5% leaf litter. The two sites at the McDonalds/Legos area were similar to each other. The site closest to the lake was 95% sediment and 5% leaf litter. The site closest to the entrance gate was 98% litter sediment and 2% leaf litter. .,;^i...« -..;"-_ •..-.;. t .^; «;:.,xg This composition is indicative of the human activities and drainage flow patterns of , site. Backstage areas in the Walt Disney World Fesort receive an artificial rain event each night during cleaning operations. This washes a continual flow over the imperviousRita wodiina ijU materials into me stonnwabr °uotem Municipalities in Brevard, Volusia and Dade counties have successfully used inlet skimmers in Florida ROD partnered with Watt Disney Imagineering (WDI) Research and Development to coordinate some basic chemical sampling for pollutant removal efficiency determination. Mr. Craig Duxbury, WDI, provided technical support and guidance for mis. An ingeniously simple device was fabricated by Suntree to allow sampling of the First Flush of water going into the units and ultimately coming out of fte skimmer boxes. Collected samples were processed and ar Laboratory. Analysis parameter were:die RdD Environmental Services Ammonia, Chemical Oxygen Demand, Fecal Cotffoon (MPN), Nitrite and Nitrate. TotalKjeWahl Nfoogen, OH and Grease, Total Phosphate, Suspended Analysis results are presented in the following table: ANALYSIS Ammonia, SafloylBte Ammonia, SaMoylate *• » f(»|1—..I—JianirtfTKHlM, OWKqrHKv Chemical Oxygen Demand Chemical Oxygen Demand Chemical Oxygen Demand CoMbrnit Fecal MPN CoMbrrn, FecaJ MPN Cofform, FeoalMPN NKnrte and Mtrtte Nftrogen, TdW KJeWahl NRroQefii Toni NHregen, ToW Otl and Grease LOCATION RF-IN RFOUT RF-OUT-I RF* RFOUT RFOUT-I w*wl RFOUT RF-OUN RF-ftM rVOUT RF^UT-I RF^N RFOW RF-OUT-1 RF-W LAB NO. 1646 1646 1646 1646 1646 1646 1646 1646 1646 1646 1646 1646 1646 1646 1646 1646 VALUE 0.36 0.23 0.25 2670 1760 1490 1600 160,000 30,000 0.08 0.04 041 24.3 10.4 11,1 526 UNITS irtf ing* OVA ni0fl AtfTT fflftl flOOml flOO ml MOO ml mgfl ntf mgfl m»4 IflQ/l fflBfl ntf Pollutant SAM-DATE Changa 0»FaW)0 0.14 OG^eWK) 1036 Chanae 37% OtPeMO -93400 O^PeMO O^FeWJO OfrPeb-00 0.036 09^eWX) 004^00 13.65 283 PoJIutati mnovsl effidendes averaged about 50% for all panmeten toted Tfc mtotaal removal was37% for Ammonia and the maximum removal w« 74% fir Suspended Solids. Colifinn bacteria wen not effectively removed by the provide water dUnfatta, Oil and GBOK are a food should piovido toot eflbct OB hactonai munbers, • bom* asbou^l), nicy are not dengned to tar baekrfai and reduction of fins poOotant Pollutant Removal Efficiency 80% 70%• Ammonia, Salicylate • Chemical Oxygen Demand • Nitrate and Nitrite Q Nitrogen, Total jgaldahl • Oil and Grease • Phosphate, Total • Solids, Suspender % Change Parameter SECTION 8.0 Section 8.0 Post Construction BMPs Maintenance Cost Responsibilities Owner Maintained: 1. Private storm drain systems 2. Vegetated Swale 3. Storm drain stenciling and signage 4. Periodic street sweeping (Private Streets) City Maintained (after acceptance by City): 1. Periodic street sweeping (off-site) 2. Public storm drain systems (off-site) SECTION 9.0 DRAINAGE STUDY FOR ROBERTSON RANCH EAST VILLAGE PLANNING AREA 21 C.T. 06-25 Job No. 01-1014 January 16, 2008 Revised: February 2009 Revised: March 2009 Prepared by: O'DAY CONSULTANTS, INC. 2710 Loker Avenue West Suite 100 Carlsbad, California 92010 Tel: (760)931-7700 Fax: (760)931-8680 Tim Carroll RCE 55381 Date Exp. 12/31/10 PA211.0UT San Diego County Rational Hydrology Program CIVILCADD/CIVILDESIGN Engineering Software, (c) 2004 Version 3.2 Rational method hydrology program based on San Diego County Flood control Division 2003 hydrology manual Rational Hydrology Study Date: 01/16/08 ROBERTSON RANCH PA 21 - BASIN 1 PROPOSED CONDITIONS G:\ACCTS\011014\PA211.OUT ********* Hydrology study control information ********** o'Day consultants, San Diego, California - S/N 10125 Rational hydrology study storm event year is 24.0 Map data precipitation entered: 6 hour, precipitation(inches) = 2.600 24 hour precipitation(inches) = 4.300 Adjusted 6 hour precipitation (inches) = 2.600 P6/P24 = 60.5% San Diego hydrology manual 'C1 values used Runoff coefficients by rational method process from Point/Station 101.000 to Point/Station 102.000 **** INITIAL AREA EVALUATION **** user specified 'C1 value of 0.600 given for subarea initial subarea flow distance = 32.00(Ft.) Highest elevation = 89.15(Ft.) Lowest elevation = 88.80(Ft.) Elevation difference = 0.3 5 (Ft.) Time of concentration calculated by the urban areas overland flow method (App X-C) = 4.94 mi n. TC = [1.8*(l.l-C)*distanceA.5)/(% slopeA(l/3)] TC = [1. 8* (1.1-0. 6000) *( 32.00A.5)/( 1.09A(l/3)]= 4.94 setting time of concentration to 5 minutes Rainfall intensity (I) = 6.850 for a 24.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.600 Subarea runoff = 0.164(CFS) Total initial stream area = 0.040(Ac.) Process from Point/Station 102.000 to Point/Station 103.000 **** PIPEFLOW TRAVEL TIME (User specified size) **** upstream point/station elevation = 86.80(Ft.) Downstream point/station elevation = 86.40(Ft.) Pipe length = 15.20(Ft.) Manning's N = 0.011 NO. of pipes = 1 Required pipe flow = 0.164(CFS) Given pipe size = 6.00(ln.) Calculated individual pipe flow = 0.164(CFS) Normal flow depth in pipe = 1.59(ln.) Flow top width inside pipe = 5.29(ln.) Page 1 PA211.OUT Critical Depth 2. 42 (in.) Pipe flow velocity = 3.96(Ft/s) Travel time through pipe = 0.06 min. Time of concentration (TC) = 5.06 min. Process from point/Station 103.000 to point/station **** SUBAREA FLOW ADDITION **** 103.000 User specified 'C' value of 0.600 given for subarea Time of concentration = 5.06 mi n. Rainfall intensity = 6.794(ln/Hr) for a 24.0 year storm Runoff coefficient used for sub-area, Rational method, Q=KCIA, C = 0.600 subarea runoff = 0.041(CFS) for 0.010(Ac.) Total runoff = 0.205(CFS) Total area = 0.05 (Ac.) Process from Point/Station 103.000 to Point/Station 104.000 **** PIPEFLOW TRAVEL TIME (User specified size) **** Upstream point/station elevation = 86.40(Ft.) Downstream point/station elevation = 86.20(Ft.) Pipe length = 9.40(Ft.) Manning's N = 0.011 NO. of pipes = 1 Required pipe flow = 0.205(CFS) Given pipe size = 6.00(in.) Calculated individual pipe flow = 0.205(CFS) Normal flow depth in pipe = 1.88 (In.) Flow top width inside pipe = 5. 57 (in.) Critical Depth = 2. 72 (In.) Pipe flow velocity = 3.91(Ft/s) Travel time through pipe = 0.04 min. Time of concentration (TC) = 5.10 min. Process from Point/Station 104.000 to Point/Station 104.000 **** SUBAREA FLOW ADDITION **** User specified 'C1 value of 0.600 given for subarea Time of concentration = 5.10 mm. Rainfall intensity = 6.760(ln/Hr) for a 24.0 year storm Runoff coefficient used for sub-area, Rational method,Q=KCIA, c = 0.600 Subarea runoff = 0.203(CFS) for 0.050(Ac.) Total runoff = 0.408(CFS) Total area = 0.10(Ac.) Process from Point/Station 104.000 to Point/Station 105.000 **** PIPEFLOW TRAVEL TIME (User specified size) **** Upstream point/station elevation =86.10(Ft.) Downstream point/station elevation = 85.90(Ft.) Pipe length = 42.40(Ft.) Manning's N =0.011 No. of pipes = 1 Required pipe flow = 0.408(CFS) Given pipe size = 8.00(ln.) Calculated individual pipe flow = 0.408(CFS) Normal flow depth in pipe = 3.60(In.) Flow top width inside pipe = 7.96(In.) Critical Depth = 3.57(in.) Pipe flow velocity = 2.68(Ft/s) Travel time through pipe = 0.26 min. Page 2 PA211.0UT Time of concentration (TC) = 5.37 min. T-~-| — I — I — I — I — I — I — I — n — I I FT i I I llliiiiiii««"«*«i'iiiiiittiii»iiiiiiiii'iiiiiiiiii»Process from Point/Station 105.000 to Point/Station 105.000 **** SUBAREA FLOW ADDITION **** User specified 'C1 value of 0.600 given for subarea Time of concentration = 5.37 mm. Rainfall intensity = 6.544(in/Hr) for a 24.0 year storm Runoff coefficient used for sub-area, Rational method, Q=KCIA, C = 0.600 Subarea runoff = 0.314(CFS) for 0.080(Ac.) Total runoff = 0.722(CFS) Total area = 0.18 (Ac.) Process from Point/Station 105.000 to Point/Station 106.000 **** PIPEFLOW TRAVEL TIME (User specified size) **** Upstream point/station elevation = 85.90(Ft.) Downstream point/station elevation = 85.50(Ft.) Pipe length = 41.50(Ft.) Manning's N = 0.011 Np. of pipes = 1 Required pipe flow = 0.722(CFS) Given pipe size = 8. 00 (In.)Calculated individual pipe flow = 0.722(CFS) Normal flow depth in pipe = 4. 07 (in.) Flow top width inside pipe = 8.00(ln.) Critical Depth = 4. 82 (In.) Pipe flow velocity = 4.05(Ft/s) Travel time through pipe = 0.17 mi n. Time of concentration (TC) = 5.54 mi n. Process from Point/Station 106.000 to Point/Station 106.000 **** SUBAREA FLOW ADDITION **** User specified 'C' value of 0.600 given for subarea Time of concentration = 5.54 mm. Rainfall intensity = 6.413(ln/Hr) for a 24.0 year storm Runoff coefficient used for sub-area, Rational method, Q=KCIA, c = 0.600 Subarea runoff = 0.038(CFS) for 0.010(Ac.)Total runoff = 0.761(CFS) Total area = 0.19 (Ac.) Process from Point/Station 106.000 to Point/Station 107.000 **** PIPEFLOW TRAVEL TIME (User specified size) **** upstream point/station elevation = 85.50(Ft.) Downstream point/station elevation = 84.90(Ft.) Pipe length = 63.30(Ft.) Manning's N = 0.011 Np. of pipes = 1 Required pipe flow = 0.761(CFS) Given pipe size = 8.00(in.) Calculated individual pipe flow = 0.761(CFS) Normal flow depth in pipe = 4. 22 (in.) Flow top width inside pipe = 7.99(ln.) Critical Depth = 4.94(in.) Pipe flow velocity = 4.07(Ft/s) Travel time through pipe = 0.26 mi n. Time of concentration (TC) = 5.80 mi n. Page 3 PA211.OUT ++++++++++ process from Point/Station 107.000 to Point/Station 107.000 **** SUBAREA FLOW ADDITION **** User specified 'C' value of 0.600 given for subarea Time of concentration = 5.80 mi n. Rainfall intensity = 6.227(ln/Hr) for a 24.0 year storm Runoff coefficient used for sub-area, Rational method, Q=KCIA, C = 0.600 Subarea runoff = 0.093(CFS) for 0.02 5 (Ac.) Total runoff = 0.854(CFS) Total area = 0.22 (Ac.) Process from Point/Station 107.000 to Point/Station 107.500 **** PIPEFLOW TRAVEL TIME (User specified size) **** upstream point/station elevation = 84.90(Ft.) Downstream point/station elevation = 84. 80 (Ft.) Pipe length = 4.50(Ft.) Manning's N = 0.011 NO. of pipes = 1 Required pipe flow = 0.854(CFS) Given pipe size = 8.00(ln.) calculated individual pipe flow = 0.854(CFS) Normal flow depth in pipe = 3.52(ln.) Flow top width inside pipe = 7.94(ln.) critical Depth = 5.26(in.) Pipe flow velocity = 5.76(Ft/s) Travel time through pipe = 0.01 mi n. Time of concentration (TC) = 5.81 mi n. Process from Point/Station 107.500 to Point/Station 107.500 **** SUBAREA FLOW ADDITION **** user specified 'C1 value of 0.600 given for subarea Time of concentration = 5.81 mi n. Rainfall intensity = 6.218(ln/Hr) for a 24.0 year storm Runoff coefficient used for sub-area, Rational method ,Q=KCIA, c = 0.600 subarea runoff = 0.093(CFS) for 0.025(Ac.) Total runoff = 0.947(CFS) Total area = 0.24 (Ac.) Process from Point/Station 107.500 to Point/Station 108.000 **** PIPEFLOW TRAVEL TIME (User specified size) **** upstream point/station elevation = 84.80(Ft.) Downstream point/station elevation = 83.80(Ft.) Pipe length = 71.20(Ft.) Manning's N = 0.011 NO. of pipes = 1 Required pipe flow = 0.947(CFS) Given pipe size = 8.00(ln.) Calculated individual pipe flow = 0.947(CFS) Normal flow depth in pipe = 4. 28 (in.) Flow top width inside pipe = 7.98(in.) Critical Depth = 5.54(ln.) Pipe flow velocity = 4.98(Ft/s) Travel time through pipe = 0.24 min. Time of concentration (TC) = 6.05 min. Process from Point/Station 107.500 to Point/Station 108.000 **** CONFLUENCE OF MINOR STREAMS **** Page 4 PA211.OUT Along Main stream number: 1 in normal stream number 1 Stream flow area = 0.240(Ac.) Runoff from this stream = 0.947(CFS) Time of concentration = 6.05 min. Rainfall intensity = 6.059(ln/Hr) Process from Point/Station 7.100 to Point/Station 7.200 **** INITIAL AREA EVALUATION **** User specified 'C1 value of 0.600 given for subarea initial subarea flow distance = 20.00(Ft.) Highest elevation = 87. 75 (Ft.) Lowest elevation = 87.50(Ft.) Elevation difference = 0.25(Ft.) Time of concentration calculated by the urban areas overland flow method (App x-C) = 3.74 mi n. TC = [1.8*(l.l-C)*distanceA.5)/(% slopeA(i/3)] TC = [1. 8* (1.1-0. 6000) *( 20.00A.5)/( 1.25A(l/3)]= 3.74 Setting time of concentration to 5 minutes Rainfall intensity (I) = 6.850 for a 24.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.600Subarea runoff = 0.041(CFS) Total initial stream area = 0.010(Ac.) Process from Point/Station 7.200 to Point/Station 7.300 **** PIPEFLOW TRAVEL TIME (user specified size) **** Upstream point/station elevation = 85.50(Ft.) Downstream point/station elevation = 85.30(Ft.) Pipe length = 16.70(Ft.) Manning's N = 0.011 No. of pipes = 1 Required pipe flow = 0.041(CFS)Given pipe size = 6.00(ln.) Calculated individual pipe flow = 0.041(CFS) Normal flow depth in pipe = 0.97 (in.) Flow top width inside pipe = 4.41(in.) Critical Depth = 1.19 (in.) Pipe flow velocity = 1.99(Ft/s) Travel time through pipe = 0.14 mi n. Time of concentration (TC) = 5.14 mi n. Process from Point/Station 7.300 to Point/Station 7.300 **** SUBAREA FLOW ADDITION **** User specified 'C1 value of 0.600 given for subarea Time of concentration = 5.14 min. Rainfall intensity = 6.730(In/Hr) for a 24.0 year storm Runoff coefficient used for sub-area, Rational method,Q=KCIA, c = 0.600 Subarea runoff = 0.081(CFS) for 0.020(Ac.) Total runoff = 0.122(CFS) Total area = 0.03(Ac.) ++++++++++++++++4-+++++++++++++++++++++++++++++++++++++++-!-+++++++++++++ Process from Point/Station 7.300 to Point/Station 7.400 **** PIPEFLOW TRAVEL TIME (user specified size) **** Upstream point/station elevation =85.30(Ft.) Page 5 PA211.0UT Downstream point/station elevation = 85.10(Ft.) Pipe length = 10.10(Ft.) Manning's N = 0.011 No. of pipes = 1 Required pipe flow = 0.122(CFS) Given pipe size = 6.00(in.) Calculated individual pipe flow = 0.122(CFS) Normal flow depth in pipe = 1.47(in.) Flow top width inside pipe = 5.16(In.) critical Depth = 2.08(ln.) Pipe flow velocity = 3.29(Ft/s) Travel time through pipe = 0.05 min. Time of concentration (TC) = 5.19 min. Process from Point/Station 7.400 to Point/Station 7.400 **** SUBAREA FLOW ADDITION **** User specified 'C1 value of 0.600 given for subarea Time of concentration = 5.19 min. Rainfall intensity = 6.687(in/Hr) for a 24.0 year storm Runoff coefficient used for sub-area, Rational method, Q=KCIA, C = 0.600 Subarea runoff = 0.040(CFS) for 0.010(Ac.) Total runoff = 0.162(CFS) Total area = 0.04 (Ac.) Process from Point/Station 7.400 to Point/Station 7.500 **** PIPEFLOW TRAVEL TIME (User specified size) **** upstream point/station elevation = 85.00(Ft.) Downstream point/station elevation = 84.60(Ft.) Pipe length = 40.90(Ft.) Manning's N = 0.011 No. of pipes = 1 Required pipe flow = 0.162(CFS) Given pipe size = 8.00(ln.) calculated individual pipe flow = 0.162(CFS) Normal flow depth in pipe = 1.83 (In.) Flow top width inside pipe = 6. 