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HomeMy WebLinkAboutCT 04-05; Vista La Costa; Vista La Costa Storm Water Management Plan; 2008-11-17STORM WATER MANAGEMENT PLAN & HYDROLOGY STUDY For Vista La Costa CT 04-05 April 28, 2008 JN 03-1060 Prepared For: Abedi Family Trust Shahla and Esrafil Abedi 22892 Ocean Breeze Way Laguna Nigel, CA 92677 Prepared By: O'DAY CONSULTANTS 2710 Loker Avenue West, Suite 100 Carlsbad, CA 92010 Meg Carroll Exp. 9/30/09 RCE 46935 Declaration of Responsible Charge I hereby declare that I am the Engineer of Work for this project, that I have exercised responsible charge over the design of this project as defined in section 6703 of the Business and Professions Code, and that the design is consistent with current standards. I understand that the check of project drawings and specifications by the City of Carlsbad is confined to a review only and does not relieve me, as the Engineer of Work, of my responsibilities for the project design. O'Day Consultants, Inc. 2710 Loker Avenue West, Suite 100 Carlsbad, CA 92010 (760)931-7700 Date: Meg R.C.E. N 935 Exp. 09/30/09 Table of Contents Section 1.0 - Introduction and Vicinity Map Section 2.0 - Project Description Section 3.0 - Site Map Section 4.0 - Pollutants and Conditions of Concern in Receiving Waters & Drainage Study Section 5.0 - LID Site Design BMPs Section 6.0 - Source Control BMPs Section 7.0 - Individual Priority Project Catagories BMPs Section 8.0 - Structural Treatment Control BMPs Section 9.0 - Maintenance Provisions Appendix A 2-year, 10-year and 100-year 6-hour Storm Rational Method Hydrologic Calculations for Existing Conditions Appendix B 2-year, 10-year and 100-year 6-hour Storm Rational Method Hydrologic Calculations for Developed Conditions Appendix C Calculations for Bioretention Swales Appendix D Detention Calculations for Underground Detention Facility Exhibits Exhibit A Exhibit B Exhibit C Exhibit D Exhibit E Exhibit F Exhibit G Exhibit H Exhibit I Exhibit J Exhibit K Exhibit M Exhibit N Exhibit O Exhibit P Exhibit Q Exhibit R Exhibit S Vicinity Map Storm Water Standards Questionnaire Site Map and Summary SWMP San Diego Region Hydrologic Boundary Map Portion of 303 (D) List for Impaired Bodies Table 2: Anticipated and Potential Pollutants Underground Detention Details and Installation Instructions Table 1: Storm Water BMP Requirements Matrix Fact Sheets: SD-12: Efficient Irrigation SD-13: Storm Drain Signage SC-43: Parking/Storage Area Maintenance SC-70: Road and Street Maintenance Fact Sheet 7: Bioretention systems WM-4: Spill Prevention and Control Table 4 Treatment Control BMP Selection Matrix Soil Group Map Runoff Coefficients for Urban Areas (Table 3-1) Intensity-Duration Design Chart Rational Formula-Overland Time of Flow Nomograph 2-year and 10-year 6-hour and 24-hour Isopluvial Maps 100-year 6-hour and 24-hour Isopluvial Maps 20-scale (Existing) Hydrologic Map 10-scale (Proposed) Hydrologic Map Section 1.0 - Introduction and Vicinity Map Federal, state and local agencies have established goals and objectives for storm water quality in the region. The municipal storm water National Pollutant Discharge Elimination System (NPDES) permit (Order No. R9-2007-0001, NPDES No. CAS0108758) issued to the County of San Diego and the City of Carlsbad by the San Diego Regional Water Quality Control Board on January 24, 2007 requires that urban runoff pollution issues be addressed for new projects. Accordingly, the County of San Diego has issued a Final Model Standard Urban Storm Water Mitigation Plan (SUSMP) dated November 6, 2007. The City of Carlsbad updated its local SUSMP in March 2008. All new development falling into "priority project" categories are subject to SUSMP requirements. Because this project is a 15-unit residential development, it is considered a priority project (See Exhibit 'B'). This Preliminary Storm Water Management Plan (SWMP) was prepared to address the water quality impacts associated with the proposed improvements shown on the Tentative Map. The plan provides guidelines for developing and implementing Best Management Practices (BMPs) for storm water quality during construction and post construction. Since the site, including the offsite grading is greater than 1 acre, a Tier 3 Storm Water Pollution Prevention Plan (SWPPP) will be required and submitted with the grading plan. See Exhibit 'A' for Vicinity Map Section 2.0 - Project Description Vista La Costa is a 15-unit residential development lying northerly of Gibraltar Street between Jerez Court and Romeria Street in the City of Carlsbad. The site is a 0.88 acre parcel. As part of the development, offsite grading is proposed bringing the total graded area to approximately 1.26 acres. Currently, the site is vacant and has been mass-graded per Grading Plans La Costa South, Unit No. 5, County of San Diego Dwg. L-5548 (Reference 1). The site drains to the south to an existing curb inlet on Gibraltar Street. A tentative map, CT 04-05, was approved by the City of Carlsbad in January 2005 and an extension to the tentative map was approved in January 2007. Also, a consistency determination CD 07-16 was approved November 19, 2007 that allowed for a change in the location of Building 2. On January 7, 2008, additional changes to the tentative map were proposed in a Substantial Conformance Exhibit, SCE 04-05. The City of Carlsbad has approved SCE 04-05 on April 4, 2008. Section 3.0 - Site Map See Exhibit 'C' for Site Map and Summary SWMP See Exhibit'S' for delineated drainage areas Section 4.0 - Pollutants and Conditions of Concern in Receiving Waters and Drainage Study According to the California 2006 303d list published by the Regional Water Quality Control Board (RWQCB), Batiquitos Lagoon is not an impaired water body associated with the direct stormwater discharge from this project (See Exhibit 'E'). Pollutants of Concern: The project will contain some pollutants commonly found on similar developments that could affect water quality. The following list is taken from Table 2 of the City of Carlsbad's Storm Water Standards Manual (Exhibit 'F'). This list is similar to the one in the County SUSMP. It includes anticipated pollutants for attached residential developments and parking lots. 1. Sediment discharge 2. Nutrients from fertilizers 3. Heavy metals 4. Trash and debris 5. Potential Oxygen demanding substances 6. Oil and grease from paved areas 7. Potential Bacteria and viruses 8. Pesticides from landscaping 9. Organic Compounds Because Batiquitos Lagoon is not an impaired water body, these pollutants are considered to be secondary pollutants of concern. The project area consists of soil group D. See soils group map, Exhibit 'K'. Drainage Study & Conditions of Concern: Existing Conditions: The project is located in the Batiquitos Hydrologic Subarea (904.51) of the San Marcos Watershed in the Carlsbad Hydrologic Unit in the San Diego Region. (See Exhibit 'D'). Currently, the site is mass-graded per Reference 1. The upper pad is at about elevation 61.0 and the lower pad is at elevation 55.5. On the northerly edge of the site, a 1.6:1 slope daylights into the La Costa Golf Course and Spa to the north. The site drains at 0.5% towards Gibraltar Street, to a curb inlet located on the southeast corner of the site. From the inlet, storm water drains to a 48" RCP pipe that runs along the easterly boundary of the site. The storm water outlets to the north, to a PCC lined drainage swale in the La Costa Golf Course and ultimately outlets to the Batiquitos Lagoon. Hydrologic calculations were performed for onsite existing conditions in order to determine the amount of storm water needed to be detained. See Exhibit 'R' for a depiction of the hydrologic nodes and subbasins for the existing site and Appendix A for hydrologic calculations. A summary of the flow rates are shown on the following page. Proposed Conditions: Fifteen (15) multi-family residential units are proposed for Vista La Costa: two main buildings, and a parking lot. A private driveway will be constructed between the two buildings that will lead into underground parking garages. Storm water from the parking lot, the landscape areas, walkways, and roof drains will be conveyed via private storm drains and vegetated swales along the perimeter of the site to two bioretention swales. The storm water will be treated by the bioretention swales prior to discharge to an underground detention system. See Appendix C for bioretention swale calculations. Private Drive 'A' drains to a trench drain located at the entrance to the underground parking garage for Building 2. The trench drain outlets to the private storm drain system and then to the underground detention system. The trench drain will include a catch basin basket by Suntree Technolgies, Inc. or equivalent, as a structural BMP. The catch basin basket will also include hydrocarbon absorption booms to collect oil and grease. See Exhibit 'L' for product information and sample data. A Filterra unit was considered here as a more efficient BMP. However, the manufacturer has indicated that this unit is infeasible due to the steep grades at Private Drive 'A'. The trench drain with elevation of 46.41 is in a sump. If the trench drain were to clog, storm water would rise 0.09' to elevation 46.5 and flow down to a catch basin and into an emergency overflow stormdrain. As stated above, stormwater will drain to an underground detention facility prior to exiting the site. The underground detention facility will limit the outflow to less than existing conditions for both the 2-year and 10-year storm events. See Appendix 'D' for detention calculations. Hydrologic calculations for these storm events are shown in Appendix A and Appendix B. See Exhibit'S' for a depiction of hydrologic nodes and sub-basins for the proposed site. See below for a summary of flowrates at the site. Summary of Flowrates at Vista La Costa Storm Event 2-year 10-year 100-year Existing Flowrates 0.53 cfs 0.78 cfs 1.16 cfs Proposed Flowrates (without detention) 1.29 cfs 1.90 cfs 2.91 cfs Proposed Flowrates (after detention) 0.53 cfs 0.72cfs 2.41 cfs Hydrologic calculations were performed utilizing the San Diego County Rational Method as described in the San Diego County Hydrology Manual, June 2003. Pertinent exhibits from the San Diego County Hydrology Manual are enclosed for reference, as follows: Exhibit K - Soil Group Map Exhibit M - Runoff Coefficients for Urban Areas (Table 3-1) Exhibit N - Intensity-Duration Design Chart Exhibit O - Rational Formula-Overland Time of Flow Nomograph Exhibit P - 2-year and 10-year 6-hour and 24-hour Isopluvial Maps Exhibit Q - 100-year 6-hour and 24-hour Isopluvial Maps 10 Section 5.0 - LID Site Design BMPS To address water quality for the project, BMPs will be implemented during construction and post construction. Required BMPs are selected from Table 1: Storm Water BMP requirements Matrix, of the City of Carlsbad's Storm Water Standards Manual (Exhibit 'H'). Also, for secondary pollutants of concern, the County's SUSMP includes Table 4. Treatment Control BMP Selection Matrix (Exhibit J). To minimize stormwater impacts, site design measures must be addressed. The following list provides site design measures involved for this site to help avoid or reduce potential impacts during project planning. These measures will control post-development peak stormwater runoff discharge rates and velocities to maintain or reduce predevelopment downstream erosion and to protect stream habitat. The major principles for site design BMP's are 1) to maintain pre- development rainfall runoff characteristics and 2) to protect slopes and channels. Minimize Project's Impervious Footprint & Conserve Natural Areas a. The driveway width is at a minimum width of 24 feet as required by the fire department for the City of Carlsbad. The parking lot dimensions are also the minimum dimensions set forth by the City. b. Building density is increased because each condominium building is 3 stories high. Also, the footprint of Building 2 was decreased by 22% with approval of CD 07-16. c. Conserve Natural Areas where Feasible: This is not applicable, since the site has already been mass-graded. Minimize Directly Connected Impervious Areas (DCIAs) a. Roof drains will outlet to a treatment control bioretention swale before entering the existing 48" storm drain. b. A portion of the parking lot will drain into a vegetated swale located on the east side of the site. Storm water from the vegetated swale ultimately drains to a bioretention swale. c. 82% of the site will drain to bioretention swales or landscape areas prior to discharge to the public storm drain. The remaining 18% drains to a trench drain equipped with a catchbasin insert. The entire site, however, drains to a detention basin prior to outletting to the public storm drain system. Protect Slopes and Channels a. Runoff from the top of slope will be conveyed via grass swales to the private storm drain system. b. All slopes and landscape areas will have permanent landscaping consistent with the Carlsbad Landscape Manual to prevent erosion of sediment. 11 Section 6.0 - Source Control BMPs Source Control BMPs help minimize the introduction of pollutants and sedimentation into storm water in order to maintain or reduce pre-development levels of pollutants. Exhibit T are fact sheets related to source control BMPS. Provide storm drain stenciling and signage All storm water conveyance inlets and catch basins shall provide concrete stamping, porcelain tile, inset permanent marking or equivalent as approved by the City of Carlsbad within the project area with prohibitive language satisfactory to the City Engineer. Design outdoor material storage areas to reduce pollution introduction: not applicable. Design Trash Storage Areas to Reduce Pollution Introduction Trash storage areas shall be paved with an impervious surface, designed not to allow run-on from adjoining areas, and contain attached lids that exclude rains. The trash enclosures will be designed in accordance with City of Carlsbad Std. Dwg. GS-16. Use Efficient Irrigation Systems & Landscape Design Irrigation systems shall employ rain shutoff devices to prevent irrigation during precipitation and be designed to each landscape area's specific water requirements consistent with the Carlsbad Landscape Manual. Maintenance of HOA areas will be performed by contract with a professional maintenance company. Street Sweeping City maintained streets will be swept routinely in order to reduce introduction of trash, debris, sediment and siltation into drainage systems. Education The homeowners association will be responsible for periodically providing the homeowners with informational packets regarding car washing, lawn & garden care, motor oil and pet waste, and the CC&Rs will include restrictions on these activities. Spill Prevention/Procedures The CC&R's will establish specific procedures for handling spills and routine cleanup similar to those used in CASQA fact sheet WM-4 (see Exhibit I). Special considerations and effort shall be applied to resident education on the proper procedures for handling clean up and disposal of pollutants. 12 Section 7.0 - Individual Priority Project Catagories BMPs Residential Driveways and Parking Areas Private Drive 'A' drains to a trench drain that will include a catch basin insert. Inserts are considered to have a low effectiveness for treatment. Initially, the more effective Filterra unit was considered but was found to be infeasible due to the steep grade of the driveway. However, it should be noted that storm water from the trench drain is conveyed to the detention system where peak flow rates will be attenuated. Where feasible, the parking area on the southeast corner of the site was drained to vegetated swales. 13 Section 8.0 - Structural Treatment Control BMPs Bioretention swales The secondary pollutants of concern identified for this project are treated with relatively high to medium efficiency with bioretention facilities as shown on Table 4, Exhibit T. Two bioretention swales will be located on the northerly portion of the site to treat the storm water per low impact development standards. 61% of the site or 0.54 acres drain to the bioretention swales. The swales are a flow-based BMP designed to treat a storm with intensity equal to 0.2 inch per hour. They will also have sufficient capacity to convey storm water from the 100-year storm event. They have been sized to provide an infiltration surface area of at least 4% of the tributary impervious area. The 18" thick soil layer below the swale will be a mixture of compost and soil designed such that the infiltration rate is equal to 5 in/hr. See Appendix 'C' for swale calculations. The pollutants that the swales will efficiently remove include sediment, nutrients, trash, metals, bacteria, oil, grease, and organics. Infiltration practice An additional 21% or 0.18 acres of the site drain to pervious landscape areas but not to the bioretention swales. The pervious landscape areas will also provide infiltration. Drainage Insert A portion of the parking lot and the private driveway make up 18% or 0.16 acres of the site. This area drains to a trench drain equipped with a catch basin basket by Suntree Technolgies, Inc. or equivalent, as a structural BMP. The catch basin basket will also include hydrocarbon absorption booms to collect oil and grease. See Exhibit L for product information and sample data. A Filterra unit was considered here as a more efficient BMP. However, the manufacturer has indicated that this unit is infeasible due to the steep grades of the private driveway. Locate BMP Near Pollutant Sources The bioretention swales are located onsite and thus are near pollutant sources for the project. Step 10: Restrictions on use of infiltration BMPs This is not applicable since infiltration BMPs are not proposed for the project. Construction BMPs The following is a list of potential construction phase BMPs to be used. 1. Check dams 2. Street sweeping and vacuuming 3. Storm drain inlet protection 4. Stabilized construction entrance/exit 5. Vehicle and equipment maintenance, cleaning, and fueling 6. Hydroseed, soil binders, or straw mulch 7. Material delivery and storage 8. Stockpile management 9. Spill prevention and control 14 10. Waste management for solid, liquid, hazardous and sanitary waste, contaminated soil. 11. Concrete waste management Construction BMPs for this project will be selected, constructed, and maintained through the SWPPP to comply with all applicable ordinances and guidance documents. The approved SWPPP shall be implemented during the construction phase. 15 Section 9.0 - Maintenance Provisions During construction, the BMPs will be monitored on a weekly basis, and observations recorded on the checklists provided in the SWPPP. The Owner and Developer will be responsible for the monitoring and maintenance of the BMPs 16 APPENDIX A Appendix A Hydrologic Calculations for Existing Conditions 2-year, 10-year and 100-year See Exhibit R for Existing Conditions Hydrologic Map 17 San Diego County Rational Hydrology Program CIVILCADD/CIVILDESIGN Engineering Software,(c)1991-2004 Version 7.4 Rational method hydrology program based on San Diego County Flood Control Division 2003 hydrology manual Rational Hydrology Study Date: 02/01/08 Existing 2 Year Storm Hydrology Vista La Costa JN 03-1060 Prepared By NF 2/1/08 g:\accts\031060\0360e.out Hydrology Study Control Information ********** Program License Serial Number 5014 Rational hydrology study storm event year is 2.0 English (in-lb) input data Units used Map data precipitation entered: 6 hour, precipitation(inches) = 1.300 24 hour precipitation(inches) = 2.000 P6/P24 = 65.0% San Diego hydrology manual 'C' values used Process from Point/Station 100.000 to Point/Station 101.000 **** INITIAL AREA EVALUATION **** Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [UNDISTURBED NATURAL TERRAIN ] (Permanent Open Space ) Impervious value, Ai = 0.000 Sub-Area C Value = 0.350 Initial subarea total flow distance = 153.500(Ft.) Highest elevation = 63.800(Ft.) Lowest elevation = 57.600(Ft.) Elevation difference = 6.200(Ft.) Slope = 4.039 % Top of Initial Area Slope adjusted by User to 0.500 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: The maximum overland flow distance is 50.00 (Ft) 18 for the top area slope value of 0.50 %, in a development type of Permanent Open Space In Accordance With Figure 3-3 Initial Area Time of Concentration = 12.03 minutes TC = [1.8*(l.l-C)*distance(Ft.)A.5)/(% slope"(l/3)] TC = [1.8*(1.1-0.3500)*( 50.000*.5)/( 0.500^(1/3)]= 12.03 Rainfall intensity (I) = 1.945(In/Hr) for a 2.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.350 Subarea runoff = 0.177(CFS) Total initial stream area = 0.260(Ac.) Process from Point/Station 102.000 to Point/Station **** IRREGULAR CHANNEL FLOW TRAVEL TIME **** 103.000 Estimated mean flow rate at midpoint of channel = Depth of flow = 0.158(Ft.), Average velocity = ******* irregular Channel Data *********** Information entered for subchannel number 1 : 0.37KCFS) 2.180(Ft/s) Point number 'X' coordinate 'Y' coordinate 1 2 3 4 5 Manning ' s 0. 10. 10. 11. 30. 'N' friction 00 00 17 50 00 factor = 0 0 0 0 0 0.015 .70 .50 .00 .12 .49 Sub-Channel flow = 0.371(CFS) 1 ' flow top width = 3.275(Ft.) ' velocity= 2.180(Ft/s) 1 ' area = 0.170(Sq.Ft) 1 ' Froude number = 1.686 56.900(Ft.) 53.100(Ft.) 0.158(Ft.) Upstream point elevation = Downstream point elevation = Flow length = 145.000(Ft.) Travel time = 1.11 min. Time of concentration = 13.14 min. Depth of flow = 0.158(Ft.) Average velocity = 2.180(Ft/s) Total irregular channel flow = 0.371(CFS) Irregular channel normal depth above invert elev. = Average velocity of channel(s) = 2.180(Ft/s) Adding area flow to channel Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [UNDISTURBED NATURAL TERRAIN ] (Permanent Open Space ) Impervious value, Ai = 0.000 Sub-Area C Value = 0.350 Rainfall intensity = 1.837(In/Hr) for a 2.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.350 CA = 0.290 19 Subarea runoff = 0.357(CFS) for 0.570(Ac.) Total runoff = 0.534(CFS) Total area = 0.830(Ac.) Depth of flow = 0.174(Ft.), Average velocity = 2.307(Ft/s) End of computations, total study area = 0.830 (Ac.) 20 San Diego County Rational Hydrology Program CIVILCADD/CIVILDESIGN Engineering Software,(c)1991-2004 Version 7.4 Rational method hydrology program based on San Diego County Flood Control Division 2003 hydrology manual Rational Hydrology Study Date: 05/03/07 Existing- lOYear Storm Hydrology Vista La Costa JN 03-1060 Prepared By: NF 5/3/07 g:\accts\031060\0360e.out ********* Hydrology Study Control Information ********** Program License Serial Number 5014 Rational hydrology study storm event year is 10.0 English (in-lb) input data Units used Map data precipitation entered: 6 hour, precipitation(inches) = 1.900 24 hour precipitation(inches) = 3.100 P6/P24 = 61.3% San Diego hydrology manual 'C' values used Process from Point/Station 100.000 to Point/Station 101.000 **** INITIAL AREA EVALUATION **** Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [UNDISTURBED NATURAL TERRAIN ] (Permanent Open Space ) Impervious value, Ai = 0.000 Sub-Area C Value = 0.350 Initial subarea total flow distance = 153.500(Ft.) Highest elevation = 63.800(Ft.) Lowest elevation = 57.600(Ft.) Elevation difference = 6.200(Ft.) Slope = 4.039 % Top of Initial Area Slope adjusted by User to 0.500 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: The maximum overland flow distance is 50.00 (Ft) for the top area slope value of 0.50 %, in a development type of Permanent Open Space In Accordance With Figure 3-3 21 Initial Area Time of Concentration = 12.03 minutes TC = [1.8M1.1-C) *distance(Ft.) A.5) /(% slope* (1/3)] TC = [1.8*(1.1-0.3500)*( 50.000A.5)/( 0.500^(1/3)]= 12.03 Rainfall intensity (I) = 2.842(In/Hr) for a 10.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.350 Subarea runoff = 0.259(CFS) Total initial stream area = 0.260(Ac.) Process from Point/Station 102.000 to Point/Station 103.000 **** IRREGULAR CHANNEL FLOW TRAVEL TIME **** Estimated mean flow rate at midpoint of channel = 0.542(CFS) Depth of flow = 0.175(Ft.), Average velocity = 2.313(Ft/s) ******* irregular Channel Data *********** Information entered for subchannel number 1 : Point number 'X1 coordinate 'Y' coordinate 1 2 3 4 5 Manning ' s ' N ' 0. 10. 10. 11. 30. friction 00 00 17 50 00 factor = 0 0 0 0 0 0.015 .70 .50 .00 .12 .49 Sub-Channel flow = 0.542(CFS) 1 ' flow top width = 4.146(Ft.) ' ' velocity= 2.313(Ft/s) 1 ' area = 0.234(Sq.Ft) 1 ' Froude number = 1.715 Upstream point elevation = 56.900(Ft.) Downstream point elevation = 53.100 (Ft.) Flow length = 145. 000 (Ft.) Travel time = 1.04 min. Time of concentration = 13.07 min. Depth of flow = 0.175(Ft.) Average velocity = 2.313(Ft/s) Total irregular channel flow = 0.542(CFS) Irregular channel normal depth above invert elev. = 0.175(Ft.) Average velocity of channel(s) = 2.313(Ft/s) Adding area flow to channel Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [UNDISTURBED NATURAL TERRAIN ] (Permanent Open Space ) Impervious value, Ai = 0.000 Sub-Area C Value = 0.350 Rainfall intensity = 2.693(In/Hr) for a 10.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.350 CA = 0.290 Subarea runoff = 0.524(CFS) for 0.570(Ac.) Total runoff = 0.782(CFS) Total area = 0.830(Ac.) Depth of flow = 0.193(Ft.), Average velocity = 2.482(Ft/s) 22 End of computations, total study area = 0.830 (Ac.) 23 San Diego County Rational Hydrology Program CIVILCADD/CIVILDESIGN Engineering Software,(c)1991-2004 Version 7.4 Rational method hydrology program based on San Diego County Flood Control Division 2003 hydrology manual Rational Hydrology Study Date: 04/23/07 Existing 100-Yr Storm Hydrology Vista La Costa JN 03-1060 Prepared By: NF 4/23/07 g:\accts\031060\0360e.out ********* Hydrology Study Control Information ********** Program License Serial Number 5014 Rational hydrology study storm event year is 100.0 English (in-lb) input data Units used Map data precipitation entered: 6 hour, precipitation(inches) = 2.800 24 hour precipitation(inches) = 5.000 P6/P24 = 56.0% San Diego hydrology manual 'C' values used Process from Point/Station 100.000 to Point/Station 101.000 **** INITIAL AREA EVALUATION **** Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [UNDISTURBED NATURAL TERRAIN ] (Permanent Open Space ) Impervious value, Ai = 0.000 Sub-Area C Value = 0.350 Initial subarea total flow distance = 153.500 (Ft.) Highest elevation = 63.800(Ft.) Lowest elevation = 57.600(Ft.) Elevation difference = 6.200(Ft.) Slope = 4.039 % Top of Initial Area Slope adjusted by User to 0.500 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: The maximum overland flow distance is 50.00 (Ft) 24 for the top area slope value of 0.50 %, in a development type of Permanent Open Space In Accordance With Figure 3-3 Initial Area Time of Concentration = 12.03 minutes TC = [1.8*(l.l-C)*distance(Ft.)A.5)/(% slope"(l/3)] TC = [1.8*(1.1-0.3500)*( 50.000A.5)/( 0.500^(1/3)]= 12.03 Rainfall intensity (I) = 4.188(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.350 Subarea runoff = 0.381(CFS) Total initial stream area = 0.260(Ac.) Process from Point/Station 102.000 to Point/Station 103.000 **** IRREGULAR CHANNEL FLOW TRAVEL TIME **** Estimated mean flow rate at midpoint of channel = 0.799(CFS) Depth of flow = 0.194(Ft.), Average velocity = 2.493(Ft/s) ******* irregular Channel Data *********** Information Point number 1 2 3 4 5 Manning ' s ' N entered for subchannel 'X1 coordinate 0.00 10. 00 10 .17 11.50 30.00 ' friction factor = number 1 '¥' coordinate 0.70 0.50 0.00 0.12 0.49 0.015 Sub-Channel flow = 0.799(CFS) ' ' flow top width = 5.086(Ft.) ' ' velocity= 2.493(Ft/s) ' ' area = 0.321(Sq.Ft) 1 ' Froude number = 1.750 Upstream point elevation = 56.900(Ft.) Downstream point elevation = 53.100(Ft.) Flow length = 145.000(Ft.) Travel time = 0.97 min. Time of concentration = 13.00 min. Depth of flow = 0.194(Ft.) Average velocity = 2.493(Ft/s) Total irregular channel flow = 0.799(CFS) Irregular channel normal depth above invert elev. = 0.194(Ft.) Average velocity of channel(s) = 2.493(Ft/s) Adding area flow to channel Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [UNDISTURBED NATURAL TERRAIN ] (Permanent Open Space ) Impervious value, Ai = 0.000 Sub-Area C Value = 0.350 Rainfall intensity = 3.984(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.350 CA = 0.290 25 Subarea runoff = 0.776(CFS) for 0.570(Ac.) Total runoff = 1.157(CFS) Total area = 0.830(Ac.) Depth of flow = 0.213(Ft.), Average velocity = 2.696(Ft/s) End of computations, total study area = 0.830 (Ac.) 26 APPENDIX B Appendix B Hydrologic Calculations for Proposed Conditions 2-year, 10-year and 100-year See Exhibit S for Proposed Conditions Hydrologic Map 27 San Diego County Rational Hydrology Program CIVILCADD/CIVILDESIGN Engineering Software,(c)1991-2004 Version 7.4 Rational method hydrology program based on San Diego County Flood Control Division 2003 hydrology manual Rational Hydrology Study Date: 05/06/08 2 Year Hydrology Study for Vista La Costa JN 031060 NF 5/6/08 g:\accts\031060\revisedsite\v2 ********* Hydrology Study Control Information ********** Program License Serial Number 5014 Rational hydrology study storm event year is English (in-lb) input data Units used Map data precipitation entered: 6 hour, precipitation(inches) = 1.300 24 hour precipitation(inches) = 2.000 P6/P24 = 65.0% San Diego hydrology manual 'C' values used 2.0 Process from Point/Station 203.000 to Point/Station 204.000 **** INITIAL AREA EVALUATION **** Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Initial subarea total flow distance = Highest elevation = 56.300(Ft.) Lowest elevation = 55.300(Ft.) Elevation difference = 1.000(Ft.) Slope = Top of Initial Area Slope adjusted by User to 1.000 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: The maximum overland flow distance is 65.00 (Ft) for the top area slope value of 1.00 %, in a development type of 24.0 DU/A or Less 1 50.000(Ft.! 2.000 % 28 In Accordance With Table 3-2 Initial Area Time of Concentration = 9.50 minutes (for slope value of 1.00 %) Rainfall intensity (I) = 2.264(In/Hr) for a 2.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.710 Subarea runoff = 0.032(CFS) Total initial stream area = 0.020(Ac.) Process from Point/Station 204.000 to Point/Station 205.