72 (in.) Critical Depth = 2.21(ln.) Pipe flow velocity = 2.70(Ft/s) Travel time through pipe = 0.25 min. Time of concentration (TC) = 5.44 min. Process from Point/Station 7.500 to Point/Station 7.500 **** SUBAREA FLOW ADDITION **** User specified 'C1 value of 0.600 given for subarea Time of concentration = 5.44 mm. Rainfall intensity = 6.485(ln/Hr) for a 24.0 year storm Runoff coefficient used for sub-area, Rational method , Q=KCIA , C = 0.600 Subarea runoff = 0.272(CFS) for 0.070(Ac.) Total runoff = 0.434(CFS) Total area = 0.11(Ac.) Process from Point/Station 7.500 to Point/Station 108.000 **** PIPEFLOW TRAVEL TIME (User specified size) **** Upstream point/station elevation = 84.60(Ft.) Downstream point/station elevation = 83.80(Ft.) Pipe length = 40.80(Ft.) Manning's N = 0.011 No. of pipes = 1 Required pipe flow = 0.434(CFS) Page 6 PA211.0UT Given pipe size = 8.00(ln.) Calculated individual pipe flow = 0.434(CFS) Normal flow depth in pipe = 2.53(in.) Flow top width inside pipe = 7.44(in.) Critical Depth = 3.69(ln.) Pipe flow velocity = 4.58(Ft/s) Travel time through pipe = 0.15 min. Time of concentration (TC) = 5.59 min. Process from Point/Station 7.500 to Point/Station **** CONFLUENCE OF MINOR STREAMS **** 108.000 Along Main Stream number: 1 in normal stream number 2 Stream flow area = 0.110(Ac.) Runoff from this stream = 0.434(CFS) Time of concentration 5.59 min. Rainfall intensity = 6.373(ln/Hr) Summary of stream data: Stream NO. Flow rate (CFS) TC (min)Rainfall intensity (in/Hr) Qmax(l) = Qmax(2) = 0.947 0.434 1.000 * 0.951 * 1.000 * 1.000 * 6.05 5.59 1.000 * 1.000 * 0.925 * 1.000 * 6.059 6.373 0.947) + 0.434) + 0.947) + 0.434) + 1.360 1.310 Total of 2 streams to confluence: Flow rates before confluence point: 0.947 0.434 Maximum flow rates at confluence using above data-1.360 1.310 Area of streams before confluence: 0.240 0.110 Results of confluence: Total flow rate = 1.360(CFS) Time of concentration = 6.049 min. Effective stream area after confluence = 0.350(Ac.) T T--TT- T TTT T T TT T TT T T T TTT T T T TT1 Process from Point/Station 108.000 to Point/Station 109.000 **** PIPEFLOW TRAVEL TIME (user specified size) **** Upstream point/station elevation =83.80(Ft.) Downstream point/station elevation = 76.00(Ft.) Pipe length = 22.10(Ft.) Manning's N = 0.011 Np. of pipes = 1 Required pipe flow = 1.360(CFS) Given pipe size = 8.00(ln.) Calculated individual pipe flow = 1.360(CFS) Normal flow depth in pipe = 2.17(in.) Flow top width inside pipe = 7.11(in.) Critical Depth = 6.59(ln.) Pipe flow velocity = 17.82(Ft/s) Travel time through pipe = 0.02 min. Time of concentration (TC) = 6.07 min. Page 7 PA211.0UT Process from Point/Station 109.000 to Point/Station 109.000 **** SUBAREA FLOW ADDITION **** User specified 'C1 value of 0.600 given for subarea Time of concentration = 6.07 mi n. Rainfall intensity = 6.045(ln/Hr) for a 24.0 year storm Runoff coefficient used for sub-area, Rational method, Q=KCIA, C = 0.600 Subarea runoff = 0.073(CFS) for 0.020(Ac.) Total runoff = 1.433(CFS) Total area = 0.3 7 (Ac.) Process from Point/Station 109.000 to Point/Station 110.000 **** PIPEFLOW TRAVEL TIME (user specified size) **** Upstream point/station elevation = 76.00(Ft.) Downstream point/station elevation = 74. 7 5 (Ft.) Pipe length = 33.60(Ft.) Manning's N = 0.011 NO. of pipes = 1 Required pipe flow = 1.433(CFS) Given pipe size = 8.00(ln.) Calculated individual pipe flow = 1.433(CFS) Normal flow depth in pipe = 4.10(ln.) Flow top width inside pipe = 8.00(in.) Critical Depth = 6.74(in.) Pipe flow velocity = 7.97(Ft/s) Travel time through pipe = 0.07 mi n. Time of concentration (TC) = 6.14 mi n. Process from Point/Station 109.000 to Point/Station 110.000 **** CONFLUENCE OF MINOR STREAMS **** Along Main Stream number: 1 in normal stream number 1 Stream flow area = 0.370(Ac.) Runoff from this stream = 1.433(CFS) Time of concentration = 6.14 mi n. Rainfall intensity = 6.001(ln/Hr) Process from Point/Station 111.000 to Point/Station 112.000 **** INITIAL AREA EVALUATION **** User specified 'C1 value of 0.600 given for subarea initial subarea flow distance = 16.00(Ft.) Highest elevation = 80. 90 (Ft.) Lowest elevation = 80.70(Ft.) Elevation difference = 0.20(Ft.) Time of concentration calculated by the urban areas overland flow method (App x-c) = 3.34 mi n. TC = [1.8*(l.l-C)*distanceA.5)/(% slopeA(l/3)] TC = [1. 8* (1.1-0. 6000) *( 16.00A.5)/( 1.25A(l/3)]= 3.34 Setting time of concentration to 5 minutes Rainfall intensity (I) = 6.850 for a 24.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.600 Subarea runoff = 0.082(CFS) Total initial stream area = 0.020(Ac.) Page 8 PA211.0UT 1 — t — T"T"1 — n — I — I — TTT — I — I — I — I — I — T~TT — r~n r~n — r~r~r"rTTT — rT"i — I — I — I — I — I — I — TT — I — TTT — n — T~TT r~i i « i i ..... i i i i i i Process from Point/Station 112.000 to Point/Station 113.000 **** PIPEFLOW TRAVEL TIME (User specified size) **** Upstream point/station elevation = 78.60(Ft.) Downstream point/station elevation = 78.40(Ft.) Pipe length = 14.40(Ft.) Manning's N = 0.011 N9- of pipes = 1 Required pipe flow = 0.082(CFS) Given pipe size = 6.00(ln.) Calculated individual pipe flow = 0.082(CFS) Normal flow depth in pipe = 1.32 (in.) Flow top width inside pipe = 4. 97 (In.) Critical Depth = 1.69(in.) Pipe flow velocity = 2.59(Ft/s) Travel time through pipe = 0.09 min. Time of concentration (TC) = 5.09 min. Process from Point/Station 113.000 to Point/Station 113.000 **** SUBAREA FLOW ADDITION **** User specified 'C' value of 0.600 given for subareaTime of concentration = 5.09 mm.Rainfall intensity = 6.770(ln/Hr) for a 24.0 year storm Runoff coefficient used for sub-area, Rational method, Q=KCIA, C = 0.600 Subarea runoff = 0.081(CFS) for 0.020(Ac.)Total runoff = 0.163(CFS) Total area = 0.04(Ac.) Process from Point/Station 113.000 to Point/Station 114.000 **** PIPEFLOW TRAVEL TIME (User specified size) **** Upstream point/station elevation = 78.40(Ft.) Downstream point/station elevation = 78.20(Ft.) Pipe length = 11.70(Ft.) Manning's N = 0.011 No. of pipes = 1 Required pipe flow = 0.163(CFS)Given pipe size = 6.00(ln.) Calculated individual pipe flow = 0.163(CFS) Normal flow depth in pipe = 1.76(ln.) Flow top width inside pipe = 5. 47 (in.) Critical Depth = 2. 42 (in.) Pipe flow velocity = 3.39(Ft/s) Travel time through pipe = 0.06 min. Time of concentration (TC) = 5.15 min. Process from Point/Station 114.000 to Point/Station 114.000 **** SUBAREA FLOW ADDITION **** user specified 'C' value of 0.600 given for subarea Time of concentration = 5.15 mm. Rainfall intensity = 6.721(ln/Hr) for a 24.0 year storm Runoff coefficient used for sub-area, Rational method, Q=KCIA, C = 0.600 Subarea runoff = 0.161(CFS) for 0.040(Ac.) Total runoff = 0.325(CFS) Total area = 0.08 (AC.) Process from Point/Station 114.000 to Point/Station 115.000 **** PIPEFLOW TRAVEL TIME (User specified size) **** Page 9 PA211.0UT upstream point/station elevation = 78.10(Ft.) Downstream point/station elevation = 77.90(Ft.) Pipe length = 18.40(Ft.) Manning's N = 0.011No. of pipes = 1 Required pipe flow = 0.32 5 (CFS) Given pipe size = 8.00(ln.)Calculated individual pipe flow = 0.32 5 (CFS) Normal flow depth in pipe = 2.54(ln.) Flow top width inside pipe = 7.44(in.)Critical Depth = 3.17(in.)Pipe flow velocity = 3.41(Ft/s) Travel time through pipe = 0.09 min. Time of concentration (TC) = 5.24 min. Process from Point/Station 115.000 to Point/Station 115.000 **** SUBAREA FLOW ADDITION **** User specified 'C' value of 0.600 given for subarea Time of concentration = 5.24 mi n.Rainfall intensity = 6.646(ln/Hr) for a 24.0 year stormRunoff coefficient used for sub-area, Rational method, Q=KCIA, c = 0.600Subarea runoff = 0.080(CFS) for 0.020(Ac.)Total runoff = 0.404(CFS) Total area = 0.10(Ac.) Process from Point/Station 115.000 to Point/Station 116.000**** PIPEFLOW TRAVEL TIME (User specified size) **** Upstream point/station elevation = 77.90(Ft.) Downstream point/station elevation = 77.40(Ft.) Pipe length = 49.60(Ft.) Manning's N = 0.011 No. of pipes = 1 Required pipe flow = 0.404(CFS) Given pipe size = 8.00(in.) Calculated individual pipe flow = 0.404(CFS)Normal flow depth in pipe = 2.91(In.) Flow top width inside pipe = 7.69(in.) Critical Depth = 3.56(ln.) Pipe flow velocity = 3.53(Ft/s) Travel time through pipe = 0.23 min. Time of concentration (TC) = 5.47 min. Process from Point/Station 116.000 to Point/Station 116.000 **** SUBAREA FLOW ADDITION **** User specified 'C' value of 0.600 given for subareaTime of concentration = 5.47 mm.Rainfall intensity = 6.461(in/Hr) for a 24.0 year stormRunoff coefficient used for sub-area, Rational method ,Q=KCIA, c = 0.600 Subarea runoff = 0.271(CFS) for 0.070(Ac.) Total runoff = 0.676(CFS) Total area = 0.17 (Ac.) Process from Point/Station 116.000 to Point/Station 117.000 **** PIPEFLOW TRAVEL TIME (User specified size) **** upstream point/station elevation = 77.40(Ft.)Downstream point/station elevation = 76.90(Ft.) Page 10 PA211.0UT Pipe length = 46.90(Ft.) Manning's N = 0.011 No. of pipes = 1 Required pipe flow = 0.676(CFS) Given pipe size = 8.00(In.) Calculated individual pipe flow = 0.676(CFS) Normal flow depth in pipe = 3.80(in.) Flow top width inside pipe = 7.99(in.) Critical Depth = 4.65(in.) Pipe flow velocity = 4.13(Ft/s) Travel time through pipe = 0.19 min. Time of concentration (TC) = 5.66 min. Process from Point/Station 117.000 to Point/Station 117.000 **** SUBAREA FLOW ADDITION **** user specified 'c' value of 0.600 given for subarea Time of concentration = 5.66 mi n. Rainfall intensity = 6.321(in/Hr) for a 24.0 year storm Runoff coefficient used for sub-area, Rational method, Q=KCIA, c = 0.600 Subarea runoff = 0.114(CFS) for 0.030(Ac.) Total runoff = 0.790(CFS) Total area = 0.20(Ac.) Process from Point/Station 117.000 to Point/Station 110.000 **** PIPEFLOW TRAVEL TIME (User specified size) **** Upstream point/station elevation = 76.90(Ft.) Downstream point/station elevation = 74.75(Ft.) Pipe length = 30.80(Ft.) Manning's N = 0.011 No. of pipes = 1 Required pipe flow = 0.790(CFS) Given pipe size = 8.00(ln.) Calculated individual pipe flow = 0.790(CFS) Normal flow depth in pipe = 2. 48 (in.) Flow top width inside pipe = 7.40(ln.) Critical Depth = 5. 04 (in.) Pipe flow velocity = 8.55(Ft/s) Travel time through pipe = 0.06 min. Time of concentration (TC) = 5.72 min. Process from Point/Station 117.000 to Point/Station 110.000 **** CONFLUENCE OF MINOR STREAMS **** Along Main Stream number: 1 in normal stream number 2 Stream flow area = 0.200(Ac.) Runoff from this stream = 0.790(CFS) Time of concentration = 5.72 min. Rainfall intensity = 6.278(in/Hr) Summary of stream data: StreamNo.Flow rate (CFS) TC (min) Rainfall Intensity (in/Hr) 1 1.433 6.14 2 0.790 5.72 Qmax(l) = 1.000 * 1.000 0.956 * 1.000Qmax(2) = Page 11 6.001 6.278 1.433) + 0.790) + =2.187 PA211.0UT 1.000 * 0.932 * 1.433) + 1.000 * 1.000 * 0.790) + = 2.125 Total of 2 streams to confluence: Flow rates before confluence point: 1.433 0.790 Maximum flow rates at confluence using above data: 2.187 2.125 Area of streams before confluence: 0.370 0.200 Results of confluence:Total flow rate = 2.187(CFS) Time of concentration = 6.140 min. Effective stream area after confluence = 0.570(Ac.) Process from Point/Station 110.000 to Point/Station 110.000 **** SUBAREA FLOW ADDITION **** User specified 'C' value of 0.600 given for subarea Time of concentration = ' 6.14 mm. Rainfall intensity = 6.001(In/Hr) for a 24.0 year storm Runoff coefficient used for sub-area, Rational method , Q=KCIA , C = 0.600 Subarea runoff = 0.108(CFS) for 0.030 (Ac.) Total runoff = 2.295(CFS) Total area = 0.60(Ac.) Process from Point/Station 110.000 to Point/Station 3014.000 **** PIPEFLOW TRAVEL TIME (user specified size) **** upstream point/station elevation = 74. 5 5 (Ft.) Downstream point/station elevation = 70. 85 (Ft.) Pipe length = 70.60(Ft.) Manning's N = 0.011 No. of pipes = 1 Required pipe flow = 2.295(CFS) Given pipe size = 12.00(ln.) Calculated individual pipe flow = 2.295(CFS) Normal flow depth in pipe = 3. 98 (in.) Flow top width inside pipe = 11. 30 (In.) Critical Depth = 7.77(ln.) Pipe flow velocity = 10.06(Ft/s) Travel time through pipe = 0.12 min. Time of concentration (TC) = 6.26 min. Process from Point/station 110.000 to Point/Station 3014.000 **** CONFLUENCE OF MINOR STREAMS **** Along Main Stream number: 1 in normal stream number 1 Stream flow area = 0.600 (Ac.) Runoff from this stream = 2.295(CFS) Time of concentration = 6.26 min. Rainfall intensity = 5.928(in/Hr) Process from Point/Station 118.000 to Point/Station 119.000 **** INITIAL AREA EVALUATION **** user specified "c1 value of 0.600 given for subarea initial subarea flow distance = 35.00(Ft.) page 12 PA211.0UT Highest elevation = 79.55(Ft.) Lowest elevation = 79. 15 (Ft.) Elevation difference = 0.40(Ft.) Time of concentration calculated by the urban areas overland flow method (App X-C) = 5.09 mi n. TC = [1.8*(l.l-C)*distanceA.5)/(% slopeA(l/3)]TC = [1. 8* (1.1-0. 6000) *( 35.00A.5)/( 1.14A(l/3)]= 5.09 Rainfall intensity (I) = 6.770 for a 24.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.600 Subarea runoff = 0.041(CFS) Total initial stream area = 0.010(Ac.) Process from Point/Station 119.000 to Point/Station 120.000 **** STREET FLOW TRAVEL TIME + SUBAREA FLOW ADDITION **** Top of street segment elevation = 78.650(Ft.) End of street segment elevation = 78.130(Ft.) Length of street segment = 65.000(Ft.) Height of curb above gutter flowline = 6.0(ln.) Width of half street (curb to crown) = 18.000(Ft.) Distance from crown to crossfall grade break = 16.500(Ft.)Slope from gutter to grade break (v/hz) = 0.020 Slope from grade break to crown (v/hz) = 0.020 Street flow is on [1] side(s) of the street Distance from curb to property line = 10.000(Ft.) Slope from curb to property line (v/hz) = 0.020 Gutter width = 1.500(Ft.) Gutter hike from flowline = 1.500(ln.) Manning's N in gutter = 0.0150 Manning's N from gutter to grade break = 0.0150 Manning's N from grade break to crown = 0.0150 Estimated mean flow rate at midpoint of street = 0.042(CFS) Depth of flow = 0.083(Ft.), Average velocity = 1.008(Ft/s)Streetflow hydraulics at midpoint of street travel: Half street flow width = 1.500 (Ft.) Flow velocity = 1.01(Ft/s)Travel time = 1.07 mi n. TC = 6.17 min. Adding area flow to street User specified 'C1 value of 0.600 given for subarea Rainfall intensity = 5.983(ln/Hr) for a 24.0 year storm Runoff coefficient used for sub-area, Rational method , Q=KCIA , c = 0.600Subarea runoff = 0.251(CFS) for 0.070(Ac.) Total runoff = 0.292(CFS) Total area = 0.08 (Ac.) street flow at end of street = 0.292(CFS) Half street flow at end of street = 0.292(CFS) Depth of flow = 0.174(Ft.), Average velocity = 1.282(Ft/s) Flow width (from curb towards crown)= 3.954(Ft.) Process from Point/Station 120.000 to Point/Station 121.000 **** STREET FLOW TRAVEL TIME + SUBAREA FLOW ADDITION **** Top of street segment elevation = 78.130(Ft.) End of street segment elevation = 77.210(Ft.) Length of street segment = 71.000(Ft.) Height of curb above gutter flowline = 6.0(ln.) width of half street (curb to crown) = 18.000(Ft.) Distance from crown to crossfall grade break = 16.500(Ft.) slope from gutter to grade break (v/hz) = 0.020 Slope from grade break to crown (v/hz) = 0.020 Page 13 PA211.0UT Street flow is on [1] side(s) of the street Distance from curb to property line = 10.000(Ft.) Slope from curb to property line (v/hz) = 0.020 Gutter width = 1.500(Ft.) Gutter hike from flow/line = 1.500(in.) Manning's N in gutter = 0.0150 Manning's N from gutter to grade break = 0.0150 Manning's N from grade break to crown = 0.0150 Estimated mean flow rate at midpoint of street = 0.312(CFS) Depth of flow = 0.166(Ft.), Average velocity = 1.590(Ft/s) Streetflow hydraulics at midpoint of street travel: Half street flow width = 3. 538 (Ft.) Flow velocity = 1.59(Ft/s) Travel time = 0.74 mi n. TC = 6.91 mi n. Adding area flow to street User specified 'C' value of 0.600 given for subarea Rainfall intensity = 5.559(ln/Hr) for a 24.0 year storm Runoff coefficient used for sub-area, Rational method, Q=KCIA, c = 0.600 Subarea runoff = 0.467(CFS) for 0.140(Ac.) Total runoff = 0.759(CFS) Total area = 0.22(Ac.) Street flow at end of street = 0.759(CFS) Half street flow at end of street = 0.759(CFS) Depth of flow = 0.211(Ft.), Average velocity = 1.871(Ft/s) Flow width (from curb towards crown;= 5.782(Ft.) Process from Point/Station 121.000 to Point/Station 122.000 **** STREET FLOW TRAVEL TIME + SUBAREA FLOW ADDITION **** Top of street segment elevation = 77.210(Ft.) End of street segment elevation = 76.980(Ft.) Length of street segment = 22.000(Ft.) Height of curb above gutter flowline = 6.0(in.) Width of half street (curb to crown) = 18.000(Ft.) Distance from crown to crossfall grade break = 16.500(Ft.) Slope from gutter to grade break (v/hz) = 0.020 Slope from grade break to crown (v/hz) = 0.020 street flow is on [1] side(s) of the street Distance from curb to property line = 10.000(Ft.) Slope from curb to property line (v/hz) = 0.020 Gutter width = 1.500(Ft.) Gutter hike from flowline = 1.500(ln.) Manning's N in gutter = 0.0150 Manning's N from gutter to grade break = 0.0150 Manning's N from grade break to crown = 0.0150 Estimated mean flow rate at midpoint of street = 0.776(CFS) Depth of flow = 0.218 (Ft.), Average velocity = 1.728(Ft/s) Streetflow hydraulics at midpoint of street travel: Halfstreet flow width = 6.146(Ft.) Flow velocity = 1.73(Ft/s) Travel time = 0.21 min. TC = 7.12 min. Adding area flow to street User specified 'C' value of 0.600 given for subarea Rainfall intensity = 5.452(in/Hr) for a 24.0 year storm Runoff coefficient used for sub-area, Rational method, Q=KCIA, C = 0.600 Subarea runoff = 0.033(CFS) for 0.010(Ac.) Total runoff = 0.792(CFS) Total area = 0.23 (Ac.) Street flow at end of street = 0.792(CFS) Half street flow at end of street = 0.792(CFS) Depth of flow = 0.219(Ft.), Average velocity = 1.736(Ft/s) Flow width (from curb towards crown)= 6. 203 (Ft.) Page 14 PA211.OUT +++++++++4 ........... Process from Point/Station 122.000 to Point/station 122.000 **** SUBAREA FLOW ADDITION **** User specified "C1 value of 0.600 given for subarea Time of concentration = 7.12 min. Rainfall intensity = 5.452(ln/Hr) for a 24.0 year storm Runoff coefficient used for sub-area, Rational method,Q=KCIA, C = 0.600 Subarea runoff = 0.752(CFS) for 0.230(Ac.) Total runoff = 1.544(CFS) Total area = 0.46(Ac.) Process from Point/Station 122.000 to Point/Station 3014.000 **** PIPEFLOW TRAVEL TIME (User specified size) **** Upstream point/station elevation = 74.00(Ft.) Downstream point/station elevation = 70.85(Ft.) Pipe length = 21.50(Ft.) Manning's N = 0.011 No. of pipes = 1 Required pipe flow = 1.544(CFS) Given pipe size = 12. 00 (In.) Calculated individual pipe flow = 1.544(CFS) Normal flow depth in pipe = 2.51(ln.) Flow top width inside pipe = 9.76(in.) Critical Depth = 6. 33 (in.) Pipe flow velocity = 12.96(Ft/s) Travel time through pipe = 0.03 mi n. Time of concentration (TC) = 7.15 mi n. Process from Point/Station 3014.000 to Point/Station 3014.000 **** SUBAREA FLOW ADDITION **** User specified 'C1 value of 0.600 given for subarea Time of concentration = 7.15 mm. Rainfall intensity = 5.438(in/Hr) for a 24.0 year storm Runoff coefficient used for sub-area, Rational method, Q=KCIA, C = 0.600 Subarea runoff = 0.196(CFS) for 0.060(Ac.) Total runoff = 1.740(CFS) Total area = 0.52 (Ac.) Process from Point/Station 3014.000 to Point/station 3014.000 **** CONFLUENCE OF MINOR STREAMS **** Along Main Stream number: 1 in normal stream number 2 Stream flow area = 0.520(Ac.) Runoff from this stream = 1.740(CFS) Time of concentration = 7.15 mi n. Rainfall intensity = 5.438(ln/Hr) Process from Point/Station 123.000 to Point/Station 124.000 **** INITIAL AREA EVALUATION **** User specified 'C1 value of 0.600 given for subarea initial subarea flow distance = 50.00(Ft.) Highest elevation = 79.70(Ft.) Lowest elevation = 79.20(Ft.) Elevation difference = 0.50(Ft.) Page 15 PA211.OUT Time of concentration calculated by the urban areas overland flow method (App x-c) = 6.36 mi n. TC = [1.8*(l.l-O*distanceA.5)/(% slopeA(i/3)]TC = [1.8*(1. 1-0. 6000) *( 50.00A.5)/( 1.00A(l/3)]= 6.36 Rainfall intensity (I) = 5.863 for a 24.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.600 Subarea runoff = 0.106(CFS) Total initial stream area = 0.030 (Ac.) Process from Point/Station 124.000 to Point/Station 124.000 **** SUBAREA FLOW ADDITION **** User specified 'C1 value of 0.600 given for subarea Time of concentration = 6.36 mm. Rainfall intensity = 5.863(ln/Hr) for a 24.0 year storm Runoff coefficient used for sub-area, Rational method, Q=KCIA, C = 0.600 Subarea runoff = 0.106(CFS) for 0.030(Ac.) Total runoff = 0.211(CFS) Total area = 0.06(Ac.) Process from Point/Station 124.000 to Point/Station 125.000 **** PIPEFLOW TRAVEL TIME (User specified size) **** upstream point/station elevation = 77.50(Ft.) Downstream point/station elevation = 76.20(Ft.) Pipe length = 71.50(Ft.) Manning's N = 0.011 No. of pipes = 1 Required pipe flow = 0.211(CFS) Given pipe size = 6.00(ln.) Calculated individual pipe flow = 0.211(CFS) Normal flow depth in pipe = 1.99(ln.) Flow top width inside pipe = 5. 65 (In.)Critical Depth = 2.76(in.) Pipe flow velocity = 3.73(Ft/s) Travel time through pipe = 0.32 mi n.Time of concentration (TC) = 6.68 mi n. Process from Point/Station 125.000 to Point/Station 125.000 **** SUBAREA FLOW ADDITION **** user specified 'C1 value of 0.600 given for subarea Time of C9ncent ration = 6.68 mm. Rainfall intensity = 5.681(ln/Hr) for a 24.0 year storm Runoff coefficient used for sub-area, Rational method , Q=KCIA , C = 0.600 subarea runoff = 0.273(CFS) for 0.080(Ac.) Total runoff = 0.484(CFS) Total area = 0.14(Ac.) Process from point/Station 125.000 to Point/Station 126.000 **** PIPEFLOW TRAVEL TIME (user specified size) **** Upstream point/station elevation = 76.10(Ft.) Downstream point/station elevation = 75.70(Ft.) Pipe length = 41.30(Ft.) Manning's N = 0.011 No. of pipes = 1 Required pipe flow = 0.484(CFS) Given pipe size = 8.00(ln.) Calculated individual pipe flow = 0.484(CFS) Normal flow depth in pipe = 3. 23 (In.) Page 16 PA211.0UT Flow top width inside pipe = 7. 85 (In.) critical Depth = 3.91(ln.) Pipe flow velocity = 3.65(Ft/s) Travel time through pipe = 0.19 mi n. Time of concentration (TC) = 6.87 mi n. Process from Point/Station 126.000 to Point/Station 126.000 **** SUBAREA FLOW ADDITION **** user specified 'C' value of 0.600 given for subarea Time of concentration = 6.87 mi n. Rainfall intensity .= 5.580(ln/Hr) for a 24.0 year storm Runoff coefficient used for sub-area, Rational method , Q=KCIA , C = 0.600 subarea runoff = 0.201(CFS) for 0.060(Ac.) Total runoff = 0.68 5 (CFS) Total area = 0.20 (Ac.) Process from Point/Station 126.000 to Point/Station 126.500**** PIPEFLOW TRAVEL TIME (user specified size) **** upstream point/station elevation = 75.70(Ft.) Downstream point/station elevation = 75.50(Ft.) Pipe length = 15.90(Ft.) Manning's N = 0.011 No. of pipes = 1 Required pipe flow = 0.685 (CFS) Given pipe size = 8.00(ln.) Calculated individual pipe flow = 0.68 5 (CFS) Normal flow depth in pipe = 3. 65 (In.) Flow top width inside pipe = 7. 97 (in.) Critical Depth = 4. 68 (in.) Pipe flow velocity = 4.41(Ft/s) Travel time through pipe = 0.06 mi n. Time of concentration (TC) = 6.93 mi n. Process from Point/Station 126.500 to Point/Station 126.500 **** SUBAREA FLOW ADDITION **** User specified 'C1 value of 0.600 given for subareaTime of concentration = 6.93 mi n. Rainfall intensity = 5.549(in/Hr) for a 24.0 year stormRunoff coefficient used for sub-area, Rational method ,Q=KCIA, C = 0.600 Subarea runoff = 0.067 (CFS) for 0.020(Ac.) Total runoff = 0.751(CFS) Total area = 0.22 (Ac.) Process from Point/Station 126.500 to Point/Station 127.000**** PIPEFLOW TRAVEL TIME (User specified size) **** Upstream point/station elevation = 75.50(Ft.) Downstream point/station elevation = 74.00(Ft.) Pipe length - 95.10(Ft.) Manning's N = 0.011No. of pipes = 1 Required pipe flow = 0.75KCFS) Given pipe size = 8.00(ln.) Calculated individual pipe flow = 0.751(CFS) Normal flow depth in pipe = 3.61(ln.) Flow top width inside pipe = 7. 96 (In.) critical Depth = 4. 92 (In.) Pipe flow velocity = 4.91(Ft/s) Page 17 PA211.0UT Travel time through pipe = 0.32 min. Time of concentration (TC) = 7.26 min. +++++++++++++++++++++++-f~l"t"H-++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 127.000 to Point/Station 127.000 **** SUBAREA FLOW ADDITION **** user specified 'c' value of 0.600 given for subarea Time of concentration = 7.26 mm. Rainfall intensity = 5.388(ln/Hr) for a 24.0 year storm Runoff coefficient used for sub-area, Rational method, Q=KCIA, C = 0.600 Subarea runoff = 0.065(CFS) for 0.020(Ac.) Total runoff = 0.816(CFS) Total area = 0.24(Ac.) ++++++++++++++++++ Process from Point/Station 127.000 to Point/Station 127.500 **** PIPEFLOW TRAVEL TIME (User specified size) **** upstream point/station elevation = 73. 95 (Ft.) Downstream point/station elevation = 73.45(Ft.) Pipe length = 13.00(Ft.) Manning's N = 0.011 Np. of pipes = 1 Required pipe flow = 0.816(CFS) Given pipe size = 8.00(ln.) Calculated individual pipe flow = 0.816(CFS) Normal flow depth in pipe = 2. 96 (in.) Flow top width inside pipe = 7. 72 (in.) Critical Depth = 5. 13 (in.) Pipe flow velocity = 6.96(Ft/s) Travel time through pipe = 0.03 mi n. Time of concentration (TC) = 7.29 mi n. Process from Point/Station 127.500 to Point/Station 127.500 **** SUBAREA FLOW ADDITION **** User specified 'C' value of 0.600 given for subarea Time of concentration = 7.29 mm. Rainfall intensity = 5.373(in/Hr) for a 24.0 year storm Runoff coefficient used for sub-area, Rational method,Q=KCIA, C = 0.600 Subarea runoff = 0.064(CFS) for 0.020(Ac.) Total runoff = 0.880(CFS) Total area = 0.26(Ac.) Process from Point/Station 127.500 to Point/Station 128.000 **** PIPEFLOW TRAVEL TIME (User specified size) **** upstream point/station elevation =73.65(Ft.) Downstream point/station elevation = 73.45(Ft.) Pipe length = 11.00(Ft.) Manning's N = 0.011 No. of pipes = 1 Required pipe flow = 0.880(CFS) Given pipe size = 8.00(In.) Calculated individual pipe flow = 0.880(CFS) Normal flow depth in pipe = 3.80(ln.) Flow top width inside pipe = 7.99(In.) Critical Depth = 5.33(In.) Pipe flow velocity = 5.39(Ft/s) Travel time through pipe = 0.03 min. Time of concentration (TC) = 7.32 min. Page 18 PA211.0UT Process from Point/Station 128.000 to Point/Station 128.000 **** SUBAREA FLOW ADDITION **** User specified 'C' value of 0.600 given for subarea Time of concentration = 7.32 mm. Rainfall intensity = 5.357(in/Hr) for a 24.0 year storm Runoff coefficient used for sub-area, Rational method, Q=KCIA, c = 0.600 subarea runoff = 0.032(CFS) for 0.010(Ac.) Total runoff = 0.912(CFS) Total area = 0.27 (Ac.) Process from Point/Station 128.000 to Point/Station 129.000 **** PIPEFLOW TRAVEL TIME (User specified size) **** Upstream point/station elevation = 73.35(Ft.) Downstream point/station elevation = 72. 45 (Ft.) Pipe length = 44.00(Ft.) Manning's N = 0.011 No. of pipes = 1 Required pipe flow = 0.912(CFS) Given pipe size = 8.00(ln.) Calculated individual pipe flow = 0.912(CFS) Normal flow depth in pipe = 3. 75 (in.) Flow top width inside pipe = 7. 98 (In.) Critical Depth = 5. 43 (in.) Pipe flow velocity = 5.69(Ft/s) Travel time through pipe = 0.13 min. Time of concentration (TC) = 7.45 min. Process from Point/Station 129.000 to Point/Station 129.000 **** SUBAREA FLOW ADDITION **** User specified 'C1 value of 0.600 given for subareaTime of concentration = 7.45 mm. Rainfall intensity = 5.297(in/Hr) for a 24.0 year storm Runoff coefficient used for sub-area, Rational method, Q=KCIA, C = 0.600Subarea runoff = 0.064(CFS) for 0.020(Ac.)Total runoff = 0.976(CFS) Total area = 0.29(Ac.) Process from Point/Station 129.000 to Point/Station 3014.000 **** PIPEFLOW TRAVEL TIME (User specified size) **** Upstream point/station elevation = 72.35(Ft.) Downstream point/station elevation = 70.50(Ft.) Pipe length = 23.00(Ft.) Manning's N = 0.011 No. of pipes = 1 Required pipe flow = 0.976(CFS) Given pipe size = 8.00(ln.) Calculated individual pipe flow = 0.976(CFS) Normal flow depth in pipe = 2. 67 (in.) Flow top width inside pipe = 7. 5 5 (in.) Critical Depth = 5. 62 (in.) Pipe flow velocity = 9.55(Ft/s) Travel time through pipe = 0.04 min. Time of concentration (TC) = 7.49 min. Process from Point/Station 129.000 to Point/Station 3014.000 Page 19 PA211.0UT **** CONFLUENCE OF MINOR STREAMS **** Along Main Stream number: 1 in normal stream number 3 stream flow area = 0.290(Ac.) Runoff from this stream = 0.976(CFS) Time of concentration = 7.49 min. Rainfall intensity = 5.279(ln/Hr) Summary of stream data: Stream Flow rate TC Rainfall Intensity No. (CFS) (min) (in/Hr) 1 2.295 6.26 5.928 2 1.740 7.15 5.4383 0.976 7.49 5.279Qmax(l) = 1.000 * 1.000 * 2.295) +1.000 * 0.875 * 1.740) + 1.000 * 0.835 * 0.976) + = 4.633 Qmax(2) =0.917 * 1.000 * 2.295) + 1.000 * 1.000 * 1.740) + 1.000 * 0.955 * 0.976) + = 4.777 Qmax(3) =0.890 * 1.000 * 2.295) +0.971 * 1.000 * 1.740) +1.000 * 1.000 * 0.976) + = 4.709 Total of 3 streams to confluence: Flow rates before confluence point: 2.295 1.740 0.976 Maximum flow rates at confluence using above data: 4.633 4.777 4.709 Area of streams before confluence: 0.600 0.520 0.290 Results of confluence: T9tal flow rate = 4.777(CFS) Time of concentration = 7.152 min. Effective stream area after confluence = 1.410(Ac.) Process from Point/Station 3014.000 to Point/Station 3174.000 **** PIPEFLOW TRAVEL TIME (user specified size) **** Upstream point/station elevation =70.03(Ft.) Downstream point/station elevation = 62.42(Ft.) Pipe length = 49.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 4.777(CFS) Given pipe size = 18.00(in.) Calculated individual pipe flow = 4.777(CFS) Normal flow depth in pipe = 4.13(In.) Flow top width inside pipe = 15.14(ln.) Critical Depth = 10.08(in.) Pipe flow velocity = 15.62(Ft/s) Travel time through pipe = 0.05 min. Time of concentration (TC) = 7.20 min. End of computations, total study area = 1.41 (Ac.) Page 20 pa212.0UT San Diego County Rational Hydrology Program CIVILCADD/CIVILDESIGN Engineering software, (c) 2004 Version 3.2 Rational method hydrology program based on San Diego county Flood Control Division 2003 hydrology manual Rational Hydrology Study Date: 01/16/08 ROBERTSON RANCH PA 21 TM - BASIN 2 PROPOSED CONDITIONS G:\ACCTS\011014\PA212.OUT _ — — ___ — — __ — — ™ — — — — — — — — — — — — — — __—._— — — ______.____„,_,__ — — __ — — — — —. — — — — — — — — — —..-._ — — — ********* Hydrology study Control information ********** O'Day Consultants, San Diego, California - S/N 10125 Rational hydrology study storm event year is 100.0 Map data precipitation entered: 6 hour, precipitation(inches) = 2.600 24 hour precipitation(inches) = 4.300 Adjusted 6 hour precipitation (inches) = 2.600 P6/P24 = 60.5% San Diego hydrology manual 'C' values used Runoff coefficients by rational method Process from Point/Station 201.000 to Point/Station 203.000 **** INITIAL AREA EVALUATION **** User specified 'C1 value of 0.600 given for subarea initial subarea flow distance = 18.00(Ft.) Highest elevation = 86. 92 (Ft.) Lowest elevation = 86. 82 (Ft.) Elevation difference = 0.10(Ft.) Time of concentration calculated by the urban areas overland flow method (App x-c) = 4.64 mi n. TC = [1.8*(l.l-C)*distanceA.5)/(% slopeA(i/3)] TC = [1. 8* (1.1-0. 