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 52.200(Ft.) Downstream point/station elevation = 51.800(Ft.) Pipe length = 17.70(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.032(CFS) Nearest computed pipe diameter = 3.00(In.) Calculated individual pipe flow = 0.032(CFS) Normal flow depth in pipe = 1.01(In.) Flow top width inside pipe = 2.84(In.) Critical Depth = 1.28(In.) Pipe flow velocity = 2.24(Ft/s) Travel time through pipe = 0.13 min. Time of concentration (TC) = 9.63 min. Process from Point/Station 204.000 to Point/Station 205.000 **** CONFLUENCE OF MAIN STREAMS **** The following data inside Main Stream is listed: In Main Stream number: 1 Stream flow area = 0.020(Ac.) Runoff from this stream = 0.032(CFS) Time of concentration = 9.63 min. Rainfall intensity = 2.244(In/Hr) Program is now starting with Main Stream No. 2 Process from Point/Station 206.100 to Point/Station 206.200 **** INITIAL AREA EVALUATION **** Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Initial subarea total flow distance = 70.000 (Ft.) Highest elevation = 59.200(Ft.) Lowest elevation = 58.500 (Ft.) Elevation difference = 0.700(Ft.) Slope = 1.000 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: 29 The maximum overland flow distance is 65.00 (Ft) for the top area slope value of 1.00 %, in a development type of 24.0 DU/A or Less In Accordance With Figure 3-3 Initial Area Time of Concentration = 5.66 minutes TC = [1.8*(l.l-C)*distance(Ft.)A.5)/(% slopeA(l/3)] TC = [1.8*(1.1-0.7100)*( 65.000*.5)/( 1.000^(1/3)]= 5.66 The initial area total distance of 70.00 (Ft.) entered leaves a remaining distance of 5.00 (Ft.) Using Figure 3-4, the travel time for this distance is 0.16 minutes for a distance of 5.00 (Ft.) and a slope of 1.00 % with an elevation difference of 0.05(Ft.) from the end of the top area Tt = [11.9*length(Mi)A3)/(elevation change(Ft.))]^.385 *60(min/hr) 0.159 Minutes Tt=[(11.9*0.0009A3)/( 0.05)]A.385= 0.16 Total initial area Ti = 5.66 minutes from Figure 3-3 formula plus 0.16 minutes from the Figure 3-4 formula = 5.82 minutes Rainfall intensity (I) = 3.106(In/Hr) for a 2.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.710 Subarea runoff = 0.066(CFS) Total initial stream area = 0.030(Ac.) Process from Point/Station 206.200 to Point/Station 211.000 **** IMPROVED CHANNEL TRAVEL TIME **** Upstream point elevation = 58.500(Ft.) Downstream point elevation = 57.600(Ft.) Channel length thru subarea = 85.000(Ft.) Channel base width = 0.000(Ft.) Slope or 'Z1 of left channel bank = 10.000 Slope or 'Z' of right channel bank = 10.000 Estimated mean flow rate at midpoint of channel = 0.143(CFS) Manning's 'N' = 0.045 Maximum depth of channel = 0.500(Ft.) Flow(q) thru subarea = 0.143(CFS) Depth of flow = 0.153(Ft.), Average velocity = 0.611(Ft/s) Channel flow top width = 3.064(Ft.) Flow Velocity = 0.61(Ft/s) Travel time = 2.32 min. Time of concentration = 8.14 min. Critical depth = 0.105(Ft.) Adding area flow to channel Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Rainfall intensity = 2.502(In/Hr) for a 2.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.710 CA = 0.071 Subarea runoff = O.lll(CFS) for 0.070(Ac.) 30 Total runoff = Depth of flow = Critical depth = 0.178(CFS) Total area = 0.166(Ft.), Average velocity = 0.114(Ft.) 0.100(Ac.) 0.644(Ft/s) Process from Point/Station 211.000 to Point/Station 205.000 **** pipEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 54.600(Ft.) Downstream point/station elevation = 51.800(Ft.) Pipe length = 48.60(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = Nearest computed pipe diameter = 3 Calculated individual pipe flow = 0 Normal flow depth in pipe = 2.10(In.) Flow top width inside pipe = 2.75(In.) Critical Depth = 2.84(In.) Pipe flow velocity = 4.84(Ft/s) Travel time through pipe = 0.17 min. Time of concentration (TC) = 8.31 min. 0.178(CFS) 00(In.) 178(CFS) Process from Point/Station 211.000 to Point/Station **** CONFLUENCE OF MAIN STREAMS **** 205.000 The following data inside Main Stream is listed: In Main Stream number: 2 Stream flow area = 0.100(Ac.) Runoff from this stream = 0.178(CFS) Time of concentration = 8.31 min. Rainfall intensity = 2.469(In/Hr) Summary of stream data: Stream No. Flow rate (CFS) TC (min) Rainfall Intensity (In/Hr) 1 2 Qmax(1) = Qmax(2) = 0.032 0.178 1.000 * 0.909 * 1.000 * 1.000 * 9.63 8.31 1.000 * 1.000 * 0.862 * 1.000 * 2.244 2.469 0.032) + 0.178) + 0.032) + 0.178) + 0.194 0.205 Total of 2 main streams to confluence: Flow rates before confluence point: 0.032 0.178 Maximum flow rates at confluence using above data: 0.194 0.205 Area of streams before confluence: 0.020 0.100 31 Results of confluence: Total flow rate = 0.205(CFS) Time of concentration = 8.305 min. Effective stream area after confluence = 0.120(Ac.) Process from Point/Station 205.000 to Point/Station 212.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 51.800(Ft.) Downstream point/station elevation = 43.300(Ft.) Pipe length = 82.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.205(CFS) Nearest computed pipe diameter = 3.00(In.) Calculated individual pipe flow = 0.205(CFS) Normal flow depth in pipe = 1.89(In.) Flow top width inside pipe = 2.90(In.) Critical depth could not be calculated. Pipe flow velocity = 6.32(Ft/s) Travel time through pipe = 0.22 min. Time of concentration (TC) = 8.52 min. Process from Point/Station 205.000 to Point/Station 212.000 **** CONFLUENCE OF MAIN STREAMS **** The following data inside Main Stream is listed: In Main Stream number: 1 Stream flow area = 0.120(Ac.) Runoff from this stream = 0.205(CFS) Time of concentration = 8.52 min. Rainfall intensity = 2.428(In/Hr) Program is now starting with Main Stream No. 2 Process from Point/Station 213.000 to Point/Station 214.000 **** INITIAL AREA EVALUATION **** Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Initial subarea total flow distance = 59.000(Ft.) Highest elevation = 56.000(Ft.) Lowest elevation = 55.000(Ft.) Elevation difference = 1.000(Ft.) Slope = 1.695 % Top of Initial Area Slope adjusted by User to 10.698 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: The maximum overland flow distance is 100.00 (Ft) for the top area slope value of 10.70 %, in a development type of 32 24.0 DU/A or Less In Accordance With Figure 3-3 Initial Area Time of Concentration = 3.19 minutes TC = [1.8*(l.l-C)*distance(Ft.)A.5)/(% slope*(1/3)] TC = [1.8*(1.1-0.7100)*( 100.000A.5)/( 10.698A(1/3)]= 3.19 Calculated TC of 3.186 minutes is less than 5 minutes, resetting TC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) = 3.425(In/Hr) for a 2.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.710 Subarea runoff = 0.097(CFS) Total initial stream area = 0.040(Ac.) Process from Point/Station 214.000 to Point/Station 215.000 **** IRREGULAR CHANNEL FLOW TRAVEL TIME **** Estimated mean flow rate at midpoint of channel = 0.280(CFS) Depth of flow = 0.096(Ft.), Average velocity = 5.278(Ft/s) ******* irregular Channel Data *********** Information entered for subchannel number 1 : Point number 'X1 coordinate 'Y' coordinate 1 2 3 4 Manning ' s ' N ' 0.00 17.50 18.83 19.00 friction factor = 0.47 0.12 0.00 0.50 0.013 Sub-Channel flow = 0.280(CFS) 1 ' flow top width = 1.100(Ft.) 1 ' velocity= 5.278(Ft/s) 1 ' area = 0.053(Sq.Ft) ' ' Froude number = 4.238 Upstream point elevation = 54.100(Ft.) Downstream point elevation = 46.410(Ft.) Flow length = 58.000(Ft.) Travel time = 0.18 min. Time of concentration = 3.37 min. Depth of flow = 0.096(Ft.) Average velocity = 5.278(Ft/s) Total irregular channel flow = 0.280(CFS) Irregular channel normal depth above invert elev. = 0.096(Ft.) Average velocity of channel(s) = 5.278(Ft/s) Adding area flow to channel Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Rainfall intensity = 3.425(In/Hr) for a 2.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.710 CA = 0.135 33 Subarea runoff = 0.365(CFS) for 0.150(Ac.) Total runoff = 0.462(CFS) Total area = 0.190(Ac.) Depth of flow = 0.116(Ft.), Average velocity = 5.983(Ft/s) Process from Point/Station 215.000 to Point/Station 212.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 44.500(Ft.) Downstream point/station elevation = 43.300(Ft.) Pipe length = 5.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.462(CFS) Nearest computed pipe diameter = 6.00(In.) Calculated individual pipe flow = 0.462(CFS) Normal flow depth in pipe = 1.66(In.) Flow top width inside pipe = 5.37(In.) Critical Depth = 4.16(In.) Pipe flow velocity = 10.40(Ft/s) Travel time through pipe = 0.01 min. Time of concentration (TC) = 3.38 min. Process from Point/Station 215.000 to Point/Station **** CONFLUENCE OF MAIN STREAMS **** 212.000 The following data inside Main Stream is listed: In Main Stream number: 2 Stream flow area = 0.190(Ac.) Runoff from this stream = 0.462(CFS) Time of concentration = 3.38 min. Rainfall intensity = 3.425(In/Hr) Summary of stream data: Stream No. Flow rate (CFS) TC (min) Rainfall Intensity (In/Hr) 1 2 Qmax(1) = Qmax(2) = 0.205 0.462 1.000 * 0.709 * 1.000 * 1.000 * 8.52 3.38 1.000 * 1.000 * 0.396 * 1.000 * 2.428 3 .425 0.205) + 0.462) + 0.205) + 0.462) + 0.533 0.543 Total of 2 main streams to confluence: Flow rates before confluence point: 0.205 0.462 Maximum flow rates at confluence using above data: 0.533 0.543 Area of streams before confluence: 0.120 0.190 34 Results of confluence: Total flow rate = 0.543(CFS) Time of concentration = 3.377 min. Effective stream area after confluence = 0.310(Ac.) Process from Point/Station 212.000 to Point/Station 217.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 43.100(Ft.) Downstream point/station elevation = 42.780(Ft.) Pipe length = 70.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.543(CFS) Nearest computed pipe diameter = 9.00(In.) Calculated individual pipe flow = 0.543(CFS) Normal flow depth in pipe = 4.42(In.) Flow top width inside pipe = 9.00(In.) Critical Depth = 4.00(In.) Pipe flow velocity = 2.51(Ft/s) Travel time through pipe = 0.46 min. Time of concentration (TC) = 3.84 min. Process from Point/Station 212.000 to Point/Station 217.000 **** CONFLUENCE OF MAIN STREAMS **** The following data inside Main Stream is listed: In Main Stream number: 1 Stream flow area = 0.310(Ac.) Runoff from this stream = 0.543(CFS) Time of concentration = 3.84 min. Rainfall intensity = 3.425(In/Hr) Program is now starting with Main Stream No. 2 Process from Point/Station 206.000 to Point/Station 207.000 **** INITIAL AREA EVALUATION **** Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Initial subarea total flow distance = 55.000(Ft.) Highest elevation = 64.000(Ft.) Lowest elevation = 57.050(Ft.) Elevation difference = 6.950(Ft.) Slope = 12.636 % Top of Initial Area Slope adjusted by User to 10.000 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: The maximum overland flow distance is 100.00 (Ft) for the top area slope value of 10.00 %, in a development type of 35 24.0 DU/A or Less In Accordance With Figure 3-3 Initial Area Time of Concentration = 3.26 minutes TC = [1.8*(1.1-C)*distance(Ft.)*.5)/(% slope* (1/3)] TC = [1.8*(1.1-0.7100)*( 100.000*.5)/( 10.000*(1/3)]= 3.26 Calculated TC of 3.258 minutes is less than 5 minutes, resetting TC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) = 3.425(In/Hr) for a 2.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.710 Subarea runoff = 0.097(CFS) Total initial stream area = 0.040(Ac.) Process from Point/Station 207.000 to Point/Station 208.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 57.050(Ft.) Downstream point/station elevation = 56.870(Ft.) Pipe length = 38.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.097(CFS) Nearest computed pipe diameter = 6.00(In.) Calculated individual pipe flow = 0.097(CFS) Normal flow depth in pipe = 2.04(In.) Flow top width inside pipe = 5.69(In.) Critical Depth = 1.85(In.) Pipe flow velocity = 1.63(Ft/s) Travel time through pipe = 0.39 min. Time of concentration (TC) = 3.65 min. Process from Point/Station 208.000 to Point/Station **** SUBAREA FLOW ADDITION **** 208.000 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Time of concentration = 3.65 min. Rainfall intensity = 3.425(In/Hr) for a 2.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.710 CA = 0.050 Subarea runoff = 0.073(CFS) for 0.030(Ac.) Total runoff = 0.170(CFS) Total area = 0.070(Ac. Process from Point/Station 208.000 to Point/Station 209.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = Downstream point/station elevation = 56.870(Ft.) 56.600(Ft.) 36 NPipe length = 53.00(Ft.) Manning's No. of pipes = 1 Required pipe flow Nearest computed pipe diameter = 6 Calculated individual pipe flow = 0 Normal flow depth in pipe = 2.72(In.) Flow top width inside pipe = 5.97(In.) Critical Depth = 2.47(In.) Pipe flow velocity = 1.95(Ft/s) Travel time through pipe = 0.45 min. Time of concentration (TC) = 4.10 min. = 0.013 0.170(CFS) 00(In.) 170(CFS) Process from Point/Station 209.000 to Point/Station 210.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 56. 600(Ft.) Downstream point/station elevation = 56.390(Ft.) Pipe length = 29.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.170(CFS) Nearest computed pipe diameter = 6.00(In.) Calculated individual pipe flow = 0.170(CFS) Normal flow depth in pipe = 2.48(In.) Flow top width inside pipe = 5.91(In.) Critical Depth = 2.47(In.) Pipe flow velocity = 2.23(Ft/s) Travel time through pipe = 0.22 min. Time of concentration (TC) = 4.31 min. Process from Point/Station 210.000 to Point/Station **** SUBAREA FLOW ADDITION **** 210.000 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Time of concentration = 4.31 min. Rainfall intensity = 3.425(In/Hr) for a 2.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.710 CA = 0.071 Subarea runoff = 0.073(CFS) for 0.030(Ac.) Total runoff = 0.243(CFS) Total area = 0.100(Ac.) Process from Point/Station 210.000 to Point/Station 220.200 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 56.390(Ft.) Downstream point/station elevation = 56.110(Ft.) Pipe length = 54.00(Ft.) Manning's N = 0.013 37 No. of pipes = 1 Required pipe flow = 0.243(CFS) Nearest computed pipe diameter = 6.00(In.) Calculated individual pipe flow = 0.243(CFS) Normal flow depth in pipe = 3.35(In.) Flow top width inside pipe = 5.96(In.) Critical Depth = 2.98(In.) Pipe flow velocity = 2.15(Ft/s) Travel time through pipe = 0.42 min. Time of concentration (TC) = 4.73 min. Process from Point/Station 220.200 to Point/Station **** SUBAREA FLOW ADDITION **** 220.200 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Time of concentration = 4.73 min. Rainfall intensity = 3.425(In/Hr) for a 2.0 .year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.710 CA = 0.085 Subarea runoff = 0.049(CFS) for 0.020(Ac.) Total runoff = 0.292(CFS) Total area = 0.120(Ac.! Process from Point/Station 220.200 to Point/Station 220.000 **** pipEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 56.110(Ft.) Downstream point/station elevation = 56.000(Ft.) Pipe length = 23.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow Nearest computed pipe diameter = Calculated individual pipe flow Normal flow depth in pipe = 3.89(In.) Flow top width inside pipe = 5.73(In.) Critical Depth = 3.28(In.) Pipe flow velocity = 2.17(Ft/s) Travel time through pipe = 0.18 min. Time of concentration (TC) = 4.91 min. 0.292(CFS) 6.00(In.) 0.292(CFS) Process from Point/Station 220.200 to Point/Station **** CONFLUENCE OF MINOR STREAMS **** 220.000 Along Main Stream number: 2 in normal stream number 1 Stream flow area = 0.120(Ac.) Runoff from this stream = 0.292(CFS) Time of concentration = 4.91 min. 38 Rainfall intensity = 3.425(In/Hr) Process from Point/Station 206.000 to Point/Station 218.000 **** INITIAL AREA EVALUATION **** Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Initial subarea total flow distance = 62.000(Ft.) Highest elevation = 64.000(Ft.) Lowest elevation = 59.300(Ft.) Elevation difference = 4.700(Ft.) Slope = 7.581 % Top of Initial Area Slope adjusted by User to 2.581 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: The maximum overland flow distance is 90.00 (Ft) for the top area slope value of 2.58 %, in a development type of 24.0 DU/A or Less In Accordance With Figure 3-3 Initial Area Time of Concentration = 4.86 minutes TC = [1.8*(1.1-C)*distance(Ft.)A.5)/(% slopeA(l/3)] TC = [1.8* (1.1-0.7100)*( 90.000*.5)/( 2.581^(1/3)]= 4.86 Calculated TC of 4.855 minutes is less than 5 minutes, resetting TC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) = 3.425(In/Hr) for a 2.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.710 Subarea runoff = 0.073(CFS) Total initial stream area = 0.030(Ac.) Process from Point/Station 218.000 to Point/Station 219.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 56.410(Ft.) Downstream point/station elevation = 56.210(Ft.) Pipe length = 40.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.073(CFS) Nearest computed pipe diameter = 6.00(In.) Calculated individual pipe flow = 0.073(CFS) Normal flow depth in pipe = 1.74(In.) Flow top width inside pipe = 5.44(In.) Critical Depth = 1.59(In.) Pipe flow velocity = 1.54(Ft/s) Travel time through pipe = 0.43 min. Time of concentration (TC) = 5.29 min. Process from Point/Station 219.000 to Point/Station 219.000 **** SUBAREA FLOW ADDITION **** 39 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Time of concentration = 5.29 min. Rainfall intensity = 3.304(In/Hr) for a 2.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.710 CA = 0.043 Subarea runoff = 0.068(CFS) for 0.030(Ac.) Total runoff = 0.141(CFS) Total area = 0.060(Ac.; Process from Point/Station 219.000 to Point/Station 220.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 56.210(Ft.) Downstream point/station elevation = 56.000(Ft.) Pipe length = 43.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.141(CFS) Nearest computed pipe diameter = 6.00(In.) Calculated individual pipe flow = 0.141(CFS) Normal flow depth in pipe = 2.49(In.) Flow top width inside pipe = 5.91(In.) Critical Depth = 2.24(In.) Pipe flow velocity = 1.83(Ft/s) Travel time through pipe = 0.39 min. Time of concentration (TC) = 5.68 min. Process from Point/Station 219.000 to Point/Station **** CONFLUENCE OF MINOR STREAMS **** 220.000 Along Main Stream number: 2 in normal stream number 2 Stream flow area = 0.060(Ac.) Runoff from this stream = 0.141(CFS) Time of concentration = 5.68 min. Rainfall intensity = 3.155(In/Hr) Summary of stream data: Stream No. Flow rate (CFS) TC (min) Rainfall Intensity (In/Hr) 1 0.292 4.91 2 0.141 5.68 Qmax(I) = 1.000 * 1.000 * 1.000 * 0.865 * Qmax(2) = 0.921 * 1.000 * 3.425 3.155 0.292) + 0.141) + = 0.292) + 0.413 40 1.000 * 1.000 * 0.141) + = 0.410 Total of 2 streams to confluence: Flow rates before confluence point: 0.292 0.141 Maximum flow rates at confluence using above data: 0.413 0.410 Area of streams before confluence: 0.120 0.060 Results of confluence: Total flow rate = 0.413(CFS) Time of concentration = 4.910 min. Effective stream area after confluence = 0.180(Ac.) Process from Point/Station 220.000 to Point/Station 222.000 **** IMPROVED CHANNEL TRAVEL TIME **** Upstream point elevation = 56.000(Ft.) Downstream point elevation = 55.000(Ft.) Channel length thru subarea = 70.000(Ft.) Channel base width = 4.000(Ft.) Slope or 'Z' of left channel bank = 3.000 Slope or 'Z1 of right channel bank = 3.000 Estimated mean flow rate at midpoint of channel = 0.466(CFS) Manning's 'N' = 0.250 Maximum depth of channel = 1.000(Ft.) Flow(q) thru subarea = 0.466(CFS) Depth of flow = 0.321(Ft.), Average velocity = 0.292(Ft/s) Channel flow top width = 5.926(Ft.) Flow Velocity = 0.29(Ft/s) Travel time = 3.99 min. Time of concentration = 8.90 min. Critical depth = 0.073(Ft.) Adding area flow to channel Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Rainfall intensity = 2.362(In/Hr) for a 2.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.710 CA = 0.185 Subarea runoff = 0.022(CFS) for 0.080(Ac.) Total runoff = 0.436(CFS) Total area = 0.260(Ac.) Depth of flow = 0.309(Ft.), Average velocity = 0.286(Ft/s) Critical depth = 0.070(Ft.) Process from Point/Station 222.000 to Point/Station 217.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** 41 Upstream point/station elevation = 51.830(Ft.) Downstream point/station elevation = 42.950 (Ft.) Pipe length = 53.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.436(CFS) Nearest computed pipe diameter = 6.00(In.) Calculated individual pipe flow = 0.436(CFS) Normal flow depth in pipe = 1.77(In.) Flow top width inside pipe = 5.47(In.) Critical Depth = 4.04(In.) Pipe flow velocity = 9.00(Ft/s) Travel time through pipe = 0.10 min. Time of concentration (TC) = 9.00 min. Process from Point/Station 222.000 to Point/Station 217.000 **** CONFLUENCE OF MAIN STREAMS **** The following data inside Main Stream is listed: In Main Stream number: 2 Stream flow area = 0.260(Ac.) Runoff from this stream = 0.436(CFS) Time of concentration = 9.00 min. Rainfall intensity = 2.345(In/Hr) Program is now starting with Main Stream No. 3 Process from Point/Station 217.100 to Point/Station 217.200 **** INITIAL AREA EVALUATION **** Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Initial subarea total flow distance = 7.000(Ft.) Highest elevation = 56.300(Ft.) Lowest elevation = 53.500(Ft.) Elevation difference = 2.800(Ft.) Slope = 40.000 % Top of Initial Area Slope adjusted by User to 30.000 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: The maximum overland flow distance is 100.00 (Ft) for the top area slope value of 30.00 %, in a development type of 24.0 DU/A or Less In Accordance With Figure 3-3 Initial Area Time of Concentration = 2.26 minutes TC = [1.8M1.1-O *distance(Ft.) A.5)/(% slope"(l/3)] TC = [1.8* (1.1-0.7100)*( 100.000A.5)/( 30.000A(1/3)]= 2.26 Calculated TC of 2.259 minutes is less than 5 minutes, resetting TC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) = 3.425(In/Hr) for a 2.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.710 Subarea runoff = 0.024(CFS) 42 Total initial stream area = 0.010(Ac.) Process from Point/Station 217.200 to Point/Station 217.000 **** IMPROVED CHANNEL TRAVEL TIME **** Upstream point elevation = 52. 900 (Ft.) Downstream point elevation = 52.600(Ft.) Channel length thru subarea = 28.000(Ft.) Channel base width = 0.000(Ft.) Slope or 'Z1 of left channel bank = 20.000 Slope or 'Z' of right channel bank = 20.000 Estimated mean flow rate at midpoint of channel = 0.049(CFS) Manning's 'N' =0.035 Maximum depth of channel = 0.500(Ft.) Flow(q) thru subarea = 0.049(CFS) Depth of flow = 0.071(Ft.), Average velocity = 0.476(Ft/s) Channel flow top width = 2.858(Ft.) Flow Velocity = 0.48(Ft/s) Travel time = 0.98 min. Time of concentration = 3.24 min. Critical depth = 0.052(Ft.) Adding area flow to channel Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Rainfall intensity = 3.425(In/Hr) for a 2.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.710 CA = 0.021 Subarea runoff = 0.049(CFS) for 0.020(Ac.) Total runoff = 0.073(CFS) Total area = 0.030(Ac.) Depth of flow = 0.083 (Ft.), Average velocity = 0.527(Ft/s) Critical depth = 0.061(Ft.) Process from Point/Station 217.200 to Point/Station 217.000 **** CONFLUENCE OF MAIN STREAMS **** The following data inside Main Stream is listed: In Main Stream number: 3 Stream flow area = 0.030(Ac.) Runoff from this stream = 0.073(CFS) Time of concentration = 3.24 min. Rainfall intensity = 3.425(In/Hr) Summary of stream data: Stream Flow rate TC Rainfall Intensity No. (CFS) (min) (In/Hr) 43 1 2 3 Qmax ( 1 ) 0 0 0 = 1 1 1 .543 .436 .073 .000 * .000 * .000 * 3 9 3 1 0 1 .84 . 00 .24 .000 * .427 * .000 * 0 0 0 .543) .436) .073) 3 2 3 + + + .425 .345 .425 =0.803 Qmax(2) = 0.685 * 1.000 * 0.543) + 1.000 * 1.000 * 0.436) + 0.685 * 1.000 * 0.073) + = 0.858 Qmax(3) = 1.000 * 0.843 * 0.543) + 1.000 * 0.360 * 0.436) + 1.000 * 1.000 * 0.073) + = 0.688 Total of 3 main streams to confluence: Flow rates before confluence point: 0.543 0.436 0.073 Maximum flow rates at confluence using above data: 0.803 0.858 0.688 Area of streams before confluence: 0.310 0.260 0.030 Results of confluence: Total flow rate = 0.858(CFS) Time of concentration = 8.997 min. Effective stream area after confluence = 0.600(Ac.) Process from Point/Station 217.000 to Point/Station 217.300 **** piPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 42.450(Ft.) Downstream point/station elevation = 42.050(Ft.) Pipe length = 20.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.858(CFS) Nearest computed pipe diameter = 9.00(In.) Calculated individual pipe flow = 0.858(CFS) Normal flow depth in pipe = 3.77(In.) Flow top width inside pipe = 8.88(In.) Critical Depth = 5.08(In.) Pipe flow velocity = 4.89(Ft/s) Travel time through pipe = 0.07 min. Time of concentration (TC) = 9.06 min. Process from Point/Station 217.000 to Point/Station 217.300 **** CONFLUENCE OF MAIN STREAMS **** The following data inside Main Stream is listed: In Main Stream number: 1 Stream flow area = 0.600(Ac.) Runoff from this stream = 0.858(CFS) 44 Time of concentration = 9.06 min. Rainfall intensity = 2.334(In/Hr) Program is now starting with Main Stream No. 2 Process from Point/Station 224.000 to Point/Station **** INITIAL AREA EVALUATION **** 225.000 45.000(Ft.) 8.444 % Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Initial subarea total flow distance = Highest elevation = 59.600(Ft.) Lowest elevation = 55.800(Ft.) Elevation difference = 3.800(Ft.) Slope = Top of Initial Area Slope adjusted by User to 10.000 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: The maximum overland flow distance is 100.00 (Ft) for the top area slope value of 10.00 %, in a development type of 24.0 DU/A or Less In Accordance With Figure 3-3 Initial Area Time of Concentration = 3.26 minutes TC = [1.8M1.1-O *distance(Ft.)".5)/(% slope*(1/3)] TC = [1.8*(1.1-0.7100)*( 100.000A.5)/( 10.000*(1/3)]= 3.26 Calculated TC of 3.258 minutes is less than 5 minutes, resetting TC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) - 3.425(In/Hr) for a 2.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.710 Subarea runoff = 0.073(CFS) Total initial stream area = 0.030(Ac.) Process from Point/Station 225.000 to Point/Station 226.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 53.400(Ft.) Downstream point/station elevation = 47.300(Ft.) Pipe length = 52.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = Nearest computed pipe diameter = 3 Calculated individual pipe flow = 0 Normal flow depth in pipe = 1.00(In.) Flow top width inside pipe = 2.83(In.) Critical Depth = 1.96(In.) Pipe flow velocity = 5.07(Ft/s) Travel time through pipe = 0.17 min. Time of concentration (TC) = 3.43 min. 0.073(CFS) 00(In.) 073(CFS) 45 Process from Point/Station 226.000 to Point/Station **** SUBAREA FLOW ADDITION **** 226.000 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Time of concentration = 3.43 min. Rainfall intensity = 3.425(In/Hr) for a 2.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.710 CA = 0.043 Subarea:runoff = 0.073(CFS) for 0.030(Ac.) Total runoff = 0.146(CFS) Total area = 0.060(Ac.) Process from Point/Station 226.000 to Point/Station 203.100 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 53.000(Ft.) Downstream point/station elevation = 52.720(Ft.) Pipe length = 53.60(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = Nearest computed pipe diameter = 6 Calculated individual pipe flow = 0.146(CFS) Normal flow depth in pipe = 2.49(In.) Flow top width inside pipe = 5.91(In.) Critical Depth = 2.28(In.) Pipe flow velocity = 1.90(Ft/s) Travel time through pipe = 0.47 min. Time of concentration (TC) = 3.90 min. 0.146(CFS) 00(In.) Process from Point/Station 226.000 to Point/Station **** CONFLUENCE OF MINOR STREAMS **** 203 .000 Along Main Stream number: 2 in normal stream number 1 Stream flow area = 0.060(Ac.) Runoff from this stream = 0.146(CFS) Time of concentration = 3.90 min. Rainfall intensity = 3.425(In/Hr) Process from Point/Station 213.000 to Point/Station **** INITIAL AREA EVALUATION **** 201.000 Decimal fraction soil group A = Decimal fraction soil group B = Decimal fraction soil group C = Decimal fraction soil group D = [HIGH DENSITY RESIDENTIAL 0.000 0.000 0.000 1.000 46 (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Initial subarea total flow distance = 22.000(Ft.) Highest elevation = 56.000(Ft.) Lowest elevation = 55.500(Ft.) Elevation difference = 0.500(Ft.) Slope = 2.273 % Top of Initial Area Slope adjusted by User to 1.000 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: The maximum overland flow distance is 65.00 (Ft) for the top area slope value of 1.00 %, in a development type of 24.0 DU/A or Less In Accordance With Figure 3-3 Initial Area Time of Concentration = 5.66 minutes TC = [1.8*(l.l-C)*distance(Ft.)A.5)/(% slope"(l/3)] TC = [1,.8*{1.1-0. 7100)* ( 65.000".5)/( 1. 000" (1/3 ) ] = 5.66 Rainfall intensity (I) = 3.162(In/Hr) for a 2.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.710 Subarea runoff = 0.022(CFS) Total initial stream area = 0.010(Ac.) Process from Point/Station 201.000 to Point/Station 203.100 **** IMPROVED CHANNEL TRAVEL TIME **** Upstream point elevation = 55.500(Ft.) Downstream point elevation = 54.500(Ft.) Channel length thru subarea = 90.000(Ft.) Channel base width = 4.000(Ft.) Slope or 'Z' of left channel bank = 3.000 Slope or 'Z1 of right channel bank = 3.000 Estimated mean flow rate at midpoint of channel = 0.090(CFS) Manning's 'N1 =0.250 Maximum depth of channel = 1.000(Ft.) Flow(q) thru subarea = 0.090(CFS) Depth of flow = 0.133(Ft.), Average velocity = 0.153(Ft/s) Channel flow top width = 4.799(Ft.) Flow Velocity = 0.15(Ft/s) Travel time = 9.79 min. Time of concentration = 15.45 min. Critical depth = 0.025(Ft.) Adding area flow to channel Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Rainfall intensity = 1.655(In/Hr) for a 2.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.710 CA = 0.050 Subarea runoff = 0.060(CFS) for 0.060(Ac.) Total runoff = 0.082(CFS) Total area = 0.070(Ac.) Depth of flow = 0.126(Ft.), Average velocity = 0.148(Ft/s) 47 Critical depth =0.023(Ft.) Process from Point/Station 201.000 to Point/Station **** CONFLUENCE OF MINOR STREAMS **** 203.100 Along Main Stream number: 2 in normal stream number 2 Stream flow area = 0.070(Ac.) Runoff from this stream = 0.082(CFS) Time of concentration = 15.45 min. Rainfall intensity = 1.655(In/Hr) Summary of stream data: Stream No. Flow rate (CFS) TC (min) Rainfall Intensity (In/Hr) 1 2 Qmax(1) 0.146 0.082 . 000 .000 Qmax(2) = 0.483 * 1.000 * 3.90 15.45 1.000 * 0.253 * 1.000 * 1.000 * 3.425 1.655 0.146) + 0.082) + 0.146) + 0.082) + 0.167 0.153 Total of 2 streams to confluence: Flow rates before confluence point: 0.146 0.082 Maximum flow rates at confluence using above data: 0.167 0.153 Area of streams before confluence: 0.060 0.070 Results of confluence: Total flow rate = 0.167(CFS) Time of concentration = 3.900 min. Effective stream area after confluence = 0.130(Ac.) Process from Point/Station 203.100 to Point/Station 229.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 52.550(Ft.) Downstream point/station elevation = 52.390(Ft.) Pipe length = 30.50(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.167(CFS) Nearest computed pipe diameter = 6.00(In.) Calculated individual pipe flow = 0.167(CFS) Normal flow depth in pipe = 2.68(In.) Flow top width inside pipe = 5.97(In.) Critical Depth = 2.44(In.) Pipe flow velocity = 1.97(Ft/s) Travel time through pipe = 0.26 min. Time of concentration (TC) = 4.16 min. 48 Process from Point/Station 203.100 to Point/Station **** CONFLUENCE OF MINOR STREAMS **** 229.000 Along Main Stream number: 2 in normal stream number 1 Stream flow area = 0.130(Ac.) Runoff from this stream = 0.167(CFS) Time of concentration = 4.16 min. Rainfall intensity = 3.425(In/Hr) Process from Point/Station 224.000 to Point/Station **** INITIAL AREA EVALUATION **** 229.100 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Initial subarea total flow distance = 49.000(Ft.) Highest elevation = 59.600(Ft.) Lowest elevation = 55.500(Ft.) Elevation difference = 4.100(Ft.) Slope = 8.367 % Top of Initial Area Slope adjusted by User to 12.000 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: The maximum overland flow distance is 100.00 (Ft) for the top area slope value of 12.00 %, in a development type of 24.0 DU/A or Less In Accordance With Figure 3-3 Initial Area Time of Concentration = 3.07 minutes TC = [1.8*(l.l-C)*distance(Ft.)A.5)/(% slope*(l/3)] TC = [1.8* (1.1-0.7100)*( 100.000A.5)/( 12 . 