6000) *( 18.00A.5)/( 0.56A(l/3)]= 4.64 setting time of concentration to 5 minutes Rainfall intensity (I) = 6.850 for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.600 Subarea runoff = 0.041(CFS) Total initial stream area = 0.010(Ac.) Process from Point/Station 203.000 to Point/Station 205.000 **** STREET FLOW TRAVEL TIME + SUBAREA FLOW ADDITION **** Top of street segment elevation = 86.820(Ft.) End of street segment elevation = 77.200(Ft.) Length of street segment = 245.000(Ft.) Height of curb above gutter flowline = 6.0(ln.)Width of half street (curb to crown) = 17.000(Ft.) Distance from crown to crossfall grade break = 15.500(Ft.) Slope from gutter to grade break (v/hz) = 0.020 Slope from grade break to crown (v/hz) = 0.020 Page 1 pa212.QUT Street flow is on [1] side(s) of the street Distance from curb to property line = 11.000(Ft.) Slope from curb to property line (v/hz) = 0.020 Gutter width = 1.500(Ft.) Gutter hike from flowline = 1.500(in.) Manning's N in gutter = 0.0150 Manning's N from gutter to grade break = 0.0150 Manning's N from grade break to crown = 0.0150 Estimated mean flow rate at midpoint of street = 0.045(CFS) Depth of flow = 0.063(Ft.), Average velocity = 1.859(Ft/s) Streetflow hydraulics at midpoint of street travel: Halfstreet flow width = 1.500(Ft.) Flow velocity = 1.86(Ft/s) Travel time = 2.20 min. TC = 7.20 min. Adding area flow to street User specified 'C1 value of 0.700 given for subarea Rainfall intensity = 5.417(ln/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method,Q=KCIA, C = 0.700 Subarea runoff = 0.682(CFS) for 0.180(Ac.) Total runoff = 0.724(CFS) Total area = 0.19(Ac.) Street flow at end of street = 0.724(CFS) Half street flow at end of street = 0.724(CFS) Depth of flow = 0.180(Ft.), Average velocity = 2.895(Ft/s) Flow width (from curb towards crown)= 4.227(Ft.) Process from Point/Station 205.000 to Point/Station 205.000 **** SUBAREA FLOW ADDITION **** User specified 'C1 value of 0.600 given for subarea Time of concentration = 7.20 min. Rainfall intensity = 5.417(ln/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method,Q=KCiA, c = 0.600 subarea runoff = 0.715(CFS) for 0.220(Ac.) Total runoff = 1.439(CFS) Total area = 0.41(Ac.) Process from Point/Station 205.000 to Point/Station 206.000 **** STREET FLOW TRAVEL TIME + SUBAREA FLOW ADDITION **** Top of street segment elevation =77.200(Ft.) End of street segment elevation = 76.500(Ft.) Length of street segment = 70.000(Ft.) Height of curb above gutter flowline = 6.0(ln.) Width of half street (curb to crown) = 17.000(Ft.) Distance from crown to crossfall grade break = 15.500(Ft.) Slope from gutter to grade break (v/hz) = 0.020 Slope from grade break to crown (v/hz) = 0.020 Street flow is on [1] side(s) of the street Distance from curb to property line = ll.OOO(Ft-) Slope from curb to property line (v/hz) = 0.020 Gutter width = 1.500(Ft.) Gutter hike from flowline = 1.500(ln.) Manning's N in gutter = 0.0150 Manning's N from gutter to grade break = 0.0150 Manning's N from grade break to crown = 0.0150 Estimated mean flow rate at midpoint of street = 1.474(CFS) Depth of flow = 0.260(Ft.), Average velocity = 1.963(Ft/s) Streetflow hydraulics at midpoint of street travel: Halfstreet flow width = 8.243(Ft.) Flow velocity = 1.96(Ft/s) Page 2 pa212.oUT TC = 7.79 rtrin.Travel time = 0.59 min. Adding area flow to street User specified 'c' value of 0.600 given for subarea Rainfall intensity = 5.146(ln/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method,Q=KCIA, c = 0.600 Subarea runoff = 0.062(CFS) for 0.020(Ac.) Total runoff = l.SOO(CFS) Total area = 0.43(Ac.) Street flow at end of street = l.SOO(CFS) Half street flow at end of street = 1.500(CFS) Depth of flow = 0.261(Ft.), Average velocity = 1.971(Ft/s) Flow width (from curb towards crown)= 8.305(Ft.) Process from Point/Station 206.000 to Point/Station 206.000 **** SUBAREA FLOW ADDITION **** User specified 'C' value of 0.600 given for subarea Time of concentration = 7.79 min. Rainfall intensity = 5.146(in/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method,Q=KCIA, c = 0.600 Subarea runoff = 0.556(CFS) for 0.180(Ac.) Total runoff = 2.056(CFS) Total area = 0.61(Ac.) Process from Point/Station 206.000 to Point/Station 207.000 **** STREET FLOW TRAVEL TIME + SUBAREA FLOW ADDITION **** Top of street segment elevation = 76.500(Ft.) End of street segment elevation = 75.650(Ft.) Length of street segment = 95.000(Ft.) Height of curb above gutter flowline = 6.0(in.) Width of half street (curb to crown) = 17.000(Ft.) Distance from crown to crossfall grade break = 15.500(Ft.) Slope from gutter to grade break (v/hz) = 0.020 Slope from grade break to crown (v/hz) = 0.020 Street flow is on [1] side(s) of the street Distance from curb to property line = 11.000(Ft.) Slope from curb to property line (v/hz) = 0.020 Gutter width = 1.500(Ft.) Gutter hike from flowline = 1.500(in.) Manning's N in gutter = 0.0150 Manning's N from gutter to grade break = 0.0150 Manning's N from grade break to crown = 0.0150 Estimated mean flow rate at midpoint of street = 2.343(CFS)Depth of flow = 0.299(Ft.), Average velocity = 2.099(Ft/s) streetflow hydraulics at midpoint of street travel: Halfstreet flow width = 10.222(Ft.)Flow vel9city = 2.10(Ft/s) Travel time = 0.75 min. TC = 8.54 min. Adding area flow to street User specified 'C' value of 0.600 given for subarea Rainfall intensity = 4.848(ln/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method,Q=KCIA, C = 0.600 Subarea runoff = 0.495(CFS) for 0.170(Ac.) Total runoff = 2.551(CFS) Total area = 0.78(Ac.) Street flow at end of street = 2.551(CFS) Half street flow at end of street = 2.551(CFS) Depth of flow = 0.307(Ft.), Average velocity = 2.142(Ft/s) Flow width (from curb towards crown)= 10.580(Ft.) Page 3 pa222.0UT .................... ++++++++++• ....... Process from Point/Station 207.000 to Point/Station 208.000 **** STREET FLOW TRAVEL TIME + SUBAREA FLOW ADDITION **** Top of street segment elevation = 75.650(Ft.) End of street segment elevation = 74.270(Ft.) Length of street segment = 138.000(Ft.) Height of curb above gutter flowline = 6.0(in.) Width of half street (curb to crown) = 17.000(Ft.) Distance from crown to crossfall grade break = 15.500(Ft.) Slope from gutter to grade break (v/hz) = 0.020 slope from grade break to crown (v/hz) = 0.020 Street flow is on [1] side(s) of the street Distance from curb to property line = 11.000(Ft.) Slope from curb to property line (v/hz) = 0.020 Gutter width = 1.500 (Ft.) Gutter hike from flowline = 1.500(ln.) Manning's N in gutter = 0.0150 Manning's N from gutter to grade break = 0.0150 Manning's N from grade break to crown = 0.0150 Estimated mean flow rate at midpoint of street = 2.927(CFS) Depth of flow = 0.314(Ft.), Average velocity = 2.310(Ft/s) Streetflow hydraulics at midpoint of street travel: Halfstreet flow width = 10.936(Ft.) Flow velocity = 2.31(Ft/s) Travel time = 1.00 mi n. TC = 9.54 min. Adding area flow to street User specified 'C1 value of 0.600 given for subarea Rainfall intensity = 4.516(ln/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method, Q=KCIA, c = 0.600 subarea runoff = 0.623(CFS) for 0.230(Ac.) Total runoff = 3.174(CFS) Total area = 1.01(Ac.)Street flow at end of street = 3.174(CFS) Half street flow at end of street = 3.174(CFS) Depth of flow = 0.321(Ft.), Average velocity = 2.355(Ft/s) Flow width (from curb towards crown)= 11. 298 (Ft.) Process from Point/Station 208.000 to Point/Station 209.000 **** STREET FLOW TRAVEL TIME + SUBAREA FLOW ADDITION **** Top of street segment elevation = 74.270(Ft.) End of street segment elevation = 72.790(Ft.) Length of street segment = 138.000(Ft.) Height of curb above gutter flowline = 6.0(ln.) width of half street (curb to crown) = 17.000(Ft.) Distance from crown to crossfall grade break = 15.500(Ft.) Slope from gutter to grade break (v/hz) = 0.020 Slope from grade break to crown (v/hz) = 0.020 Street flow is on [1] side(s) of the street Distance from curb to property line = 11.000(Ft.) Slope from curb to property line (v/hz) = 0.020 Gutter width = 1.500(Ft.) Gutter hike from flowline = 1.500(in.) Manning's N in gutter = 0.0150 Manning's N from gutter to grade break = 0.0150 Manning's N from grade break to crown = 0.0150 Estimated mean flow rate at midpoint of street = 3.535(CFS) Depth of flow = 0.328 (Ft.), Average velocity = 2.482(Ft/s) Streetflow hydraulics at midpoint of street travel: Halfstreet flow width = 11. 632 (Ft.) Flow velocity = 2.48(Ft/s) Page 4 pa212.0UT Travel time = 0.93 mi n. TC = 10.47 min. Adding area flow to street User specified "c" value of 0.600 given for subarea Rainfall intensity = 4.254(in/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method, Q=KCIA, C = 0.600 Subarea runoff = 0.587(CFS) for 0.230(Ac.) Total runoff = 3.761(CFS) Total area = 1.24(Ac.) Street flow at end of street = 3.761(CFS) Half street flow at end of street = 3.761(CFS) Depth of flow = 0.333(Ft.), Average velocity = 2.520(Ft/s) Flow width (from curb towards crown)= 11. 922 (Ft.) Process from Point/Station 209.000 to Point/Station 7006.000 **** STREET FLOW TRAVEL TIME + SUBAREA FLOW ADDITION **** Top of street segment elevation = 72.790(Ft.) End of street segment elevation = 70.130(Ft.) Length of street segment = 210.000(Ft.) Height of curb above gutter flowline = 6.0(ln.) Width of half street (curb to crown) = 17.000(Ft.) Distance from crown to crossfall grade break = 15.500(Ft.) Slope from gutter to grade break (v/hz) = 0.020 Slope from grade break to crown (v/hz) = 0.020 Street flow is on [1] side(s) of the street Distance from curb to property line = ll.OOO(Ft-) Slope from curb to property line (v/hz) = 0.020 Gutter width = 1.500(Ft.) Gutter hike from flowline = 1.500(in.) Manning's N in gutter = 0.0150 Manning's N from gutter to grade break = 0.0150 Manning's N from grade break to crown = 0.0150 Estimated mean flow rate at midpoint of street = 4.231(CFS) Depth of flow = 0.337 (Ft.), Average velocity = 2.761(Ft/s)Streetflow hydraulics at midpoint of street travel: Halfstreet flow width = 12.087(Ft.) Flow velocity = 2.76(Ft/s) Travel time = 1.27 min. TC = 11.73 min. Adding area flow to street user specified 'c' value of 0.600 given for subarea Rainfall intensity = 3.951(ln/Hr) for a 100.0 year stormRunoff coefficient used for sub-area, Rational method, Q=KCIA, c = 0.600 subarea runoff = 0.735(CFS) for 0.310(Ac.) Total runoff = 4.496(CFS) Total area = 1.55(Ac.) street flow at end of street = 4.496(CFS) Half street flow at end of street = 4.496(CFS) Depth 9f flow = 0.343 (Ft.), Average velocity = 2.802(Ft/s) Flow width (from curb towards crown)= 12. 382 (Ft.) Process from Point/Station 7006.000 to Point/Station 7006.000 **** SUBAREA FLOW ADDITION **** user specified 'C1 value of 0.600 given for subarea Time of concentration = 11.73 mm. Rainfall intensity = 3.951(ln/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method, Q=KCIA, c = 0.600 Subarea runoff = 1.494(CFS) for 0.630(Ac.) Total runoff = 5.989(CFS) Total area = 2. 18 (Ac.) Page 5 pa212.QUT +++++++++++++++++-M-+-H- 7003.000 Tl—T~l—I—I—(""I""!—TT—ft—t—I—I—I—k ~T—TTT TTTT-T I T T I T^T-T T^-TT T FTT rT^T^T^T rTTT^T^T^T^T T TT^T^ Process from Point/Station 7006.000 to Point/Station **** PIPEFLOW TRAVEL TIME (User specified size) **** Upstream point/station elevation =61.03(Ft.) Downstream point/station elevation = 60.30(Ft.) Pipe length = 5.31(Ft.) Manning's N = 0.011 Np. of pipes = 1 Required pipe flow = 5.989(CFS) Given pipe size = 12.00(ln.) Calculated individual pipe flow = 5.989(CFS) Normal flow depth in pipe = 5.16(in.) Flow top width inside pipe = 11.88(in.) Critical depth could not be calculated. Pipe flow velocity = 18.57(Ft/s) Travel time through pipe = 0.00 min. Time of concentration (TC) = 11.74 min. process from Point/Station 7006.000 to Point/Station 7003.000 **** CONFLUENCE OF MAIN STREAMS **** The following data inside Main Stream is listed: in Main Stream number: 1 Stream flow area = 2.180(Ac.) Runoff from this stream = 5.989(CFS) Time of concentration = 11.74 min. Rainfall intensity = 3.950(ln/Hr) program is now starting with Main Stream No. 2 Process from Point/Station 211.000 to Point/Station 212.000 **** INITIAL AREA EVALUATION **** user specified 'C' value of 0.600 given for subarea initial subarea flow distance = 35.00(Ft.) Highest elevation = 88. 85 (Ft.) Lowest elevation = 88.50(Ft.) Elevation difference = 0.35 (Ft.) Time of concentration calculated by the urban areas overland flow method (App x-C) = 5.32 min. TC = [1.8*(l.l-C)*distanceA.5)/(% slopeA(l/3)]TC = [1. 8* (1.1-0. 6000) *( 35.00A.5)/( 1.00A(l/3)]= 5.32 Rainfall intensity (I) = 6.578 for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.600 Subarea runoff = 0.158(CFS) Total initial stream area = 0.040(Ac.) Process from Point/Station 212.000 to Point/Station 213.000 **** PIPEFLOW TRAVEL TIME (user specified size) **** upstream point/station elevation = 86.50(Ft.) Downstream point/station elevation = 83.50(Ft.) Pipe length = 7.00(Ft.) Manning's N = 0.011 NO. of pipes = 1 Required pipe flow = 0.158(CFS) Given pipe size = 6.00(ln.) calculated individual pipe flow = 0.158(CFS) Normal flow depth in pipe = 0.78 (in.) Flow top width inside pipe = 4.04(in.) critical Depth = 2. 38 (in.) Page 6 pa212.oUT Pipe flow velocity = 10.49(Ft/s) Travel time through pipe = 0.01 min. Time of concentration (TC) = 5.34 min. 1 ^ TT^T I I I I I TT I—I—I—I—I—I—I—I—I I TT I Process from point/Station 213.000 to Point/Station 213.000 **** SUBAREA FLOW ADDITION **** User specified 'C1 value of 0.600 given for subarea Time of concentration = 5.34 min. Rainfall intensity = 6.569(ln/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method,Q=KCIA, C = 0.600 Subarea runoff = 0.079(CFS) for 0.020(Ac.) Total runoff = 0.237(CFS) Total area = 0.06(Ac.) Process from Point/Station 213.000 to Point/Station 214.000 **** PIPEFLOW TRAVEL TIME (user specified size) **** Upstream point/station elevation = 83.50(Ft.) Downstream point/station elevation = 77.50(Ft.) Pipe length = 56.00(Ft.) Manning's N = 0.011 No. of pipes = 1 Required pipe flow = 0.237(CFS)Given pipe size = 6.00(ln.) Calculated individual pipe flow = 0.237(CFS) Normal flow depth in pipe = 1.34 (In.)Flow top width inside pipe = 5.00(ln.) Critical Depth = 2. 93 (In.) Pipe flow velocity = 7.26(Ft/s)Travel time through pipe = 0.13 mi n. Time of concentration (TC) = 5.46 mi n. Process from Point/Station 214.000 to Point/Station **** SUBAREA FLOW ADDITION **** 214.000 User specified 'C1 value of 0.600 given for subarea Time of cpncentration = 5.46 mm. Rainfall intensity = 6.469(in/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method ,Q=KCIA, c = 0.600Subarea runoff = 0.233(CFS) for 0.060(Ac.) Total runoff = 0.470(CFS) Total area = 0.12 (Ac.) Process from Point/Station 214.000 to Point/Station **** PIPEFLOW TRAVEL TIME (User specified size) ****215.000 Upstream point/station elevation = 77.00(Ft.) Downstream point/station elevation = 74. 98 (Ft.) Pipe length = 40.01(Ft.) Manning's N = 0.011 No. of pipes = 1 Required pipe flow = 0.470(CFS) Given pipe size = 8.00(ln.) Calculated individual pipe flow = 0.470(CFS) Normal flow depth in pipe = 2. 07 (in.) Fl9w top width inside pipe = 7. 00 (in.) Critical Depth = 3.84(ln.) Pipe flow velocity = 6.56(Ft/s) Travel time through pipe = 0.10 mi n. Time of concentration (TC) = 5.57 mi n. Page 7 pa212.0UT T — n — i — n — n — f m n I F n T iitiii»iii'«'«>i«iiiiiiiiiiiiiitii»iii»iiit«iii«"«*"' Process from Point/Station 215.000 to Point/Station 215.000 **** SUBAREA FLOW ADDITION **** user specified 'C1 value of 0.600 given for subarea Time of concentration = 5.57 mm. Rainfall intensity = 6.393(ln/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method, Q=KCIA, C = 0.600 subarea runoff = 0.153(CFS) for 0.040(Ac.) Total runoff = 0.623(CFS) Total area = 0.16(Ac.) Process from Point/Station 215.000 to Point/Station 216.000 **** PIPEFLOW TRAVEL TIME (User specified size) **** Upstream point/station elevation = 74. 98 (Ft.) Downstream point/station elevation = 72. 92 (Ft.) Pipe length = 40.79(Ft.) Manning's N = 0.011 No. of pipes = 1 Required pipe flow = 0.62 3 (CFS) Given pipe size = 8.00(ln.) Calculated individual pipe flow = 0.623 (CFS) Normal flow depth in pipe = 2. 39 (In.) Flow top width inside pipe = 7. 32 (In.) Critical Depth = 4.46(in.) Pipe flow velocity = 7.12(Ft/s) Travel time through pipe = 0.10 mi n. Time of concentration (TC) = 5.66 mi n. Process from Point/Station 216.000 to Point/Station 216.000 **** SUBAREA FLOW ADDITION **** User specified 'C1 value of 0.600 given for subarea Time of concentration = 5.66 mm. Rainfall intensity = 6.323(ln/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method, Q=KCIA, C = 0.600 subarea runoff = 0.417(CFS) for 0.110(Ac.) Total runoff = 1.040(CFS) Total area = 0.27(Ac.) Process from Point/Station 216.000 to Point/Station 217.000 **** PIPEFLOW TRAVEL TIME (User specified size) **** Upstream point/station elevation = 72.92(Ft.) Downstream point/station elevation = 70. 