000* (1/3)]= 3.07 Calculated TC of 3.066 minutes is less than 5 minutes, resetting TC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) = 3.425(In/Hr) for a 2.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.710 Subarea runoff = 0.049(CFS) Total initial stream area = 0.020(Ac.) Process from Point/Station 229.100 to Point/Station 229.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 52.700(Ft.) Downstream point/station elevation = 52.390(Ft.) Pipe length = 8.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = Nearest computed pipe diameter = Calculated individual pipe flow Normal flow depth in pipe = 1.08(In.) Flow top width inside pipe = 2.88(In. 0.049(CFS) 3.00(ln.) 0.049(CFS) 49 Critical Depth = 1.59(In.) Pipe flow velocity = 3.04(Ft/s) Travel time through pipe = 0.04 min. Time of concentration (TC) = 3.11 min. Process from Point/Station 229.100 to Point/Station **** CONFLUENCE OF MINOR STREAMS **** 229.000 Along Main Stream number: 2 in normal stream number 2 Stream flow area = 0.020(Ac.) Runoff from this stream = 0.049(CFS) Time of concentration = 3.11 min. Rainfall intensity = 3.425(In/Hr) Summary of stream data: Stream No. Flow rate (CFS) TC (min) Rainfall Intensity (In/Hr) 1 2 Qmax ( I ) 0.167 0.049 = 1.000 * 1.000 * 4.16 3 .11 1.000 * 1.000 * Qmax(2) = 1.000 1.000 0.748 * 1.000 * 3.425 3.425 0.167) + 0.049) + 0.167) 0.049) 0.215 0.173 Total of 2 streams to confluence: Flow rates before confluence point: 0.167 0.049 Maximum flow rates at confluence using above data: 0.215 0.173 Area of streams before confluence: 0.130 0.020 Results of confluence: Total flow rate = 0.215(CFS) Time of concentration = 4.159 min. Effective stream area after confluence = 0.150(Ac, Process from Point/Station 229.000 to Point/Station 228.000 **** piPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 52.390(Ft.) Downstream point/station elevation = 52.150(Ft.) Pipe length = 48.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow Nearest computed pipe diameter = 6 Calculated individual pipe flow = 0.215(CFS) Normal flow depth in pipe = 3.15(In.) Flow top width inside pipe = 5.99(In.) Critical Depth = 2.79(In.) Pipe flow velocity = 2.06(Ft/s) 0.215(CFS) 00(ln.) 50 Travel time through pipe = 0.39 min. Time of concentration (TC) = 4.55 min. Process from Point/Station 229.000 to Point/Station 228.000 **** CONFLUENCE OF MINOR STREAMS **** Along Main Stream number: 2 in normal stream number 1 Stream flow area = 0.150(Ac.) Runoff from this stream = 0.215(CFS) Time of concentration = 4.55 min. Rainfall intensity = 3.425(In/Hr) Process from Point/Station 224.000 to Point/Station 228.200 **** INITIAL AREA EVALUATION **** Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Initial subarea total flow distance = 45.000(Ft.) Highest elevation = 59.600(Ft.) Lowest elevation = 55.500(Ft.) Elevation difference = 4.100(Ft.) Slope = 9.111 % Top of Initial Area Slope adjusted by User to 12.000 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: The maximum overland flow distance is 100.00 (Ft) for the top area slope value of 12.00 %, in a development type of. 24.0 DU/A or Less In Accordance With Figure 3-3 Initial Area Time of Concentration = 3.07 minutes TC = [1.8*(1.1-C)*distance(Ft.)*.5)/(% slope*(1/3)] TC = [1.8*(1.1-0.7100)*( 100.000".5)/( 12.000*(1/3)]= 3.07 Calculated TC of 3.066 minutes is less than 5 minutes, resetting TC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) = 3.425(In/Hr) for a 2.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.710 Subarea runoff = 0.073(CFS) Total initial stream area = 0.030(Ac.) Process from Point/Station 228.200 to Point/Station 228.000 **** piPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 52.700(Ft.) Downstream point/station elevation = 52.150(Ft.) Pipe length = 10.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.073(CFS) Nearest computed pipe diameter = 3.00(In.) 51 Calculated individual pipe flow = 0.073(CFS) Normal flow depth in pipe = 1.22(In.) Flow top width inside pipe = 2.95(In.) Critical Depth = 1.96(In.) Pipe flow velocity = 3.85(Ft/s) Travel time through pipe = 0.04 miri. Time of concentration (TC) = 3.11 min. Process from Point/Station 228.200 to Point/Station 228.000 **** CONFLUENCE OF MINOR STREAMS **** Along Main Stream number: 2 in normal stream number 2 Stream flow area = 0.030(Ac.) Runoff from this stream = 0.073(CFS) Time of concentration = 3.11 min. Rainfall intensity = 3.425(In/Hr) Summary of stream data: Stream No. Flow rate (CFS) TC (min) Rainfall Intensity (In/Hr) 1 2 Qmax(1) 0.215 0.073 000 000 Qmax(2) = 1.000 * 1.000 * 4.55 3.11 1.000 * 1.000 * 0.684 * 1.000 * 3.425 3.425 0.215) + 0.073) + 0.215) + 0.073) + 0 .288 0.220 Total of 2 streams to confluence: Flow rates before confluence point: 0.215 0.073 Maximum flow rates at confluence using above data: 0.288 0.220 Area of streams before confluence: 0.150 0.030 Results of confluence: Total flow rate = 0.288(CFS) Time of concentration = 4.547 min. Effective stream area after confluence = 0.180(Ac.) Process from Point/Station 228.000 to Point/Station 228.100 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 52.150(Ft.) Downstream point/station elevation = 52.100(Ft.) Pipe length = 7.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.288(CFS) Nearest computed pipe diameter = 6.00(In.) Calculated individual pipe flow = 0.288(CFS) Normal flow depth in pipe = 3.38(In.) 52 Flow top width inside pipe = 5.95(In.) Critical Depth = 3.25(In.) Pipe flow velocity = 2.53(Ft/s) Travel time through pipe = 0.05 min. Time of concentration (TC) = 4.59 min. Process from Point/Station 228.100 to Point/Station 223.000 **** IMPROVED CHANNEL TRAVEL TIME **** Upstream point elevation = 52.100(Ft.) Downstream point elevation = 51.200(Ft.) Channel length thru subarea = 74.000(Ft.) Channel base width = 4.000(Ft.) Slope or 'Z' of left channel bank = 3.000 Slope or 'Z' of right channel bank = 3.000 Estimated mean flow rate at midpoint of channel = 0.368(CFS) Manning's 'N' = 0.250 Maximum depth of channel = 1.000(Ft.) Flow(q) thru subarea = 0.368(CFS) Depth of flow = 0.294(Ft.), Average velocity = 0.257(Ft/s) Channel flow top width = 5.764(Ft.) Flow Velocity = 0.26(Ft/s) Travel time = 4.81 min. Time of concentration = 9.40 min. Critical depth = 0.063 (Ft.) Adding area flow to channel Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Rainfall intensity = 2.280(In/Hr) for a 2.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.710 CA = 0.199 Subarea runoff = 0.165(CFS) for 0.100(Ac.) Total runoff = 0.453(CFS) Total area = 0.280(Ac.) Depth of flow = 0.331(Ft.), Average velocity = 0.275(Ft/s) Critical depth = 0.072(Ft.) Process from Point/Station 223.000 to Point/Station 217.300 **** piPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 48.000(Ft.) Downstream point/station elevation = 42.550(Ft.) Pipe length = 63.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.453(CFS) Nearest computed pipe diameter = 6.00(In.) Calculated individual pipe flow = 0.453(CFS) Normal flow depth in pipe = 2.15(In.) Flow top width inside pipe = 5.75(In.) 53 Critical Depth = 4.12(In.) Pipe flow velocity = 7.17(Ft/s) Travel time through pipe = 0.15 min. Time of concentration (TC) = 9.54 min. Process from Point/Station 223.000 to Point/Station **** CONFLUENCE OF MAIN STREAMS **** 217.300 The following data inside Main Stream is listed: In Main Stream number: 2 Stream flow area = 0.280(Ac.) Runoff from this stream = 0.453(CFS) Time of concentration = 9.54 min. Rainfall intensity = 2.257(In/Hr) Summary of stream data: Stream No. Flow rate (CFS) TC (min) Rainfall Intensity (In/Hr) 1 2 Qmax(1) = 0.858 0.453 Qmax(2) = .000 ,000 0.967 * 1.000 * 9.06 9.54 1.000 * 0.950 * 1.000 * 1.000 * 2.334 2.257 0.858) + 0.453) + 0.858) + 0.453) + 1.288 1.283 Total of 2 main streams to confluence: Flow rates before confluence point: 0.858 0.453 Maximum flow rates at confluence using above data: 1.288 1.283 Area of streams before confluence: 0.600 0.280 Results of confluence: Total flow rate = 1.288(CFS) Time of concentration = 9.065 min. Effective stream area after confluence =0.880(Ac.) Process from Point/Station 217.300 to Point/Station 217.400 **** piPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 42.050(Ft.) Downstream point/station elevation = 37.990(Ft.) Pipe length = 3.00 (Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 1.288(CFS) Nearest computed pipe diameter = 6.00(In.) Calculated individual pipe flow = 1.288(CFS) Normal flow depth in pipe = 1.81(In.) 54 Flow top width inside pipe = 5.50(In.) Critical depth could not be calculated. Pipe flow velocity = 25.85(Ft/s) Travel time through pipe = 0.00 min. Time of concentration (TC) = 9.07 min. End of computations, total study area = 0.880 (Ac. 55 San Diego County Rational Hydrology Program CIVILCADD/CIVILDESIGN Engineering Software,(c)1991-2004 Version 7.4 Rational method hydrology program based on San Diego County Flood Control Division 2003 hydrology manual Rational Hydrology Study Date: 05/05/08 100 Year Proposed Hydrology for Vista La Costa JN 031060 NF 5/5/08 G:\ACCTS\031060\REVISEDSITE\V100 ********* Hydrology Study Control Information ********** Program License Serial Number 5014 Rational hydrology study storm event year is 10.0 English (in-lb) input data Units used Map data precipitation entered: 6 hour, precipitation(inches) = 1.900 24 hour precipitation(inches) = 3.100 P6/P24 = 61.3% San Diego hydrology manual 'C' values used Process from Point/Station 203.000 to Point/Station 204.000 **** INITIAL AREA EVALUATION **** Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Initial subarea total flow distance = 50.000(Ft.) Highest elevation = 56.300(Ft.) Lowest elevation = 55.300(Ft.) Elevation difference = 1.000(Ft.) Slope = 2.000 % Top of Initial Area Slope adjusted by User to 1.000 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: The maximum overland flow distance is 65.00 (Ft) for the top area slope value of 1.00 %, in a development type of 24.0 DU/A or Less 56 In Accordance With Table 3-2 Initial Area Time of Concentration = 9.50 minutes (for slope value of 1.00 %) Rainfall intensity (I) = 3.309(In/Hr) for a 10.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.710 Subarea runoff = 0.047(CFS) Total initial stream area = 0.020(Ac.) Process from Point/Station 204.000 to Point/Station 205.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 52.200(Ft.) Downstream point/station elevation = 51.800(Ft.) Pipe length = 17.70(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.047(CFS) Nearest computed pipe diameter = 3.00(In.) Calculated individual pipe flow = 0.047(CFS) Normal flow depth in pipe = 1.22(In.) Flow top width inside pipe = 2.95(In.) Critical Depth = 1.56(In.) Pipe flow velocity = 2.46(Ft/s) Travel time through pipe = 0.12 min. Time of concentration (TC) = 9.62 min. Process from Point/Station 204.000 to Point/Station 205.000 **** CONFLUENCE OF MAIN STREAMS **** The following data inside Main Stream is listed: In Main Stream number: 1 Stream flow area = 0.020(Ac.) Runoff from this stream = 0.047(CFS) Time of concentration = 9.62 min. Rainfall intensity = 3.282(In/Hr) Program is now starting with Main Stream No. 2 Process from Point/Station 206.100 to Point/Station 206.200 **** INITIAL AREA EVALUATION **** Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Initial subarea total flow distance = 70.000(Ft.) Highest elevation = 59.200(Ft.) Lowest elevation = 58.500(Ft.) Elevation difference = 0.700(Ft.) Slope = 1.000 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: 57 The maximum overland flow distance is 65.00 (Ft) for the top area slope value of 1.00 %, in a development type of 24.0 DU/A or Less In Accordance With Figure 3-3 Initial Area Time of Concentration = 5.66 minutes TC = [1.8*(1.1-C)*distance(Ft.)A.5)/(% slopeA(l/3)] TC = [1.8* (1.1-0.7100)*( 65.000A.5)/( 1.000^(1/3)]= 5.66 The initial area total distance of 70.00 (Ft.) entered leaves a remaining distance of 5.00 (Ft.) Using Figure 3-4, the travel time for this distance is 0.16 minutes for a distance of 5.00 (Ft.) and a slope of 1.00 % with an elevation difference of 0.05(Ft.) from the end of the top area Tt = [11.9*length(Mi)A3)/(elevation change(Ft.))]A.385 *60(min/hr) = 0.159 Minutes Tt=[(11,9*0.0009A3)/( 0.05)]A.385= 0.16 Total initial area Ti = 5.66 minutes from Figure 3-3 formula plus 0.16 minutes from the Figure 3-4 formula = 5.82 minutes Rainfall intensity (I) = 4.540(In/Hr) for a 10.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.710 Subarea runoff = 0.097(CFS) Total initial stream area = 0.030(Ac.) Process from Point/Station 206.200 to Point/Station 211.000 **** IMPROVED CHANNEL TRAVEL TIME **** Upstream point elevation = 58. 500(Ft.) Downstream point elevation = 57.600(Ft.) Channel length thru subarea = 85.000(Ft.) Channel base width = 0.000(Ft.) Slope or 'Z' of left channel bank = 10.000 Slope or 'Z' of right channel bank = 10.000 Estimated mean flow rate at midpoint of channel = 0.210(CFS) Manning's 'N' = 0.045 Maximum depth of channel = 0.500(Ft.) Flow(q) thru subarea = 0.210(CFS) Depth of flow = 0.177(Ft.), Average velocity = 0.672(Ft/s) Channel flow top width = 3. 532 (Ft.) Flow Velocity = 0.67(Ft/s) Travel time = 2.11 min. Time of concentration = 7.93 min. Critical depth = 0.122(Ft.) Adding area flow to channel Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Rainfall intensity = 3.719(In/Hr) for a 10.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.710 CA = 0.071 Subarea runoff = 0.167(CFS) for 0.070(Ac.) 58 Total runoff = Depth of flow = Critical depth = 0.264(CFS) Total area = 0.193(Ft.), Average velocity = 0.134(Ft.) 0.100(Ac.) 0.712(Ft/s) Process from Point/Station 211.000 to Point/Station 205.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 54.600(Ft.) Downstream point/station elevation = 51. 800(Ft.) Pipe length = 48.60(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.264(CFS) Nearest computed pipe diameter = 6.00(In.) Calculated individual pipe flow = 0.264(CFS) Normal .flow depth in pipe = 1.80(In.) Flow top width inside pipe = 5.50(In.) Critical Depth = 3.11(In.) Pipe flow velocity = 5.32(Ft/s) Travel time through pipe = 0.15 min. Time of concentration (TC) = 8.08 min. Process from Point/Station 211.000 to Point/Station **** CONFLUENCE OF MAIN STREAMS **** 205 .000 The following data inside Main Stream is listed: In Main Stream number: 2 Stream flow area = 0.100(Ac.) Runoff from this stream = 0.264(CFS) Time of concentration = 8.08 min. Rainfall intensity = 3.673(In/Hr) Summary of stream data: Stream No. Flow rate (CFS) TC (min) Rainfall Intensity (In/Hr) 1 2 Qmax(1) = Qmax(2) = 0.047 0.264 1.000 * 0.894 * 1.000 * 1.000 * 9.62 8.08 1.000 * 1.000 * 0.840 * 1.000 * 3 .282 3 .673 0.047) + 0.264) + 0.047) + 0.264) + 0 .283 0.303 Total of 2 main streams to confluence: Flow rates before confluence point: 0.047 0.264 Maximum flow rates at confluence using above data: 0.283 0.303 Area of streams before confluence: 0.020 0.100 59 Results of confluence: Total flow rate = 0.303(CFS) Time of concentration = 8.080 min. Effective stream area after confluence 0.120(Ac.) Process from Point/Station 205.000 to Point/Station 212.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 51.800(Ft.) Downstream point/station elevation = 43.300(Ft.) Pipe length = 82.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = Nearest computed pipe diameter = Calculated individual pipe flow = Normal flow depth in pipe = 1.66(In.) Flow top width inside pipe = 5.37(In.) Critical Depth = 3.34(In.) Pipe flow velocity = 6.83(Ft/s) Travel time through pipe = 0.20 min. Time of concentration (TC) = 8.28 min. 0.303(CFS) 6.00(In.) 0.303(CFS) Process from Point/Station 205.000 to Point/Station **** CONFLUENCE OF MAIN STREAMS **** 212.000 The following data inside Main Stream is listed: In Main Stream number: 1 Stream flow area = 0.120(Ac.) Runoff from this stream = 0.303(CFS) Time of concentration = 8.28 min. Rainfall intensity = 3.616(In/Hr) Program is now starting with Main Stream No. 2 Process from Point/Station 213.000 to Point/Station **** INITIAL AREA EVALUATION **** 214.000 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Initial subarea total flow distance Highest elevation = 56.000(Ft.) Lowest elevation = 55.000(Ft.) Elevation difference = 1.000(Ft.) Slope = Top of Initial Area Slope adjusted by User to 10.698 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: The maximum overland flow distance is 100.00 (Ft) for the top area slope value of 10.70 %, in a development type of 59.000(Ft.) 1.695 % 60 24.0 DU/A or Less In Accordance With Figure 3-3 Initial Area Time of Concentration = 3.19 minutes TC = [1.8*(l.l-C)*distance(Ft.)".5)/(% slope* (1/3)] TC = [1.8*(1.1-0.7100)*( 100.000".5)/( 10.698A(1/3)]= 3.19 Calculated TC of 3.186 minutes is less than 5 minutes, resetting TC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) = 5.006(In/Hr) for a 10.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.710 Subarea runoff = 0.142(CFS) Total initial stream area = 0.040(Ac.) Process from Point/Station 214.000 to Point/Station **** IRREGULAR CHANNEL FLOW TRAVEL TIME **** 215.000 Estimated mean flow rate at midpoint of channel = 0.409(CFS) Depth of flow = 0.111(Ft.), Average velocity = 5.803(Ft/s) ******* irregular Channel Data *********** Information entered for subchannel number 1 : Point number 'X' coordinate 'Y' coordinate 1 2 3 4 Manning ' s 0.00 17.50 18.83 19.00 'N' friction factor = 0.47 0.12 0.00 0.50 0.013 Sub-Channel flow = 0.409(CFS) ' ' flow top width = 1.269(Ft.) ' ' velocity= 5.803(Ft/s) 1 ' area = 0.070(Sq.Ft) 1 ' Froude number = 4.340 Upstream point elevation = 54.100(Ft.) Downstream point elevation = 46.410 (Ft.) Flow length = 58.000(Ft.) Travel time = 0.17 min. Time of concentration = 3.35 min. Depth of flow = 0.111(Ft.) Average velocity = 5.803(Ft/s) Total irregular channel flow = 0.409(CFS) Irregular channel normal depth above invert elev. = 0.111(Ft.) Average velocity of channel(s) = 5.803(Ft/s) Adding area flow to channel Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Rainfall intensity = 5.006(In/Hr) for a 10.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.710 CA = 0.135 61 Subarea runoff = Total runoff = Depth of flow = 0.533(CFS) for 0.150(Ac.) 0.675(CFS) Total area = 0.190(Ac.) 0.141(Ft.), Average velocity = 5.512(Ft/s) Process from Point/Station 215.000 to Point/Station 212.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 44.500(Ft.) Downstream point/station elevation = 43.300(Ft.) Pipe length = 5.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow Nearest computed pipe diameter = Calculated individual pipe flow = Normal flow depth in pipe = 2.03(In.) Flow top width inside pipe = 5.68(In.) Critical Depth = 4.99(In.) Pipe flow velocity = 11.58(Ft/s) Travel time through pipe = 0.01 min. Time of concentration (TC) = 3.36 min. 0.675(CFS) 6.00(In.) 0.675(CFS) Process from Point/Station 215.000 to Point/Station **** CONFLUENCE OF MAIN STREAMS **** 212.000 The following data inside Main Stream is listed: In Main Stream number: 2 Stream flow area = 0.190(Ac.) Runoff from this stream = 0.675(CFS) Time of concentration = 3.36 min. Rainfall intensity = 5.006(In/Hr) Summary of stream data: Stream No. Flow rate (CFS) TC (min) Rainfall Intensity (In/Hr) 1 2 Qmax(1) 0.303 0.675 1.000 * 0.722 * Qmax(2) = 1.000 1.000 8.28 3.36 1.000 * 1.000 * 0.406 * 1.000 * 3.616 5 .006 0.303) + 0.675) + 0.303) + 0.675) + 0.791 0.798 Total of 2 main streams to confluence: Flow rates before confluence point: 0.303 0.675 Maximum flow rates at confluence using above data: 0.791 0.798 Area of streams before confluence: 0.120 0.190 62 Results of confluence: Total flow rate = 0.798(CFS) Time of concentration = 3.360 min. Effective stream area after confluence = 0.310(Ac. Process from Point/Station 212.000 to Point/Station 217.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 43.100(Ft.) Downstream point/station elevation = 42.780(Ft.) Pipe length = 70.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.798(CFS) Nearest computed pipe diameter = 9.00(In.) Calculated individual pipe flow = 0.798(CFS) Normal flow depth in pipe = 5.63(In.) Flow top width inside pipe = 8.71(In.) Critical Depth = 4.89(In.) Pipe flow velocity = 2.75(Ft/s) Travel time through pipe = 0.42 min. Time of concentration (TC) = 3.78 min. Process from Point/Station 212.000 to Point/Station 217.000 **** CONFLUENCE OF MAIN STREAMS **** The following data inside Main Stream is listed: In Main Stream number: 1 Stream flow area = 0.310(Ac.) Runoff from this stream = 0.798(CFS) Time of concentration = 3.78 min. Rainfall intensity = 5.006(In/Hr) Program is now starting with Main Stream No. 2 Process from Point/Station 206.000 to Point/Station 207.000 **** INITIAL AREA EVALUATION **** Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Initial subarea total flow distance = 55.000(Ft.) Highest elevation = 64.000(Ft.) Lowest elevation = 57.050(Ft.) Elevation difference = 6.950(Ft.) Slope = 12.636 % Top of Initial Area Slope adjusted by User to 10.000 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: The maximum overland flow distance is 100.00 (Ft) for the top area slope value of 10.00 %, in a development type of 63 24.0 DU/A or Less In Accordance With Figure 3-3 Initial Area Time of Concentration = 3.26 minutes TC = [1.8*(1.1-C)*distance(Ft.)^.5)/(% slopeA(l/3)] TC = [1.8*(1.1-0.7100)*( 100.000A.5)/( 10.000^(1/3)]= 3.26 Calculated TC of 3.258 minutes is less than 5 minutes, resetting TC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) = 5.006(In/Hr) for a 10.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.710 Subarea runoff = 0.142(CFS) Total initial stream area = 0.040(Ac.) Process from Point/Station 207.000 to Point/Station 208.000 **** pipEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 57.050(Ft.) Downstream point/station elevation = 56.870(Ft.) Pipe length = 38.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.142(CFS) Nearest computed pipe diameter = 6.00(In.) Calculated individual pipe flow = 0.142(CFS) Normal flow depth in pipe = 2.51(In.) Flow top width inside pipe = 5.92(In.) Critical Depth = 2.25(In.) Pipe flow velocity = 1.81(Ft/s) Travel time through pipe = 0.35 min. Time of concentration (TC) = 3.61 min. Process from Point/Station **** SUBAREA FLOW ADDITION **** 208.000 to Point/Station 208.000 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Time of concentration = 3.61 min. Rainfall intensity = 5.006(In/Hr) for a 10.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.710 CA = 0.050 Subarea runoff = 0.107(CFS) for 0.030(Ac.) Total runoff = 0.249(CFS) Total area = 0.070(Ac.) Process from Point/Station 208.000 to Point/Station 209.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 56.870(Ft.) Downstream point/station elevation = 56.600(Ft.) 64 Pipe length = 53.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.249(CFS) Nearest computed pipe diameter = 6.00(In.) Calculated individual pipe flow = 0.249(CFS) Normal flow depth in pipe = 3.42(In.) Flow top width inside pipe = 5.94(In.) Critical Depth = 3.01(In.) Pipe flow velocity = 2.15(Ft/s) Travel time through pipe = 0.41 min. Time of concentration (TC) = 4.02 min. Process from Point/Station 209.000 to Point/Station 210.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 56.600(Ft.) Downstream point/station elevation = 56.390 (Ft.) Pipe length = 29.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = Nearest computed pipe diameter Calculated individual pipe flow Normal flow depth in pipe = 3.07(In.) Flow top width inside pipe = 6.00(In.) Critical Depth = 3.01(In.) Pipe flow velocity = 2.46(Ft/s) Travel time through pipe = 0.20 min. Time of concentration (TC) = 4.22 min. 0.249(CFS) 6.00(In.) 0.249(CFS) Process from Point/Station 210.000 to Point/Station **** SUBAREA FLOW ADDITION **** 210.000 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Time of concentration = 4.22 min. Rainfall intensity = 5.006(In/Hr) for a 10.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.710 CA = 0.071 Subarea runoff = 0.107(CFS) for 0.030(Ac.) Total runoff = 0.355(CFS) Total area = 0.100(Ac.) Process from Point/Station 210.000 to Point/Station 220.200 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 56.390(Ft.) Downstream point/station elevation = 56.110(Ft.) Pipe length = 54.00(Ft.) Manning's N = 0.013 65 No. of pipes = 1 Required pipe flow = 0.355(CFS) Nearest computed pipe diameter = 6.00(In.) Calculated individual pipe flow = 0.355(CFS) Normal flow depth in pipe = 4.36(In.) Flow top width inside pipe = 5.35(In.) Critical Depth = 3.63(In.) Pipe flow velocity = 2.32(Ft/s) Travel time through pipe = 0.39 min. Time of concentration (TC) = 4.60 min. Process from Point/Station 220.200 to Point/Station **** SUBAREA FLOW ADDITION **** 220.200 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL, ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Time of concentration = 4.60 min. Rainfall intensity = 5.006(In/Hr) for a 10.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.710 CA = 0.085 Subarea runoff = 0.071(CFS) for 0.020(Ac.) Total runoff = 0.427(CFS) Total area = 0.120(Ac.) Process from Point/Station 220.200 to Point/Station 220.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 56.110(Ft.) Downstream point/station elevation = 56.000 (Ft.) Pipe length = 23.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.427(CFS) Nearest computed pipe diameter = 9.00(In.) Calculated individual pipe flow = 0.427(CFS) Normal flow depth in pipe = 3.81(In.) Flow top width inside pipe = 8.89(In.) Critical Depth = 3.52(In.) Pipe flow velocity = 2.40(Ft/s) Travel time through pipe = 0.16 min. Time of concentration (TC) = 4.76 min. Process from Point/Station 220.200 to Point/Station **** CONFLUENCE OF MINOR STREAMS **** 220.000 Along Main Stream number: 2 in normal stream number 1 Stream flow area = 0.120(Ac.) Runoff from this stream = 0.427(CFS) Time of concentration = 4.76 min. 66 Rainfall intensity = 5.006(In/Hr) Process from Point/Station 206.000 to Point/Station 218.000 **** INITIAL AREA EVALUATION **** Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Initial: subarea total flow distance = 62.000(Ft.) Highest elevation = 64.000(Ft.) Lowest elevation = 59.300(Ft.) Elevation difference = 4.700(Ft.) Slope = 7.581 % Top of Initial Area Slope adjusted by User to 2.581 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: The maximum overland flow distance is 90.00 (Ft) for the top area slope value of 2.58 %, in a development type of 24.0 DU/A or Less In Accordance With Figure 3-3 Initial Area Time of Concentration = 4.86 minutes TC = [1.8*(1.1-O*distance(Ft.)A.5)/(% slope" (1/3)] TC = [1.8* (1.1-0.7100)*( 90.000^.5)/( 2.581A(1/3)]= 4.86 Calculated TC of 4.855 minutes is less than 5 minutes, resetting TC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) = 5.006(In/Hr) for a 10.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.710 Subarea runoff = 0.107(CFS) Total initial stream area = 0.030(Ac.) Process from Point/Station 218.000 to Point/Station 219.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 56.410(Ft.) Downstream point/station elevation = 56.210(Ft.) Pipe length = 40.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.107(CFS) Nearest computed pipe diameter = 6.00(In.) Calculated individual pipe flow = 0.107(CFS) Normal flow depth in pipe = 2.11(In.) Flow top width inside pipe = 5.73(In.) Critical Depth = 1.94(In.) Pipe flow velocity = 1.71(Ft/s) Travel time through pipe = 0.39 min. Time of concentration (TC) = 5.25 min. Process from Point/Station 219.000 to Point/Station 219.000 **** SUBAREA FLOW ADDITION **** 67 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Time of concentration = 5.25 min. Rainfall intensity = 4.854(In/Hr) for a 10.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.710 CA = 0.043 Subarea runoff = O.IOO(CFS) for 0.030(Ac.) Total runoff = 0.207(CFS) Total area = 0.060(Ac.) Process from Point/Station 219.000 to Point/Station 220.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 56.210(Ft.) Downstream point/station elevation = 56.000(Ft.) Pipe length = 43.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow =0.207(CFS) Nearest computed pipe diameter Calculated individual pipe flow = Normal flow depth in pipe = 3.09(In.) Flow top width inside pipe = 6.00(In.) Critical Depth = 2.73(In.) Pipe flow velocity = 2.02(Ft/s) Travel time through pipe = 0.35 min. Time of concentration (TC) = 5.60 min. 6.00(ln.) 0.207(CFS) Process from Point/Station 219.000 to Point/Station **** CONFLUENCE OF MINOR STREAMS **** 220.000 Along Main Stream number: 2 in normal stream number 2 Stream flow area = 0.060(Ac.) Runoff from this stream = 0.207(CFS) Time of concentration = 5.60 min. Rainfall intensity = 4.653(In/Hr) Summary of stream data: Stream No. Flow rate (CFS) TC (min) Rainfall Intensity (In/Hr) 1 0.427 4.76 2 0.207 5.60 Qmax(1) = 1.000 * 1.000 * 1.000 * 0.851 * Qmax(2) = 0.930 * 1.000 * 5.006 4.653 0.427) + 0.207) + = 0.427) + 0.602 68 1.000 * 1.000 * 0.207) + = 0.603 Total of 2 streams to confluence: Flow rates before confluence point: 0.427 0.207 Maximum flow rates at confluence using above data: 0.602 0.603 Area of streams before confluence: 0.120 0.060 Results of confluence: Total flow rate = 0.603(CFS) Time of concentration = 5.599 min. Effective stream area after confluence = 0.180(Ac.) Process from Point/Station 220.000 to Point/Station 222.000 **** IMPROVED CHANNEL TRAVEL TIME **** Upstream point elevation = 56.000(Ft.) Downstream point elevation = 55.000(Ft.) Channel length thru subarea = 70.000(Ft.) Channel base width = 4.000(Ft.) Slope or 'Z' of left channel bank = 3.000 Slope or 'Z' of right channel bank = 3.000 Estimated mean flow rate at midpoint of channel = 0.646(CFS) Manning's 'N1 = 0.250 Maximum depth of channel = 1.000(Ft.) Flow(q) thru subarea = 0.646(CFS) Depth of flow = 0.386(Ft.), Average velocity = 0.325(Ft/s) Channel flow top width = 6.315(Ft.) Flow Velocity = 0.32(Ft/s) Travel time = 3.59 min. Time of concentration = 9.19 min. Critical depth = 0.091(Ft.) Adding area flow to channel Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Rainfall intensity = 3.380(In/Hr) for a 10.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.710 CA = 0.185 Subarea runoff = 0.02KCFS) for 0.080 (Ac,) Total runoff = 0.624(CFS) Total area = 0.260(Ac.) Depth of flow = 0.378(Ft.), Average velocity = 0.321(Ft/s) Critical depth = 0.089(Ft.) Process from Point/Station 222.000 to Point/Station 217.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** 69 Upstream point/station elevation = 51.830(Ft.) Downstream point/station elevation = 42.950(Ft.) Pipe length = 53.