12 (Ft.) Pipe length = 55.51(Ft.) Manning's N = 0.011 No. of pipes = 1 Required pipe flow = 1.040(CFS) Given pipe size = 8.00(ln.) Calculated individual pipe flow = 1.040(CFS) Normal flow depth in pipe = 3. 13 (In.) Flow top width inside pipe = 7.81(in.) Critical Depth = 5.81(ln.) Pipe flow velocity = 8.21(Ft/s) Travel time through pipe = 0.11 mi n. Time of concentration (TC) = 5.77 mi n. Page 8 pa212.0UT Process from point/Station 217.000 to Point/Station 217.000 **** SUBAREA FLOW ADDITION **** User specified 'c' value of 0.600 given for subarea Time of concentration = 5.77 mm. Rainfall intensity = 6.243(in/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method, Q=KCIA, C = 0.600 Subarea runoff = 0.749(CFS) for 0.200(Ac.) Total runoff = 1.789(CFS) Total area = 0.47(Ac.) Process from Point/Station 217.000 to Point/Station 218.000 **** PIPEFLOW TRAVEL TIME (user specified size) **** upstream point/station elevation = 70. 12 (Ft.) Downstream point/station elevation = 66. 88 (Ft.) Pipe length = 64.20(Ft.) Manning's N = 0.011 NO. of pipes = 1 Required pipe flow = 1.789(CFS) Given pipe size = 8.00(ln.) Calculated individual pipe flow = 1.789(CFS) Normal flow depth in pipe = 4. 27 (in.) Flow top width inside pipe = 7. 98 (In.) Critical Depth = 7.31(ln.) Pipe flow velocity = 9.44(Ft/s) Travel time through pipe = 0.11 mi n. Time of concentration (TC) = 5.89 mi n. Process from Point/Station 218.000 to Point/Station 218.000 **** SUBAREA FLOW ADDITION **** User specified 'C1 value of 0.600 given for subarea Time of C9ncentration = 5.89 mm. Rainfall intensity = 6.165(ln/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method, Q=KCIA, c = 0.600 Subarea runoff = 0.888(CFS) for 0.240(Ac.) Total runoff = 2.677(CFS) Total area = 0.71(Ac.) Process from Point/Station 218.000 to Point/Station 219.000 **** PIPEFLOW TRAVEL TIME (user specified size) **** upstream point/station elevation = 66. 5 5 (Ft.) Downstream point/station elevation = 65.00(Ft.) Pipe length = 155.14(Ft.) Manning's N = 0.011 N9- of pipes = 1 Required pipe flow = 2.677(CFS) Given pipe size = 15.00(in.) Calculated individual pipe flow = 2.677(CFS) Normal flow depth in pipe = 6. 13 (in.) Flow top width inside pipe = 14. 75 (in.) Critical Depth = 7. 88 (in.) Pipe flow velocity = 5.67(Ft/s) Travel time through pipe = 0.46 mi n. Time of concentration (TC) = 6.34 mi n. Process from Point/Station 219.000 to Point/Station 219.000 **** SUBAREA FLOW ADDITION **** Page 9 pa212.0UT User specified 'C' value of 0.600 given for subarea Time of concentration = 6.34 mm. Rainfall intensity = 5.876(in/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method, Q=KCIA, C = 0.600 Subarea runoff = 0.635(CFS) for 0.180(Ac.) Total runoff = 3.312(CFS) Total area = 0.89(Ac.) Process from Point/Station 219.000 to Point/Station 220.000 **** PIPEFLOW TRAVEL TIME (User specified size) **** Upstream point/station elevation = 65.00(Ft.) Downstream point/station elevation = 63. 58 (Ft.) Pipe length = 141. 42 (Ft.) Manning's N = 0.011 No. of pipes = 1 Required pipe flow = 3.312(CFS) Given pipe size = 15.00(ln.) Calculated individual pipe flow = 3.312(CFS) Normal flow depth in pipe = 6.90(ln.) Flow top width inside pipe = 14. 95 (In.) Critical Depth = 8.80(ln.) Pipe flow velocity = 6.01(Ft/s) Travel time through pipe = 0.39 mi n. Time of concentration (TC) = 6.74 mi n. Process from Point/Station 219.000 to Point/Station 220.000 **** CONFLUENCE OF MINOR STREAMS **** Along Main Stream number: 2 in normal stream number 1Stream flow area = 0.890 (Ac.) Runoff from this stream = 3.312(CFS) Time of concentration = 6.74 mi n. Rainfall intensity = 5.653(ln/Hr) Process from Point/Station 250.000 to Point/Station 251.000 **** INITIAL AREA EVALUATION **** User specified 'C1 value of 0.600 given for subarea Initial subarea flow distance = 50. 00 (Ft.) Highest elevation = 77.25(Ft.) Lowest elevation = 76. 75 (Ft.)Elevation difference = 0.50(Ft.) Time of concentration calculated by the urban areas overland flow method (App x-c) = 6.36 mi n. TC = [1.8*(l.l-C)*distanceA.5)/(% slopeA(l/3)]TC = [1. 8* (1.1-0. 6000) *( 50.00A.5)/( 1.00A(l/3)]= 6.36Rainfall intensity (I) = 5.863 for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.600Subarea runoff = 0.106(CFS) Total initial stream area = 0.030(Ac.) Process from Point/Station 251.000 to Point/Station 252.000 **** PIPEFLOW TRAVEL TIME (user specified size) **** Upstream point/station elevation = 75.20(Ft.)Dpwnstream point/station elevation = 75.00(Ft.) Pipe length = 4.50(Ft.) Manning's N = 0.011 Page 10 pa212.OUT No. of pipes = 1 Required pipe flow = 0.106(CFS) Given pipe size = 6.00(ln.)Calculated individual pipe flow = 0.106(CFS) Normal flow depth in pipe = 1.12 (in.) Flow top width inside pipe = 4. 67 (in.) Critical Depth = 1.93(ln.) Pipe flow velocity = 4.20(Ft/s) Travel time through pipe = 0.02 mi n. Time of concentration (TC) = 6.38 mi n. Process from Point/Station 252.000 to Point/Station 252.000 **** SUBAREA FLOW ADDITION **** User specified 'C' value of 0.600 given for subarea Time of concentration = 6.38 mm. Rainfall intensity = 5.853(In/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method, Q=KCIA, C = 0.600 Subarea runoff = O.IOS(CFS) for 0.030(Ac.) Total runoff = 0.211(CFS) Total area = 0.06(Ac.) Process from Point/Station 252.000 to Point/Station 253.000 **** PIPEFLOW TRAVEL TIME (user specified size) **** upstream point/station elevation = 75.00(Ft.)Downstream point/station elevation = 73. 40 (Ft.) Pipe length = 71.30(Ft.) Manning's N = 0.011 No. of pipes = 1 Required pipe flow = 0.211(CFS) Given pipe size = 6.00(ln.) Calculated individual pipe flow = 0.211(CFS) Normal flow depth in pipe = 1.88 (in.) Flow top width inside pipe = 5.57(ln.) Critical Depth = 2.76(ln.) Pipe flow velocity = 4.02(Ft/s) Travel time through pipe = 0.30 mi n. Time of concentration (TC) = 6.68 mi n. Process from Point/Station 253.000 to Point/Station 253.000 **** SUBAREA FLOW ADDITION **** User specified 'c1 value of 0.600 given for subarea Time of concentration = 6.68 mm. Rainfall intensity = 5.684(ln/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method , Q=KCIA , C = 0.600 Subarea runoff = 0.290(CFS) for 0.085 (Ac.) Total runoff = O.SOl(CFS) Total area = 0.15 (Ac.) Process from Point/Station 253.000 to Point/Station 258.000 **** PIPEFLOW TRAVEL TIME (user specified size) **** Upstream point/station elevation = 73.30(Ft.) Downstream point/station elevation = 73.00(Ft.) Pipe length = 63.10(Ft.) Manning's N = 0.011 No. of pipes = 1 Required pipe flow = O.SOl(CFS) Given pipe size = 8.00(ln.) Calculated individual pipe flow = O.SOl(CFS) Page 11 pa212.QUT Normal flow depth in pipe = 4. 04 (In.) Flow top width inside pipe = 8.00(ln.) Critical Depth = 3.98(ln.) Pipe flow velocity = 2.83(Ft/s) Travel time through pipe = 0.37 mi n. Time of concentration (TC) = 7.05 mi n. Process from Point/Station 258.000 to Point/station 258.000 **** SUBAREA FLOW ADDITION **** User specified 'C' value of 0.600 given for subarea Time of concentration = 7.05 mm. Rainfall intensity = 5.489(ln/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method , Q=KCIA , C = 0.600 Subarea runoff = 0.099(CFS) for 0.030(Ac.) Total runoff = 0.600(CFS) Total area = 0.18 (Ac.) Process from Point/Station 258.000 to Point/Station 259.000**** PIPEFLOW TRAVEL TIME (user specified size) **** Upstream point/station elevation = 73.00(Ft.) Downstream point/station elevation = 72.90(Ft.) Pipe length = 4.50(Ft.) Manning's N = 0.011 NO. of pipes = 1 Required pipe flow = 0.600(CFS) Given pipe size = 8.00(in.) Calculated individual pipe flow = 0.600(CFS) Normal flow depth in pipe = 2.91(ln.) Flow top width inside pipe = 7.69(in.) Critical Depth = 4. 37 (in.) Pipe flow velocity = 5.24(Ft/s) Travel time through pipe = 0.01 mi n. Time of concentration (TC) = 7.06 mi n. Process from Point/Station 259.000 to Point/Station **** SUBAREA FLOW ADDITION **** 259.000 user specified 'C' value of 0.600 given for subarea Time of concentration = 7.06 mm. Rainfall intensity = 5.482(in/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method ,Q=KCIA, C = 0.600 Subarea runoff = 0.099(CFS) for 0.030(Ac.) Total runoff = 0.698(CFS) Total area = 0.21(Ac.) Process from Point/Station 259.000 to Point/Station 260.000 **** PIPEFLOW TRAVEL TIME (User specified size) **** Upstream point/station elevation = 72.90(Ft.) Downstream point/station elevation = 72.20(Ft.) Pipe length = 70.90(Ft.) Manning's N = 0.011 No. of pipes = 1 Required pipe flow = 0.698(CFS) Given pipe size = 8.00(ln.) Calculated individual pipe flow = 0.698(CFS) Normal flow depth in pipe = 3.96(in.) Flow top width inside pipe = 8. 00 (in.) Critical Depth = 4. 73 (In.) Page 12 pa212.0UTPipe flow velocity = 4.05(Ft/s)Travel time through pipe = 0.29 min.Time of concentration (TC) = 7.35 min. Process from Point/Station 260.000 to Point/Station 260.000 **** SUBAREA FLOW ADDITION **** User specified 'c' value of 0.600 given for subareaTime of concentration = 7.35 mm. Rainfall intensity = 5.341(in/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method,Q=KCIA, C = 0.600 Subarea runoff = 0.048(CFS) for 0.015(Ac.) Total runoff = 0.746(CFS) Total area = 0.22(Ac.) Process from Point/Station 260.000 to Point/Station 261.000**** PIPEFLOW TRAVEL TIME (User specified size) **** Upstream point/station elevation = 72.20(Ft.)Downstream point/station elevation = 71.60(Ft.)Pipe length = 41.00(Ft.) Manning's N = 0.011No. of pipes = 1 Required pipe flow = 0.746(CFS)Given pipe size = 8. 00 (in.)Calculated individual pipe flow = 0.746(CFS)Normal flow depth in pipe = 3.67(in.)Flow top width inside pipe = 7. 97 (in.)Critical Depth = 4. 89 (In.)Pipe flow velocity = 4.77(Ft/s)Travel time through pipe = 0.14 min.Time of concentration (TC) = 7.50 min. Process from Point/Station 261.000 to Point/Station 261.000 **** SUBAREA FLOW ADDITION **** User specified 'C' value of 0.600 given for subareaTime of concentration = 7.50 mm.Rainfall intensity = 5.275(ln/Hr) for a 100.0 year stormRunoff coefficient used for sub-area, Rational method, Q=KCIA, C = 0.600Subarea runoff = 0.253(CFS) for 0.080(Ac.) Total runoff = l.OOO(CFS) Total area = 0.30(Ac.) Process from Point/Station 261.000 to Point/Station 220.000**** PIPEFLOW TRAVEL TIME (user specified size) **** Upstream point/station elevation = 71.60(Ft.)D9wnstream point/station elevation = 63.75(Ft.)Pipe length = 84.00(Ft.) Manning's N = 0.011No. of pipes = 1 Required pipe flow = l.OOO(CFS)Given pipe size = 8.00(in.) Calculated individual pipe flow = l.OOO(CFS) Normal flow depth in pipe = 2. 60 (in.)Flow top width inside pipe = 7.50(in.) Critical Depth = 5.69(In.) Pipe flow velocity = 10.14(Ft/s) Travel time through pipe = 0.14 min.Time of concentration (TC) = 7.64 min. Page 13 pa212.0UT Process from Point/Station 261.000 to Point/Station **** CONFLUENCE OF MINOR STREAMS **** 220.000 Along Main Stream number: 2 in normal stream number 2 Stream flow area = 0.300(Ac.) Runoff from this stream = 1.000(CFS) Time of concentration = 7.64 min. Rainfall intensity = 5.213(ln/Hr) Summary of stream data: Stream No. Flow rate (CFS) TC (min) Rainfall Intensity (in/Hr) 1 2 Qmax(l) Qmax(2) = .312 .000 1.000 * 1.000 * 0.922 * 1.000 * 6.74 7.64 5.653 5.213 1.000 * 0.882 * 1.000 * 1.000 * 3.312) + 1.000) + 3.312) + 1.000) + 4.193 4.054 Total of 2 streams to confluence: Flow rates before confluence point: 3.312 1.000Maximum flow rates at confluence using above data: 4.193 4.054 Area of streams before confluence: 0.890 0.300 Results of confluence: T9tal flow rate = 4.193(CFS) Time of concentration = 6.735 min. Effective stream area after confluence = 1.190(Ac.) Process from Point/Station 220.000 to Point/Station 220.000 **** SUBAREA FLOW ADDITION **** User specified 'c1 value of 0.600 given for subarea Time of C9ncentration = 6.74 mm. Rainfall intensity = 5.653(ln/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method,Q=KCIA, C = 0.600 Subarea runoff = 0.610(CFS) for 0.180(Ac.) Total runoff = 4.804(CFS) Total area = 1.37(Ac.) Process from Point/Station 220.000 to Point/Station 221.000 **** PIPEFLOW TRAVEL TIME (user specified size) **** Upstream point/station elevation = 63.25(Ft.) Downstream point/station elevation = 61.69(Ft.) Pipe length = 131.05(Ft.) Manning's N = 0.011 No. of pipes = 1 Required pipe flow = 4.804(CFS) Given pipe size = 18.00(ln.) Calculated individual pipe flow = 4.804(CFS) Normal flow depth in pipe = 7.41(ln.) Flow top width inside pipe = 17.72(In.) Page 14 pa212.OUT Critical Depth = 10.11(ln.) Pipe flow velocity = 7.01(Ft/s) Travel time through pipe = 0.31 min. Time of concentration (TC) = 7.05 min. Process from Point/Station 221.000 to Point/Station 221.000 **** SUBAREA FLOW ADDITION **** User specified 'C1 value of 0.600 given for subarea Time of concentration = 7.05 min. Rainfall intensity = 5.490(ln/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method, Q=KCIA, c = 0.600 Subarea runoff = 0.593(CFS) for 0.180(Ac.) Total runoff = 5.397(CFS) Total area = 1.5 5 (Ac.) Process from Point/Station 221.000 to Point/Station 222.000 **** PIPEFLOW TRAVEL TIME (user specified size) **** Upstream point/station elevation = 61.69(Ft.) Downstream point/station elevation = 60.04(Ft.) Pipe length = 137.50(Ft.) Manning's N = 0.011 No. of pipes = 1 Required pipe flow = 5.397(CFS) Given pipe size = 18.00(ln.) Calculated individual pipe flow = 5.397(CFS) Normal flow depth in pipe = 7.88(In.) Flow top width inside pipe = 17.86(ln.) Critical Depth = 10.74(in.) Pipe flow velocity = 7.25(Ft/s) Travel time through pipe = 0.32 min. Time of concentration (TC) = 7.36 min. Process from Point/Station 221.000 to Point/Station 222.000 **** CONFLUENCE OF MINOR STREAMS **** Along Main Stream number: 2 in normal stream number 1 Stream flow area = 1.550(Ac.)Runoff from this stream = 5.397(CFS) Time of concentration = 7.36 min. Rainfall intensity = 5.337(in/Hr) Process from Point/Station 223.000 to Point/Station 224.000 **** INITIAL AREA EVALUATION **** User specified 'C1 value of 0.600 given for subarea initial subarea flow distance = 50.00(Ft.) Highest elevation = 87.10(Ft.) Lowest elevation = 86.60(Ft.) Elevation difference = 0.50(Ft.) Time of concentration calculated by the urban areas overland flow method (App x-C) = 6.36 min. TC = [1.8*(l.l-C)*distanceA.5)/(% slopeA(l/3)] TC = [1. 8* (1.1-0. 6000) *( 50.00A.5)/( 1.0QA(l/3)]= 6.36 Rainfall intensity (I) = 5.863 for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.600 Subarea runoff = 0.106(CFS) Page 15 pa212.OUT Total initial stream area = 0.030(Ac.) Process from Point/Station 224.000 to Point/Station 224.000 **** SUBAREA FLOW ADDITION **** User specified 'C1 value of 0.600 given for subarea Time of concentration = 6.36 mm. Rainfall intensity = 5.863(ln/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method, Q=KCIA, C = 0.600 Subarea runoff = 0.106(CFS) for 0.030(Ac.) Total runoff = 0.211(CFS) Total area = 0.06(Ac.) Process from Point/Station 224.000 to Point/Station 225.000 **** PIPEFLOW TRAVEL TIME (User specified size) **** Upstream point/station elevation = 84.50(Ft.) Downstream point/station elevation = 83.30(Ft.) Pipe length = 70.80(Ft.) Manning's N = 0.011 No. of pipes = 1 Required pipe flow = 0.211(CFS) Given pipe size = 6.00(ln.) Calculated individual pipe flow = 0.211(CFS) Normal flow depth in pipe = 2. 02 (In.) Flow top width inside pipe = 5. 