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow Nearest computed pipe diameter = Calculated individual pipe flow = Normal flow depth in pipe = 2.14(In.) Flow top width inside pipe = 5.75(In.) Critical Depth = 4.81(In.) Pipe flow velocity = 9.95(Ft/s) Travel time through pipe = 0.09 min. Time of concentration (TC) = 9.28 min. 0.624(CFS) 6.00{In.) 0.624(CFS) Process, from Point/Station 222.000 to Point/Station **** CONFLUENCE OF MAIN STREAMS **** 217.000 The following data inside Main Stream is listed: In Main Stream number: 2 Stream flow area = 0.260(Ac.) Runoff from this stream = 0.624(CFS) Time of concentration = 9.28 min. Rainfall intensity = 3.359(In/Hr) Program is now starting with Main Stream No. 3 Process from Point/Station 217.100 to Point/Station **** INITIAL AREA EVALUATION **** 217.200 7.0 0 0(Ft.! Slope = 40.000 % Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Initial subarea total flow distance Highest elevation = 56.300(Ft.) Lowest elevation = 53.500(Ft.) Elevation difference = 2.800(Ft.) Top of Initial Area Slope adjusted by User to 30.000 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: The maximum overland flow distance is 100.00 (Ft) for the top area slope value of 30.00 %, in a development type of 24.0 DU/A or Less In Accordance With Figure 3-3 Initial Area Time of Concentration = 2.26 minutes TC = [1.8*(1.1-C)*distance(Ft.)A.5)/(% slopeA(l/3)] TC = [1.8*(1.1-0.7100)*( 100.000^.5)/( 30.000^(1/3)]= 2.26 Calculated TC of 2.259 minutes is less than 5 minutes, resetting TC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) = 5.006(In/Hr) for a 10.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.710 Subarea runoff = 0.036(CFS) 70 Total initial stream area = 0.010(Ac.) Process from Point/Station 217.200 to Point/Station 217.000 **** IMPROVED CHANNEL TRAVEL TIME **** Upstream point elevation = 52.900(Ft.) Downstream point elevation = 52.600(Ft.) Channel length thru subarea = 28.000(Ft.) Channel base width = 0.000(Ft.) Slope or 'Z' of left channel bank = 20.000 Slope or 'Z' of right channel bank = 20.000 Estimated mean flow rate at midpoint of channel = 0.071(CFS) Manning's 'N' =0.035 Maximum depth of channel = 0.500(Ft.) Flow(q) thru subarea = 0.071(CFS) Depth of flow = 0.082(Ft.), Average velocity = 0.524(Ft/s) Channel flow top width = 3.295(Ft.) Flow Velocity = 0.52(Ft/s) Travel time = 0.89 min. Time of concentration = 3.15 min. Critical depth = 0.060(Ft.) Adding area flow to channel Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Rainfall intensity = 5.006(In/Hr) for a 10.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.710 CA = 0.021 Subarea runoff = 0.071(CFS) for 0.020(Ac.) Total runoff = 0.107(CFS) Total area = 0.030(Ac.) Depth of flow = 0.096(Ft.), Average velocity = 0.580(Ft/s) Critical depth = 0.071(Ft.) Process from Point/Station 217.200 to Point/Station 217.000 **** CONFLUENCE OF MAIN STREAMS **** The following data inside Main Stream is listed: In Main Stream number: 3 Stream flow area = 0.030(Ac.) Runoff from this stream = 0.107(CFS) Time of concentration = 3.15 min. Rainfall intensity = 5.006(In/Hr) Summary of stream data: Stream Flow rate TC Rainfall Intensity No. (CFS) (min) (In/Hr) 71 1 2 3 Qmax ( 1 ) 0 0 0 = 1 1 1. . 798 .624 .107 .000 * .000 * .000 * 3 9 3 1 0 1. .78 .28 .15 .000 * .408 * .000 * 0 0 0 .798) .624) .107) 5, 3 . 5, + + + . 006 .359 .006 =1.159 Qmax(2) = 0.671 * 1.000 * 0.798) + 1.000 * 1.000 * 0.624) + 0.671 * 1.000 * 0.107) + = 1.231 Qmax(3) = 1.000 * 0.833 * 0.798) + 1.000 * 0.339 * 0.624) + 1.000 * 1.000 * 0.107) + = 0.983 Total of 3 main streams to confluence: Flow rates before confluence point: 0.798 0.624 0.107 Maximum flow rates at confluence using above data: 1.159 1.231 0.983 Area of streams before confluence: 0.310 0.260 0.030 Results of confluence: Total flow rate = 1.231(CFS) Time of concentration = 9.282 min. Effective stream area after confluence = 0.600(Ac.) Process from Point/Station 217.000 to Point/Station 217.300 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 42.450(Ft.) Downstream point/station elevation = 42.050(Ft.) Pipe length = 20.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 1.231(CFS) Nearest computed pipe diameter = 9.00(In.) Calculated individual pipe flow = 1.231(CFS) Normal flow depth in pipe = 4.64(In.) Flow top width inside pipe = 9.00(In.) Critical Depth = 6.12(In.) Pipe flow velocity = 5.36(Ft/s) Travel time through pipe = 0.06 min. Time of concentration (TC) = 9.34 min. Process from Point/Station 217.000 to Point/Station 217.300 **** CONFLUENCE OF MAIN STREAMS **** The following data inside Main Stream is listed: In Main Stream number: 1 Stream flow area = 0.600(Ac.) Runoff from this stream = 1.231(CFS) 72 Time of concentration = 9.34 min. Rainfall intensity = 3.345(In/Hr) Program is now starting with Main Stream No. 2 Process from Point/Station 224.000 to Point/Station 225.000 **** INITIAL AREA EVALUATION **** Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Initial subarea total flow distance = 45.000(Ft.) Highest elevation = 59.600(Ft.) Lowest elevation = 55.800(Ft.) Elevation difference = 3.800(Ft.) Slope = 8.444 % Top of Initial Area Slope adjusted by User to 10.000 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: The maximum overland flow distance is 100.00 (Ft) for the top area slope value of 10.00 %, in a development type of 24.0 DU/A or Less In Accordance With Figure 3-3 Initial Area Time of Concentration = 3.26 minutes TC = [1.8*(1.1-C)*distance(Ft.)A.5)/(% slopeA(l/3)] TC = [1.8* (1.1-0.7100)*( 100.000A.5)/( 10.000*(1/3)]= 3.26 Calculated TC of 3.258 minutes is less than 5 minutes, resetting TC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) = 5.006(In/Hr) for a 10.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.710 Subarea runoff = 0.107(CFS) Total initial stream area = 0.030(Ac.) Process from Point/Station 225.000 to Point/Station 226.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 53.400(Ft.) Downstream point/station elevation = 47.300(Ft.) Pipe length = 52.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.107(CFS) Nearest computed pipe diameter = 3.00(In.) Calculated individual pipe flow = 0.107(CFS) Normal flow depth in pipe = 1.22(In.) Flow top width inside pipe = 2.95(In.) Critical Depth = 2.37(In.) Pipe flow velocity = 5.62(Ft/s) Travel time through pipe = 0.15 min. Time of concentration (TC) = 3.41 min. 73 Process from Point/Station 226.000 to Point/Station **** SUBAREA FLOW ADDITION **** 226.000 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Time of concentration = 3.41 min. Rainfall intensity = 5.006(In/Hr) for a 10.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.710 CA = 0.043 Subarea, runoff = 0.107(CFS) for 0.030(Ac.) Total runoff = 0.213(CFS) Total area = 0.060(Ac.; Process from Point/Station 226.000 to Point/Station 203.100 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 53.000(Ft.) Downstream point/station elevation = 52.720(Ft.) Pipe length = 53.60(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow Nearest computed pipe diameter = Calculated individual pipe flow = Normal flow depth in pipe = 3.09(In.) Flow top width inside pipe = 6.00(In.) Critical Depth = 2.78(In.) Pipe flow velocity = 2.09(Ft/s) Travel time through pipe = 0.43 min. Time of concentration (TC) = 3.84 min. 0.213(CFS) 6.00(In.) 0.213(CFS) Process from Point/Station 226.000 to Point/Station **** CONFLUENCE OF MINOR STREAMS **** 203.000 Along Main Stream number: 2 in normal stream number 1 Stream flow area = 0.060(Ac.) Runoff from this stream = 0.213(CFS) Time of concentration = 3.84 min. Rainfall intensity = 5.006(In/Hr) Process from Point/Station 213.000 to Point/Station **** INITIAL AREA EVALUATION **** 201.000 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL 74 (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Initial subarea total flow distance = 22.000(Ft.) Highest elevation = 56.000(Ft.) Lowest elevation = 55.500 (Ft.) Elevation difference = 0.500(Ft.) Slope = 2.273 % Top of Initial Area Slope adjusted by User to 1.000 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: The maximum overland flow distance is 65.00 (Ft) for the top area slope value of 1.00 %, in a development type of 24.0 DU/A or Less In Accordance With Figure 3-3 Initial Area Time of Concentration = 5.66 minutes TC = [1.8M1.1-C) *distance(Ft.)*.5)/(% slopeA(l/3)] TC = [1,. 8* (1.1-0.7100) *( 65.000A.5)/( 1.000^(1/3)]= 5.66 Rainfall intensity (I) = 4.621(In/Hr) for a 10.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.710 Subarea runoff = 0.033(CFS) Total initial stream area = 0.010(Ac.) Process from Point/Station 201.000 to Point/Station 203.100 **** IMPROVED CHANNEL TRAVEL TIME **** Upstream point elevation = 55.500(Ft.) Downstream point elevation = 54.500(Ft.) Channel length thru subarea = 90.000(Ft.) Channel base width = 4.000(Ft.) Slope or 'ZT of left channel bank = 3.000 Slope or 'Z' of right channel bank = 3.000 Estimated mean flow rate at midpoint of channel = 0.106(CFS) Manning's 'N' =0.250 Maximum depth of channel = 1.000(Ft.) Flow(q) thru subarea = 0.106(CFS) Depth of flow = 0.146(Ft.), Average velocity = 0.162(Ft/s) Channel flow top width = 4.878(Ft.) Flow Velocity = 0.16(Ft/s) Travel time = 9.24 min. Time of concentration = 14.90 min. Critical depth = 0.028(Ft.) Adding area flow to channel Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Rainfall intensity = 2.476(In/Hr) for a 10.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.710 CA = 0.050 Subarea runoff = 0.090(CFS) for 0.060(Ac.) Total runoff = 0.123(CFS) Total area = 0.070(Ac.) Depth of flow = 0.160(Ft.), Average velocity = 0.171(Ft/s) 75 Critical depth =0.031(Ft.) Process from Point/Station 201.000 to Point/Station **** CONFLUENCE OF MINOR STREAMS **** 203.100 Along Main Stream number: 2 in normal stream number 2 Stream flow area = 0.070(Ac.) Runoff from this stream = 0.123(CFS) Time of concentration = 14.90 min. Rainfall intensity = 2.476(In/Hr) Summary of stream data: Stream No. Flow rate (CFS) TC (min) Rainfall Intensity (In/Hr) 1 2 Qmax ( 1 ) 0.213 0.123 = 1.000 * 1.000 * 3.84 14.90 1.000 * 0.258 * Qmax(2) = 0.495 * 1.000 * 1.000 * 1.000 * 5.006 2.476 0.213) + 0.123) + 0.213) + 0.123) + 0.245 0.228 Total of 2 streams to confluence: Flow rates before confluence point: 0.213 0.123 Maximum flow rates at confluence using above data: 0.245 0.228 Area of streams before confluence: 0.060 0.070 Results of confluence: Total flow rate = 0.245(CFS) Time of concentration = 3.840 min. Effective stream area after confluence = 0.130(Ac.) Process from Point/Station 203.100 to Point/Station 229.000 **** piPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 52.550(Ft.) Downstream point/station elevation = 52.390(Ft.) Pipe length = 30.50(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = Nearest computed pipe diameter = Calculated individual pipe flow = 0.245(CFS) Normal flow depth in pipe = 3.35(In.) Flow top width inside pipe = 5.96(In.) Critical Depth = 2.99(In.) Pipe flow velocity = 2.16(Ft/s) Travel time through pipe = 0.23 min. Time of concentration (TC) = 4.07 min. 0.245(CFS) 00(In.) 76 Process from Point/Station 203.100 to Point/Station **** CONFLUENCE OF MINOR STREAMS **** 229.000 Along Main Stream number: 2 in normal stream number 1 Stream flow area = 0.130(Ac.) Runoff from this stream = 0.245(CFS) Time of concentration = 4.07 min. Rainfall intensity = 5.006(In/Hr) Process from Point/Station 224.000 to Point/Station **** INITIAL AREA EVALUATION **** 229.100 49.000(Ft.) 8.367 % Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Initial subarea total flow distance Highest elevation = 59. 600(Ft.) Lowest elevation = 55.500(Ft.) Elevation difference = 4.100(Ft.) Slope = Top of Initial Area Slope adjusted by User to 12.000 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: The maximum overland flow distance is 100.00 (Ft) for the top area slope value of 12.00 %, in a development type of 24.0 DU/A or Less In Accordance With Figure 3-3 Initial Area Time of Concentration = 3.07 minutes TC = [1.8*(l.l-C)*distance(Ft.)*.5)/(% slope"(l/3)] TC = [1.8* (1.1-0.7100)*( 100.000^.5)/( 12 . 000A (1/3)] = 3.07 Calculated TC of 3.066 minutes is less than 5 minutes, resetting TC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) = 5.006(In/Hr) for a 10.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.710 Subarea runoff = 0.071(CFS) Total initial stream area = 0.020(Ac.) Process from Point/Station 229.100 to Point/Station 229.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 52.700(Ft.) Downstream point/station elevation = 52.390(Ft.) Pipe length = 8.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.07KCFS) Nearest computed pipe diameter = 3.00(In.) Calculated individual pipe flow = 0.071(CFS) Normal flow depth in pipe = 1.34(In.) Flow top width inside pipe = 2. 98(In.) 77 Critical Depth = 1.93(In.) Pipe flow velocity = 3.37(Ft/s) Travel time through pipe = 0.04 min. Time of concentration (TC) = 3.11 min. Process from Point/Station 229.100 to Point/Station **** CONFLUENCE OF MINOR STREAMS **** 229. 000 Along Main Stream number: 2 in normal stream number 2 Stream flow area = 0.020(Ac.) Runoff from this stream = 0.071(CFS) Time of concentration = 3.11 min. Rainfall intensity = 5.006(In/Hr) Summary of stream data: Stream No. Flow rate (CFS) TC (min) Rainfall Intensity (In/Hr) 1 2 Qmax ( 1 ) 0.245 0.071 = 1.000 * 1.000 * 4.07 3.11 1.000 * 1.000 * Qmax(2) = 1.000 * 1.000 * 0.762 * 1.000 * 5.006 5. 006 0.245) + 0.071) + 0.245) 0.071) 0.316 0 .258 Total of 2 streams to confluence: Flow rates before confluence point: 0.245 0.071 Maximum flow rates at confluence using above data: 0.316 0.258 Area of streams before confluence: 0.130 0.020 Results of confluence: Total flow rate = 0.316(CFS) Time of concentration = 4.075 min. Effective stream area after confluence = 0.150(Ac.) Process from Point/Station 229.000 to Point/Station 228.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 52.390(Ft.) Downstream point/station elevation = 52.150(Ft.) Pipe length = 48.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = Nearest computed pipe diameter = Calculated individual pipe flow Normal flow depth in pipe = 4.05(In.) Flow top width inside pipe = 5.62(In.) Critical Depth = 3.42(In.) Pipe flow velocity = 2.24(Ft/s) 0.316(CFS) 6.00(In.) 0.316(CFS) 78 Travel time through pipe = 0.36 min. Time of concentration (TC) = 4.43 min. Process from Point/Station 229.000 to Point/Station **** CONFLUENCE OF MINOR STREAMS **** 228.000 Along Main Stream number: 2 in normal stream number 1 Stream flow area = 0.150(Ac.) Runoff from this stream = 0.316(CFS) Time of concentration = 4.43 min. Rainfall intensity = 5.006(In/Hr) Process from Point/Station 224.000 to Point/Station **** INITIAL AREA EVALUATION **** 228.200 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Initial subarea total flow distance = 45.000(Ft.) Highest elevation = 59.600(Ft.) Lowest elevation = 55.500(Ft.) Elevation difference = 4.100(Ft.) Slope = 9.111 % Top of Initial Area Slope adjusted by User to 12.000 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: The maximum overland flow distance is 100.00 (Ft) for the top area slope value of 12.00 %, in a development type of 24.0 DU/A or Less In Accordance With Figure 3-3 Initial Area Time of Concentration = 3.07 minutes TC = [1.8*(l.l-C)*distance(Ft.P.5)/(% slope* (1/3) ] TC = [1.8* (1.1-0.7100)*( 100.000*.5)/( 12 . 000A (1/3)] = 3.07 Calculated TC of 3.066 minutes is less than 5 minutes, resetting TC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) = 5.006(In/Hr) for a 10.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.710 Subarea runoff = 0.107(CFS) Total initial stream area = 0.030(Ac.) Process from Point/Station 228.200 to Point/Station 228.000 **** piPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 52.700(Ft.) Downstream point/station elevation = 52.150 (Ft.) Pipe length = 10.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.107(CFS) Nearest computed pipe diameter = 3.00(In.) 79 Calculated individual pipe flow = O.IOV(CFS) Normal flow depth in pipe = 1.53(In.) Flow top width inside pipe = 3.00(In.) Critical Depth = 2.37(In.) Pipe flow velocity = 4.26(Ft/s) Travel time through pipe = 0.04 min. Time of concentration (TC) = 3.11 min. Process from Point/Station 228.200 to Point/Station **** CONFLUENCE OF MINOR STREAMS **** 228.000 Along Main Stream number: 2 in normal stream number 2 Stream flow area = 0.030(Ac.) Runoff from this stream = 0.107(CFS) Time of concentration = 3.11 min. Rainfall intensity = 5.006(In/Hr) Summary of stream data: Stream No. Flow rate (CFS) TC (min) Rainfall Intensity (In/Hr) 1 2 Qmax ( 1 ) 0.316 0.107 = 1.000 * 1.000 * 4.43 3.11 1.000 * 1.000 * 5.006 5.006 Qmax(2) = 1.000 * 1.000 * 0.701 * 1.000 * 0.316) + 0.107) + 0.316) + 0.107) + 0.423 0.328 Total of 2 streams to confluence: Flow rates before confluence point: 0.316 0.107 Maximum flow rates at confluence using above data: 0.423 0.328 Area of streams before confluence: 0.150 0.030 Results of confluence: Total flow rate = 0.423(CFS) Time of concentration = 4.431 min. Effective stream area after confluence = 0.180(Ac.) Process from Point/Station 228.000 to Point/Station 228.100 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 52.150(Ft.) Downstream point/station elevation = 52.100(Ft.) Pipe length = 7.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.423(CFS) Nearest computed pipe diameter = 6.00(In.) Calculated individual pipe flow = 0.423(CFS) Normal flow depth in pipe = 4.41(In.) 80 Flow top width inside pipe = 5.30(In.) Critical Depth = 3.97(In.) Pipe flow velocity = 2.73(Ft/s) Travel time through pipe = 0.04 min. Time of concentration (TC) = 4.47 min. Process from Point/Station 228.100 to Point/Station 223.000 **** IMPROVED CHANNEL TRAVEL TIME **** Upstream point elevation = 52.100(Ft.) Downstream point elevation = 51.200(Ft.) Channel length thru subarea = 74.000(Ft.) Channel base width = 4.000(Ft.) Slope or 'Z' of left channel bank = 3.000 Slope or 'Z' of right channel bank = 3.000 Estimated mean flow rate at midpoint of channel = 0.540(CFS) Manning's 'N1 = 0.250 Maximum depth of channel = 1.000(Ft.) Flow(q) thru subarea = 0.540(CFS) Depth of flow = 0.365(Ft.), Average velocity = 0.290(Ft/s) Channel flow top width = 6.190(Ft.) Flow Velocity = 0.29(Ft/s) Travel time = 4.25 min. Time of concentration = 8.72 min. Critical depth = 0.081(Ft.) Adding area flow to channel Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Rainfall intensity = 3.497(In/Hr) for a 10.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.710 CA = 0.199 Subarea runoff = 0.272(CFS) for 0.100(Ac.) Total runoff = 0.695(CFS) Total area = 0.280(Ac.) Depth of flow = 0.420(Ft.), Average velocity = 0.314(Ft/s) Critical depth = 0.096(Ft.) Process from Point/Station 223.000 to Point/Station 217.300 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 48.000(Ft.) Downstream point/station elevation = 42.550(Ft.) Pipe length = 63.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.695(CFS) Nearest computed pipe diameter = 6.00(In.) Calculated individual pipe flow = 0.695(CFS) Normal flow depth in pipe = 2.72(In.) Flow top width inside pipe = 5.97(In.) 81 Critical Depth = 5.05(In.) Pipe flow velocity = 8.05(Ft/s) Travel time through pipe = 0.13 min. Time of concentration (TC) = 8.85 min. Process from Point/Station 223.000 to Point/Station **** CONFLUENCE OF MAIN STREAMS **** 217.300 The following data inside Main Stream is listed: In Main Stream number: 2 Stream flow area = 0.280(Ac.) Runoff from this stream = 0.695(CFS) Time of concentration = 8.85 min. Rainfall intensity = 3.463(In/Hr) Summary of stream data: Stream No. Flow rate (CFS) TC (min) Rainfall Intensity (In/Hr) 1 2 Qmax(1) = Qmax(2) = 1.231 0.695 = 1.000 * 0.966 * 1.000 * 1.000 * 9.34 8.85 3 .345 3.463 1.000 * 1.000 * 0.947 * 1.000 * 1.231) + 0.695) + 1.231) + 0.695) + 1.903 1.862 Total of 2 main streams to confluence: Flow rates before confluence point: 1.231 0.695 Maximum flow rates at confluence using above data: 1.903 1.862 Area of streams before confluence: 0.600 0.280 Results of confluence: Total flow rate = 1.903(CFS) Time of concentration = 9.344 min. Effective stream area after confluence 0.880(Ac.) Process from Point/Station 217.300 to Point/Station 217.400 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 42.050 (Ft.) Downstream point/station elevation = 37.990(Ft.) Pipe length = 3.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 1.903(CFS) Nearest computed pipe diameter = 6.00(In.) Calculated individual pipe flow = 1.903(CFS) Normal flow depth in pipe = 2.22(In.) 82 Flow top width inside pipe = 5.79(In.) Critical depth could not be calculated. Pipe flow velocity = 28.84(Ft/s) Travel time through pipe = 0.00 min. Time of concentration (TC) = 9.35 min. End of computations, total study area = 0.880 (Ac.) 83 San Diego County Rational Hydrology Program CIVILCADD/CIVILDESIGN Engineering Software,(c)1991-2004 Version 7.4 Rational method hydrology program based on San Diego County Flood Control Division 2003 hydrology manual Rational Hydrology Study Date: 05/05/08 100 Year Proposed Hydrology for Vista La Costa JN 031060 NF 5/5/08 G:\ACCTS\031060\REVISEDSITE\V100 *********Hydrology Study Control Information ********** Program License Serial Number 5014 Rational hydrology study storm event year is 100.0 English (in-lb) input data Units used Map data precipitation entered: 6 hour, precipitation(inches) = 2.800 24 hour precipitation(inches) = 5.000 P6/P24 = 56.0% San Diego hydrology manual 'C' values used Process from Point/Station 203.000 to Point/Station 204.000 **** INITIAL AREA EVALUATION **** Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Initial subarea total flow distance = 50.000(Ft.) Highest elevation = 56.300(Ft.) Lowest elevation = 55.300(Ft.) Elevation difference = 1.000(Ft.) Slope = 2.000 % Top of Initial Area Slope adjusted by User to 1.000 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: The maximum overland flow distance is 65.00 (Ft) for the top area slope value of 1.00 %, in a development type of 24.0 DU/A or Less 84 In Accordance With Table 3-2 Initial Area Time of Concentration = 9.50 minutes (for slope value of 1.00 %) Rainfall intensity (I) = 4.876(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.710 Subarea runoff = 0.069(CFS) Total initial stream area = 0.020(Ac.) Process from Point/Station 204.000 to Point/Station 205.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 52.200(Ft.) Downstream point/station elevation = 51.800(Ft.) Pipe length = 17.70(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.069(CFS) Nearest computed pipe diameter = 3.00(In.) Calculated individual pipe flow = 0.069(CFS) Normal flow depth in pipe = 1.53(In.) Flow top width inside pipe = 3.00(In.) Critical Depth = 1.91(In.) Pipe flow velocity = 2.73(Ft/s) Travel time through pipe = 0.11 min. Time of concentration (TC) = 9.61 min. Process from Point/Station 204.000 to Point/Station 205.000 **** CONFLUENCE OF MAIN STREAMS **** The following data inside Main Stream is listed: In Main Stream number: 1 Stream flow area = 0.020(Ac.) Runoff from this stream = 0.069(CFS) Time of concentration = 9.61 min. Rainfall intensity = 4.841(In/Hr) Program is now starting with Main Stream No. 2 Process from Point/Station 206.100 to Point/Station 206.200 **** INITIAL AREA EVALUATION **** Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Initial subarea total flow distance = 70.000(Ft.) Highest elevation = 59.200(Ft.) Lowest elevation = 58.500(Ft.) Elevation difference = 0.700(Ft.) Slope = 1.000 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: 85 The maximum overland flow distance is 65.00 (Ft) for the top area slope value of 1.00 %, in a development type of 24.0 DU/A or Less In Accordance With Figure 3-3 Initial Area Time of Concentration = 5.66 minutes TC = [1.8*(1.1-C)*distance(Ft.)A.5)/(% slopeA(l/3)] TC = [1.8*(1.1-0.7100)*( 65.000A.5)/( 1.000^(1/3)]= 5.66 The initial area total distance of 70.00 (Ft.) entered leaves a remaining distance of 5.00 (Ft.) Using Figure 3-4, the travel time for this distance is 0.16 minutes for a distance of 5.00 (Ft.) and a slope of 1.00 % with an elevation difference of 0.05(Ft.) from the end of the top area Tt = [11.9*length(Mi)*3)/(elevation change(Ft.))]*.385 *60(min/hr) 0.159 Minutes Tt=[(ll,.9*0.0009A3)/( 0.05)]A.385= 0.16 Total initial area Ti = 5.66 minutes from Figure 3-3 formula plus 0.16 minutes from the Figure 3-4 formula = 5.82 minutes Rainfall intensity (I) = 6.690(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.710 Subarea runoff = 0.142(CFS) Total initial stream area = 0.030(Ac.) Process from Point/Station 206.200 to Point/Station 211.000 **** IMPROVED CHANNEL TRAVEL TIME **** Upstream point elevation = 58.500(Ft.) Downstream point elevation = 57.600(Ft.) Channel length thru subarea = 85.000(Ft.) Channel base width = 0.000(Ft.) Slope or 'Z' of left channel bank = 10.000 Slope or 'Z' of right channel bank = 10.000 Estimated mean flow rate at midpoint of channel = 0.309(CFS) Manning's 'N' = 0.045 Maximum depth of channel = 0.500(Ft.) Flow(q) thru subarea = 0.309(CFS) Depth of flow = 0.204(Ft.), Average velocity = 0.740(Ft/s) Channel flow top width = 4.085(Ft.) Flow Velocity = 0.74(Ft/s) Travel time = 1.91 min. Time of concentration = 7.73 min. Critical depth = 0.143(Ft.) Adding area flow to channel Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Rainfall intensity = 5.569(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.710 CA = 0.071 Subarea runoff = 0.253(CFS) for 0.070(Ac.) 86 Total runoff = Depth of flow = Critical depth = 0.395(CFS) Total area = 0.224(Ft.), Average velocity = 0.157(Ft.) 0.100(Ac.) 0.787(Ft/s) Process from Point/Station 211.000 to Point/Station 205.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 54. 600 (Ft.) Downstream point/station elevation = 51. 800 (Ft.) Pipe length = 48. 60 (Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = Nearest computed pipe diameter = Calculated individual pipe flow = Normal flow depth in pipe = 2. 23 (In.) Flow top width inside pipe = 5. 80 (In.) Critical Depth = 3. 84 (In.) Pipe flow velocity = 5.96(Ft/s) Travel time through pipe = 0.14 min. Time of concentration (TC) = 7.87 min. 0.395(CFS) 6. 00 (In.) 0.395(CFS) Process from Point/Station 211.000 to Point/Station **** CONFLUENCE OF MAIN STREAMS **** 205.000 The following data inside Main Stream is listed: In Main Stream number: 2 Stream flow area = 0.100(Ac.) Runoff from this stream = 0.395(CFS) Time of concentration = 7.87 min. Rainfall intensity = 5.506(In/Hr) Summary of stream data: Stream No. Flow rate (CFS) TC (min) Rainfall Intensity (In/Hr) 1 2 Qmax(1) = Qmax(2) = 0.069 0 .395 1.000 * 0.879 * 1.000 * 1.000 * 9.61 7 .87 1.000 * 1.000 * 0.819 * 1.000 * 4.841 5.506 0.069) + 0.395) + 0.069) + 0.395) + 0.417 0.452 Total of 2 main streams to confluence: Flow rates before confluence point: 0.069 0.395 Maximum flow rates at confluence using above data: 0.417 0.452 Area of streams before confluence: 0.020 0.100 87 Results of confluence: Total flow rate = 0.452(CFS) Time of concentration = 7.869 min. Effective stream area after confluence = 0.120(Ac.) Process from Point/Station 205.000 to Point/Station 212.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 51.800(Ft.) Downstream point/station elevation = 43.300(Ft.) Pipe length = 82.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.452(CFS) Nearest computed pipe diameter = 6.00(In.) Calculated individual pipe flow = 0.452(CFS) Normal flow depth in pipe = 2.04(In.) Flow top width inside pipe = 5.69(In.) Critical Depth = 4.11(In.) Pipe flow velocity = 7.65(Ft/s) Travel time through pipe = 0.18 min. Time of concentration (TC) = 8.05 min. Process from Point/Station 205.000 to Point/Station 212.000 **** CONFLUENCE OF MAIN STREAMS **** The following data inside Main Stream is listed: In Main Stream number: 1 Stream flow area = 0.120(Ac.) Runoff from this stream = 0.452(CFS) Time of concentration = 8.05 min. Rainfall intensity = 5.427(In/Hr) Program is now starting with Main Stream No. 2 Process from Point/Station 213.000 to Point/Station 214.000 **** INITIAL AREA EVALUATION **** Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Initial subarea total flow distance = 59.000(Ft.) Highest elevation = 56.000(Ft.) Lowest elevation = 55.000(Ft.) Elevation difference = 1.000(Ft.) Slope = 1.695 % Top of Initial Area Slope adjusted by User to 10.698 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: The maximum overland flow distance is 100.00 (Ft) for the top area slope value of 10.70 %, in a development type of 24.0 DU/A or Less In Accordance With Figure 3-3 Initial Area Time of Concentration = 3.19 minutes TC = [1.8*(l.l-C)*distance(Ft.)A.5)/(% slope*(1/3)] TC = [1.8*(1.1-0.7100)*( 100.000*.5)/( 10.698*(1/3)]= 3.19 Calculated TC of 3.186 minutes is less than 5 minutes, resetting TC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) = 7.377(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.710 Subarea runoff = 0.210(CFS) Total initial stream area = 0.040(Ac.) Process from Point/Station 214.000 to Point/Station 215.000 **** IRREGULAR CHANNEL FLOW TRAVEL TIME **** Estimated mean flow rate at midpoint of channel = 0.602(CFS) Depth of flow = 0.135(Ft.), Average velocity = 5.549(Ft/s) ******* irregular Channel Data *********** Information entered for subchannel number 1 : Point number 'X' coordinate 'Y' coordinate 1 2 3 4 Manning ' s ' N ' 0.00 17.50 18.83 19 . 00 friction factor = 0.47 0.12 0.00 0 .50 0.013 Sub-Channel flow = 0.602(CFS) 1 ' flow top width = 2.128(Ft.) 1 ' velocity= 5.549(Ft/s) 1 ' area = 0.109(Sq.Ft) ' ' Froude number = 4.329 Upstream point elevation = 54.100(Ft.) Downstream point elevation = 46.410(Ft.) Flow length = 58.000(Ft.) Travel time = 0.17 min. Time of concentration = 3.36 min. Depth of flow = 0.135(Ft.) Average velocity = 5.549(Ft/s) Total irregular channel flow = 0.602(CFS) Irregular channel normal depth above invert elev. = 0.135(Ft.) Average velocity of channel(s) = 5.549(Ft/s) Adding area flow to channel Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Rainfall intensity = 7.377(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.710 CA = 0.135 89 Subarea runoff = Total runoff = Depth of flow = 0.786(CFS) for 0.150(Ac.) 0.995(CFS) Total area = 0.190(Ac.) 0.159(Ft.), Average velocity = 5.683 (Ft/s) Process from Point/Station 215.000 to Point/Station 212.000 **** piPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 44.500(Ft.) Downstream point/station elevation = 43.300(Ft.) Pipe length = 5.