67 (In.) Critical Depth = 2.76(ln.) Pipe flow velocity = 3.63(Ft/s) Travel time through pipe = 0.32 mi n. Time of concentration (TC) = 6.69 mi n. Process from Point/Station 225.000 to Point/Station 225.000 **** SUBAREA FLOW ADDITION **** User specified 'C1 value of 0.600 given for subarea Time of concentration = 6.69 mm. Rainfall intensity = 5.678(ln/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method, Q=KCIA, C = 0.600 Subarea runoff = 0.647(CFS) for 0.190(Ac.) Total runoff = 0.858(CFS) Total area = 0.2 5 (Ac.) Process from Point/Station 225.000 to Point/Station 226.000 **** PIPEFLOW TRAVEL TIME (user specified size) **** Upstream point/station elevation = 83.20(Ft.) Downstream point/station elevation = 82.50(Ft.) Pipe length = 63.70(Ft.) Manning's N = 0.011 NO. of pipes = 1 Required pipe flow = 0.858(CFS) Given pipe size = 8.00(ln.) Calculated individual pipe flow = 0.858(CFS) Normal flow depth in pipe = 4. 34 (in.) Flow top width inside pipe = 7.97(in.) critical Depth = 5.27(ln.) Pipe flow velocity = 4.43(Ft/s) Travel time through pipe = 0.24 mi n. Time of concentration (TC) = 6.93 mi n. Page 16 pa212.OUT Process from Point/Station 226.000 to point/Station 226.000 **** SUBAREA FLOW ADDITION **** User specified "C1 value of 0.600 given for subarea Time or concentration = 6.93 mi n. Rainfall intensity = 5.551(ln/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method, Q=KCIA, c = 0.600 Subarea runoff = O.IOO(CFS) for 0.030(Ac.) Total runoff = 0.958(CFS) Total area = 0.28 (Ac.) Process from Point/Station 226.000 to Point/Station 226.500 **** PIPEFLOW TRAVEL TIME (User specified size) **** Upstream point/station elevation = 82.30(Ft.) Downstream point/station elevation = 82.20(Ft.) Pipe length = 4.50(Ft.) Manning's N = 0.011 NO. of pipes = 1 Required pipe flow = 0.958(CFS) Given pipe size = 12.00(ln.) Calculated individual pipe flow = 0.958(CFS) Normal flow depth in pipe = 3. 17 (in.) Flow top width inside pipe = 10.58(in.) Critical Depth = 4. 92 (In.) Pipe flow velocity = 5.78(Ft/s) Travel time through pipe = 0.01 mi n. Time of concentration (TC) = 6.94 mi n. Process from Point/Station 226.500 to Point/Station 226.500 **** SUBAREA FLOW ADDITION **** User specified 'C1 value of 0.600 given for subarea Time of concentration = 6.94 mm. Rainfall intensity = 5.544(in/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method , Q=KCIA , c = 0.600 Subarea runoff = O.IOO(CFS) for 0.030(Ac.) Total runoff = 1.058(CFS) Total area = 0.31(Ac.) Process from Point/Station 226.500 to Point/Station 227.000 **** PIPEFLOW TRAVEL TIME (user specified size) **** Upstream point/station elevation = 82.20(Ft.) Dpwnstream point/station elevation = 82.00(Ft.) Pipe length = 71.30(Ft.) Manning's N = 0.011 No. of pipes = 1 Required pipe flow = 1.058(CFS) Given pipe size = 12.00(ln.) Calculated individual pipe flow = 1.058(CFS) Normal flow depth in pipe = 5. 82 (In.) Flow top width inside pipe = 11.99(ln.) Critical Depth = 5. 18 (in.) Pipe flow velocity = 2.80(Ft/s) Travel time through pipe = 0.42 min. Time of concentration (TC) = 7.37 min. Process from Point/Station 227.000 to Point/station 227.000 **** SUBAREA FLOW ADDITION **** Page 17 pa212.OUT User specified 'c' value of 0.600 given for subarea Time of concentration = 7.37 mm.Rainfall intensity = 5.336(ln/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method, Q=KCIA, C = 0.600 Subarea runoff = 0.608(CFS) for 0.190(Ac.)Total runoff = 1.666(CFS) Total area = 0.50(Ac.) Process from Point/Station 227.000 to Point/Station **** PIPEFLOW TRAVEL TIME (User specified size) **** 228.000 Upstream point/station elevation = 82.00(Ft.) Downstream point/station elevation = 81.70(Ft.) Pipe length = 63.20(Ft.) Manning's N = 0.011 No. of pipes = 1 Required pipe flow = 1.666(CFS) Given pipe size = 12.00(ln.) Calculated individual pipe flow = 1.666(CFS) Normal flow depth in pipe = 6. 52 (In.) Flow top width inside pipe = 11. 95 (in.) Critical Depth = 6. 58 (In.) Pipe flow velocity = 3.82(Ft/s) Travel time through pipe = 0.28 mi n. Time of concentration (TC) = 7.64 mi n. Process from Point/Station 228.000 to Point/Station 228.000 **** SUBAREA FLOW ADDITION **** User specified 'C' value of 0.600 given for subarea Time of concentration = 7.64 mm. Rainfall intensity = 5.211(ln/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method ,Q=KCIA, C = 0.600 Subarea runoff = 0.188(CFS) for 0.060(Ac.) Total runoff = 1.854(CFS) Total area = 0.56(Ac.) Process from Point/Station 228.000 to Point/Station 229.000 **** PIPEFLOW TRAVEL TIME (User specified size) **** upstream point/station elevation = 81.60(Ft.) Downstream point/station elevation = 80.40(Ft.) Pipe length = 68.70(Ft.) Manning's N = 0.011 N9. of pipes = 1 Required pipe flow = 1.854(CFS) Given pipe size = 12.00(ln.) Calculated individual pipe flow = 1.854(CFS) Normal flow depth in pipe = 4. 77 (in.) Flow top width inside pipe = 11.74(in.) Critical Depth = 6.97(ln.) Pipe flow velocity = 6.37(Ft/s) Travel time through pipe = 0.18 min. Time of concentration (TC) = 7.82 min. Process from Point/Station 229.000 to Point/Station 229.000 **** SUBAREA FLOW ADDITION **** User specified 'C1 value of 0.600 given for subareaTime of concentration = 7.82 mm. Page 18 pa212.0UT Rainfall intensity = 5.133(ln/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method, Q=KCIA, C = 0.600 subarea runoff = 0.585(CFS) for 0.190(Ac.) Total runoff = 2.439(CFS) Total area = 0.75 (Ac.) Process from Point/Station 229.000 to Point/Station 230.000 **** PIPEFLOW TRAVEL TIME (User specified size)**** Upstream point/station elevation = 80.40(Ft.) Downstream point/station elevation = 79.80(Ft.) Pipe length = 65.80(Ft.) Manning's N = 0.011 N9- of pipes = 1 Required pipe flow = 2.439(CFS) Given pipe size = 12.00(In.) Calculated individual pipe flow = 2.439(CFS) Normal flow depth in pipe = 6. 74 (in.) Flow top width inside pipe = 11.91(in.) Critical Depth = 8. 03 (In.) Pipe flow velocity = 5.36(Ft/s) Travel time through pipe = 0.20 mi n. Time of concentration (TC) = 8.03 mi n. Process from Point/Station 230.000 to Point/Station 230.000 **** SUBAREA FLOW ADDITION **** User specified 'C' value of 0.600 given for subarea Time of C9ncent ration = 8.03 mi n. Rainfall intensity = 5.049(ln/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method, Q=KCIA, C = 0.600 Subarea runoff = 0.182(CFS) for 0.060(Ac.) Total runoff = 2.621(CFS) Total area = 0.81(Ac.) Process from Point/Station 230.000 to Point/Station 231.000 **** PIPEFLOW TRAVEL TIME (user specified size) **** Upstream point/station elevation = 79.70(Ft.) Downstream point/station elevation = 78.90(Ft.) Pipe length = 62.90(Ft.) Manning's N = 0.011 N9- of pipes = 1 Required pipe flow = 2.621(CFS) Given pipe size = 12.00(In.) Calculated individual pipe flow = 2.621(CFS) Normal flow depth in pipe = 6.36(ln.) Flow top width inside pipe = 11. 98 (in.) Critical Depth = 8.33(in.) Pipe flow velocity = 6.19(Ft/s) Travel time through pipe = 0.17 mi n. Time of concentration (TC) = 8.19 mi n. Process from Point/Station 231.000 to Point/Station 231.000 **** SUBAREA FLOW ADDITION **** User specified 'C1 value of 0.600 given for subarea Time of concentration = 8.19 mm. Rainfall intensity = 4.981(ln/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method , Q=KCIA , C = 0.600 Subarea runoff = 0.299(CFS) for 0.100 (Ac.) Page 19 pa212.0UT Total runoff = 2.920(CFS) Total area = 0.91(Ac.) Process from Point/Station 231.000 to Point/Station 232.000 **** PIPEFLOW TRAVEL TIME (User specified size) **** Upstream point/station elevation =69.10(Ft.) Downstream point/station elevation = 68.70(Ft.) Pipe length = 16.20(Ft.) Manning's N = 0.011 No. of pipes = 1 Required pipe flow = 2.920(CFS) Given pipe size = 12.00(ln.) Calculated individual pipe flow = 2.920(CFS) Normal flow depth in pipe = 5.58(in.) Flow top width inside pipe = 11.97(in.) critical Depth = 8.78(In.) Pipe flow velocity = 8.16(Ft/s) Travel time through pipe = 0.03 min. Time of concentration (TC) = 8.23 min. Process from Point/Station 232.000 to Point/Station 232.000 **** SUBAREA FLOW ADDITION **** User specified 'C' value of 0.600 given for subarea Time of concentration = 8.23 mi n. Rainfall intensity = 4.968(In/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method, Q=KCIA, C = 0.600 Subarea runoff = 0.268(CFS) for 0.090(Ac.) Total runoff = 3.188(CFS) Total area = 1.00(Ac.) Process from Point/Station 232.000 to Point/Station 233.000 **** PIPEFLOW TRAVEL TIME (User specified size) **** upstream point/station elevation = 68.70(Ft.) Downstream point/station elevation = 67.80(Ft.) Pipe length = 40.60(Ft.) Manning's N = 0.011 Np. of pipes = 1 Required pipe flow = 3.188(CFS) Given pipe size = 12. 00 (In.) Calculated individual pipe flow = 3.188(CFS) Normal flow depth in pipe = 6.06(ln.) Flow top width inside pipe = 12.00(ln.) Critical Depth = 9. 18 (In.) Pipe flow velocity = 8.01(Ft/s) Travel time through pipe = 0.08 mi n. Time of concentration (TC) = 8.31 mi n. Process from Point/Station 233.000 to Point/Station 233.000 **** SUBAREA FLOW ADDITION **** User specified 'C1 value of 0.600 given for subarea Time of concentration = 8.31 mm. Rainfall intensity = 4.936(ln/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method, Q=KCIA, C = 0.600 Subarea runoff = O.llS(CFS) for 0.040(Ac.) Total runoff = 3.307(CFS) Total area = 1.04 (Ac.) Page 20 pa212.0UT Process from Point/Station 233.000 to Point/Station 222.000 **** PIPEFLOW TRAVEL TIME (user specified size) **** upstream point/station elevation =67.80(Ft.) Downstream point/station elevation = 60.27(Ft.) Pipe length = 65.60(Ft.) Manning's N = 0.011 No. of pipes = 1 Required pipe flow = 3.307(CFS) Given pipe size = 12.00(ln.) Calculated individual pipe flow = 3.307(CFS) Normal flow depth in pipe = 3.93(in.) Flow top width inside pipe = 11.26(ln.) Critical Depth = 9.34(ln.) Pipe flow velocity = 14.79(Ft/s) Travel time through pipe = 0.07 min. Time of concentration (TC) = 8.39 min. Process from Point/Station 233.000 to Point/Station 222.000 **** CONFLUENCE OF MINOR STREAMS **** Along Main Stream number: 2 in normal stream number 2 Stream flow area = 1.040(Ac.) Runoff from this stream = 3.307(CFS) Time of concentration = 8.39 mi n. Rainfall intensity = 4.907(in/Hr) Process from Point/Station 270.000 to Point/Station 271.000 **** INITIAL AREA EVALUATION **** user specified 'C1 value of 0.600 given for subarea initial subarea flow distance = 50.00(Ft.)Highest elevation = 74. 40 (Ft.) Lowest elevation = 73.90(Ft.) Elevation difference = 0.50(Ft.) Time of concentration calculated by the urban areas overland flow method (App X-C) = 6.36 mi n. TC = [1.8*(l.l-C)*distanceA.5)/(% slopeA(l/3)]TC = [1. 8* (1.1-0. 6000) *( 50.00A.5)/( 1.0QA(l/3)]= 6.36 Rainfall intensity (I) = 5.863 for a 100.0 year stormEffective runoff coefficient used for area (Q=KCIA) is C = 0.600 Subarea runoff = 0.106(CFS) Total initial stream area = 0.030(Ac.) Process from Point/Station 271.000 to Point/Station 272.000 **** PIPEFLOW TRAVEL TIME (user specified size) **** Upstream point/station elevation = 71.90(Ft.) Downstream point/station elevation = 71.70(Ft.) Pipe length = 4.50(Ft.) Manning's N = 0.011 No. of pipes = 1 Required pipe flow = 0.106(CFS) Given pipe size = 6.00(ln.) Calculated individual pipe flow = 0.106(CFS) Normal flow depth in pipe = 1.12 (in.) Flow top width inside pipe = 4. 67 (in.) Critical Depth = 1.93 (in.) Pipe flow velocity = 4.20(Ft/s) Travel time through pipe = 0.02 min. Page 21 pa212.0UT Time of concentration (TC) = 6.38 min. Process from Point/Station 272.000 to Point/Station 272.000 **** SUBAREA FLOW ADDITION **** user specified 'c' value of 0.600 given for subarea Time of concentration = 6.38 mm. Rainfall intensity = 5.853(in/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method, Q=KCIA, C = 0.600 Subarea runoff = O.IOS(CFS) for 0.030(Ac.) Total runoff = O.Zll(CFS) Total area = 0.06(Ac.) Process from Point/Station 272.000 to Point/Station 273.000 **** PIPEFLOW TRAVEL TIME (user specified size) **** Upstream point/station elevation = 71.70(Ft.) Downstream point/station elevation = 70.40(Ft.) Pipe length = 73.40(Ft.) Manning's N = 0.011 N9- of pipes = 1 Required pipe flow = 0.211(CFS) Given pipe size = 6.00(in.) Calculated individual pipe flow = 0.211(CFS) Normal flow depth in pipe = 2. 00 (in.) Flow top width inside pipe = 5. 65 (In.) Critical Depth = 2. 76 (In.) Pipe flow velocity = 3.69(Ft/s) Travel time through pipe = 0.33 tnin. Time of concentration (TC) = 6.71 mi n. Process from Point/Station 273.000 to Point/Station 273.000 **** SUBAREA FLOW ADDITION **** User specified 'C' value of 0.600 given for subarea Time of concentration = 6.71 mm. Rainfall intensity = 5.665(ln/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method , Q=KCIA , C = 0.600 Subarea runoff = 0.340(CFS) for 0.100(Ac.) Total runoff = 0.551(CFS) Total area = 0.16(Ac.) Process from Point/Station 273.000 to Point/Station 274.000 **** PIPEFLOW TRAVEL TIME (user specified size) **** Upstream point/station elevation = 70.30(Ft.) Downstream point/station elevation = 70.00(Ft.) Pipe length = 61.60(Ft.) Manning's N = 0.011 No. of pipes = 1 Required pipe flow = 0.551(CFS) Given pipe size = 8.00(In.) Calculated individual pipe flow = 0.551(CFS) Normal flow depth in pipe = 4.24(in.) Flow top width inside pipe = 7. 99 (in.) Critical Depth = 4. 18 (in.) Pipe flow velocity = 2.93(Ft/s) Travel time through pipe = 0.35 min. Time of concentration (TC) = 7.06 min. Page 22 pa212.OUT++++++++++ Process from Point/Station 274.000 to Point/Station 274.000 **** SUBAREA FLOW ADDITION **** User specified 'C1 value of 0.600 given for subarea Time of concentration = 7.06 mm. Rainfall intensity = 5.481(in/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method,Q=KCIA, c = 0.600 Subarea runoff = 0.099(CFS) for 0.030(Ac.) Total runoff = 0.649(CFS) Total area = 0.19(Ac.) Process from Point/station 274.000 to Point/Station 275.000**** PIPEFLOW TRAVEL TIME (user specified size) **** Upstream point/station elevation = 70.00(Ft.)Downstream point/station elevation = 69.90(Ft.)Pipe length = 4.50(Ft.) Manning's N = 0.011No. of pipes = 1 Required pipe flow = 0.649(CFS)Given pipe size = 8.00(ln.)Calculated individual pipe flow = 0.649(CFS)Normal flow depth in pipe = 3. 03 (In.)Flow top width inside pipe = 7.76(ln.)Critical Depth = 4.56(ln.) Pipe flow velocity = 5.35(Ft/s)Travel time through pipe = 0.01 min.Time of concentration (TC) = 7.08 min. Process from Point/Station 275.000 to Point/Station 275.000 **** SUBAREA FLOW ADDITION **** user specified 'C' value of 0.600 given for subareaTime of concentration = 7.08 mm.Rainfall intensity = 5.474(ln/Hr) for a 100.0 year stormRunoff coefficient used for sub-area, Rational method, Q=KCIA, c = 0.600Subarea runoff = 0.099(CFS) for 0.030(Ac.)Total runoff = 0.748(CFS) Total area = 0.22 (Ac.) Process from Point/Station 275.000 to Point/Station 276.000 **** PIPEFLOW TRAVEL TIME (user specified size) **** Upstream point/station elevation = 69.90(Ft.) Downstream point/station elevation = 69.40(Ft.) Pipe length = 64.00(Ft.) Manning's N = 0.011 No. of pipes = 1 Required pipe flow = 0.748(CFS) Given pipe size = 8.00(ln.)Calculated individual pipe flow = 0.748(CFS)Normal flow depth in pipe = 4. 43 (in.)Flow top width inside pipe = 7. 