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.995(CFS) Nearest computed pipe diameter = 6.00(In.) Calculated individual pipe flow = 0.995(CFS) Normal flow depth in pipe = 2.50(In.) Flow top width inside pipe = 5.92(In.) Critical Depth = 5.66(In.) Pipe flow velocity = 12.88(Ft/s) Travel time through pipe = 0.01 min. Time of concentration (TC) = 3.37 min. Process from Point/Station 215.000 to Point/Station **** CONFLUENCE OF MAIN STREAMS **** 212.000 The following data inside Main Stream is listed: In Main Stream number: 2 Stream flow area = 0.190(Ac.) Runoff from this stream = 0.995(CFS) Time of concentration = 3.37 min. Rainfall intensity = 7.377(In/Hr) Summary of stream data: Stream No. Flow rate (CFS) TC (min) Rainfall Intensity (In/Hr) 1 2 Qmax(1) = 0 .452 0.995 1.000 * 0.736 * Qmax(2) = 1.000 1.000 8.05 3.37 1.000 * 1.000 * 0.418 * 1.000 * 5.427 7.377 0.452) + 0.995) + 0.452) + 0.995) + 1.184 1.184 Total of 2 main streams to confluence: Flow rates before confluence point: 0.452 0.995 Maximum flow rates at confluence using above data: 1.184 1.184 Area of streams before confluence: 0.120 0.190 90 Results of confluence: Total flow rate = 1.184(CFS) Time of concentration = 3.367 min. Effective stream area after confluence = 0.310(Ac. Process from Point/Station 212.000 to Point/Station 217.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 43.100(Ft.) Downstream point/station elevation = 42.780(Ft.) Pipe length = 70.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 1.184(CFS) Nearest computed pipe diameter = 12.00(In.) Calculated individual pipe flow = 1.184(CFS) Normal flow depth in pipe = 5.94(In.) Flow top width inside pipe = 12.00(In.) Critical Depth = 5.50(In.) Pipe flow velocity = 3.05(Ft/s) Travel time through pipe = 0.38 min. Time of concentration (TC) = 3.75 min. Process from Point/Station 212.000 to Point/Station 217.000 **** CONFLUENCE OF MAIN STREAMS **** The following data inside Main Stream is listed: In Main Stream number: 1 Stream flow area = 0.310(Ac.) Runoff from this stream = 1.184(CFS) Time of concentration = 3.75 min. Rainfall intensity = 7.377(In/Hr) Program is now starting with Main Stream No. 2 Process from Point/Station 206.000 to Point/Station 207.000 **** INITIAL AREA EVALUATION **** Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Initial subarea total flow distance = 55.000(Ft.) Highest elevation = 64.000(Ft.) Lowest elevation = 57.050(Ft.) Elevation difference = 6.950(Ft.) Slope = 12.636 % Top of Initial Area Slope adjusted by User to 10.000 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: The maximum overland flow distance is 100.00 (Ft) for the top area slope value of 10.00 %, in a development type of 91 24.0 DU/A or Less In Accordance With Figure 3-3 Initial Area Time of Concentration = 3.26 minutes TC = [1.8*(1.1-C)*distance(Ft.)A.5)/(% slope*(1/3)] TC = [1. 8*(1.1-0. 7100)*( 100.000*.5)/( 10 . 000* (1/3)]= 3.26 Calculated TC of 3.258 minutes is less than 5 minutes, resetting TC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) = 7.377(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.710 Subarea runoff = 0.210(CFS) Total initial stream area = 0.040(Ac.) Process from Point/Station 207.000 to Point/Station 208.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 57.050(Ft.) Downstream point/station elevation = 56.870(Ft.) Pipe length = 38.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.210(CFS) Nearest computed pipe diameter = 6.00(In.) Calculated individual pipe flow = 0.210(CFS) Normal flow depth in pipe = 3.14(In.) Flow top width inside pipe = 5.99(In.) Critical Depth = 2.75(In.) Pipe flow velocity = 2.00(Ft/s) Travel time through pipe = 0.32 min. Time of concentration (TC) = 3.57 min. Process from Point/Station 208.000 to Point/Station **** SUBAREA FLOW ADDITION **** 208.000 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Time of concentration = 3.57 min. Rainfall intensity = 7.377(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.710 CA = 0.050 Subarea runoff = 0.157(CFS) for 0.030(Ac.) Total runoff = 0.367(CFS) Total area = 0.070(Ac.) Process from Point/Station 208.000 to Point/Station 209.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = Downstream point/station elevation = 56.870(Ft.) 56.600(Ft.) 92 Pipe length = 53.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.367(CFS) Nearest computed pipe diameter = 6.00(In.) Calculated individual pipe flow = 0.367(CFS) Normal flow depth in pipe = 4.52(In.) Flow top width inside pipe = 5.17(In.) Critical Depth = 3.69(In.) Pipe flow velocity = 2.31(Ft/s) Travel time through pipe = 0.38 min. Time of concentration (TC) = 3.96 min. Process from Point/Station 209.000 to Point/Station 210.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 56.600(Ft.) Downstream point/station elevation = 56.390(Ft.) Pipe length = 29.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.367(CFS) Nearest computed pipe diameter = 6.00(In.) Calculated individual pipe flow = 0.367(CFS) Normal flow depth in pipe = 3.94(In.) Flow top width inside pipe = 5.70(In.) Critical Depth = 3.69(In.) Pipe flow velocity = 2.68(Ft/s) Travel time through pipe = 0.18 min. Time of concentration (TC) = 4.14 min. Process from Point/Station 210.000 to Point/Station **** SUBAREA FLOW ADDITION **** 210 .000 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Time of concentration = 4.14 min. Rainfall intensity = 7.377(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.710 CA = 0.071 Subarea runoff = 0.157(CFS) for 0.030(Ac.) Total runoff = 0.524(CFS) Total area = 0.100(Ac.) Process from Point/Station 210.000 to Point/Station 220.200 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 56.390(Ft.) Downstream point/station elevation = 56.110(Ft.) Pipe length = 54.00(Ft.) Manning's N = 0.013 93 No. of pipes = 1 Required pipe flow = 0.524(CFS) Nearest computed pipe diameter = 9.00(In.) Calculated individual pipe flow = 0.524(CFS) Normal flow depth in pipe = 4.18(In.) Flow top width inside pipe = 8.98(In.) Critical Depth = 3.92(In.) Pipe flow velocity = 2.61(Ft/s) Travel time through pipe = 0.34 min. Time of concentration (TC) = 4.48 min. Process from Point/Station 220.200 to Point/Station **** SUBAREA FLOW ADDITION **** 220.200 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Time of concentration = 4.48 min. Rainfall intensity = 7.377(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.710 CA = 0.085 Subarea runoff = O.IOB(CFS) for 0.020(Ac.) Total runoff = 0.629(CFS) Total area = 0.120(Ac.) Process from Point/Station 220.200 to Point/Station 220.000 **** pipEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 56.110(Ft.) Downstream point/station elevation = 56.000(Ft.) Pipe length = 23.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow Nearest computed pipe diameter = Calculated individual pipe flow = Normal flow depth in pipe = 4.76(In.) Flow top width inside pipe = 8.99(In.) Critical Depth = 4.32(In.) Pipe flow velocity = 2.65(Ft/s) Travel time through pipe = 0.14 min. Time of concentration (TC) = 4.63 min. 0.629(CFS) 9.00(In.) 0.629(CFS) Process from Point/Station 220.200 to Point/Station **** CONFLUENCE OF MINOR STREAMS **** 220.000 Along Main Stream number: 2 in normal stream number 1 Stream flow area = 0.120(Ac.) Runoff from this stream = 0.629(CFS) Time of concentration = 4.63 min. 94 Rainfall intensity = 7.377(In/Hr) Process from Point/Station 206.000 to Point/Station 218.000 **** INITIAL AREA EVALUATION **** Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Initial subarea total flow distance = 62.000(Ft.) Highest, elevation = 64. 000 (Ft.) Lowest elevation = 59.300(Ft.) Elevation difference = 4.700(Ft.) Slope = 7.581 % Top of Initial Area Slope adjusted by User to 2.581 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: The maximum overland flow distance is 90.00 (Ft) for the top area slope value of 2.58 %, in a development type of 24.0 DU/A or Less In Accordance With Figure 3-3 Initial Area Time of Concentration = 4.86 minutes TC = [1.8*(1.1-C)*distance(Ft.)A.5)/(% slopeA(l/3)] TC = [1. 8*(1.1-0.7100)*( 90.000A.5)/( 2 . 581A(1/3)]= 4.86 Calculated TC of 4.855 minutes is less than 5 minutes, resetting TC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) = 7.377(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.710 Subarea runoff = 0.157(CFS) Total initial stream area = 0.030(Ac.) Process from Point/Station 218.000 to Point/Station 219.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 56.410 (Ft.) Downstream point/station elevation = 56.210(Ft.) Pipe length = 40.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.157(CFS) Nearest computed pipe diameter = 6.00(In.) Calculated individual pipe flow = 0.157(CFS) Normal flow depth in pipe = 2.63(In.) Flow top width inside pipe = 5.95(In.) Critical Depth = 2.37(In.) Pipe flow velocity = 1.90(Ft/s) Travel time through pipe = 0.35 min. Time of concentration (TC) = 5.21 min. Process from Point/Station 219.000 to Point/Station 219.000 **** SUBAREA FLOW ADDITION **** 95 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Time of concentration = 5.21 min. Rainfall intensity = 7.188(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.710 CA = 0.043 Subarea runoff = 0.149(CFS) for 0.030(Ac.) Total runoff = 0.306(CFS) Total area = 0.060(Ac.; Process from Point/Station 219.000 to Point/Station 220.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 56.210(Ft.) Downstream point/station elevation = 56.000(Ft.) Pipe length = 43.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.306(CFS) Nearest computed pipe diameter = 6.00(In.) Calculated individual pipe flow = 0.306(CFS) Normal flow depth in pipe = 3.98(In.) Flow top width inside pipe = 5.67(In.) Critical Depth = 3.36(In.) Pipe flow velocity = 2.21(Ft/s) Travel time through pipe = 0.32 min. Time of concentration (TC) = 5.53 min. Process from Point/Station 219.000 to Point/Station 220.000 **** CONFLUENCE OF MINOR STREAMS **** Along Main Stream number: 2 in normal stream number 2 Stream flow area = 0.060(Ac.) Runoff from this stream = 0.306(CFS) Time of concentration = 5.53 min. Rainfall intensity = 6.913(In/Hr) Summary of stream data: Stream Flow rate TC Rainfall Intensity No. (CFS) (min) (In/Hr) 1 0.629 4.63 7.377 2 0.306 5.53 6.913 Qmax(1) = 1.000 * 1.000 * 0.629) + 1.000 * 0.837 * 0.306) + = 0.885 Qmax(2) = 0.937 * 1.000 * 0.629) + 96 1.000 * 1.000 * 0.306) + = 0.895 Total of 2 streams to confluence: Flow rates before confluence point: 0.629 0.306 Maximum flow rates at confluence using above data: 0.885 0.895 Area of streams before confluence: 0.120 0.060 Results of confluence: Total flow rate = 0.895(CFS) Time of concentration = 5.530 min. Effective stream area after confluence = 0.180(Ac.) Process^ from Point/Station 220.000 to Point/Station 222.000 **** IMPROVED CHANNEL TRAVEL TIME **** Upstream point elevation = 56.000(Ft.) Downstream point elevation = 55.000(Ft.) Channel length thru subarea = 70.000(Ft.) Channel base width = 4.000(Ft.) Slope or 'Z' of left channel bank = 3.000 Slope or 'Z' of right channel bank = 3.000 Estimated mean flow rate at midpoint of channel = 0.968(CFS) Manning's 'N' = 0.250 Maximum depth of channel = 1.000(Ft.) Flow(q) thru subarea = 0.968(CFS) Depth of flow = 0.483(Ft.), Average velocity = 0.368(Ft/s) Channel flow top width = 6.897(Ft.) Flow Velocity = 0.37(Ft/s) Travel time = 3.17 min. Time of concentration = 8.70 min. Critical depth = 0.119(Ft.) Adding area flow to channel Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Rainfall intensity = 5.161(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.710 CA = 0.185 Subarea runoff = 0.058(CFS) for 0.080(Ac.) Total runoff = 0.953(CFS) Total area = 0.260(Ac.) Depth of flow = 0.479(Ft.), Average velocity = 0.366(Ft/s) Critical depth = 0.117(Ft.) Process from Point/Station 222.000 to Point/Station 217.000 **** pipEFLOW TRAVEL TIME (Program estimated size) **** 97 Upstream point/station elevation = 51. 830(Ft.) Downstream point/station elevation = 42.950(Ft.) Pipe length = 53.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = Nearest computed pipe diameter = Calculated individual pipe flow = Normal flow depth in pipe = 2.69(In.) Flow top width inside pipe = 5.97(In.) Critical Depth = 5.61(In.) Pipe flow velocity = 11.15(Ft/s) Travel time through pipe = 0.08 min. Time of concentration (TC) = 8.78 min. 0.953(CFS) 6.00(In.) 0.953(CFS) Process from Point/Station 222.000 to Point/Station **** CONFLUENCE OF MAIN STREAMS **** 217.000 The following data inside Main Stream is listed: In Main Stream number: 2 Stream flow area = 0.260(Ac.) Runoff from this stream = 0.953(CFS) Time of concentration = 8.78 min. Rainfall intensity = 5.131(In/Hr) Program is now starting with Main Stream No. 3 Process from Point/Station 217.100 to Point/Station **** INITIAL AREA EVALUATION **** 217.200 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Initial subarea total flow distance = 7.000(Ft.) Highest elevation = 56.300(Ft.) Lowest elevation = 53.500(Ft.) Elevation difference = 2.800(Ft.) Slope = 40.000 % Top of Initial Area Slope adjusted by User to 30.000 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: The maximum overland flow distance is 100.00 (Ft) for the top area slope value of 30.00 %, in a development type of 24.0 DU/A or Less In Accordance With Figure 3-3 Initial Area Time of Concentration = 2.26 minutes TC = [1.8*(1.1-C)*distance(Ft.)A.5)/(% slopeA(l/3)] TC = [1.8* (1.1-0.7100)*( 100.000".5)/( 30.000A(1/3)]= 2.26 Calculated TC of 2.259 minutes is less than 5 minutes, resetting TC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) = 7.377(ln/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.710 Subarea runoff = 0.052(CFS) Total initial stream area = 0.010(Ac.) Process from Point/Station 217.200 to Point/Station 217.000 **** IMPROVED CHANNEL TRAVEL TIME **** Upstream point elevation = 52.900(Ft.) Downstream point elevation = 52. 600(Ft.) Channel length thru subarea = 28.000(Ft.) Channel base width = 0.000 (Ft.) Slope or 'Z' of left channel bank = 20.000 Slope or 'Z' of right channel bank = 20.000 Estimated mean flow rate at midpoint of channel = 0.105(CFS) Manning's 'N1 = 0.035 Maximum depth of channel = 0.500(Ft.) Flow(q) thru subarea = 0.105(CFS) Depth of flow = 0.095 (Ft.), Average velocity = 0.577(Ft/s) Channel flow top width = 3.811(Ft.) Flow Velocity = 0.58(Ft/s) Travel time = 0.81 min. Time of concentration = 3.07 min. Critical depth = 0.070(Ft.) Adding area flow to channel Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Rainfall intensity = 7.377(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.710 CA = 0.021 Subarea runoff = O.IOS(CFS) for 0.020(Ac.) Total runoff = 0.157(CFS) Total area = 0.030(Ac.) Depth of flow = 0.111(Ft.), Average velocity = 0.639(Ft/s) Critical depth = 0.083(Ft.) Process from Point/Station 217.200 to Point/Station 217.000 **** CONFLUENCE OF MAIN STREAMS **** The following data inside Main Stream is listed: In Main Stream number: 3 Stream flow area = 0.030(Ac.) Runoff from this stream = 0.157(CFS) Time of concentration = 3.07 min. Rainfall intensity = 7.377(In/Hr) Summary of stream data: Stream Flow rate TC Rainfall Intensity No. (CFS) (min) (In/Hr) 99 1 2 3 Qmax ( 1 ) 1 0 0 = 1 1 1 .184 .953 .157 .000 * .000 * .000 * 3 8 3 1 0 1 .75 .78 .07 .000 * .427 * .000 * 1 0 0 .184) .953) .157) 7 5 7 + + + .377 .131 .377 =1.748 Qmax(2) = 0.696 * 1.000 * 1.184) + 1.000 * 1.000 * 0.953) + 0.696 * 1.000 * 0.157) + = 1.886 Qmax(3) = 1.000 * 0.818 * 1.184) + 1.000 * 0.350 * 0.953) + 1.000 * 1.000 * 0.157) + = 1.459 Total of 3 main streams to confluence: Flow rates before confluence point: 1.184 0.953 0.157 Maximum flow rates at confluence using above data: 1.748 1.886 1.459 Area of streams before confluence: 0.310 0.260 0.030 Results of confluence: Total flow rate = 1.886(CFS) Time of concentration = 8.778 min. Effective stream area after confluence = 0.600(Ac.) Process from Point/Station 217.000 to Point/Station 217.300 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 42.450(Ft.) Downstream point/station elevation = 42.050(Ft.) Pipe length = 20.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 1.886(CFS) Nearest computed pipe diameter = 9.00(In.) Calculated individual pipe flow = 1.886(CFS) Normal flow depth in pipe = 6.12(In.) Flow top width inside pipe = 8.39(In.) Critical Depth = 7.52(In.) Pipe flow velocity = 5.89(Ft/s) Travel time through pipe = 0.06 min. Time of concentration (TC) = 8.83 min. Process from Point/Station 217.000 to Point/Station 217.300 **** CONFLUENCE OF MAIN STREAMS **** The following data inside Main Stream is listed: In Main Stream number: 1 Stream flow area = 0.600(Ac.) Runoff from this stream = 1.886(CFS) 100 Time of concentration = 8.83 min. Rainfall intensity = 5.110(In/Hr) Program is now starting with Main Stream No. 2 Process from Point/Station 224.000 to Point/Station 225.000 **** INITIAL AREA EVALUATION **** Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Initial subarea total flow distance = 45.000(Ft.) Highest elevation = 59.600(Ft.) Lowest elevation = 55.800(Ft.) Elevation difference = 3.800(Ft.) Slope = 8.444 % Top of Initial Area Slope adjusted by User to 10.000 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: The maximum overland flow distance is 100.00 (Ft) for the top area slope value of 10.00 %, in a development type of 24.0 DU/A or Less In Accordance With Figure 3-3 Initial Area Time of Concentration = 3.26 minutes TC = [1.8*(l.l-C)*distance(Ft.)A.5)/(% slope" (1/3)] TC = [1.8*(1.1-0.7100)*( 100.000*.5)/( 10.000A (1/3)]= 3.26 Calculated TC of 3.258 minutes is less than 5 minutes, resetting TC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) = 7.377(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.710 Subarea runoff = 0.157(CFS) Total initial stream area = 0.030(Ac.) Process from Point/Station 225.000 to Point/Station 226.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 53.400(Ft.) Downstream point/station elevation = 47.300(Ft.) Pipe length = 52.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.157(CFS) Nearest computed pipe diameter = 3.00(In.) Calculated individual pipe flow = 0.157(CFS) Normal flow depth in pipe = 1.53(In.) Flow top width inside pipe = 3.00(In.) Critical Depth = 2.75(In.) Pipe flow velocity = 6.21(Ft/s) Travel time through pipe = 0.14 min. Time of concentration (TC) = 3.40 min. 101 Process from Point/Station 226.000 to Point/Station **** SUBAREA FLOW ADDITION **** 226.000 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Time of concentration = 3.40 min. Rainfall intensity = 7.377(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.710 CA = 0.043 Subarea runoff = 0.157(CFS) for 0.030(Ac.) Total runoff = 0.314(CFS) Total area = 0.060(Ac.) Process from Point/Station 226.000 to Point/Station 203.100 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 53.000(Ft.) Downstream point/station elevation = 52.720(Ft.) Pipe length = 53.60(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.314(CFS) Nearest computed pipe diameter = 6.00(In.) Calculated individual pipe flow = 0.314(CFS) Normal flow depth in pipe = 3.96(In.) Flow top width inside pipe = 5.68(In.) Critical Depth = 3.41(In.) Pipe flow velocity = 2.28(Ft/s) Travel time through pipe = 0.39 min. Time of concentration (TC) = 3.79 min. Process from Point/Station 226.000 to Point/Station **** CONFLUENCE OF MINOR STREAMS **** 203.000 Along Main Stream number: 2 in normal stream number 1 Stream flow area = 0.060(Ac.) Runoff from this stream = 0.314(CFS) Time of concentration = 3.79 min. Rainfall intensity =7.377(In/Hr) Process from Point/Station 213.000 to Point/Station **** INITIAL AREA EVALUATION **** 201.000 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL 102 (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Initial subarea total flow distance = 22.000(Ft.) Highest elevation = 56.000(Ft.) Lowest elevation = 55.500(Ft.) Elevation difference = 0.500(Ft.) Slope = 2.273 % Top of Initial Area Slope adjusted by User to 1.000 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: The maximum overland flow distance is 65.00 (Ft) for the top area slope value of 1.00 %, in a development type of 24.0 DU/A or Less In Accordance With Figure 3-3 Initial Area Time of Concentration = 5.66 minutes TC = [1.8*(l.l-C)*distance(Pt.)A.5)/(% slopeA(l/3)] TC = [1.8* (1.1-0.7100)*( 65.000A.5)/( 1.000^(1/3)]= 5.66 Rainfall intensity (I) = 6.810(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.710 Subarea runoff = 0.048(CFS) Total initial stream area = 0.010(Ac.) Process from Point/Station 201.000 to Point/Station 203.100 **** IMPROVED CHANNEL TRAVEL TIME **** Upstream point elevation = 55.500(Ft.) Downstream point elevation = 54.500(Ft.) Channel length thru subarea = 90.000(Ft.) Channel base width = 4.000 (Ft.) Slope or 'Z1 of left channel bank = 3.000 Slope or 'Z' of right channel bank = 3.000 Estimated mean flow rate at midpoint of channel = 0.158(CFS) Manning's 'N' =0.250 Maximum depth of channel = 1.000(Ft.) Flow(q) thru subarea = 0.158(CFS) Depth of flow = 0.185(Ft.), Average velocity = 0.187(Ft/s) Channel flow top width = 5.112(Ft.) Flow Velocity = 0.19(Ft/s) Travel time = 8.02 min. Time of concentration = 13.68 min. Critical depth = 0.036(Ft.) Adding area flow to channel Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Rainfall intensity = 3.855(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.710 CA = 0.050 Subarea runoff = 0.143(CFS) for 0.060(Ac.) Total runoff = 0.192(CFS) Total area = 0.070(Ac.) Depth of flow = 0.207(Ft.), Average velocity = 0.200(Ft/s) 103 Critical depth =0.041(Ft.) Process from Point/Station 201.000 to Point/Station **** CONFLUENCE OF MINOR STREAMS **** 203.100 Along Main Stream number: 2 in normal stream number 2 Stream flow area = 0.070(Ac.) Runoff from this stream = 0.192(CFS) Time of concentration = 13.68 min. Rainfall intensity = 3.855(In/Hr) Summary of stream data: Stream No. Flow rate (CFS) TC (min) Rainfall Intensity (In/Hr) 1 2 Qmax ( 1 ) 0.314 0.192 = 1.000 * 1.000 * 3.79 13.68 1.000 * 0.277 * Qmax(2) = 0.523 1.000 1.000 * 1.000 * 7.377 3.855 0.314) + 0.192) + 0.314) 0.192) 0.367 0.356 Total of 2 streams to confluence: Flow rates before confluence point: 0.314 0.192 Maximum flow rates at confluence using above data: 0.367 0.356 Area of streams before confluence: 0.060 0.070 Results of confluence: Total flow rate = 0.367(CFS) Time of concentration = 3.790 min. Effective stream area after confluence = 0.130(Ac.) Process from Point/Station 203.100 to Point/Station 229.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 52.550(Ft.) Downstream point/station elevation = 52.390(Ft.) Pipe length = 30.50(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = Nearest computed pipe diameter = Calculated individual pipe flow = Normal flow depth in pipe = 4.48(In.) Flow top width inside pipe = 5.22(In.) Critical Depth = 3.69(In.) Pipe flow velocity = 2.34(Ft/s) Travel time through pipe = 0.22 min. Time of concentration (TC) = 4.01 min. 0.367(CFS) 6.00(In.) 0.367(CFS) 104 Process from Point/Station 203.100 to Point/Station 229.000 **** CONFLUENCE OF MINOR STREAMS **** Along Main Stream number: 2 in normal stream number 1 Stream flow area = 0.130(Ac.) Runoff from this stream = 0.367(CFS) Time of concentration = 4.01 min. Rainfall intensity = 7.377(In/Hr) Process from Point/Station 224.000 to Point/Station 229.100 **** INITIAL AREA EVALUATION **** Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Initial subarea total flow distance = 49.000(Ft.) Highest elevation = 59.600(Ft.) Lowest elevation = 55.500(Ft.) Elevation difference = 4.100(Ft.) Slope = 8.367 % Top of Initial Area Slope adjusted by User to 12.000 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: The maximum overland flow distance is 100.00 (Ft) for the top area slope value of 12.00 %, in a development type of 24.0 DU/A or Less In Accordance With Figure 3-3 Initial Area Time of Concentration = 3.07 minutes TC = [1.8*(1.1-C)*distance(Ft.)*.5)/(% slope*(1/3)] TC = [1.8*(1.1-0.7100)*( 100.000*.5)/( 12.000*(1/3)]= 3.07 Calculated TC of 3.066 minutes is less than 5 minutes, resetting TC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) = 7.377(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.710 Subarea runoff = O.IOS(CFS) Total initial stream area = 0.020(Ac.) Process from Point/Station 229.100 to Point/Station 229.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 52.700(Ft.) Downstream point/station elevation = 52.390(Ft.) Pipe length = 8.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = O.IOS(CFS) Nearest computed pipe diameter = 3.00(In.) Calculated individual pipe flow = O.IOS(CFS) Normal flow depth in pipe = 1.67(In.) Flow top width inside pipe = 2.98(In.) 105 Critical Depth = 2.35(In.) Pipe flow velocity = 3.70(Ft/s) Travel time through pipe = 0.04 min. Time of concentration (TC) = 3.10 min. Process from Point/Station 229.100 to Point/Station **** CONFLUENCE OF MINOR STREAMS **** 229.000 Along Main Stream number: 2 in normal stream number 2 Stream flow area = 0.020(Ac.) Runoff from this stream = 0.105(CFS) Time of concentration = 3.10 min. Rainfall intensity = 7.377(In/Hr) Summary of stream data: Stream No. Flow rate (CFS) TC (min) Rainfall Intensity (In/Hr) 1 2 Qmax(1) 0.367 0.105 .000 .000 Qmax(2) = 1.000 * 1.000 * 4.01 3.10 1.000 * 1.000 * 0.774 * 1.000 * 7.377 7.377 0.367) + 0.105) + 0.367) + 0.105) + 0.472 0.389 Total of 2 streams to confluence: Flow rates before confluence point: 0.367 0.105 Maximum flow rates at confluence using above data: 0.472 0.389 Area of streams before confluence: 0.130 0.020 Results of confluence: Total flow rate = 0.472(CFS) Time of concentration = 4.006 min. Effective stream area after confluence = 0.150(Ac. Process from Point/Station 229.000 to Point/Station 228.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 52. 390 (Ft.) Downstream point/station elevation = 52. 150 (Ft.) Pipe length = 48. 00 (Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = Nearest computed pipe diameter = Calculated individual pipe flow = Normal flow depth in pipe = 3. 98 (In.) Flow top width inside pipe = 8. 94 (In.) Critical Depth = 3. 72 (In.) Pipe flow velocity = 2.51(Ft/s) 0.472 (CFS) 9. 00 (In.) 0.472 (CFS) 106 Travel time through pipe = 0.32 min. Time of concentration (TC) = 4.33 min. Process from Point/Station 229.000 to Point/Station 228.000 **** CONFLUENCE OF MINOR STREAMS **** Along Main Stream number: 2 in normal stream number 1 Stream flow area = 0.150(Ac.) Runoff from this stream = 0.472(CFS) Time of concentration = 4.33 min. Rainfall intensity = 7.377(In/Hr) Process from Point/Station 224.000 to Point/Station 228.200 **** INITIAL AREA EVALUATION **** Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Initial subarea total flow distance = 45.000(Ft.) Highest elevation = 59.600(Ft.) Lowest elevation = 55.500(Ft.) Elevation difference = 4.100(Ft.) Slope = 9.111 % Top of Initial Area Slope adjusted by User to 12.000 % INITIAL AREA TIME OF CONCENTRATION CALCULATIONS: The maximum overland flow distance is 100.00 (Ft) for the top area slope value of 12.00 %, in a development type of 24.0 DU/A or Less In Accordance With Figure 3-3 Initial Area Time of Concentration = 3.07 minutes TC = [1.8*(1.1-C)*distance(Ft.)*.5)/(% slope*(1/3)] TC = [1.8*(1.1-0.7100)*( 100.000A.5)/( 12.000*(1/3)]= 3.07 Calculated TC of 3.066 minutes is less than 5 minutes, resetting TC to 5.0 minutes for rainfall intensity calculations Rainfall intensity (I) = 7.377(In/Hr) for a 100.0 year storm Effective runoff coefficient used for area (Q=KCIA) is C = 0.710 Subarea runoff = 0.157(CFS) Total initial stream area = 0.030(Ac.) Process from Point/Station 228.200 to Point/Station 228.000 **** piPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 52.700(Ft.) Downstream point/station elevation = 52.150(Ft.) Pipe length = 10.00 (Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.157(CFS) Nearest computed pipe diameter = 3.00(In.) 107 Calculated individual pipe flow = 0.157(CFS) Normal flow depth in pipe = 1.95(In.) Flow top width inside pipe = 2.86(In.) Critical Depth = 2. 75(In.) Pipe flow velocity = 4.64(Ft/s) Travel time through pipe = 0.04 rain. Time of concentration (TC) = 3.10 min. Process from Point/Station 228.200 to Point/Station **** CONFLUENCE OF MINOR STREAMS **** 228.000 Along Main Stream number: 2 in normal stream number 2 Stream flow area = 0.030(Ac.) Runoff from this stream = 0.157(CFS) Time of concentration = 3.10 min. Rainfall intensity = 7.377(In/Hr) Summary of stream data: Stream No. Flow rate (CFS) TC (min) Rainfall Intensity (In/Hr) 1 2 Qmax ( 1 ) 0.472 0 .157 = 1.000 * 1.000 * 4.33 3.10 1.000 * 1.000 * 7.377 7.377 0.472) + 0.157) + Qmax(2) = 1.000 * 1.000 * 0.717 * 1.000 * 0.472) 0.157) 0.629 0.496 Total of 2 streams to confluence: Flow rates before confluence point: 0.472 0.157 Maximum flow rates at confluence using above data: 0.629 0.496 Area of streams before confluence: 0.150 0.030 Results of confluence: Total flow rate = 0.629(CFS) Time of concentration = 4.326 min. Effective stream area after confluence = 0.180(Ac.) Process from Point/Station 228.000 to Point/Station 228.100 **** piPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 52.150(Ft.) Downstream point/station elevation = 52.100(Ft.) Pipe length = 7.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 0.629(CFS) Nearest computed pipe diameter = 9.00(In.) Calculated individual pipe flow = 0.629(CFS) Normal flow depth in pipe = 4.23(In.) 108 Flow top width inside pipe = 8.98(In.) Critical Depth = 4.32(In.) Pipe flow velocity = 3.08(Ft/s) Travel time through pipe = 0.04 min. Time of concentration (TC) = 4.36 min. Process from Point/Station 228.100 to Point/Station 223.000 **** IMPROVED CHANNEL TRAVEL TIME **** Upstream point elevation = 52.100(Ft.) Downstream point elevation = 51.200(Ft.) Channel length thru subarea = 74.000(Ft.) Channel base width = 4.000(Ft.) Slope or '2' of left channel bank = 3.000 Slope or 'Z' of right channel bank = 3.000 Estimated mean flow rate at midpoint of channel = 0.804(CFS) Manning's 'N' = 0.250 Maximum depth of channel = 1.000(Ft.) Flow(q) thru subarea = 0.804(CFS) Depth of flow = 0.456(Ft.), Average velocity = 0.329(Ft/s) Channel flow top width = 6.734(Ft.) Flow Velocity = 0.33(Ft/s) Travel time = 3.75 min. Time of concentration = 8.11 min. Critical depth = 0.105(Ft.) Adding area flow to channel Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 [HIGH DENSITY RESIDENTIAL ] (24.0 DU/A or Less ) Impervious value, Ai = 0.650 Sub-Area C Value = 0.710 Rainfall intensity = 5.398(In/Hr) for a 100.0 year storm Effective runoff coefficient used for total area (Q=KCIA) is C = 0.710 CA = 0.199 Subarea runoff = 0.444(CFS) for 0.100(Ac.) Total runoff = 1.073(CFS) Total area = 0.280(Ac.) Depth of flow = 0.534(Ft.), Average velocity = 0.359(Ft/s) Critical depth = 0.127(Ft.) Process from Point/Station 223.000 to Point/Station 217.300 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 48.000(Ft.) Downstream point/station elevation = 42.550(Ft.) Pipe length = 63.