95 (In.)Critical Depth = 4.91(in.)Pipe flow velocity = 3.77(Ft/s)Travel time through pipe = 0.28 min.Time of concentration (TC) = 7.36 min. Process from Point/Station 276.000 to Point/Station 276.000 **** SUBAREA FLOW ADDITION **** Page 23 pa212=OUT User specified 'C1 value of 0.600 given for subarea Time of concentration = 7.36 min. Rainfall intensity = 5.338(ln/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method,Q=KCIA, c = 0.600 Subarea runoff = 0.032(CFS) for 0.010(Ac.) Total runoff = 0.780(CFS) Total area = 0.23(Ac.) ++++++++++++++++++4-+++++++++++++++++++++++++H-+++++++++++++++++++++ Process from Point/Station 276.000 to Point/Station 277.000 **** PIPEFLOW TRAVEL TIME (User specified size) **** upstream point/station elevation = 69.40(Ft.) Downstream point/station elevation = 68.10(Ft.) Pipe length = 41.10(Ft.) Manning's N = 0.011 No. of pipes = 1 Required pipe flow = 0.780(CFS) Given pipe size = 8.00(ln.) Calculated individual pipe flow = 0.780(CFS) Normal flow depth in pipe = 3.04(In.) Flow top width inside pipe = 7.77(in.) Critical Depth = 5.01(in.) Pipe flow velocity = 6.40(Ft/s) Travel time through pipe = 0.11 min. Time of concentration (TC) = 7.47 min. Process from Point/Station 277.000 to Point/Station 277.000 **** SUBAREA FLOW ADDITION **** User specified 'c1 value of 0.600 given for subarea Time of concentration = 7.47 mi n. Rainfall intensity = 5.288(In/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method, Q=KCIA, c = 0.600 Subarea runoff = 0.127(CFS) for 0.040(Ac.) Total runoff = 0.907(CFS) Total area = 0.27 (Ac.) Process from Point/Station 277.000 to Point/Station 222.000 **** PIPEFLOW TRAVEL TIME (user specified size) **** Upstream point/station elevation = 68. 10 (Ft.) Downstream point/station elevation = 60. 48 (Ft.) Pipe length = 85.20(Ft.) Manning's N = 0.011 N9- of pipes = 1 Required pipe flow = 0.907(CFS) Given pipe size = 8.00(ln.) Calculated individual pipe flow = 0.907(CFS) Normal flow depth in pipe = 2.50(in.) Flow top width inside pipe = 7. 42 (In.) Critical Depth = 5. 42 (in.) Pipe flow velocity = 9.72(Ft/s) Travel time through pipe = 0.15 mi n. Time of concentration (TC) = 7.61 mi n. Process from Point/Station 277.000 to Point/Station 222.000 **** CONFLUENCE OF MINOR STREAMS **** Along Main stream number: 2 in normal stream number 3 Stream flow area = 0.270(Ac.) Page 24 Runoff from this stream = Time of concentration = Rainfall intensity = 5 Summary of stream data: pa212.ouT 0.907(CFS) 7.61 min. .223(ln/Hr) Stream NO. 1 2 3 Qmax(l) Qmax(2) Qmax(3) Flow rate (CFS) 5.397 3.307 0 . 907= 1.000 * 1.000 * 1.000 * = 0.920 * 1.000 * 0.940 *= 0.979 * 1.000 * 1.000 * TC (min) 7.36 8.39 7.61 Rainfall intensity (in/Hr) 5.337 4.907 5.223 1.000 0.878 0.967 1. 1.1. 000 000 000 1.000 * 0.908 * 1.000 * 5.397) + 3.307) +0.907) + 5.397) +3.307) +0.907) + 5.397) + 3.307) + 0.907) + 9.177 9.121 9.191 Total of 3 streams to confluence: Flow rates before confluence point: 5.397 3.307 0.907 Maximum flow rates at confluence using above data: 9.177 9.121 9.191 Area of streams before confluence: 1.550 1.040 0.270 Results of confluence: Total flow rate = 9.191(CFS) Time of concentration = 7.615 min. Effective stream area after confluence = 2.860(Ac.) Process from Point/Station 222.000 to Point/Station 7003.000 **** PIPEFLOW TRAVEL TIME (user specified size) **** Upstream point/station elevation =60.04(Ft.) Downstream point/station elevation = 59.80(Ft.) Pipe length = 20.41(Ft.) Manning's N = 0.011 NO. of pipes = 1 Required pipe flow = 9.191(CFS) Given pipe size = 18.00(in.) Calculated individual pipe flow = 9.191(CFS) Normal flow depth in pipe = 10.91(ln.) Flow top width inside pipe = 17.59(in.) critical Depth = 14.08(in.) Pipe flow velocity = 8.20(Ft/s) Travel time through pipe = 0.04 min. Time of concentration (TC) = 7.66 min. Process from Point/Station 222.000 to Point/Station 7003.000 **** CONFLUENCE OF MAIN STREAMS **** The f9llowing data inside Main stream is listed: in Main Stream number: 2 Stream flow area = 2.860(Ac.) Page 25 pa212.0UT Runoff from this stream = 9.191(CFS) Time of concentration = 7.66 mi n. Rainfall intensity = 5.204(in/Hr) Program is now starting with Main Stream No. 3 Process from Point/Station 235.000 to Point/Station 236.000 **•** INITIAL AREA EVALUATION **** user specified 'C1 value of 0.600 given for subarea Initial subarea flow distance = 18. 00 (Ft.) Highest elevation = 79.80(Ft.) Lowest elevation = 79. 35 (Ft.) Elevation difference = 0.45 (Ft.) Time of concentration calculated by the urban areas overland flow method (App x-C) = 2.81 mi n. TC = [1.8*(l.l-C)*distanceA.5)/(% slopeA(l/3)]TC = [1. 8* (1.1-0. 6000) *( 18.00A.5)/( 2. 50A(l/3)]= 2.81 Setting time of concentration to 5 minutes Rainfall intensity (I) = 6.850 for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.600 Subarea runoff = 0.041(CFS) Total initial stream area = 0.010(Ac.) Process from Point/Station 236.000 to Point/Station 237.000 **** IMPROVED CHANNEL TRAVEL TIME **** Upstream point elevation = 79. 3 5 (Ft.) Downstream point elevation = 78.84(Ft.) Channel length thru subarea = 80.00(Ft.) Channel base width = 0.000(Ft.) Slope or 'Z1 of left channel bank = 50.000 Slope or 'Z1 of right channel bank = 50.000 Estimated mean flow rate at midpoint of channel = 0.288(CFS) Manning's 'N1 = 0.015 Maximum depth of channel = 0.500(Ft.) Flow(q) thru subarea = 0.288(CFS) Depth of flow = 0.079(Ft.), Average velocity = 0.918(Ft/s) Channel flow top width = 7. 915 (Ft.) Flow velocity = 0.92(Ft/s) Travel time = 1.45 mi n. Time of concentration = 6.45 mi n. Critical depth - 0.073 (Ft.) Adding area flow to channel User specified 'c1 value of 0.600 given for subarea Rainfall intensity = 5.812(ln/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method, Q=KCIA, c = 0.600 Subarea runoff = 0.418(CFS) for 0.120(Ac.) Total runoff = 0.460(CFS) Total area = 0.13 (Ac.) Process from Point/Station 237.000 to Point/Station 238.000 **** STREET FLOW TRAVEL TIME + SUBAREA FLOW ADDITION **** Top of street segment elevation = 78.340(Ft.) End of street segment elevation = 75.680(Ft.) Length of street segment = 245.000(Ft.) Height of curb above gutter flowline = 6.0(in.) Width of half street (curb to crown) = 17.000(Ft.) Page 26 pa212.0UT Distance from crown to crossfall grade break = 15.500(Ft.) Slope from gutter to grade break (v/hz) = 0.020 Slope from grade break to crown (v/hz) = 0.020 Street flow is on [1] side(s) of the street Distance from curb to property line = 11.000(Ft.) Slope from curb to property line (v/hz) = 0.020 Gutter width = 1.500(Ft.) Gutter hike from flowline = 1.500(In.) Manning's N in gutter = 0.0150 Manning's N from gutter to grade break = 0.0150 Manning's N from grade break to crown = 0.0150 Estimated mean flow rate at midpoint of street = 1.078(CFS) Depth of flow = 0.236(Ft.), Average velocity = 1.886(Ft/s) Streetflow hydraulics at midpoint of street travel: Half street flow width = 7. 073 (Ft.) Flow velocity = 1.89(Ft/s) Travel time = 2.16 mi n. TC = 8.62 min. Adding area flow to street User specified 'C' value of 0.600 given for subarea Rainfall intensity = 4.822(ln/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method, Q=KCIA, C = 0.600 subarea runoff = 1.013(CFS) for 0.350(Ac.) Total runoff = 1.472(CFS) Total area = 0.48 (Ac.) Street flow at end of street = 1.472(CFS) Half street flow at end of street = 1.472(CFS) Depth of flow = 0.257(Ft.), Average velocity = 2.026(Ft/s) Flow width (from curb towards crown)= 8.096(Ft.) Process from Point/Station 238.000 to Point/Station 239.000 **** STREET FLOW TRAVEL TIME + SUBAREA FLOW ADDITION **** Top of street segment elevation = 75.680(Ft.) End of street segment elevation = 74.340(Ft.) Length of street segment = 138.000(Ft.) Height of curb above gutter flowline = 6.0(ln.)Width of half street (curb to crown) = 17.000(Ft.)Distance from crown to crossfall grade break = 15.500(Ft.)Slope from gutter to grade break Qv/hz) = 0.020 Slope from grade break to crown (v/hz) = 0.020street flow is on [1] side(s) of the streetDistance from curb to property line = 11.000(Ft.) Slope from curb to property line (v/hz) = 0.020 Gutter width = 1.500(Ft.) Gutter hike from flowline = 1.500(ln.) Manning's N in gutter = 0.0150 Manning's N from gutter to grade break = 0.0150 Manning's N from grade break to crown = 0.0150 Estimated mean flow rate at midpoint of street = 1.825(CFS) Depth of flow = 0.276(Ft.), Average velocity = 2.041(Ft/s) Streetflow hydraulics at midpoint of street travel: Half street flow width = 9. 072 (Ft.) Flow velocity = 2.04(Ft/s) Travel time = 1.13 min. TC = 9.74 min. Adding area flow to street User specified 'C' value of 0.600 given for subarea Rainfall intensity = 4.455(ln/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method, Q=KCIA, C = 0.600 Subarea runoff = 0.615(CFS) for 0.230(Ac.) Total runoff = 2.087(CFS) Total area = 0.71(Ac.) Street flow at end of street = 2.087(CFS) Half street flow at end of street = 2.087(CFS) Page 27 pa212.OUT Depth of flow = 0.287(Ft.), Average velocity = 2.107(Ft/s) Flow width (from curb towards crown)= 9.589(Ft.) Process from Point/Station 239.000 to Point/Station 240.000 **** STREET FLOW TRAVEL TIME + SUBAREA FLOW ADDITION **** Top of street segment elevation =74.340(Ft.) End of street segment elevation = 72.840(Ft.) Length of street segment = 139.000(Ft.) Height of curb above gutter flowline = 6.0(ln.) Width of half street (curb to crown) = 17.000(Ft.) Distance from crown to crossfall grade break = 15.500(Ft.) Slope from gutter to grade break (v/hz) = 0.020 Slope from grade break to crown (v/hz) = 0.020 Street flow is on [1] side(s) of the street Distance from curb to property line = 11.000(Ft.) Slope from curb to property line (v/hz) = 0.020 Gutter width = 1.500(Ft.) Gutter hike from flowline = 1.500(ln.) Manning's N in gutter = 0.0150 Manning's N from gutter to grade break = 0.0150 Manning's N from grade break to crown = 0.0150 Estimated mean flow rate at midpoint of street = 2.425(CFS) Depth of flow = 0.295(Ft.), Average velocity = 2.273(Ft/s) Streetflow hydraulics at midpoint of street travel: Halfstreet flow width = 9.979(Ft.) Flow velocity = 2.27(Ft/s) Travel time = 1.02 min. TC = 10.76 min. Adding area flow to street User specified 'C1 value of 0.600 given for subarea Rainfall intensity = 4.178(in/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method,Q=KCIA, c = 0.600 Subarea runoff = 0.577(CFS) for 0.230(Ac.) Total runoff = 2.664(CFS) Total area = 0.94(Ac.) Street flow at end of street = 2.664(CFS) Half street flow at end of street = 2.664(CFS) Depth of flow = 0.302(Ft.), Average velocity = 2.324(Ft/s) Flow width (from curb towards crownj= 10.367(Ft.) Process from Point/Station 240.000 to Point/Station 7010.000 **** STREET FLOW TRAVEL TIME + SUBAREA FLOW ADDITION **** Top of street segment elevation = 72.840(Ft.) End of street segment elevation = 70.130(Ft.) Length of street segment = 214.000(Ft.) Height of curb above gutter flowline = 6.0(in.) Width of half street (curb to crown) = 17.000(Ft.) Distance from crown to crossfall grade break = 15.500(Ft.) slope from gutter to grade break (v/hz) = 0.020 Slope from grade breaK to crown (v/hz) = 0.020 Street flow is on [1] side(s) of the street Distance from curb to property line = 11.000(Ft.) Slope from curb to property line (v/hz) = 0.020 Gutter width = 1.500(Ft.) Gutter hike from flowline = 1.500(ln.) Manning's N in gutter = 0.0150 Manning's N from gutter to grade break = 0.0150 Manning's N from grade break to crown = 0.0150 Estimated mean flow rate at midpoint of street = 3.103(CFS) Page 28 pa212.0UT Depth of flow = 0.309(Ft.), Average velocity = 2.S62(Ft/s) Streetflow hydraulics at midpoint of street travel: Half street flow width = 10.676(Ft.) Flow velocity = 2.56(Ft/s) Travel time = 1.39 min. TC = 12.15 min. Adding area flow to street User specified 'C' value of 0.600 given for subarea Rainfall intensity = 3.863(ln/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method, Q=KCIA, C = 0.600 subarea runoff = 0.718(CFS) for 0.310(Ac.) Total runoff = 3.382(CFS) Total area = 1.2 5 (Ac.) Street flow at end of street = 3.382(CFS) Half street flow at end of street = 3.382(CFS) Depth of flow = 0.316(Ft.), Average velocity = 2.616(Ft/s) Flow width (from curb towards crown)= 11.053(Ft.) Process from Point/Station 7010.000 to Point/Station 7010.000 **** SUBAREA FLOW ADDITION **** User specified 'C1 value of 0.600 given for subarea Time of concentration = 12.15 mm. Rainfall intensity = 3.863(ln/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method, Q=KCIA, C = 0.600 Subarea runoff = 0.070(CFS) for 0.030(Ac.) Total runoff = 3.452(CFS) Total area = 1.28 (Ac.) Process from Point/Station 7010.000 to Point/Station 7003.000 **** PIPEFLOW TRAVEL TIME (User specified size) **** Upstream point/station elevation = 61.88(Ft.) Downstream point/station elevation = 60.30(Ft.) Pipe length = 25.35(Ft.) Manning's N = 0.011 No. of pipes = 1 Required pipe flow = 3.452(CFS) Given pipe size = 12.00(in.) Calculated individual pipe flow = 3.452(CFS) Normal flow depth in pipe = 4.73(in.) Flow top width inside pipe = 11.73(In.) critical Depth = 9.53(in.) Pipe flow velocity = 11.99(Ft/s)Travel time through pipe = 0.04 min. Time of concentration (TC) = 12.19 min. Process from Point/Station 7010.000 to Point/Station 7003.000 **** CONFLUENCE OF MAIN STREAMS **** The following data inside Main Stream is listed: In Main Stream number: 3 Stream flow area = 1.280(AC.) Runoff from this stream = 3.452(CFS) Time of concentration = 12.19 min. Rainfall intensity = 3.855(ln/Hr) Summary of stream data: Stream Flow rate TC Rainfall intensity NO. (CFS) (min) (In/Hr) Page 29 pa212.OUT 1 5.989 11.74 3.950 2 9.191 7.66 5.2043 3.452 12.19 3.855Qmax(l) =1.000 * 1.000 * 5.989) +0.759 * 1.000 * 9.191) + 1.000 * 0.963 * 3.452) + = 16.289 Qmax(2) = 1.000 * 0.652 * 5.989) + 1.000 * 1.000 * 9.191) + 1.000 * 0.628 * 3.452) + = 15.265 Qmax(3) = 0.976 * 1.000 * 5.989) + 0.741 * 1.000 * 9.191) + 1.000 * 1.000 * 3.452) + = 16.106 Total of 3 main streams to confluence: Flow rates before confluence point: 5.989 9.191 3.452 Maximum flow rates at confluence using above data: 16.289 15.265 16.106Area of streams before confluence: 2.180 2.860 1.280 Results of confluence: Total flow rate = 16.289(CFS) Time of concentration = 11.739 min. Effective stream area after confluence = 6.320(Ac.) End of computations, total study area = 6.32 (Ac.) Page 30 San Diego County Rational Hydrology Program CIVILCADD/CIVILDESIGN Engineering Software, (c) 2004 Version 3.2 Rational method hydrology program based on San Diego County Flood Control Division 2003 hydrology manual Rational Hydrology Study Date: 11/13/07 ROBERTSON RANCH PA 21 T - BASIN 3 PROPOSED CONDITIONS G:\ACCTS\011014\PA213.0UT ********* Hydrology Study Control Information ********** O'Day Consultants, San Diego, California - S/N 10125 Rational hydrology study storm event year is 100.0 Map data precipitation entered: 6 hour, precipitation(inches) = 2.600 24 hour precipitation(inches) = 4.300 Adjusted 6 hour precipitation (inches) = 2.600 P6/P24 = 60.5% San Diego hydrology manual 'C' values used Runoff coefficients by rational method Process from Point/Station 301.000 to Point/Station 302.000 **** INITIAL AREA EVALUATION **** User specified 'C1 value of 0.600 given for subarea Initial subarea flow distance = 20.00(Ft.) Highest elevation = 89.20(Ft.) Lowest elevation = 88.85(Ft.) Elevation difference = 0.35(Ft.) Time of concentration calculated by the urban areas overland flow method (App X-C) = 3.34 min. TC = [1.8*(l.l-C)*distanceA.5)/(% slopeA(l/3)] TC = [1.8*(1.1-0.6000)*( 20.00A.5)/( 1.75A(l/3)]= 3.34 Setting time of concentration to 5 minutes Rainfall intensity (I) = 6.850 for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.600 Subarea runoff = 0.041(CFS) Total initial stream area = 0.010(Ac.) Process from Point/Station 302.000 to Point/Station 303.000 **** IMPROVED CHANNEL TRAVEL TIME **** Upstream point elevation = 88.85(Ft.) Downstream point elevation = 87.88(Ft.) Channel length thru subarea = 115.00(Ft.) Channel base width = 0.000(Ft.) Slope or 'Z1 of left channel bank = 50.000 Slope or 'Z' of right channel bank = 50.000 Estimated mean flow rate at midpoint of channel = 0.288(CFS) Manning's 'N1 = 0.015 Maximum depth of channel = 0.500(Ft.) Flow(q) thru subarea = 0.288(CFS) Depth of flow = 0.075(Ft.), Average velocity.