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 1.073(CFS) Nearest computed pipe diameter = 6.00(In.) Calculated individual pipe flow = 1.073(CFS) Normal flow depth in pipe = 3.52(In.) Flow top width inside pipe = 5.91(In.) 109 Critical depth could not be calculated. Pipe flow velocity = 8.95(Ft/s) Travel time through pipe = 0.12 min. Time of concentration (TC) = 8.23 min. Process from Point/Station 223.000 to Point/Station **** CONFLUENCE OF MAIN STREAMS **'** 217.300 The following data inside Main Stream is listed: In Main Stream number: 2 Stream flow area = 0.280(Ac.) Runoff from this stream = 1.073(CFS) Time of concentration = 8.23 min. Rainfall intensity = 5.349(In/Hr) Summary of stream data: Stream No. Flow rate (CFS) TC (min) Rainfall Intensity (In/Hr) 1 ] 2 ] Qmax(1) = Qmax(2) = .886 .073 1.000 * 0.955 * 1.000 * 1.000 * 8.83 8.23 1.000 * 1.000 * 0.932 * 1.000 * 1.886) 1.073) 5.110 5.349 1.886) + 1.073) +2.911 2.830 Total of 2 main streams to confluence: Flow rates before confluence point: 1..886 1.073 Maximum flow rates at confluence using above data: 2.911 2.830 Area of streams before confluence: 0.600 0.280 Results of confluence: Total flow rate = 2.911(CFS) Time of concentration = 8.835 min. Effective stream area after confluence =0.880(Ac.) Process from Point/Station 217.300 to Point/Station 217.400 **** piPEFLOW TRAVEL TIME (Program estimated size) **** Upstream point/station elevation = 42.050(Ft.) Downstream point/station elevation = 37.990(Ft.) Pipe length = 3.00(Ft.) Manning's N = 0.013 No. of pipes = 1 Required pipe flow = 2.911(CFS) Nearest computed pipe diameter = 6.00(In.) Calculated individual pipe flow = 2.911(CFS) Normal flow depth in pipe = 2.81(In.) 110 Flow top width inside pipe = 5.99(In.) Critical depth could not be calculated. Pipe flow velocity = 32.30(Ft/s) Travel time through pipe = 0.00 min. Time of concentration (TC) = 8.84 min. End of computations, total study area = 0.880 (Ac.) Ill APPENDIX C Appendix C Calculations for the Bioretention Swales 112 Calculations for Bioretention Swales Two bioretention swales are proposed for the site as shown on Exhibit'S'. The County of San Diego SUSMP Fact Sheet 7 describes bioretention systems. It also refers to the California Stormwater Quality Association (CASQA) Stormwater Best Management Practice Handbook for design guidelines. See Exhibit I for fact sheet and CASQA excerpt. According to CASQA, a vegetated swale is an open, shallow channel with vegetation covering the side slopes and bottom that collects and slowly conveys runoff flow downstream. This is an inexpensive and effective way to eliminate pollution that infiltrate into the storm water. CASQA recommends the following: 1) minimum length of swale of 100'; 2) slope less than 2.5%; and, 3) minimum residence time of 10 minutes. The table below lists the characteristics for the two bioretention swales. Swale lengths are the maximum lengths available given site constraints. See Exhibit S for swale locations. Bioretention Swale # 1 2 Length (feet) 72 82 Slope 1.2% 1% Residence Time (minutes) 11 12 In the table above, residence time was calculated based on a treatment flow rate of 0.04 cfs, as follows: Calculation for Treatment Flowrate Q= CIA; where C= Runoff coefficient = 0.71 for High Density Residential (Table 3-1 San Diego County Hydrology Manual) 1= Intensity (in/hr) Use 0.2in/hr for flow based BMP calcs A= Max Area of Site to flow into Swale 0.29 acres (Appendix 'B') Q=(0.2in/hr)*(0.71)(0.29ac)= 0.04 cfs 113 ****** ****** * ** ** * *** ** * *** *** *** |< ( 4.52') >| *** ***AXAAAAA* Water Depth ( o.09')AAAAAAAA*** * * * * ** * * * *** *** *** ***!< ( 4.001) >!*** ************************ Trapezoidal Channel Flowrate 0.040 CFS Velocity 0.112 fps Depth of Flow 0.086 feet Critical Depth 0.034 feet Freeboard 0.000 feet Total Depth 0.086 feet Width at Water Surface .... 4.516 feet Top Width 4.516 feet Slope of Channel 1.000 % Left Side Slope 3.000 : 1 Right Side Slope 3.000:1 Base Width 4.000 feet X-Sectional Area 0.366 sq. ft. Wetted Perimeter 4.543 feet ARA(2/3) 0.068 Mannings 'n1 0.250 The residence time is 72V0.11 ft/s *(lmin/60s)= 10.9 min for Bioretention Swale #1. Similarly, the residence time is 8270.11 ft/s *(lmin/60s)= 12.4 min for Bioretention Swale #2. The County's SUSMP provides additional criteria for bioretention swales: minimum area of swale is equivalent to 4% of the impervious area draining to the swale. This was determined assuming that the swale would treat runoff from a 0.2in/hr storm event and that the infiltration rate of the planting medium is 5 inches/hour: BMP Area/Impervious Area = 0.2 in/hr/ 5 in/hr = 0.04 Impervious Area * 0.04 = BMP Area Required The table that follows summarizes the impervious area draining to each bioretention swale and the required and actual surface area of each swale. 114 Bioretention Swale # 1 2 Drainage Area (AC) 0.25 0.29 Impervious Area (S.F.) 7,100 9,018 BMP Area Req'd (S.F.) 284 361 Width of Channel (feet)** 4' 4.5' Length of Channel (feet) 72 82 BMP Area Provided (S.F.) 288 369 * See Appendix 'B' for drainage areas. * *Width of vegetated channel excludes 3:1 sideslopes. In addition to the surface area requirements stated above, each swale was designed to convey the 100-year storm event with a minimum of 6" of freeboard. The table below summarizes the calculations. Detailed calculations are shown on the following page. 100- Year Storm Event - Geometry of Swales Bioretention Swale # 1 2 Flowrate 0.95 cfs 1.07cfs Swale Slope 1.2% 1% Width of Swale 4.5' 4.5' Depth of Channel 0.5' 0.5' Total Depth of Channel* 1.0' 1.0' *Total Depth of Swale includes 6" freeboard 115 ****** ****** *** *** *** *** *** ** * *** |< ( 6.95') >| *** ******* Water Depth ( o .49 ') AAAA*AA *** *** *** *** *** * ** ***!< ( 4.001) >i*** Trapezoidal Channel Flowrate 0.920 CFS Velocity 0.341 fps Depth of Flow 0.491 feet Critical Depth 0.113 feet Freeboard 0.000 feet Total Depth 0.491 feet Width at Water Surface .... 6.947 feet Top Width 6.947 feet Slope of Channel 1.200 % Left Side Slope 3.000 : 1 Right Side Slope 3.000:1 Base Width 4.000 feet X-Sectional Area 2.689 sq. ft. Wetted Perimeter 7.107 feet ARA(2/3) 1.407 Mannings 'n' 0.250 116 APPENDIX D Appendix D Detention Calculations 117 Underground Detention Calculations Per Appendix A, the 10 year existing flow rate is 0.78 cfs and the 10 year proposed flowrate is 1 .90 cfs. At least 1 . 12 cfs will need to be detained in an underground detention system. An underground detention system, like Hancor's Land Max System will be used to detain the storm water. A 60" ADS N-12 or equivalent storm drain, 50' long will be sufficient to detain the 1.12 cfs. A 3' long, 36" ADS N-12 will be connected at the end of the 60" pipe. The 36" pipe will drain at 0.5% into a type 'A-4' cleanout. A 4" ADS N-12 storm drain will outlet at the bottom of the cleanout at elevation 37.35. According to the calculations below the exiting flowrate will be 0.72 cfs, less than the existing conditions. In addition to the 4" storm drain an 8" ADS N-12 storm drain will be constructed to outlet the cleanout at elevation 41.50. This 8" storm drain will act as an emergency overflow if the 4" storm drain becomes clogged or if the flow exceeds a 10- year storm event. See Exhibit 'G' for the underground detention details. Proposed Conditions (Inflow) (Appendix B): Qioo= 1.90cfs A=0.88 AC Tc=9.35 min P6=1.9" Inflow Hydrograph- Refer to San Diego County Hydrology Manual (Section 6) A. Rainfall Distribution- For 6-hour Rainfall (Rational Method) The total amount of rainfall (PT(N)) for any given block (N) is determined by the equation below: PT(N)= (IT(N)*TT(N))/60 Since TT(N)=NTc in minutes, where (N= an integer number representing the given block number of rainfall) and I=7.44P6DA(-.645), substituting yields: PT(N)=0. 124P6(NTc)A(0.355) The distribution of the blocks are (2/3, 1/3), so the peak would occur at (2/3)*6 4hours. So the actual rainfall for any given time is PN=PT(N)-PT(N-1) Calculations: Tc= 9.35 min.~ rounded is 9 min. (6hr*60min)/9 = Number of Blocks •> 40 Blocks For Block 1- Where the Peak Rainfall Occurs PT(N)=0.124*(1.9")*(l*9min)A(0.355)-»0.514 118 For Block 2- T(N)=0.124*(1.9")*(2*9imn)A(0.355)-».657 So the actual rainfall for block 2 is (0.657-0.514)= 0.143 The table below is a summary of all the values for the rainfall distribution. Calculations for Rainfall Distribution- Vista La Costa Time (min) 0 9 18 27 36 45 54 63 72 81 90 99 108 117 126 135 144 153 162 171 180 189 198 207 216 225 234 243 252 261 270 279 288 297 306 315 324 333 Number of Block 39 38 36 35 33 32 30 29 27 26 24 23 21 20 18 17 15 14 12 11 9 8 6 5 3 2 1 4 7 10 13 16 19 22 25 28 31 Tt(N) 351 342 324 315 297 288 270 261 243 234 216 207 189 180 162 153 135 126 108 99 81 72 54 45 27 18 9 36 63 90 117 144 171 198 225 252 279 Pt(N) 0.000 1.887 1.870 1.834 1.816 1.778 1.759 1.719 1.699 1.656 1.634 1.588 1.564 1.515 1.489 1.434 1.405 1.344 1.312 1.242 1.204 1.121 1.075 0.971 0.910 0.759 0.657 0.514 0.841 1.026 1.164 1.278 1.375 1.462 1.540 1.611 1.678 1.739 P(N) 0 0.017 0.018 0.018 0.019 0.019 0.020 0.021 0.021 0.022 0.023 0.024 0.024 0.026 0.027 0.029 0.030 0.033 0.034 0.038 0.040 0.046 0.050 0.061 0.069 0.102 0.143 0.514 0.082 0.055 0.043 0.036 0.031 0.028 0.025 0.023 0.022 0.020 119 Calculations for Rainfall Distribution- Vista La Costa (cont.) Time (min) 342 351 360 Number of Block 34 37 40 Tt(N) 306 333 360 Pt(N) 1.797 1.852 1.904 P(N) 0.019 0.018 0.017 B. Incremental Hydrograph Using the Rainfall Distribution QN=CAI(N) (cfs);Where C= 0.71 A=0.88AC I(N)= 60* PN/Tc Calculations: At Block 1 (Peak Flow Rate) = 1.90 cfs At Block 2,1(N)= 60* 0.143/9 min.=0.953 in/hr QN=0.71*0.88*0.953-* 0.595 cfs The table below is a summary of all the calculations for the incremental hydrograph for Vista La Costa. Each QN occurs at the time interval +1/2 Tc (See San Diego County Hydrology Manual Section 6.2.2). 6-Hour RM Hydrograph Calcs KN) 0.115 0.117 0.122 0.124 0.129 0.131 0.137 0.140 0.147 0.151 0.159 0.163 0.173 0.179 0.192 0.199 0.217 0.227 0.252 0.267 0.306 0.332 Q(N) 0 0.07 0.07 0.08 0.08 0.08 0.08 0.09 0.09 0.09 0.09 0.10 0.10 0.11 0.11 0.12 0.12 0.14 0.14 0.16 0.17 0.19 0.21 T (min) 4.5 13.5 22.5 31.5 40.5 49.5 58.5 67.5 76.5 85.5 94.5 103.5 112.5 121.5 130.5 139.5 148.5 157.5 166.5 175.5 184.5 193.5 202.5 120 6-Hour RM Hydrograph Calcs (cont.) KN) 0.406 0.462 0.678 0.953 3.041 0.544 0.364 0.285 0.239 0.208 0.185 , 0.168 0.155 0.143 0.134 0.126 0.120 0.114 Q(N) 0.25 0.29 0.42 0.60 1.90 0.34 0.23 0.18 0.15 0.13 0.12 0.11 0.10 0.09 0.08 0.08 0.07 0.07 T (min) 211.5 220.5 229.5 238.5 247.5 256.5 265.5 274.5 283.5 292.5 301.5 310.5 319.5 328.5 337.5 346.5 355.5 364.5 Flood Routing Calculations The underground detention will consist of a 60" ADS N-12 or equivalent storm drain, 50' long. A 3' long, 36" ADS N-12 storm drain will be connected at the end of the 60" pipe. The 36" pipe will drain at 0.5% into a type 'A-4' cleanout. A 4" ADS N-12 storm drain will outlet at the bottom of the cleanout at elevation 37.35. According to the calculations below the exiting flowrate will be 0.78 cfs, the same as existing conditions. In addition to the 4" storm drain, an 8" ADS N-12 storm drain will be constructed to outlet the cleanout at elevation 41.50. This 8" storm drain will act as an emergency overflow if the 4" storm drain becomes clogged or if the flow exceeds a 10-year storm event. See Exhibit 'M' for the underground detention details. The detention calculations were preformed with the Hydraflow Hydrographs by Intellisolve software v9.22. Similar flood routing calculations were performed for the 2 and 10 year storm events. 121 Watershed Model Schematic Hydraflow Hydrographs by Intelisolve v9.22 1-10 Year Inflow Hydrograph 2 - Inflow vs. Outflow Project: VLdO.gpw Tuesday, May 6, 2008 Hydrograph Summary Report Hydraflow Hydrographs by Intelisolve v9.22 Hyd. No. 1 2 Hydrograph type (origin) Manual Reservoir Peak flow (cfs) 1.900 0.715 Time interval (min) 1 1 Time to peak (min) 243 250 VLCIO.gpw Hyd. volume (cuft) 3,991 3,990 Inflow hyd(s) .... 1 Maximum elevation (ft) 41.58 Return Period: 10 Year Total strge used (cuft) 779 Hydrograph description 10 Year Inflow Hydrograph Inflow vs. Outflow Tuesday, May 6, 2008 Hydrograph Report ydraflow Hydrographs by Intelisolve v9.22 Hyd. No. 1 10 Year Inflow Hydrograph Hydrograph type = Manual Storm frequency = 10yrs Time interval = 1 min Tuesday, May 6, 2008 Peak discharge Time to peak Hyd. volume 1.900 cfs 243 min 3,991 cuft Q (cfs) 2.00 10 Year Inflow Hydrograph Hyd. No. 1 -10 Year 1.00 0.00 Q (cfs) 2.00 1.00 360 0.00 420 Time (min) Hydrograph Report Hydraflow Hydrographs by Intelisolve v9.22 Hyd. No. 2 Inflow vs. Outflow Tuesday, May 6, 2008 Hydrograph type Storm frequency Time interval Inflow hyd. No. Reservoir name Reservoir Peak discharge 10 yrs Time to peak 1 min Hyd. volume 1 -10 Year Inflow Hydrograph Max. Elevation Hancor Underground Detention Facility Max. Storage 0.715 cfs 250 min 3,990 cuft 41.58ft 779 cuft Storage Indication method used. Q (cfs) 2.00 Inflow vs. Outflow Hyd. No. 2-10 Year 1.00 0.00 Q (cfs) 2.00 1.00 60 Hyd No. 2 120 180 Hyd No. 1 240 300 360 ] Total storage used = 779 cuft 0.00 420 Time (min) Pond Report Hydraflow Hydrographs by Intelisolve v9.22 Tuesday, May 6, 2008 Pond No. 1 - Hancor Underground Detention Facility Pond Data UG Chambers - Invert elev. = 37.74 ft, Rise x Span = 5.00 x 5.00 ft, Barrel Len = 50.00 ft, No. Barrels = 1, Slope = 0.50%, Headers = No Stage / Storage Table Stage (ft) Elevation (ft)Contour area (sqft) Incr. Storage (cuft) Total storage (cuft) 0.00 37.74 n/a 0.53 38.27 n/a 1.05 38.79 n/a 1.58 39.32 n/a 2.10 39.84 n/a 2.63 40.37 n/a 3.15 40.89 n/a 3.68 41.42 n/a 4.20 41.94 n/a 4.73 42.47 n/a 5.25 42.99. n/a Culvert / Orifice Structures [A] [BJ [C] [PrfRsr] Rise (in) = 4.00 8.00 0.00 0.00 Span (in) = 4.00 8.00 0.00 0.00 No. Barrels =1 1 00 Invert El. (ft) = 37.74 41 .50 0.00 0.00 Length (ft) =40.91 41.30 0.00 0.00 Slope (%) = 8.19 18.15 0.00 n/a N-Value = .013 .013 .013 n/a Orifice Coeff. = 0.60 0.60 0.60 0.60 Multi-Stage = n/a No No No 0 0 37 37 88 125 111 237 124 361 130 491 130 621 124 746 111 857 88 945 37 982 Weir Structures [A] [B] Crest ten (ft) = 0.00 0.00 Crest El. (ft) = 0.00 0.00 Weir Coeff. = 3.33 3.33 Weir Type = — Multi-Stage = No No Exfil.(in/hr) = 0.000 (by Contour) TW Elev. (ft) = 0.00 [C] [D] 0.00 0.00 0.00 0.00 3.33 3.33 ... No No Note: Culvert/Orifice outflows are analyzed under inlet (ic) and outlet (oc) control. Weir risers checked for orifice conditions (ic) and submergence (s). Stage / Storage / Discharge Table Stage Storage Elevation Civ A CIvB CIvC ft cuft ft cfs cfs cfs 0.00 0 37.74 0.00 0.00 0.05 4 37.79 0.01 ic 0.00 0.11 7 37.85 0.03 ic 0.00 0.16 11 37.90 0.05 ic 0.00 0.21 15 37.95 0.09 ic 0.00 0.26 19 38.00 0.13 ic 0.00 0.32 22 38.06 0.16ic 0.00 0.37 26 38.11 0.1 9 ic 0.00 0.42 30 38.16 0.21 ic 0.00 0.47 34 38.21 0.23 ic 0.00 0.53 37 38.27 0.25 ic 0.00 0.58 46 38.32 0.27 ic 0.00 0.63 55 38.37 0.29 ic 0.00 0.68 64 38.42 0.30 ic 0.00 0.74 73 38.48 0.32 ic 0.00 0.79 81 38.53 0.33 ic 0.00 0.84 90 38.58 0.34 ic 0.00 0.89 99 38.63 0.36 ic 0.00 0.95 108 38.69 0.37 ic 0.00 1.00 117 38.74 0.38 ic 0.00 1.05 125 38.79 0.39 ic 0.00 1.10 136 38.84 0.41 ic 0.00 1.16 148 38.90 0.42 ic 0.00 1.21 159 38.95 0.43 ic 0.00 1.26 170 39.00 0.44 ic 0.00 1.31 181 39.05 0.45 ic 0.00 1.37 192 39.11 0.46 ic 0.00 1.42 203 39.16 0.47 ic 0.00 1.47 214 39.21 0.48 ic 0.00 1.52 225 39.26 0.49 ic 0.00 1.58 237 39.32 0.50 ic 0.00 PrfRsr WrA Wr B WrC cfs cfs cfs cfs — — ... — ... — — ... — — — — — — ... ... — ... — — — ... ... ... — — — ... — ... WrD Exfil User Total cfs cfs cfs cfs o.ooo 0.007 0.026 0.055 0.090 -- 0.129 0.163 0.188 0.211 0.232 0.251 0.269 — 0.286 0.302 0.317 0.331 0.345 0.358 0.371 0.383 0.395 0.406 0.418 0.429 0.439 0.450 0.460 0.470 0.480 0.489 0.499 Continues on next page... Hancor Underground Detention Facility Stage / Storage / Discharge Table Stage ft 1.63 1.68 1.73 1.79 1.84 1.89 1.94 2.00 2.05 2.10 2.15 2.21 2.26 2.31 2.36 2.42 2.47 2.52 2.57 2.63 2.68 2.73 2.78 2.84 2.89 2.94 2.99 3.05 3.10 3.15 3.20 3.26 3.31 3.36 3.41 3.47 3.52 3.57 3.62 3.68 3.73 3.78 3.83 3.89 3.94 3.99 4.04 4.10 4.15 4.20 4.25 4.31 4.36 4.41 4.46 4.51 4.57 4.62 4.67 4.73 4.78 4.83 4.88 4.93 4.99 5.04 5.09 5.14 5.20 5.25 Storage cuft 249 261 274 286 299 311 324 336 348 361 374 387 400 413 426 439 452 465 478 491 504 517 530 543 556 569 582 595 608 621 634 646 659 671 683 696 708 721 733 746 757 768 779 790 801 812 823 835 846 857 866 874 883 892 901 910 918 927 936 945 949 952 956 960 963 967 971 975 978 982 Elevation ft 39.37 39.42 39.47 39.53 39.58 39.63 39.68 39.74 39.79 39.84 39.89 39.95 40.00 40.05 40.10 40.16 40.21 40.26 40.31 40.37 40.42 40.47 40.52 40.58 40.63 40.68 40.73 40.79 40.84 40.89 40.94 41.00 41.05 41.10 41.15 41.21 41.26 41.31 41.36 41.42 41.47 41.52 41.57 41.63 41.68 41.73 41.78 41.84 41.89 41.94 41.99 42.05 42.10 42.15 42.20 42.26 42.31 42.36 42.41 42.47 42.52 42.57 42.62 42.68 42.73 42.78 42.83 42.89 42.94 42.99 Civ A cfs 0.51 ic 0.52 ic 0.53 ic 0.53 ic 0.54 ic 0.55 ic 0.56 ic 0.57 ic 0.58 ic 0.58 ic 0.59 ic 0.60 ic 0.61 ic 0.61 oc 0.62 oc 0.62 oc 0.62 oc 0.62 oc 0.63 oc 0.63 oc 0.63 oc 0.64 oc 0.64 oc 0.64 oc 0.64 oc 0.65 OC 0.65 oc 0.65 oc 0.66 oc 0.66 oc 0.66 OC 0.66 oc 0.67 oc 0.67 OC 0.67 oc 0.68 oc 0.68 oc 0.68 oc 0.68 OC 0.69 oc 0.69 oc 0.69 oc 0.69 OC 0.70 oc 0.70 oc 0.70 oc 0.71 oc 0.71 oc 0.71 OC 0.71 oc 0.72 oc 0.72 oc 0.72 oc 0.72 oc 0.73 oc 0.73 OC 0.73 OC 0.73 oc 0.74 oc 0.74 OC 0.74 oc 0.74 oc 0.75 oc 0.75 OC 0.75 OC 0.75 oc 0.76 OC 0.76 OC 0.76 oc 0.76 oc CIvB CIvC PrfRsr WrA Wr 8 cfs cfs cfs cfs cfs n nn*j.\j\j 0.00o.oo o.ooo.ooo.ooo.ooo.ooo.ooo.ooo.oo 0.00o.ooo.ooo.ooo.oo o.ooo.ooo.ooo.ooo.oo 0.00o.oo 0.00o.ooo.ooo.ooo.ooo.ooo.ooo.ooo.oo 0.00 0.00o.oo 0.00o.ooo.ooo.oo 0.00 0.00 0.00 ic — 0.02 ic — 0.05 ic — O.HJC — 0.17ic — 0.26 ic — 0.35 ic — 0.45 ic — 0.55 ic — 0.66 ic — 0.77 ic — 0.87 ic — 0.95 ic — 1.02ic — 1.09ic — 1.16JC — 1.22JC — 1.28ic 1.34ic —139 jc ... 1.44ic — 1.49ic — 1.54ic — 1.59ic — 1.64ic — 1.68IC — 1.72ic — 1.77ic — 1.81JC — WrC WrD Exfil User Total cfs cfs cfs cfs cfs 0.508 0.517 0.526 0.534 0.543 0.552 0.560 0.568 0.576 0.584 0.592 0.600 0.608 0.612 0.615 0.618 0.621 0.624 0.627 0.630 0.633 0.636 0.639 n R4.O\J.\J*T& n fixe— ™ -" -" U.U*TJ 0.648 0.650 0.653 0.656 0.659 0.662 0.665 0.667 0.670 0.673 0.676 0.678 0.681 0.684 0.686 0.689 0.693 0.713 0.752 0.807 0.877 0.960 1.054 1.156 1.265 1.376 1.486 1.589 1.675 1.747 1.820 1.888 1.953o nm™ — -" £..\J IO 2.074 2.131 2.186 2.239 2.290 2.340 2.388 2.435 2.482 2.526 2.570 ...End EXHIBIT A EXHIBIT 'A' Cm OF OCEAHSttE CHY OF VISTA cm OFSAH UMCOS PROJECT SITE CmOFOKttiTAS NO SCALE EXHIBIT B FXK181T '& DEVELOPMENT APPLICATION STORM WATER STANDARDS QUESTIONNAIRE INSTRUCTIONS: This questionnaire must be completed by applicant in advance of submitting for a development application (subdivision and land use planning approvals and construction permits). The results of the questionnaire determine the level of storm water pollution prevention standards applied to a proposed development or redevelopment project. Many aspects of project site design are dependent upon the storm water pollution protection standards applied to a project. Applicant responses to the questionnaire represent an initial assessment of the proposed project conditions and impacts. City staff has responsibility for making the final assessment after submission of the development application. A staff determination that the development application is subject to more stringent storm water standards, than initially assessed by the applicant, Will result in the return of the development application as incomplete. If applicants are unsure about the meaning of a question or need help in determining how to respond to one or more of the questions, they are advised to seek assistance from Engineering Department Development Services staff. A separate completed and signed questionnaire must be submitted for each new development application submission. Only one completed and signed questionnaire is required when multiple development applications for the same project are submitted concurrently. In addition to this questionnaire, applicants for construction permits must also complete, sign and submit a Construction Activity Storm Water Standards Questionnaire. To address pollutants that may be generated from new development, the City requires that new development and significant redevelopment priority projects incorporate Permanent Storm Water Best Management Practices (BMPs) into the project design, which are described in Section 2 of the City's Storm Water Standards Manual This questionnaire should be used to categorize new development and significant redevelopment projects as priority or non-priority, to determine what level of storm water standards are required or if the project is exempt. 1. Is your project a significant redevelopment? Definition: Significant redevelopment is defined as the creation or addition of at least 5,000 square feet of impervious surface on an already developed site. Significant redevelopment includes, but is not limited to: the expansion of a building footprint; addition to or replacement of a structure; structural development including an increase in gross floor area and/or exterior construction remodeling; replacement of an impervious surface that is not part of a routine maintenance activity; and land disturbing activities related with structural or impervious surfaces. Replacement of impervious surfaces includes any activity that is not part of a routine maintenance activity where impervious material(s) are removed, exposing underlying soil during construction. Note: If the Significant Redevelopment results in an increase of less than fifty percent of the impervious surfaces of a previously existing development, and the existing development was not subject to SUSMP requirements, the numeric sizing criteria discussed in Section F.1.b. (2)(c) applies only to the addition, and not to the entire development. 2. If your project IS considered significant redevelopment, then please skip Section 1 and proceed with Section 2. 3. If your project IS NOT considered significant redevelopment, then please proceed to Section 1. SECTION 1 NEW DEVELOPMENT PRIORITY PROJECT TYPE Does you project meet one or more of the following criteria: 1. Home subdiviston 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 development areater than 100.000 sauare feet includina parking areas. Any development on private land that is not for heavy industrial or residential uses. Example: Hospitals, Hotels, Recreational Facilities, Shopping Malls, etc. 4. Heavv 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 shoo. 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 5812 7. Hillside development (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, highways, 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 NO 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 an addition to an existing priority project type? (Priority projects are defined in Section D YES NO 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 one of the following: a. Trenching and resurfacing associated with utility work? b. Resurfacing and reconfiguring surface parking lots? c. New sidewalk construction, pedestrian ramps, or bike land on public and/or private existing roads? d. Replacement of damaged pavement? If you answered NO to ALL of the questions, then proceed to Question 3. If you answered YES to ONE OR MORE of the questions 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. 3. Will the development create or add at least 5,000 square feet of impervious surfaces on an existing development or, be located within 200 feet of the Pacific Ocean and (1 )create more than 2500 square feet of impermeable surface or (2) increases impermeable surface on property by more than 10%? If you answered YES, you ARE a significant redevelopment, and you ARE subject to PRIORITY project requirements. Please check the "MEETS PRIORITY REQUIREMENTS" box in Section 3 below. If you 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: 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. Q MY PROJECT DOES NOT MEET PRIORITY REQUIREMENTS AND MUST ONLY COMPLY WITH STANDARD STORM WATER REQUIREMENTS. Applicant Information and Signature Box Address: Assessor Parcel Number(s): Applicant Name: Applicant Signature: Applicant Title: Date: This Box for City Use Only City Concurrence:Ycss No By: Date: Project ID: EXHIBIT C EXHIBIT D 1.11 MLM "-» 113 I«D u •**•« uui IUKMV xvcmuxic ui i*» ;«JMTO HtOK J,«fc-*H» M * KA»U«» H<*Cl at« IMI^ w HOfM^t^^^^H >- M \\-\--p*—',,,, »'-,/ \,^rPSii. ^, - ^, •^'•.i^ • ^-,.^v '-••./-:..>,>4,?- \ ;N V;v •- k, ...--"••: I } I :'. X, .- ! ,S.V- \'-^^^ \ / ->f'/^~ ~~^~^ Airli ;trlR.*ltt«: J«lt i*T« AMi**«: ««C«H (••* Iwt^ltoaM M4 MMlWl*« I««HM » 5ut« of Colifornl* REGIONAL WATER QUALITY CONTROL BOARD San Diego Region (9) SAN OiEGO HYDROLOGIC BASIN PLANNING AREA (SO) Scat* I' 250,000 ,„ 10 •!•««. o:oHCO EXHIBIT E 2006 CWA SECTION 303(d) LIST OF WATER QUALITY LIMITED SEGMENTS REQUIRING TMDLS SAN DIEGO REGIONAL WATER QUALITY CONTROL BOARD USEPA APPROVAL DATE: JUNE 28, 2007 REGION TYPE NAME CALWATER WATERSHED POLLUTANT/STRESSOR POTENTIAL SOURCES ESTIMATED PROPOSED TMDL SIZE AFFECTED COMPLETION 9 R Agua Hedionda Creek 9 E Agua Hedionda Lagoon 9 R Aliso Creek 90431000 90431000 90113000 Manganese Selenium Sulfates Total Dissolved Solids Indicator bacteria Sedimentation/Siltation Indicator bacteria Source Unknown Source Unknown Source Unknown Urban Runoff/Storm Sewers Unknown Nonpoint Source Unknown point source Nonpoint/Point Source Nonpoint/Point Source 7 Miles 7 Miles 7 Miles 7 Miles 2019 2019 2019 2019 6.8 Acres 6.8 Acres 19 Miles 2006 2019 2005 This listing for indicator bacteria applies to the Aliso Creek mainstem and all the major tributaries of Aliso Creek which are Sulphur Creek, Wood Canyon, Aliso Hills Canyon, Dairy Fork, and English Canyon. Urban Runoff/Storm Sewers Unknown point source Nonpoint/Point Source Phosphorus 19 Miles 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 Hills Canyon, Dairy Fork, and English Canyon. Urban Runofl/Storm Sewers Unknown Nonpoint Source Unknown point source Page 1 of 27 2006 CWA SECTION 303(d) LIST OF WATER QUALIi i LIMITED SEGMENTS REQUIRING TMDLS SAN DIEGO REGIONAL WATER QUALITY CONTROL BOARD USEPA APPROVAL DATE: JUNE 28, 2007 REGION TYPE NAME CALWATER WATERSHED POLLUTANT/STRESSOR POTENTIAL SOURCES ESTIMATED PROPOSED TMDL SIZE AFFECTED COMPLETION 9 E Aliso Creek (mouth) 9 L Barrett Lake 9 R Bueaa Creek 9 R Buena Vista Creek 9 E Buena Vista Lagoon 90113000 91130000 90432000 90421000 90421000 Toxicity 19 Miles 2019 This listing for toxicity applies to the Aliso Creek mainstem and all the major tributaries of Aliso Creek which are Sulphur Creek, Wood Canyon, Aliso Hills Canyon, Dairy Fork, and English Canyon. Urban Runoff/Storm Sewers Unknown Nonpoint Source Unknown point source Indicator bacteria Color Manganese pH DDT Nitrate and Nitrite Phosphate Sediment Toxicity Indicator bacteria Page 2 of 27 Nonpoint/Point Source Source Unknown Source Unknown Source Unknown Source Unknown Source Unknown Source Unknown Source Unknown Nonpoint/Point Source 0.29 Acres 125 Acres 125 Acres 125 Acres 4.8 Miles 4.8 Miles 4.8 Miles 11 Miles 202 Acres 2005 2019 2019 2019 2019 2019 2019 2019 2008 2006 CWA SECTION 303(d) LIST OF WATER QUALITY LIMITED SEGMENTS REQUIRING TMDLS SAN DIEGO REGIONAL WATER QUALITY CONTROL BOARD USEPA APPROVAL DATE: JUNE 28, 2007 REGION TYPE NAME CALWATER WATERSHED POLLUTANT/STRESSOR POTENTIAL SOURCES ESTIMATED PROPOSED TMDL SIZE AFFECTED COMPLETION 9 R Chollas Creek 9 R Cloverdaie Creek 9 R Cottonwood Creek (San Marcos Creek watershed) 90822000 90532000 90451000 Nutrients Estimated size of impairment is 150 acres located in upper portion of lagoon. Nonpoint/Point Source Sedimentatton/Siltation Nonpoint/Point Source Copper Indicator bacteria Lead Zinc Phosphorus Total Dissolved Solids DDT Nonpoint/Point Source Nonpoint/Point Source Nonpoint/Point Source NonpointfPoint Source Urban Runoff/Storm Sewers Unknown Nonpoint Source Unknown point source Urban Runoff/Storm Sewers Unknown Nonpoint Source Unknown point source 202 Acres 202 Acres 3.5 Miles 3.5 Miles 3.5 Miles 3.5 Miles 1.2 Miles 1.2 Miles 1.9 Miles 2019 2019 2004 2005 2004 2004 2019 2019 2019 Source Unknown Page 3 of 27 2006 CWA SECTION 303(d) LIST OF WATER QUALI11 UMITED SEGMENTS REQUIRING TMDLS SAM DIEGO REGIONAL WATER QUALITY CONTROL BOARD USEPA APPROVAL DATE: JUNE 28, 2007 REGION TYPE NAME CALWATER WATERSHED POLLUTANT/STRESSOR POTENTIAL SOURCES ESTIMATED PROPOSED TMDL SIZE AFFECTED COMPLETION 9 B Dana Point Harbor 9 R De Liu Creek 9 L El Capstan Lake 9 R Encinitas Creek 90114000 90221000 90731000 90451000 Phosphorus Sediment Toxicity Source Unknown Source Unknown Indicator bacteria Impairment located at Baby Beach. Urban Runoff/Storm Sewers Marinas and Recreational Boating Unknown Nonpoint Source Unknown point source Iron Manganese Color Manganese pH Phosphorus Source Unknown Source Unknown Source Unknown Source Unknown Source Unknown Source Unknown 1.9 Miles 1.9 Miles 119 Acres 14 Miles 14 Miles 1454 Acres 1454 Acres 1454 Acres 3 Miles 2019 2019 2006 2019 2019 2019 2019 2019 2019 Page 4 of27 2006 CWA SECTION 303(d) LIST OF WATER QUALITY LIMITED SEGMENTS REQUIRING TMDLS SAN DIEGO REGIONAL WATER QUALITY CONTROL BOARD USEPA APPROVAL DATE: JUNE 28, 2007 REGION TYPE NAME CALWATER WATERSHED POLLUTANT/STRESSOR POTENTIAL SOURCES ESTIMATED PROPOSED TMDL SIZE AFFECTED COMPLETION 9 R English Canyon 9 R Escondido Creek 9 E Famosa Slough and Channel 9 R FeliciU Creek 90113000 90462000 90711000 90523000 Benzo[b]fluoranthene Dieldrin Sediment Toxicity DDT Manganese Phosphate Selenium Sulfates Total Dissolved Solids Eutrophic Aluminum Source Unknown Source Unknown Source Unknown Source Unknown Source Unknown Source Unknown Source Unknown Source Unknown Source Unknown Nonpoint Source Source Unknown 3.6 Miles 3.6 Miles 3.6 Miles 26 Miles 26 Miles 26 Miles 26 Miles 26 Miles 26 Miles 32 Acres 0.92 Mites 2019 2019 2019 2019 2019 2019 2019 2019 2019 2019 2019 PageS of 27 2006 CWA SECTION 303(d) LIST OF WATER QUALITY LIMITED SEGMENTS REQUIRING TMDLS SAN DIEGO REGIONAL WATER QUALITY CONTROL BOARD USEPA APPROVAL DATE: JUNE 28, 2007 REGION TYPE NAME CALWATERWATERSHED POLLUTANT/STRESSOR POTENTIAL SOURCES ESTIMATED SIZE AFFECTED PROPOSED TMDL 1 COMPLETION 1 R Forester Creek 90712000 Total Dissolved Solids Agricultural Return Flows Urban Runoff/Storm Sewers Flow Regulation/Modification Unknown Nonpoint Source Unknown point source Fecal Coliform Impairment Located at lower 1 mile. Urban RunoflVStorm Sewers Spills Unknown Nonpoint Source Unknown point source Oxygen, Dissolved Source Unknown PH Impairment Located at upper 3 miles. Industrial Point Sources Habitat Modification Spills Unknown Nonpoint Source Unknown point source Phosphorus Source Unknown Total Dissolved Solids Impairment Located at lower 1 mile. Agricultural Return Flows Urban Runoff/Storm Sewers Flow Regulation/Modification Unknown Nonpoint Source Unknown point source 0.92 Miles 6.4 Miles 6.4 Miles 6.4 Miles 6.4 Miles 6.4 Miles 2019 2005 2019 2019 2019 2019 Page 6 of 27 2006 CWA SECTION 303(d) LIST OF WATER QUALITi LIMITED SEGMENTS REQUIRING TMDLS SAN DIEGO REGIONAL WATER QUALITY CONTROL BOARD USEPA APPROVAL DATE: JUNE 28, 2007 REGION TYPE NAME CALWATER WATERSHED POLLUTANT/STRESSQR POTENTIAL SOURCES ESTIMATED PROPOSED TMDL SIZE AFFECTED COMPLETION 9 R Green Valley Creek 9 L Guajome Lake 9 L Hodges, Lake 90521000 90311000 90521000 Chloride Manganese Pentachlorophenol (PCP) Sulfates Eutropnic Color Manganese Nitrogen Source Unknown Source Unknown Source Unknown Urban Runoff/Storm Sewers Natural Sources Unknown Nonpoint Source Unknown point source Nonpoint/Point Source Urban Runoff/Storm Sewers Unknown Nonpoint Source Unknown point source Source Unknown Agriculture Dairies Urban Runoff/Storm Sewers Unknown Nonpoint Source Unknown point source 0.98 Miles 0.98 Miles 0.98 Miles 0.98 Miles 33 Acres 1104 Acres 1104 Acres 1104 Acres 2019 2019 2019 2019 2019 2019 2019 2019 Page 7 of 27 2006 CWA SECTION 303(d) LIST OF WATER QUALITY LIMITED SEGMENTS REQUIRING TMDLS SAN DIEGO REGIONAL WATER QUALITY CONTROL BOARD USEPA APPROVAL DATE: JUNE 28, 2007 REGION TYPE NAME CALWATER WATERSHED POLLUTANT/STRESSOR POTENTIAL SOURCES ESTIMATED PROPOSED TMDL SIZE AFFECTED COMPLETION 9 R Kit Carson Creek 9 R Laguna Canyon Channel 9 E Loma Alta Slough 90521000 90112000 90410000 PH Phosphorus Turbidity Pentachlorophenol (PCP) Total Dissolved Solids Sediment Toxicity Eutrophic Indicator bacteria Source Unknown Agriculture Dairies Urban Runoff/Storm Sewers Unknown Nonpoint Source Unknown point source Source Unknown Source Unknown Agricultural Return Flows Urban Runofl/Storm Sewers Flow Regulation/Modification Unknown Nonpoint Source Unknown point source Source Unknown Nonpoint Source Nonpoint Source 1104 Acres 1104 Acres 1104 Acres 0.99 Miles 0.99 Miles 1.6 Miles 8.2 Acres 8.2 Acres 2019 2019 2019 2019 2019 2019 2019 2008 PageS of 27 2006 CWA SECTION 303(d) LIST OF WATER QUALI11 LIMITED SEGMENTS REQUIRING TMDLS SAN DIEGO REGIONAL WATER QUALITY CONTROL BOARD USEPA APPROVAL DATE: JUNE 28, 2007 ESTIMATED PROPOSED TMDL I SIZE AFFECTED COMPLETION IREGION TYPE NAME CALWATER WATERSHED POLLUTANT/STRESSOR POTENTIAL SOURCES 9 R Long Canyon Creek 9 R Los Penasquitos Creek 9 E Los Penasquitos Lagoon 9 L Loveland Reservoir 90283000 90610000 90610000 90931000 9 B Mission Bay (area at mouth of Rose Creek 90640000 only) Total Dissolved Solids Phosphate Total Dissolved Solids Sedimentation/SUtation Aluminum Manganese Oxygen, Dissolved Source Unknown Source Unknown Source Unknown Nonpoint/Point Source Source Unknown Source Unknown Source Unknown This listing was made by USEPA for 2006. Source Unknown Eutrophic Lead Nonpoint/Point Source Nonpoint/Point Source 83 Miles 12 Miles 12 Miles 469 Acres 420 Acres 420 Acres 420 Acres 420 Acres 9.2 Acres 9.2 Acres 2019 2019 2019 2019 2019 2019 2019 2019 2019 2019 Page 9 of 27 2006 CWA SECTION 303(d) LIST OF WATER QUALI11 UMITED SEGMENTS REQUIRING TMDLS SAN DIEGO REGIONAL WATER QUALITY CONTROL BOARD USEPA APPROVAL DATE: JUNE 28, 2007 REGION TYPE NAME CALWATER WATERSHED POLLUTANT/STRESSOR POTENTIAL SOURCES ESTIMATED PROPOSED TMDL SIZE AFFECTED COMPLETION 9 B Mission Bay (area at mouth of Tecolote Creek only) 90650000 9 C Mission Bay Shoreline 9 L Morena Reservoir 9 L Murray Reservoir 9 R Murrieta Creek 90630000 91150000 90711000 90252000 Eutrophic Lead Nonpoint/Point Source Nonpoint/Point Source Indicator bacteria This listing was made by VSEPAfor 2006. Source Unknown Color Mangane pH Iron Manganese Nitrogen Source Unknown Source Unknown Source Unknown Source Unknown Source Unknown Source Unknown Source Unknown 3.1 Acres 3.1 Acres 28 Miles 104 Acres 104 Acres 104 Acres 119 Acres 12 Maes 12 Miles 12 Miles 2019 2019 2019 2019 2019 2019 2019 2019 2019 2019 Page 10 of27 2006 CWA SECTION 303(d) LIST OF WATER QUALITY LIMITED SEGMENTS REQUIRING TMDLS SAN DIEGO REGIONAL WATER QUALITY CONTROL BOARD USEPA APPROVAL DATE: JUNE 28, 2007 REGION TYPE NAME CALWATER WATERSHED POLLUTANT/STRESSOR POTENTIAL SOURCES ESTIMATED PROPOSED TMDL SIZE AFFECTED COMPLETION 9 R Oso Creek (at Mission Viejo Golf Course) 90120000 Phosphorus Chloride Urban Runoff/Storm Sewers Unknown Nonpoint Source Unknown point source 12 Miles 1 Miles 2019 2019 Sulfotes Source Unknown 1 Miles 2019 Total Dissolved Solids Source Unknown 1 Miles 2019 9 L Otay Reservoir, Lower 91031000 Color Source Unknown 1050 Acres 2019 Iron Source Unknown 1050 Acres 2019 Source Unknown 9 C Pacific Ocean Shoreline, Aliso USA 90113000 Manganese Source Unknown Nitrogen, ammonia (Total Ammonia) pH(high) Source Unknown Source Unknown 1050 Acres 1050 Acres 1050 Acres Indicator bacteria 0.65 Miles Impairment located at Laguna Beach at Lagunita Place /Blue Lagoon Place, Aliso Beach. Nonpoint/Point Source 2019 2019 2019 2005 Page 11 of 27 2006 CWA SECTION 303(d) LIST OF WATER QUALI11 1.IMITED SEGMENTS REQUIRING TMDLS SAN DIEGO REGIONAL WATER QUALITY CONTROL BOARD USEPA APPROVAL DATE: JUNE 28, 2007 REGION TYPE NAME CALWATER WATERSHED POLLUTANT/STRESSOR POTENTIAL SOURCES ESTIMATED PROPOSED TMDL SIZE AFFECTED COMPLETION 9 C Pacific Ocean Shoreline, Buena Vista Creek 90421000 HA 9 C Pacific Ocean Shoreline, Dana Point HSA 90114000 9 C Pacific Ocean Shoreline, Escoodido Creek 90461000 HA C Pacific Ocean Shoreline, Imperial Beach Pier C Pacific Ocean Shoreline, Laguna Beach HSA 9 C Pacific Ocean Shoreline, Loma Alta HA C Pacific Ocean Shoreline, Lower San Juan HSA 91010000 90112000 90410000 90120000 Indicator bacteria 1-2 Miles 2008 Impairment located at Buena Vista Creek, Carlsbad City Beach at Carlsbad Village Drive. Carlsbad State Beach at Pine Avenue. Nonpoint/Point Source Indicator bacteria 2 Miles 2005 Impairment located at Aliso Beach at West Street, Aliso Beach at Table Rock Drive, 1000 Steps Beach at Pacific Coast Hwy (Hospital, 9th Ave). Salt Creek (large outlet). Salt Creek Beach at Salt Creek service road, Salt Creek Beach at Dana Strand Road, and Monarch Beach. Nonpoint/Point Source Indicator bacteria 0.44 Miles 2008 Impairment located at San Elijo Lagoon outlet. Nonpoint/Point Source PCBs (For/chlorinated biphenyls) 0.42 Miles 2019 Source Unknown Indicator bacteria 1.8 Miles 2005 Impairment located at Main Laguna Beach, Laguna Beach at Ocean Avenue, Laguna Beach at Laguna Avenue, Laguna Beach at Cleo Street, Arch Cove at Bluebird Canyon Road, Laguna Beach at Dumond Drive. Nonpoint/Point Source Indicator bacteria Impairment located at Loma Alta Creek Mouth. Nonpoint/Point Source Indicator bacteria 1.1 Miles 2008 1.2 Miles 2008 Impairment located at North Beach Creek, San Juan Creek (large outlet), Capistrano Beach, South Capistrano Beach at Beach Road. Nonpoint/Point Source Page 12 of 27 2006 CWA SECTION 303(d) LIST OF WATER QUALITY LIMITED SEGMENTS REQUIRING TMDLS SAN DIEGO REGIONAL WATER QUALITY CONTROL BOARD USEPA APPROVAL DATE: JUNE 28, 2007 REGION TYPE NAME CALWATER WATERSHED POLLUTANT/STRESSOR POTENTIAL SOURCES ESTIMATED PROPOSED TMDL SIZE AFFECTED COMPLETION 9 C Pacific Ocean Shoreline, San Clemente HA 90130000 9 C Pacific Ocean Shoreline, Sao Diego HU 90711000 C Pacific Ocean Shoreline, San Diequito HU 90511000 C Pacific Ocean Shoreline, San Joaquin Hills USA 9 C Pacific Ocean Shoreline, Scripps HA 90111000 9 C Pacific Ocean Shoreline, San Luis Rey HU 90311000 9 C Pacific Ocean Shoreline, San Marcos HA 90451000 90630000 3.7 Miles 2005Indicator bacteria Impairment located at Poche Beach (large outlet), Ole Hanson Beach Club Beach at Pico Drain, San Clemente City Beach at El Portal St. Stairs. San Clemente City Beach at Mariposa St., San Clemente City Beach at Linda Lane, San Clemente City Beach at South Linda Lane, San Clemente City Beach at Lifeguard Headquarters, Under San Clemente Municipal Pier, San Clemente City Beach at Trafalgar Canyon (Trafalgar Ln.), San Clemente State Beach at Riviera Beach, San Clemente State Beach at Cypress Shores. Nonpoint/Point Source Indicator bacteria 037 Miles Impairment located at San Diego River Mouth (oka Dog Beach). Nonpoint/Point Source Indicator bacteria 0.86 Miles Impairment located at San Dieguito Lagoon Mouth, Solatia Beach. Nonpoint/Point Source Indicator bacteria 0.63 Miles Impairment located at Cameo Cove at Irvine Cove Dr./Riviera Way, Heisler Park-North Urban Runoff/Storm Sewers Unknown Nonpoint Source Unknown point source Indicator bacteria Impairment located at San Luis Rey River Mouth. Nonpoint/Point Source Indicator bacteria Impairment located at Moonlight State Beach. Nonpoint/Point Source 0.49 Miles 0.5 Miles 2005 2005 2005. 2005 2005 Indicator bacteria 3.9 Miles 2019 This listing for indicator bacteria onliy applies to the Childrens Pool Beach area of this ocean shoreline segment. Nonpoint/Point Source Page 13 of 27 2006 CWA SECTION 303(d) LIST OF WATER QUALIT* iJMITED SEGMENTS REQUIRING TMDLS SAN DIEGO REGIONAL WATER QUALITY CONTROL BOARD USEPA APPROVAL DATE: JUNE 28, 2007 REGION TYPE NAME CALWATER WATERSHED POLLUTANT/STRESSOR POTENTIAL SOURCES ESTIMATED PROPOSED TMDL SIZE AFFECTED COMPLETION 9 C Pacific Ocean Shoreline, Tijuana HU 91111000 9 R Pine Valley Creek (Upper) 9 R Pogi Canyon Creek 9 R Prinu Deshecha Creek 9 R Rainbow Creek 91141000 91020000 90130000 90222000 Indicator bacteria Impairment located from the border, extending north along the shore. Nonpoint/Point Source Enterococcus Phosphorus Turbidity DDT Phosphorus Turbidity Iron Grazing-Related Sources Concentrated Animal Feeding Operations (permitted, point source) Transient encampments Source Unknown Source Unknown Source Unknown Urban Runoff/Storm Sewers Unknown Nonpoint Source Unknown point source Urban Runoff/Storm Sewers Unknown Nonpoint Source Unknown point source Source Unknown 3 Miles 2.9 Miles 2.9 Miles 2.9 Miles 7.8 Miles 1.2 Miles 1.2 Miles 5 Miles 2010 2010 2019 2019 2019 2019 2019 2019 Page 14 of 27 2006 CWA SECTION 303(d) LIST OF WATER QUALITY UMITED SEGMENTS REQUIRING TMDLS SAN DIEGO REGIONAL WATER QUALITY CONTROL BOARD USEPA APPROVAL DATE: JUNE 28, 2007 REGION TYPE NAME CALWATER WATERSHED POLLUTANT/STRESSOR POTENTIAL SOURCES ESTIMATED PROPOSED TMDL SIZE AFFECTED COMPLETION 9 K Reidy Canyon Creek 90462000 9 B San Diego Bay 91010000 B San Diego Bay Shoreline, 32nd St San 90822000 Diego Naval Station Sulfates Total Dissolved Solids Phosphorus Source Unknown Source Unknown Source Unknown PCBs (Polychlorinated biphenyls) Source Unknown 9 B San Diego Bay Shoreline, at Americas Cup 90810000 Harbor B San Diego Bay Shoreline, at Bayside Park 90911000 (J Street) 9 B San Diego Bay Shoreline, at Coronado Cays 91010000 Bentbic Community Effects Sediment Toxicity Copper Nonpoint/Point Source Nonpoint/Point Source Source Unknown Indicator bacteria This listing was made by USEPA for 2006. Source Unknown Copper 5 Miles 2019 5 Miles 2019 3.9 Miles 2019 10783 Acres 2019 103 Acres 103 Acres 2019 2019 88 Acres 2019 SO Acres 2019 47 Acres 2019 Source Unknown Page IS of27 2006 CWA SECTION 303(d) LIST OF WATER QUALITY LIMITED SEGMENTS REQUIRING TMDLS SAIN DIEGO REGIONAL WATER QUALITY CONTROL BOARD USEPA APPROVAL DATE: JUNE 28, 2007 REGION TYPE NAME CALWATER POTENTIAL WATERSHED POLLUTANT/STRESSOR SOURCES ESTIMATED PROPOSED TMDL SIZE AFFECTED COMPLETION 9 B San Diego Bay Shoreline, at Glorietta Bay 91010000 9 B San Diego Bay Shoreline, at Harbor Island 90821000 (East Basin) B San Diego Bay Shoreline, at Harbor Island 90810000 (West Basin) B San Diego Bay Shoreline, at Marriott 90821000 Marina 9 B San Diego Bay Shoreline, between Sampson 90822000 and 28th Streets Copper Copper Source Unknown Source Unknown Copper Source Unknown Copper Source Unknown Copper Mercury Nonpoint/Point Source Nonpoint/Point Source PAHs (Polycyclic Aromatic Hydrocarbons) Nonpoint/Point Source PCBs (Polychlorinated biphenyls) Nonpoint/Point Source Nonpoint/Point Source 52 Acres 73 Acres 132 Acres 24 Acres S3 Acres S3 Acres 53 Acres 53 Acres 53 Acres 2019 2019 2019 2019 2005 2006 2006 2019 2019 Page 16 of27 2006 CWA SECTION 303(d) LIST OF WATER QUALIT* ^IMITED SEGMENTS REQUIRING TMDLS SAN DIEGO REGIONAL WATER QUALITY CONTROL BOARD USEPA APPROVAL DATE: JUNE 28, 2007 REGION TYPE NAME CALWATER WATERSHED POLLUTANT/STRESSOR POTENTIAL SOURCES ESTIMATED PROPOSED TMDL SIZE AFFECTED COMPLETION C Sao Diego Bay Shoreline, Cbula Vista Marina B San Diego Bay Shoreline, Downtown Anchorage C San Diego Bay Shoreline, G Street Pier B San Diego Bay Shoreline, near Chollas Creek B San Diego Bay Shoreline, near Coronado Bridge B San Diego Bay Shoreline, near sub base 90912000 90821000 90821000 90822000 90822000 90810000 Copper Bentbic Community Effects Sediment Toxicity Indicator bacteria Bentbic Community Effects Sediment Toiicity Source Unknown Nonpoint/Point Source Nonpoint/Point Source Urban Runoff/Storm Sewers Unknown Nonpoint Source Unknown point source Nonpoint/Point Source Nonpoint/Point Source 0.41 Miles 7.4 Acres 7.4 Acres 0.42 Miles IS Acres IS Acres Benthic Community Effects 37 Acres Nonpoint/Point Source Sediment Toiicity 37 Acres Includes Crosby Street/Cesar Chavez Park area, that will receive additional monitoring. Nonpoint/Point Source Benthic Community Effects Sediment Toxicity Nonpoint/Point Source Nonpoint/Point Source 16 Acres 16 Acres 2019 2019 2019 2006 2006 2006 2019 2019 2019 2019 Page 17 of 27 2006 CWA SECTION 303(d) LIST OF WATER QUALITY LIMITED SEGMENTS REQUIRING TMDLS SAN DIEGO REGIONAL WATER QUALITY CONTROL BOARD Creek B San Diego Bay Shoreline, North of 24th Street Marine Terminal 9 B San Diego Bay Shoreline, Seventh Street Channel C San Diego Bay Shoreline, Shelter Island Shoreline Park 90832000 90831000 90810000 Chlordane Urban Runoff/Storm Sewers Other Boatyards Nonpoint/Point Source Ludane/Hexachlorocyclohexane (HCH) Urban Runoff/Storm Sewers Other Boatyards Nonpoint/Point Source PAHs (Polycyclic Aromatic Hydrocarbons) Urban Runoff/Storm Sewers Other Boatyards Nonpoint/Point Source Benthic Community Effects Sediment Toxicity Benthic Community Effects Sediment Toxicity Indicator bacteria Nonpoint/Point Source Nonpoint/Point Source Nonpoint/Point Source Nonpoint/Point Source Unknown Nonpoiut Source Unknown point source USEPA APPROVAL DATE: JUNE 28, 2007 1 REGION TYPE NAME 9 B San Diego Bay Shoreline, near CALWATER WATERSHED Switzer 90821000 POLLUTANT/STRESSOR POTENTIAI/ SOURCES ESTIMATED SIZE AFFECTED PROPOSED TMDL COMPLETION 5.5 Acres 5.5 Acres S3 Acres 93 Acres 93 Acres 9 Acres 9 Acres 0.42 Miles 2019 2019 2019 2019 2019 2008 2008 2006 Page IS of 27 2006 CWA SECTION 303(d) LIST OF WATER QUALITY UMITED SEGMENTS REQUIRING TMDLS SAN DIEGO REGIONAL WATER QUALITY CONTROL BOARD USEPA APPROVAL PATE: JUNE 28, 2007 ESTIMATED PROPOSED TMDL SIZE AFFECTED COMPLETIONREGION TYPE NAME CALWATER WATERSHED POLLUTANT/STRESSOR POTENTIAL SOURCES San Diego Bay Shoreline, Vicinity of B St and Broadway Piers 90821000 R San Diego River (Lower)90711000 Benthic Community Effects Nonpoint/Point Source Indicator bacteria Estimated size of impairment is 0.4 miles around the shoreline of the bay. Urban Runoff/Storm Sewers Unknown Nonpoint Source Unknown point source Sediment Toxicity Nonpoint/Point Source Fecal Conform Lower 6 miles. Urban Runoff/Storm Sewers Wastewater Nonpoint/Point Source Low Dissolved Oxygen Impairment transcends adjacent Calwater wtareshed 90712. Urban Runoff/Storm Sewers Unknown Nonpoint Source Unknown point source Phosphorus Impairment transcends adjacent Calwater watershed 90712. Urban Runoff/Storm Sewers Unknown Nonpoint Source Unknown point source Total Dissolved Solids Impairment transcends adjacent Calwater watershed 90712. Urban Runoff/Storm Sewers Flow Regulation/Modification Natural Sources Unknown Nonpoint Source Unknown point source 9.9 Acres 9.9 Acres 9.9 Acres 16 Miles 16 Miles 16 Miles 16 Miles 2019 2006 2019 2005 2019 2019 2019 Page 19 of 27 2006 CWA SECTION 303(d) LIST OF WATER QUALITY LIMITED SEGMENTS REQUIRING TMDLS SAN DIEGO REGIONAL WATER QUALITY CONTROL BOARD USEPA APPROVAL DATE: JUNE 28, 2007 REGION TYPE NAME CAL WATER WATERSHED POLLUTANT/STRESSOR POTENTIAL SOURCES ESTIMATED PROPOSED TMDL SIZE AFFECTED COMPLETION 9 E San Elijo Lagoon 9 R San Juan Creek 90461000 90120000 Eutrophic Estimated size of impairment is 330 acres. Nonpoint/Point Source Indicator bacteria Estimated size of impairment is 150 acres. Nonpoint/Point Source Sedimentation/Siltation Estimated size of impairment is ISO acres. Nonpoint/Point Source DDE 566 Acres 566 Acres 566 Acres 1 Miles 2019 2008 2019 2019 Indicator bacteria Source Unknown 1 Miles 2005 9 E San Juan Creek (mouth) 9 R San Luis Rey River 90120000 90311000 Indicator bacteria Nonpoint/Point Source Nonpoint/Point Source Chloride Impairment located at lower 13 miles. Urban Runoff/Storm Sewers Unknown Nonpoint Source Unknown point source 63 Acres 19 Miles 2008 2019 Page 20 of27 2006 CWA SECTION 303(d) LIST OF WATER QUALITY LIMITED SEGMENTS REQUIRING TMDLS SAN DIEGO REGIONAL WATER QUALITY CONTROL BOARD USEPA APPROVAL DATE: JUNE 28, 2007 REGION TYPE NAME CALWATER WATERSHED POLLUTANT/STRESSOR POTENTIAL SOURCES ESTIMATED PROPOSED TMDL SIZE AFFECTED COMPLETION 9 R San Marcos Creek 9 L Sao Marcos Lake 9 L San Vicente Reservoir 90451000 90452000 90721000 Total Dissolved Solids DDE Phosphorus Sediment Tozicity Ammonia as Nitrogen Nutrients Phosphorus Chloride Industrial Point Sources Agriculture-storm runoff Urban Runoff/Storm Sewers Surf ace Mining Flow Regulation/Modification Natural Sources Golf course activities Unknown Nonpoint Source Unknown point source Source Unknown Source Unknown Source Unknown Source Unknown Source Unknown Source Unknown Source Unknown 19 Miles 19 Miles 19 Miles 19 Miles 17 Acres 17 Acres 17 Acres 1058 Acres 2019 2019 2019 2019 2019 2019 2019 2019 Page 21 of 27 2006 C WA SECTION 303(d) LIST OF WATER QUALIT i ^IMITED SEGMENTS REQUIRING TMDLS SAN DIEGO REGIONAL WATER QUALITY CONTROL BOARD USEPA APPROVAL DATE: JUNE 28, 2007 REGION TYPE NAME CAL WATER WATERSHED POLLUTANT/STRESSOR POTENTIAL SOURCES ESTIMATED - PROPOSED TMDL SIZE AFFECTED COMPLETION Color 1058 Acres 2019 Manganese pH(high) Sulfates Source Unknown Source Unknown Source Unknown 10S8 Acres 1058 Acres 1058 Acres 2019 2019 2019 9 R Sandia Creek 90222000 Iron Source Unknown IS Miles 2019 Manganese Nitrogei Sulfates Source Unknown Source Unknown Source Unknown 1.5 Miles 1.5 Miles 1.5 Miles 2019 2019 2019 Total Dissolved Solids Source Unknown 1.5 Miles 2019 9 E Santa Margarita Lagoon 90211000 Eutropbic Urban RunoO/Storm Sewers Flow Regulation/Modification Natural Sources Unknown Nonpoint Source Unknown point source Nonpoint/Point Source 28 Acres 2019 Page 22 of27 2006 CWA SECTION 303(d) LIST OF WATER QUALITY LIMITED SEGMENTS REQUIRING TMDLS SAN DIEGO REGIONAL WATER QUALITY CONTROL BOARD USEPA APPROVAL DATE: JUNE 28, 2007 REGION TYPE NAME CALWATER WATERSHED POLLUTANT/STRESSOR POTENTIAL SOURCES ESTIMATED PROPOSED TMDL SIZE AFFECTED COMPLETION 9 R Santa Margarita River (Upper) 9 R Segunda Deshecha Creek 9 R Soledad Canyon 9 L Sutherland Reservoir 90222000 90130000 90610000 90553000 Phosphorus Phosphorus Turbidity Sediment Toxicity Color Manganese Urban Runoff/Storm Sewers Unknown Nonpoint Source Unknown point source Urban Runofi/Storm Sewers Unknown Nonpoint Source Unknown point source Construction/Land Development Urban Runoff/Storm Sewers Channelization Flow Regulation/Modification Unknown Nonpoint Source Unknown point source Source Unknown Urban RunofPStorm Sewers Unknown Nonpoint Source Unknown point source Source Unknown Source Unknown 18 Miles 2019 0.92 Miles 2019 0.92 Miles 2019 1.7 Miles 2019 561 Acres 2019 561 Acres 2019 561 Acres 2019 Page 23 of 27 2006 CWA SECTION 303(d) LIST OF WATER QUALITY LIMITED SEGMENTS REQUIRING TMDLS SAN DIEGO REGIONAL WATER QUALITY CONTROL BOARD USEPA APPROVAL DATE: JUNE 28, 2007 REGION TYPE NAME CALWATER WATERSHED POLLUTANT/STRESSOR POTENTIAL SOURCES ESTIMATED PROPOSED TMDL SIZE AFFECTED COMPLETION 9 L Sweetwater Reservoir 9 R Tecolote Creek 9 R Temecula Creek 90921000 90650000 90251000 Oxygen, Dissolved Cadmium Copper Indicator bacteria Lead Phosphorus Toxkity Turbidity Zinc Nitrogen Phosphorus Source Unknown Nonpoint/Point Source Nonpoint/Point Source Nonpoint/Point Source Nonpoint/Point Source Source Unknown Nonpoint/Point Source Source Unknown Nonpoint/Point Source Source Unknown Source Unknown 925 Acres 6.6 Miles 6.6 Miles 6.6 Miles 6.6 Miles 6.6 Miles 6.6 Miles 6.6 Miles 6.6 Miles 44 Miles 44 Miles 2019 2019 2019 2006 2019 2019 2019 2019 2019 2019 2019 Page 24 oj'27 2006 CWA SECTION 303(d) LIST OF WATER QUALI11 LIMITED SEGMENTS REQUIRING TMDLS SAN DIEGO REGIONAL WATER QUALITY CONTROL BOARD USEPA APPROVAL DATE: JUNE 28,2007 REGION TYPE NAME CALWATER WATERSHED POLLUTANT/STRESSOR POTENTIAL SOURCES ESTIMATED PROPOSED TMDL SIZE AFFECTED COMPLETION 9 K Tijuana River E Tijuana River Estuary 91111000 91111000 Total Dissolved Solids Eutrophic Indicator bacteria Low Dissolved Oxygen Pesticides Solids Synthetic Organic: Trace Elements Trash Source Unknown Nonpoint/Point Source Nonpoint/Point Source Nonpoint/Point Source Nonpoint/Point Source Nonpoint/Point Source Nonpoint/Point Source Nonpoint/Point Source Nonpoint/Point Source Eutrophic Estimated size of impairment is 1 acre. Nonpoint/Point Source Indicator bacteria Estimated size of impairment is 150 acres. Nonpoint/Point Source 44 Miles 6 Miles 6 Miles 6 Miles 6 Miles 6 Miles 6 Miles 6 Miles 6 Miles 1319 Acres 1319 Acres 2019 2019 2010 2019 2019 2019 2019 2019 2019 2019 2010 Page 25 of 27 2006 CWA SECTION 303(d) LIST OF WATER QUALITY LIMITED SEGMENTS REQUIRING TMDLS SAN DIEGO REGIONAL WATER QUALITY CONTROL BOARD USEPA APPROVAL DATE: JUNE 28, 2007 REGION TYPE NAME CALWATER WATERSHED POLLUTANT/STRESSOR POTENTIAL SOURCES ESTIMATED PROPOSED TMDL SIZE AFFECTED COMPLETION Lead Estimated size of impairment is I acre. Nonpoiat/Point Source Low Dissolved Oxygen Urban Runoff/Storm Sewers Wastewater Unknown Nonpoint Source Unknown point source Nickel Estimated size of impairment is 1 acre. Nonpoint/Point Source Pesticides Estimated size of impairment is 1 acre. Nonpoiot/Poiot Source Thallium Estimated size of impairment is 1 acre. Nonpoint/Point Source Trash Estimated size of impairment is 1 acre. Nonpoint/Point Source Turbidity Source Unknown 1319 Acres 1319 Acres 1319 Acres 1319 Acres 1319 Acres 1319 Acres 1319 Acres 2019 2019 2019 2019 2019 2019 2019 Page 26 of 27 2006 CWA SECTION 303(d) LIST OF WATER QUALI1 * LIMITED SEGMENTS REQUIRING TMDLS SAN DIEGO REGIONAL WATER QUALITY CONTROL BOARD USEPA APPROVAL DATE: JUNEJ8, 2007 REGION TYPE NAME CALWATER WATERSHED POLLUTANT/STRESSOR POTENTIAL SOURCES ESTIMATED PROPOSED TMDL SIZE AFFECTED COMPLETION REGIONAL WATER QUALITY CONTROL BOARDS 1 North Coast 2 San Francisco Bay 3 Central Coast 4 Los Angeles 5 Central VaUey 6 Lahontan 7 Colorado River Basin 8 Santa Ana 9 San Diego WATER BODY TYPE B « Bays and Harbors C - Coastal Shorelines/Beaches E - Estuaries L = Lakes/Reserviors R = Rivers and Streams S= Saline Lakes T= Wetlands, Tidal W~ Wetlands, Freshwater CALWATER WATERSHED "Calwater Watershed" is the State Water Resources Control Board bydrological subunit area or an even smaller area delineation. GROUP A PESTICIDES OR CHEM A aldrin, dieldrin, chlordane, endrin, beptachlor, heptachlor epoxide, hexachlorocyclohexane (including lindane), endosulfan, and toxaphene Page 27 of 27 EXHIBIT F '* 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 listed 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 >100,000ft2 Heavy industry /industrial development Automotive Repair Shops Restaurants Steep Hillside Development >5,000 ft2 Parking Lots Retail Gasoline Outlets Streets, Highways & Freeways */„ >.-. ' "^ - / - General Pollutant &aiegorfe«; '-,*•'" * . " Sediments X X pd) X X p(1) X Nutrients X X pd) X p(1) p(1) Heavy Metals X X X X X Organic Compounds p(2) X X(4)<5) X X<4) Trash & Debris X X X X X X X X X X Oxygen Demanding Substances X pd) p<5> X X X pd) X p(5) Oil& Grease X p(2) X X X X X X X X Bacteria & Viruses X pd) p(3) X Pesticides X X p(5) X pd) 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. March 2008 EXHIBIT G Pipe fcr In addition to chambers, another pop- ular choice for storm water runoff control is to store the water under- ground in large diameter pipe net- works. These can be either retention systems which allow the water to be absorbed by the surrounding soil, or detention systems which release the stored water through outlet pipes to receiving streams, sewers or ditches. These systems preserve valuable surface land, require little mainte- nance, and do not disturb the aes- thetics of the development. A typical retention/detention system uses multiple runs of large diameter pipe connected at one or both ends to a manifold. ADS supplies corrugat- ed HOPE pipe with integral water tight joints in diameters up through 60", as well as a complete selection of standard and custom-fabricated fit- tings and manifolds to complete the system. In addition, ADS has produced a comprehensive CD-ROM presenta- tion that outlines preferred engineer- ing practices in determining the size of the system, flow rates and capaci- ty requirements. The Storm Water Retention/Detention Design Tool presents data on watershed defini- tion, rainfall frequency, duration and intensity, runoff coefficients, peak flow rates, and drainage pattern lay- outs. Examples of actual installed systems are also included. The CD is available from any ADS representa- tive. f CLASS I OR tt MATERIALPER ASTU D2«1. LATEST EDITION, _ COMPACTED IN MAX. 3' LOOSE LIFTS TO 9SX MN. Of UAX. SPO BEDDING (CmSS ' CW H UAFERlAL) - 4" MiN. FOfl I2'-2*" N-12 42"-60' M - 6" WIN FOR 30'--36" N-12 12" FOR UP TO AND tWCLUCHNG JS* N-12 24" F0« 42--SO" N-12 90- BKND SINGLi COUPONSNT X)UBU COIIPONINT TRIPL1 COMPONKNT EXHIBIT H Table 1 Standard Development Project & Priority Project Storm Water BMP Requirements Matrix Standard Projects Site Design BMPs(1) R Source Control BMPs(2) R BMPs Applicable to Individual Priority Project Categories'3'a. Private RoadsR b. ResidentialDriveways & GuestParkingR S1•fi8 6 R d. Maintenance BaysR e. Vehicle Wash AreasR f. Equipment WashAreasR g. Outdoor ProcessingAreasR h. Surface ParkingAreasR % 1 D) "03 U_ R j. Hillside LandscapingR Treatment Control BMPs'41 O Priority Projects: Detached Residential Development Attached Residential Development Commercial Development greater than 100,000 ft2 Heavy industry /industrial Automotive Repair Shop Restaurants Steep Hillside Development greater than 5,000 ft2 Parking Lots Retail Gasoline Outlets Streets, Highways & Freeways 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 R R R R R R R R R R R R R R(5) R R R R R S S S S S S S S S S 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. City 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 Section 2.3.3.1 (2) Refer to Section 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 Section 2.3.3.3 (4) Refer to Section 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. March 2008 EXHIBIT BEST ORIGINAL Efficient Irrigation SD-12 Design Objectives / Maximize Infiltration / Provide Retention / Slow Runoff Minimize Impervious Land Coverage Prohibit Dumping of Improper Materials 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. • 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. '• ;'ivA.C >\ S Q A California Stormwatvr Quality Association January 2003 California Stormwater BMP Handbook New Development and Redevelopment 1 of 2 SD-12 Efficient Irrigation • Design timing and application methods of irrigation water to minimize the runoff of excess irrigation water into the storm water drainage system. • Group plants with similar water requirements in order to reduce excess irrigation runoff and promote surface nitration. 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) hi 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 /arious 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. 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 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 Qualify Control Measures, July 2002. 2 of 2 California Stormwater BMP Handbook January 2003 New Development and Redevelopment Storm Drain Signage ORIGINAL SD-13 Design Objectives 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: 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 - CASQA California Stormwatw Quality Association January 2003 California Stormwater BMP Handbook New Development and Redevelopment 1 of 2 SD-13 Storm Drain Signage DRAINS TO OCEAN" and/or other graphical icons to discourage illegal dumping. • 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 m 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 property title to maintain the legibility of placards or signs. Placement • 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, July 2002. 2 of 2 California Stormwater BMP Handbook January 2003 New Development and Redevelopment Road and Street Maintenance SC-70 Objectives • Cover • Contain • Educate • Reduce/Minimize • Product Substitution Description Streets, roads, and highways are significant sources of pollutants in stormwater discharges, and operation and maintenance (O&M) practices, if not conducted properly, can contribute to the problem. Stormwater pollution from roadway and bridge maintenance should be addressed on a site-specific basis. Use of the procedures outlined below, that address street sweeping and repair, bridge and structure maintenance, and unpaved roads will reduce pollutants in stormwater. Approach Pollution Prevention m Use the least toxic materials available (e.g. water based paints, gels 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 m Maintain a consistent sweeping schedule. Provide minimum monthly sweeping of curbed streets. • Perform street cleaning during dry weather if possible. Targeted Constituents Sediment 7" Nutrients Trash / Metals / Bacteria Oil and Grease / Organlcs <* Oxygen Demanding / California Stormwattr >'\ Quality Association January 2003 California Stormwater BMP Handbook 1 Of 9 Parking/Storage Area Maintenance sc-43 Description Parking lots and storage areas can contribute a number of substances, such as trash, suspended solids, hydrocarbons, oil and grease, and heavy metals that can enter receiving waters through stormwater runoff or non-stormwater discharges. The following protocols are intended to prevent or reduce the discharge of pollutants from parking/storage areas and include using good housekeeping practices, following appropriate cleaning BMPs, and training employees. Approach Pollution Prevention m Encourage alternative designs and maintenance strategies for impervious parking lots. (See New Development and Redevelopment BMP Handbook). • Keep accurate maintenance logs to evaluate BMP implementation. Suggested Protocols General • Keep the parking and storage areas clean and orderly. Remove debris in a timely fashion. • Allow sheet runoff to flow into biofilters (vegetated strip and swale) and/or infiltration devices. • Utilize sand filters or oleophilic collectors for oily waste in low concentrations. Objectives • Cover • Contain • Educate • Reduce/Minimize • Product Substitution Targeted Constituents Sediment < Nutrients < Trash i Metals i Bacteria < Oil and Grease < Organic* < Oxygen Demanding < ( J California Stormwatcr Quality Association January 2003 California Stormwater BMP Handbook 1 of 4 SC-43 Parking/Storage Area Maintenance • Arrange rooftop drains to prevent drainage directly onto paved surfaces. • Design lot to include semi-permeable hardscape. Controlling Litter m Post "No Littering" signs and enforce anti-litter laws. • Provide an adequate number of litter receptacles. • Clean out and cover litter receptacles frequently to prevent spillage. • Provide trash receptacles in parking lots to discourage litter. • Routinely sweep, shovel and dispose of litter in the trash. Surface cleaning m Use dry cleaning methods (e.g. sweeping or vacuuming) to prevent the discharge of pollutants into the stormwater conveyance system. • Establish frequency of public parking lot sweeping based on usage and field observations of waste accumulation. • Sweep all parking lots at least once before the onset of the wet season. • If water is used follow the procedures below: - Block the storm drain or contain runoff. - Wash water should be collected and pumped to the sanitary sewer or discharged to a pervious surface, do not allow wash water to enter storm drains. Dispose of parking lot sweeping debris and dirt at a landfill. • When cleaning heavy oily deposits: Use absorbent materials on oily spots prior to sweeping or washing. - Dispose of used absorbents appropriately. Surface Repair • Pre-heat, transfer or load hot bituminous material away from storm drain inlets. • Apply concrete, asphalt, and seal coat during dry weather to prevent contamination form contacting stormwater runoff. Cover and seal nearby storm drain inlets (with waterproof material or mesh) and manholes before applying seal coat, slurry seal, etc., where applicable. Leave covers in place until job is complete and until all water from emulsified oil sealants has drained or evaporated. Clean any debris from these covered manholes and drains for proper disposal. 