= 1.020(Ft/s) Channel flow top width = 7.511(Ft.) Flow Velocity = 1.02(Ft/s) Travel time = 1.88 min. Time of concentration = 6.88 min. Critical depth = 0.073(Ft.) Adding area flow to channel User specified 'C' value of 0.600 given for subarea Rainfall intensity = 5.576(In/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method,Q=KCIA, C = 0.600 Subarea runoff = 0.401(CFS) for 0.120(Ac.) Total runoff = 0.443(CFS) Total area = 0.13(Ac.) Process from Point/Station 303.000 to Point/Station 303.000 **** SUBAREA FLOW ADDITION **** User specified 'C1 value of 0.600 given for subarea Time of concentration = 6.88 min. Rainfall intensity = 5.576(In/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method,Q=KCIA, C = 0.600 Subarea runoff = 0.033(CFS) for 0.010 (Ac.) Total runoff = 0.476(CFS) Total area = 0.14(Ac.) Process from Point/Station 303.000 to Point/Station 304.000 **** STREET FLOW TRAVEL TIME + SUBAREA FLOW ADDITION **** Top of street segment elevation = 87.380(Ft.) End of street segment elevation = 86.360(Ft.) Length of street segment = 72.000(Ft.) Height of curb above gutter flowline = 6.0(In.) Width of half street (curb to crown) = 17.000(Ft.) Distance from crown to crossfall grade break = 15.500(Ft.) Slope from gutter to grade break (v/hz) = 0.020 Slope from grade break to crown (v/hz) = , 0.020 Street flow is on [1] side(s) of the street Distance from curb to property line = 11.000(Ft.) Slope from curb to property line (v/hz) = 0.020 Gutter width = 1.500(Ft.) Gutter hike from flowline = 1.500(In.) Manning's N in gutter = 0.0150 Manning's N from gutter to grade break = 0.0150 Manning's N from grade break to crown = 0.0150 Estimated mean flow rate at midpoint of street = 0.612(CFS) Depth of flow = 0.197(Ft.), Average velocity = 1.855(Ft/s) Streetflow hydraulics at midpoint of street travel: Halfstreet flow width = 5.087(Ft.) Flow velocity = 1.85(Ft/s) Travel time = 0.65 min. TC = 7.53 min. Adding area flow to street User specified CC' value of 0.700 given for subarea Rainfall intensity = 5.262(In/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method,Q=KCIA, C = 0.700 Subarea runoff = 0.295{CFS) for 0.080(Ac.) Total runoff = 0.771(CFS) Total area = 0.22(Ac.) Street flow at end of street = 0.771(CFS) Half street flow at end of street = 0.771(CFS) Depth of flow = 0.209 (Ft.), Average velocity = 1.945(Ft/s) Flow width (from curb towards crown)= 5.701(Ft.) Process from Point/Station 304.000 to Point/Station 305.000 **** STREET FLOW TRAVEL TIME + SUBAREA FLOW ADDITION **** Top of street segment elevation = 86.360(Ft.) End of street segment elevation = 85.270(Ft.) Length of street segment = 140.000(Ft.) Height of curb above gutter flowline = 6.0(In.) Width of half street (curb to crown) = 17.000(Ft.) Distance from crown to crossfall grade break = 15.500(Ft.) Slope from gutter to grade break (v/hz) = 0.020 Slope from grade break to crown (v/hz) = 0.020 Street flow is on [1] side(s) of the street Distance from curb to property line = 11.000(Ft.) Slope from curb to property line (v/hz) = 0.020 Gutter width = 1.500(Ft.) Gutter hike from flowline = 1.500(In.) Manning's N in gutter = 0.0150 Manning's N from gutter to grade break = 0.0150 Manning's N from grade break to crown = 0.0150 Estimated mean flow rate at midpoint of street = 0.998(CFS) Depth of flow = 0.242(Ft.), Average velocity = 1.630(Ft/s) Streetflow hydraulics at midpoint of street travel: Halfstreet flow width = 7.357(Ft.) Flow velocity = 1.63(Ft/s) Travel time = 1.43 min. TC = 8.96 min. Adding area flow to street User specified 'C1 value of 0.700 given for subarea Rainfall intensity = 4.703(In/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method,Q=KCIA, C = 0.700 Subarea runoff = 0.428(CFS) for 0.130(Ac.) Total runoff = 1.199(CFS) Total area = 0.35(Ac.) Street flow at end of street = 1.199(CFS) Half street flow at end of street = 1.199(CFS) Depth of flow = 0.254 (Ft.), Average velocity = 1.700(Ft/s) Flow width (from curb towards crown)= 7.962(Ft.) Process from Point/Station 305.000 to Point/Station 305.000 **** SUBAREA FLOW ADDITION **** User specified 'C1 value of 0.600 given for subarea Time of concentration = 8.96 min. Rainfall intensity = 4.703(In/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method,Q=KCIA, C = 0.600 Subarea runoff = 0.339(CFS) for 0.120(Ac.) Total runoff = 1.537(CFS) Total area = 0.47(Ac.) Process from Point/Station 305.000 to Point/Station 306.000 **** STREET FLOW TRAVEL TIME + SUBAREA FLOW ADDITION **** Top of street segment elevation = 85.270(Ft.) End of street segment elevation = 83.890(Ft.) Length of street segment = 138.000(Ft.) Height of curb above gutter flowline = 6.0(In.) Width of half street (curb to crown) = 17.000(Ft.) Distance from crown to crossfall grade break = 15.500(Ft.) Slope from gutter to grade break (v/hz) = 0.020 Slope from grade break to crown (v/hz) = 0.020 Street flow is on [1] side(s) of the street Distance from curb to property line = 13.000(Ft.) Slope from curb to property line (v/hz) = 0.020 Gutter width = 1.500(Ft.) Gutter hike from flowline = 1.500(In.) Manning's N in gutter = 0.0150 Manning's N from gutter to grade break = 0.0150 Manning's N from grade break to crown = 0.0150 Estimated mean flow rate at midpoint of street = 2.044(CFS) Depth of flow = 0.284(Ft.), Average velocity = 2.120(Ft/s) Streetflow hydraulics at midpoint of street travel: Halfstreet flow width = 9.450(Ft.) Flow velocity = 2.12(Ft/s) Travel time = 1.08 min. TC = 10.04 min. Adding area flow to street User specified 'C' value of 0.600 given for subarea Rainfall intensity = 4.369(In/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method,Q=KCIA, C = 0.600 Subarea runoff = 0.813(CFS) for 0.310(Ac.) Total runoff = 2.350(CFS) Total area = 0.78(Ac.) Street flow at end of street = 2.350(CFS) Half street flow at end of street = 2.350(CFS) Depth of flow = 0.295(Ft.), Average velocity = 2.191(Ft/s) Flow width (from curb towards crown)= 10.006(Ft.) Process from Point/Station 306.000 to Point/Station 307.000 **** STREET FLOW TRAVEL TIME + SUBAREA FLOW ADDITION **** Top of street segment elevation = 83.890(Ft.) End of street segment elevation = 82.500(Ft.) Length of street segment = 138.000(Ft.) Height of curb above gutter flowline = 6.0(In.) Width of half street (curb to crown) = 17.000(Ft.) Distance from crown to crossfall grade break = 15.500(Ft.) Slope from gutter to grade break (v/hz) = 0.020 Slope from grade break to crown (v/hz) = 0.020 Street flow is on [1] side(s) of the street Distance from curb to property line = 13.000(Ft.) Slope from curb to property line (v/hz) = 0.020 Gutter width = 1.500(Ft.) Gutter hike from flowline = 1.500(In.) Manning's N in gutter = 0.0150 Manning's N from gutter to grade break = 0.0150 Manning's N from grade break to crown = 0.0150 Estimated mean flow rate at midpoint of street = 2.817(CFS) Depth of flow = 0.310 (Ft.), Average velocity = 2.295(Ft/s) Streetflow hydraulics at midpoint of street travel: Halfstreet flow width = 10.753(Ft.) Flow velocity = 2.29(Ft/s) Travel time = 1.00 min. TC = 11.04 min. Adding area flow to street User specified 'C1 value of 0.600 given for subarea Rainfall intensity = 4.109(In/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method,Q=KCIA, C = 0.600 Subarea runoff = 0.764(CFS) for 0.310(Ac.) Total runoff = 3.114(CFS) Total area = 1.09(Ac.) Street flow at end of street = 3.114(CFS) Half street flow at end of street = 3.114(CFS) Depth of flow = 0.319 (Ft.), Average velocity = 2.351(Ft/s) Flow width (from curb towards crown)= 11.196(Ft.) Process from Point/Station 307.000 to Point/Station 308.000 **** STREET FLOW TRAVEL TIME + SUBAREA FLOW ADDITION **** Top of street segment elevation = 82.500(Ft.) End of street segment elevation = 81.030(Ft.) Length of street segment = 139.000(Ft.) Height of curb above gutter flowline = 6.0(In.) Width of half street (curb to crown) = 17.000(Ft.) Distance from crown to crossfall grade break = 15.500(Ft.) Slope from gutter to grade break (v/hz) = 0.020 Slope from grade break to crown (v/hz) = 0.020 Street flow is on [1] side(s) of the street Distance from curb to property line = 13.000(Ft.) Slope from curb to property line (v/hz) = 0.020 Gutter width = 1.500(Ft.) Gutter hike from flowline = 1.500(In.) Manning's N in gutter = 0.0150 Manning's N from gutter to grade break = 0.0150 Manning's N from grade break to crown = 0.0150 Estimated mean flow rate at midpoint of street = 3.557(CFS) Depth of flow = 0.329(Ft.), Average velocity = 2.473(Ft/s) Streetflow hydraulics at midpoint of street travel: Halfstreet flow width = 11.693(Ft.) Flow velocity = 2.47(Ft/s) Travel time = 0.94 min. TC = 11.98 min. Adding area flow to street User specified 'C1 value of 0.600 given for subarea Rainfall intensity = 3.899(In/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method,Q=KCIA, C = 0.600 Subarea runoff = 0.725(CFS) for 0.310(Ac.) Total runoff = 3.839(CFS) Total area = 1.40(Ac.) Street flow at end of street = 3.839(CFS) Half street flow at end of street = 3.839(CFS) Depth of flow = 0.336(Ft.), Average velocity = 2.519(Ft/s) Flow width (from curb towards crown)= 12.054(Ft.) Process from Point/Station 308.000 to Point/Station 309.000 **** STREET FLOW TRAVEL TIME + SUBAREA FLOW ADDITION **** Top of street segment elevation = 81.030(Ft.) End of street segment elevation = 75.470(Ft.) Length of street segment = 312.000(Ft.) Height of curb above gutter flowline = 6.0(In.) Width of half street (curb to crown) = 17.000(Ft.) Distance from crown to crossfall grade break = 15.500(Ft.) Slope from gutter to grade break (v/hz) = 0.020 Slope from grade break to crown (v/hz) = 0.020 Street flow is on [1] side(s) of the street Distance from curb to property line = 13.000(Ft.) Slope from curb to property line (v/hz) = 0.020 Gutter width = 1.500 (Ft.) Gutter hike from flowline = 1.500(In.) Manning's N in gutter = 0.0150 Manning's N from gutter to grade break = 0.0150 Manning's N from grade break to crown = 0.0150 Estimated mean flow rate at midpoint of street = 4.25KCFS) Depth of flow = 0.321(Ft.), Average velocity = 3.146(Ft/s) Streetflow hydraulics at midpoint of street travel: Halfstreet flow width = 11.312(Ft.) Flow velocity = 3.15(Ft/s) Travel time = 1.65 min. TC = 13.63 min. Adding area flow to street User specified 'C' value of 0.600 given for subarea Rainfall intensity = 3.587(In/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method,Q=KCIA, C = 0.600 Subarea runoff = 0.646(CFS) for 0.300(Ac.) Total runoff = 4.485(CFS) Total area = 1.70(Ac.) Street flow at end of street = 4.485(CFS) Half street flow at end of street = 4.485(CFS) Depth of flow = 0.326(Ft.), Average velocity = 3.187(Ft/s) Flow width (from curb towards crown)= 11.558(Ft.) Process from Point/Station 309.000 to Point/Station 309.000 **** SUBAREA FLOW ADDITION **** User specified 'C1 value of 0.600 given for subarea Time of concentration = 13.63 min. Rainfall intensity = 3.587(In/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method,Q=KCIA, C = 0.600 Subarea runoff = 0.108(CFS) for 0.050(Ac.) Total runoff = 4.593(CFS) Total area = 1.75(Ac.) End of computations, total study area = 1.75 (Ac.) PA21CL.OUT San Diego County Rational Hydrology Program CIVILCADD/CIVILDESIGN Engineering software, (c) 2004 Version 3.2 Rational method hydrology program based on San Diego County Flood Control Division 2003 hydrology manual Rational Hydrology Study Date: 01/16/08 ROBERTSON RANCH PA 21 - TYP CLUSTER PROPOSED CONDITIONS G:\ACCTS\011014\PA21CL.OUT ********* Hydrology Study control information ********** O'Day Consultants, San Diego, California - S/N 10125 Rational hydrology study storm event year is 100.0 Map data precipitation entered: 6 hour, precipitation(inches) = 2.600 24 hour precipitationCinches) = 4.300 Adjusted 6 hour precipitation (inches) = 2.600 P6/P24 = 60.5% San Diego hydrology manual 'c1 values used Runoff coefficients by rational method Process from Point/Station 25.100 to Point/Station 25.200 **** INITIAL AREA EVALUATION **** user specified 'C1 value of 0.600 given for subarea initial subarea flow distance = 25.00(Ft.) Highest elevation = 86.75(Ft.) Lowest elevation = 86.45(Ft.) Elevation difference = 0.30(Ft.) Time of concentration calculated by the urban areas overland flow method (App X-C) = 4.23 min. TC = [1.8*(l.l-C)*distanceA.5)/(% slopeA(i/3)] TC = [1.8*(1.1-0.6000)*( 25.00A.5)/( 1.2QA(l/3)]= 4.23 Setting time of concentration to 5 minutes Rainfall intensity (I) = 6.850 for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.600 Subarea runoff = 0.164(CFS) Total initial stream area = 0.040(Ac.) Process from Point/Station 25.200 to Point/Station 25.300 **** PIPEFLOW TRAVEL TIME (user specified size) **** Upstream point/station elevation = 84.45(Ft.) Downstream point/station elevation = 84.00(Ft.) Pipe length = 12.00(Ft.) Manning's N = 0.011 No. of pipes = 1 Required pipe flow = 0.164(CFS) Given pipe size = 6.00(ln.) ^ Calculated individual pipe flow = 0.164(CFS) Normal flow depth in pipe = 1.45(In.) Flow top width inside pipe = 5.13(in.) Page 1 PA21CL.OUT Critical Depth = 2.42(ln.) Pipe flow velocity = 4.49(Ft/s) Travel time through pipe = 0.04 mi n. Time of concentration (TC) = 5.04 mi n. Process from Point/Station 25.300 to Point/Station 25.300 **** SUBAREA FLOW ADDITION **** User specified 'C' value of 0.600 given for subarea Time of concentration = 5.04 mm. Rainfall intensity = 6.811(ln/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method, Q=KCIA, C = 0.600 Subarea runoff = 0.041(CFS) for 0.010(Ac.) Total runoff = 0.205(CFS) Total area = 0.05 (AC.) Process from Point/Station 25.300 to Point/Station 25.400**** PIPEFLOW TRAVEL TIME (User specified size) **** Upstream point/station elevation = 84.00(Ft.) Downstream point/station elevation = 83.80(Ft.) Pipe length = 10.80(Ft.) Manning's N = 0.011 N9- of pipes = 1 Required pipe flow = 0.205(CFS) Given pipe size = 6.00(ln.) Calculated individual pipe flow = 0.205(CFS) Normal flow depth in pipe = 1.95(in.) Flow top width inside pipe = 5.62(in.) Critical Depth = 2.72(in.) Pipe flow velocity = 3.73(Ft/s) Travel time through pipe = 0.05 min.Time of concentration (TC) = 5.09 min. Process from Point/Station 25.400 to Point/Station 25.400 **** SUBAREA FLOW ADDITION **** User specified 'C1 value of 0.600 given for subarea Time of concentration = 5.09 mm. Rainfall intensity = 6.769(ln/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method, Q=KCIA, C = 0.600 subarea runoff = 0.203(CFS) for 0.050(Ac.)Total runoff = 0.408(CFS) Total area = 0.10(Ac.) Process from Point/Station 25.400 to Point/Station 25.500 **** PIPEFLOW TRAVEL TIME (User specified size) **** Upstream point/station elevation = 83.70(Ft.) Downstream point/station elevation = 83.50(Ft.) Pipe length = 41.00(Ft.) Manning's N = 0.011 N9- of pipes = 1 Required pipe flow = 0.408(CFS) Given pipe size = 8. 00 (in.) Calculated individual pipe flow = 0.408(CFS) Normal flow depth in pipe = 3.56(In.) Flow top width inside pipe = 7. 95 (in.) Critical Depth = 3.57(ln.) Pipe flow velocity = 2.71(Ft/s) Travel time through pipe = 0.25 mi n. Page 2 PA21CL.OUT Time of concentration (TC) = 5.34 min, Process from Point/Station 25.500 to Point/Station 25.500 **** SUBAREA FLOW ADDITION **** User specified 'C1 value of 0.600 given for subarea Time of concentration = 5.34 mm. Rainfall intensity = 6.562(in/Hr) for a 100.0 year storm Runoff coefficient used for sub-area, Rational method,Q=KCIA, c = 0.600 Subarea runoff = 0.315(CFS) for 0.080(Ac.) Total runoff = 0.723(CFS) Total area = 0.18(Ac.) Process from Point/Station 25.500 to Point/Station 225.000 **** PIPEFLOW TRAVEL TIME (user specified size) **** Upstream point/station elevation = 83.50(Ft.) Downstream point/station elevation = 83.20(Ft.) Pipe length = 41.50(Ft.) Manning's N = 0.011 No. of pipes = 1 Required pipe flow = 0.723(CFS) Given pipe size = 8.00(ln.) Calculated individual pipe flow = 0.723(CFS) Normal flow depth in pipe = 4.45(in.) Flow top width inside pipe = 7.95(In.) Critical Depth = 4.82(in.) Pipe flow velocity = 3.63(Ft/s) Travel time through pipe = 0.19 min. Time of concentration (TC) = 5.54 mi n. End of computations, total study area = 0.18 (Ac.) Page 3 SECTION 10.0