2 of 4 California Stormwater BMP Handbook January 2003 Parking/Storage Area Maintenance SC-43 • Use only as much water as necessary for dust control, to avoid runoff. • Catch drips from paving equipment that is not in use with pans or absorbent material placed under the machines. Dispose of collected material and absorbents properly. Inspection m Have designated personnel conduct inspections of the parking facilities and stormwater conveyance systems associated with them on a regular basis. • Inspect cleaning equipment/sweepers for leaks on a regular basis. Training m Provide regular training to field employees and/or contractors regarding cleaning of paved areas and proper operation of equipment. • Train employees and contractors in proper techniques for spill containment and cleanup. Spill Response and Prevention m Refer to SC-H, Spill Prevention, Control & Cleanup. • Keep your Spill Prevention Control and countermeasure (SPCC) plan up-to-date, nad implement accordingly. • Have spiU 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 Considerations m Limitations related to sweeping activities at large parking facilities may include high equipment costs, the need for sweeper operator training, and the inability of current sweeper technology to remove oil and grease. Requirements Costs Cleaning/sweeping costs can be quite large, construction and maintenance of stormwater structural controls can be quite expensive as well. Maintenance m Sweep parking lot to minimize cleaning with water. • Clean out oil/water/sand separators regularly, especially after heavy storms. • Clean parking facilities on a regular basis to prevent accumulated wastes and pollutants from being discharged into conveyance systems during rainy conditions. January 2003 California Stormwater BMP Handbook 3 of 4 Municipal sc-43 Parking/Storage Area Maintenance Supplemental Information Further Detail of the BMP Surf ace Repair Apply concrete, asphalt, and seal coat during dry weather to prevent contamination form contacting stonnwater runoff. Where applicable, cover and seal nearby storm drain inlets (with waterproof material or mesh) and manholes before applying seal coat, slurry seal, etc. Leave covers in place until job is complete and until all water from emulsified oil sealants has drained or evaporated. Clean any debris from these covered manholes and drains for proper disposal. Use only as much water as necessary for dust control, to avoid runoff. References and Resources http://www.stormwatercenter.net/ California's Nonpoint Source Program Plan http://www.swrcb.ca.sov/npa/index.html 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 (Revised February 2002 by the California Coastal Commission). Jrange County Stonnwater Program http://www.ocwatersheds.com/StormWater/swp_introduction.asp Oregon Association of Clean Water Agencies. Oregon Municipal Stonnwater Toolbox for Maintenance Practices. June 1998. Pollution from Surface Cleaning Folder. 1996. Bay Area Stonnwater Management Agencies Association (BASMA/0 http://www.basma.org San Diego Stormwater Co-permittees Jurisdictional Urban Runoff Management Program (URMP) http://www.prQiectcleanwater.org/Ddf/Model%20Program962QMunicipal962oFacilitiea.pdf 4 of 4 California Stormwater BMP Handbook January 2003 Munlcloal SC-70 Road and Street Maintenance i Avoid wet cleaning or flushing of street, and utilize dry methods where possible. i Consider increasing sweeping frequency based on factors such as traffic volume, land use, field observations of sediment and trash accumulation, proximity to water courses, 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 litter 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. • 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. 2 of 9 California Stormwater BMP Handbook January 2003 Munlrinal Road and Street Maintenance SO70 • 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 pans 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 he disposed of properly. • Use water based paints whenever possible. If using water based paints, clean the application equipment in 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 little 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. • Wash concrete trucks off site or in designated areas on site designed to preclude discharge of wash water to drainage system. January 2003 California Stormwater BMP Handbook 3 of 9 Mlinlrlnal 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, slurry seal, etc. Leave covers in place until job is complete and until all water from emulsified oil sealants has drained or evaporated. Clean 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 inlets. Designate an area for clean up and proper disposal of excess materials. i Use only as much water as necessary for dust control, to avoid runoff. • Sweep, never hose down streets to clean up tracked dirt. Use a street sweeper or vacuum truck. Do not dump vacuumed liquid in storm drains. • Catch drips from paving equipment that 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 m 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) that is connected to the sanitary sewer. Bridge and Structure Maintenance Paint and Paint Removal i 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 California Stormwater BMP Handbook January 2003 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 sander with a vacuum filter bag. • 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 ha2ardous waste facility. Graffiti Removal m 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 properly 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 runoff 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. January 2003 California Stormwater BMP Handbook 5 of 9 Muni"!..-I SC-70 Road and Street Maintenance • 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 will hold the soils in place while the vegetation is establishing. Native vegetation should be used if possible. • If vegetation cannot be established immediately, apply temporary erosion control mats/blankets; a comma straw, or gravel as appropriate. • If sediment is already eroded and mobilized in roadside areas, temporary controls should be installed. These may include: sediment control fences, fabric-covered triangular dikes, gravel-filled 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. i Train employees on proper spill containment and clean up, and in identifying non- stormwater discharges. 6 or 9 California Stormwater BMP Handbook January 2003 M. .«l-!«t Road and Street Maintenance SC-70 Spill Response and Prevention • Refer to SC-n, Spill Prevention, Control & Cleanup. • Keep your Spill Prevention Control and countermeasure (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 Considerations 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. • Limitations 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 Costa • The maintenance of local roads and bridges is already a consideration of most community public works or transportation departments. Therefore, the cost of pollutant reducing management practices will involve the training and equipment required to implement these new practices. • The largest expenditures for street sweeping programs are in 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. • A street sweeping program may require the following. - Sweeper operators, maintenance, supervisory, and administrative personnel are required. - 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. January 2003 California Stormwater BMP Handbook 7 of 9 Munlrlnal 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 rules, as well as being a source of revenue. Maintenance m Not applicable Supplemental Information Further Detail o/the BMP Street sweeping There are advantages and disadvantages to the two common types of sweepers. The best choice depends on your specific conditions. Many communities find it useful to have a compliment of both types in their fleet Mechanical Broom Sweepers - More effective at picking up large debris and cleaning wet streets. Less costly to purchase and operate. Create more airborne dust. 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 Flushers - Not affected by biggest interference to cleaning, parked cars. May remove finer sediments, moving them toward the gutter and stormwater 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 carry relatively high concentrations of-polkrtants. 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. 8 of 9 California Stormwater BMP Handbook Januaru 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-icing m Do not over-apply deicing salt and sand, and routinely calibrate spreaders. • Near reservoirs, restrict the application of deicing salt and redirect any runoff away from reservoirs. . • Consider using alternative deicing agents (less toxic, biodegradable, etc.). References and Resources 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://vMyw.ocwatershed3.com/stonnwater/swp introdaction.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 htto://www.eDa.gov/npdes/menuofbmDs/poll w.htm January 2003 California Stormwater BMP Handbook q nf « r The County of San Diego Fact Sheet 7. Bioretention Systems LID Appendix Typical Bioretention cross section, Anatomy of a Rain Garden, n.d. Bioretention systems are essentially a surface and sub-surface water filtration system. In function they are similar to sand filters. Bioretention systems incorporate both plants and underlying filter soils for removal of contaminants. These facilities normally consist of a treatment train approach: filter strip, sand bed, ponding area, organic layer, planting soil, and plants. CHARACTERISES • Effective in removing sediments and attached pollutants by filtration through surface vegetation, ground cover and underlying filter media layer • Delay runoff peaks by providing retention capacity and reducing flow velocities. • Vegetation increases aesthetic value while also enhancing filtration capacity and helping to maintain the porosity of the filter media. • Can be constructed as either large or small scale devices, with native or amended soils. • Small scale units are usually located in a residential planter box that filters collected stormwater through the filter media and to an outlet. • Larger scale devices work on the same methodology, however are generally located along the streetscapes and retarding basins over large open areas. • In addition, there are two main types of bioretention system: Non-conveyance systems, which generally pond runoff volume, and Conveyance, which generally convey minor storm events along longitudinal channels. Such conveyance systems generally include an amended soil layer under the surface for additional storage and filtration APPLICATION • Effective in removing medium to fine size sediments and attached pollutants (such as nutrients, free oils/grease and metals), but typically have higher pollutant Final -42-12/31/2007 The County of San Diego LID Appendix removal efficiencies for a wider range of contaminants due to enhanced filtration/biological processes associated with the surface vegetation. • Best suited to small residential, commercial, and industrial developments with high percentages of impervious areas, including parking lots, high density residential housing, and roadways. • Aesthetic benefits due to the surface vegetation make bioretention systems appealing for incorporation into streetscape and general landscape features. DESIGN • Provide a gentle slope for overland flow and adequate water storage. No water should be allowed to pond in the bioretention system for longer than 72 hours. • Usually designed in conjunction with swales and other devices upstream so as to reduce filter clogging and provide water treatment (treatment train). • Filter media employed is usually the plant growing material, which may comprise soil, sand and peat mixtures. • "Planting box" type systems should be restricted to very small catchment areas. • A subdrain system should be included in urban areas along with associated cleanout to facilitate maintenance. • For more precise design techniques, see: CASQA (2003, January) California Stormwater BMP Handbook: New Development and Redevelopment MAINTENANCE • Generally, only routine periodic maintenance typical of any landscaped area (mulching, plant replacement, pruning, weeding) is necessary. • Regular inspections and maintenance are particularly important during the vegetation establishment period. • Routine maintenance should include a biannual health evaluation of the trees and shrubs and subsequent removal of any dead or diseased vegetation. • Other potential tasks include soil pH regulation, erosion repair at inflow points, mulch replenishment, unclogging the under-drain, and repairing overflow structures. LIMITATIONS • Adequate sunlight is required for vegetation growth. • The use of irrigation may not meet State water conservation goals. Appropriate drought-tolerant plants should be considered. • Placement may be limited by the need for upstream pre-treatment so as to avoid filter clogging (treatment train). • Contributing drainage area should be less than 1 acre for small-scale, on-lot devices • Bioretention (a BMP with incidental infiltration) is not an appropriate BMP when: o the seasonal high groundwater table is within 6 feet of the ground surface (US EPA 1999) o at locations where or where surrounding soil stratum is unstable • exceptions to the 6 foot separation can be made when: o the BMP is designed with an under-drain and approved by a qualified licensed professional, or when: Final -43- 12/31/2007 The County of San Diego LID Appendix o written approval of a separation in the interval of 4-6 feet has been obtained by the Regional Water Quality Control Board and the Department of Environmental Health. • Site must contain sufficient elevation relief so that subdrain system may discharge to receiving swale, curb or storm drain system. ECONOMICS • Construction cost estimates for a bioretention area are slightly greater than those for the required landscaping for a new development (EPA, 1999). • The operation and maintenance costs for a bioretention facility will be comparable to those of typical landscaping required for a site. (CASQA, 2003) • Maintenance costs are projected at 5-7% of the construction cost annually. REFERENCES • California Stormwater Quality Association. (2003, January) California Stormwater BMP Handbook: New Development and Redevelopment. • URS Australia Pty Ltd, (2004, May), Water Sensitive Urban Design: Technical Guidelines for Western Sydney, Upper Parramatta River Catchment Trust. • US EPA (1999, September) BMP Fact Sheet 832-F-99-012. http://www.epa.gov/owm/mtb/biortn.pdf • US EPA (1999, August) Preliminary Studies: Preliminary Data Summary of Urban Stormwater Best Management Practices. EPA-821-R-99-012 Part D. • For additional information pertaining to Bioretention Systems, see the works cited in the San Diego County LID Literature Index. Final -44- 12/31/2007 Vegetated Swale TC-30 •'"• The topography of the site should permit the design of a channel with appropriate slope and cross-sectional area. Site topography may also dictate a need for additional structural controls. Recommendations for longitudinal slopes range between 2 and 6 percent. Flatter slopes can be used, if sufficient to provide adequate conveyance. Steep slopes increase flow velocity, decrease detention time, and may require energy dissipating and grade check. Steep slopes also can be managed using a series of check dams to terrace the swale and reduce the slope to within acceptable limits. The use of check dams with swales also promotes infiltration. Additional Design Guidelines Most of the design guidelines adopted for swale design specify a minimum hydraulic residence time of 9 minutes. This criterion is based on the results of a single study conducted in Seattle, Washington (Seattle Metro and Washington Department of Ecology, 1992), and is not well supported. Analysis of the data collected in that study indicates that pollutant removal at a residence time of 5 minutes was not significantly different, although there is more variability in that data. Therefore, additional research in the design criteria for swales is needed. Substantial pollutant removal has also been observed for vegetated controls designed solely for conveyance (Barrett et al, 1998); consequently, some flexibility in the design is warranted. Many design guidelines recommend that grass be frequently mowed to maintain dense coverage near the ground surface. Recent research (Colwell et al., 2000) has shown mowing frequency or grass height has little or no effect on pollutant removal. Summary of Design Recommendations 1) The swale should have a length that provides a minimum hydraulic residence time of / at least 10 minutes. The maximum bottom width should not exceed 10 feet unless a dividing berm is provided. The depth of flow should not exceed 2/3rds the height of the grass at the peak of the water quality design storm intensity. The channel slope should not exceed 2.5%. 2) A design grass height of 6 inches is recommended. 3) Regardless of the recommended detention time, the swale should be not less than 100 feet in length. 4) The width of the swale should be determined using Manning's Equation, at the peak of the design storm, using a Manning's n of 0.25. 5) The swale can be sized as both a treatment facility for the design storm and as a conveyance system to pass the peak hydraulic flows of the loo-year storm if it is located "on-line." The side slopes should be no steeper than 3:1 (H:V). 6) Roadside ditches should be regarded as significant potential swale/buffer strip sites and should be utilized for this purpose whenever possible. If flow is to be introduced through curb cuts, place pavement slightly above the elevation of the vegetated areas. Curb cuts should be at least 12 inches wide to prevent clogging. 7) Swales must be vegetated in order to provide adequate treatment of runoff. It is important to maximize water contact with vegetation and the soil surface. For general purposes, select fine, close-growing, water-resistant grasses. If possible, divert runoff (other than necessary irrigation) during the period of vegetation January 2003 California Stormwater BMP Handbook 5 of 13 New Development and Redevelopment Spill Prevention and Control WM-4 Description and Purpose Prevent or reduce the discharge of pollutants to drainage systems or watercourses from leaks and spills by reducing the chance for spills, stopping the source of spills, containing and cleaning up spills, properly disposing of spill materials, and training employees. This best management practice covers only spill prevention and control. However, WM-i, Materials Delivery and Storage, and WM-2, Material Use, also contain useful information, particularly on spill prevention. For information on wastes, see the waste management BMPs in this section. Suitable Applications This BMP is suitable for all construction projects. Spill control procedures are implemented anytime chemicals or hazardous substances are stored on the construction site, including the following materials: • Soil stabilizers/binders • Dust palliatives • Herbicides • Growth inhibitors • Fertilizers • Deicing/anti-icing chemicals Objectives EC SE TC WE NS WM Erosion Control Sediment Control Tracking Control Wind Erosion Control Non-Stormwater Management Control Waste Management and Materials Pollution Control Legend: ir Primary Objective •/ Secondary Objective Targeted Constituents Sediment i Nutrients i Trash i Metals i Bacteria Oil and Grease i Organics t Potential Alternatives None CASQA California Stormwater Quality Association January 2003 California Stormwater BMP Handbook Construction www.cabmohandbooks.com 1 of 6 Spill Prevention and Control WM-4 • Store and dispose of used clean up materials, contaminated materials, and recovered spill material that is no longer suitable for the intended purpose in conformance with the provisions in applicable BMPs. • Do not allow water used for cleaning and decontamination to enter storm drains or watercourses. Collect and dispose of contaminated water in accordance with WM-io, Liquid Waste Management. • Contain water overflow or minor water spillage and do not allow it to discharge into drainage facilities or watercourses. • Place proper storage, cleanup, and spill reporting instructions for hazardous materials stored or used on the project site in an open, conspicuous, and accessible location. • Keep waste storage areas clean, well organized, and equipped with ample cleanup supplies as appropriate for the materials being stored. Perimeter controls, containment structures, covers, and liners should be repaired or replaced as needed to maintain proper function. Cleanup • Clean up leaks and spills immediately. • Use a rag for small spills on paved surfaces, a damp mop for general cleanup, and absorbent material for larger spills. If the spilled material is hazardous, then the used cleanup materials are also hazardous and must be sent to either a certified laundry (rags) or disposed of as hazardous waste. • Never hose down or bury dry material spills. Clean up as much of the material as possible and dispose of properly. See the waste management BMPs in this section for specific information. Minor Spills • Minor spills typically involve small quantities of oil, gasoline, paint, etc. which can be controlled by the first responder at the discovery of the spill. • Use absorbent materials on small spills rather than hosing down or burying the spill. • Absorbent materials should be promptly removed and disposed of properly. • Follow the practice below for a minor spill: - Contain the spread of the spill. Recover spilled materials. Clean the contaminated area and properly dispose of contaminated materials. Semi-Significant Spills • Semi-significant spills still can be controlled by the first responder along with the aid of other personnel such as laborers and the foreman, etc. This response may require the cessation of all other activities. January 2003 California Stormwater BMP Handbook 3 of 6 Construction www.cabmphandbooks.com Spill Prevention and Control WM-4 Vehicle and Equipment Maintenance m If maintenance must occur onsite, use a designated area and a secondary containment, located away from drainage courses, to prevent the runon of stormwater and the runoff of spills. • Regularly inspect onsite 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. • Place drip pans or absorbent materials under paving equipment when not in use. • Use absorbent materials on small spills rather than hosing down or burying the spill. Remove the absorbent 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 pollute 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 the oil supplier or recycler about recycling oil filters. • 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 If fueling must occur onsite, use designate areas, located away from drainage courses, to prevent the runon of stormwater and the runoff of spills. • Discourage "topping off' of fuel tanks. • Always use secondary containment, such as a drain pan, when fueling to catch spills/ leaks. Costs Prevention of leaks and spills is inexpensive. Treatment and/ or disposal of contaminated soil or water can be quite expensive. Inspection and Maintenance • Inspect and verify that activity-based BMPs are in place prior to the commencement of associated activities. While activities associated with the BMP are under way, inspect weekly during the rainy season and of two-week intervals in the non-rainy season to verify continued BMP implementation. • Inspect BMPs subject to non-stormwater discharge daily while non-stormwater discharges occur. January 2003 California Stormwater BMP Handbook 5 of 6 Construction www.cabmphandbooks.com EXHIBITJ EXHIBIT 2.3.3.5 Structural Treatment BMP Selection Procedure Priority projects shall 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, note pollutant(s) receiving water(s) is/are listed for. 2. If the project is anticipated to generate a pollutant (per Table 2) that the receiving water is listed for, 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 during treatment Pollutants that tend to be dissolved following treatment Bioretention Facilities (LID) High High Medium Settling Basins (Dry Ponds) 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 biofilters High Medium Low High-rate media filters High Medium Low Trash Racks & Hydro -dynamic Devices High Low Low 2.3.3.6 Notes on Treatment Control BMP Categories All rankings are relative. Ranking of all facilities assumes proper sizing, design, and periodic maintenance. Following are general descriptions of each category. • Bioretention Facilities (infiltration planters, flow-through planters, bioretention areas, and bioretention swales). Facilities are designed to capture runoff and infiltrate slowly through soil media which also supports vegetation. Bioretention facilities, except for flow-through planters, effectively promote infiltration into native soils. In clay soils, facilities may capture excess treated runoff in an underdrain piped to the municipal storm drain system. Typical criteria: an infiltration surface area at least 4% of tributary impervious area, 6-inch average depth of top reservoir, 18- inch soil layer, 12-inch to 18-inch gravel subsurface storage layer. • Settling Basins and Wetlands (extended detention basins, "wet" basins, decorative or recreational lakes or water features also used for stormwater treatment, constructed wetlands). Facilities are designed to capture a minimum water quality volume of 80% of total runoff and detain for a minimum of 48 hours. Some wetland designs have proven effective in removing nutrients, but performance varies. • Infiltration Facilities or Practices (infiltration basins, infiltration trenches, dry wells, dispersal of runoff to landscape, pervious pavements). These facilities and landscape designs capture, retain, and infiltrate a minimum of 80% of runoff into the ground. Infiltration facilities are generally only feasible in permeable (Hydrologic Soil Group A or B) soils. Volume and area of infiltration facilities depends on soil permeability and safety factor used. Typical criteria: Infiltration facilities should have pretreatment to remove silt to prolong life of the facility. A 10-foot vertical separation from average seasonal groundwater depth is required. Dispersal to landscape may be accomplished in 15 March 2008 0CHISI7 any soil type and generally requires a maximum 2:1 ratio impervious:pervious and concave topography to ensure the first 1 inch of rainfall is retained. • Media Filters (sand filters). Filters designed to treat runoff produced by a rainfall of 0.2 inches per hour (or 2 x 85th percentile hourly rainfall intensity) by slow infiltration through sand or other media. Typical criteria: Surface loading rate not to exceed 5 inches/hour. Entire surface of the sand must be accessible for maintenance. • High Rate Biofilters (tree wells, typically proprietary). Biofilters with specially designed media to rapidly filter runoff while removing some pollutants. Filterra® (proprietary version) recommends surface loading rates of up to 100 inches/hour. • High-rate Media Filters (typically proprietary). Vaults with replaceable cartridge filters filled with inorganic media. • Drainage Inserts have low effectiveness in removing pollutants that tend to associate with fine particles and have medium effectiveness in removing coarse sediment and trash. They are sometimes used to augment more effective treatment facilities and are sometimes used alone when more effective facilities have been deemed infeasible. 2.3.3.7 Notes on Pollutants of Concern In Table 4, Structural Treatment Control BMP Selection Matrix, pollutants of concern are grouped as coarse pollutants, pollutants that tend to associate with fine particles, and pollutants that remain dissolved. 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 2.3.3.8 Restrictions on the Use of Infiltration Treatment BMPs Treatment control BMPs that are designed to primarily function as infiltration devices shall meet the following conditions (these conditions do not apply to treatment BMPs which allow incidental infiltration and are not designed to primarily function as infiltration devices, such as grassy swales, detention basins, vegetated buffer strips, constructed wetlands, etc.): (1) urban runoff from commercial developments shall undergo pretreatment to remove both physical and chemical contaminants, such as sedimentation or filtration, prior to infiltration; (2) all dry weather flows shall be diverted from infiltration devices except for those non-storm water discharges authorized pursuant to 40 CFR 122.26(d)(2)(iv)(B)(1): diverted stream flows, rising ground waters, uncontaminated ground water infiltration [as defined at 40 CFR 35.2005(20)] to storm water conveyance systems, uncontaminated pumped ground water, foundation drains, springs, water from crawl space pumps, footing drains, air conditioning condensation, flow from riparian habitats and wetlands, water line flushing, landscape irrigation, discharges from potable water sources other than water main breaks, irrigation water, individual residential car washing, and dechlorinated swimming pool discharges; (3) pollution prevention and source control BMPs shall be implemented at a level appropriate to protect groundwater quality at sites where infiltration structural treatment BMPs are to be used; (4) the vertical distance from the base of any infiltration structural treatment BMP to the seasonal high groundwater mark shall be at least 10 feet. Where groundwater does not support beneficial uses, this vertical distance criterion may be reduced, provided groundwater quality is maintained; (5) the soil through which infiltration is to occur shall have physical and chemical characteristics that are adequate for proper infiltration durations and treatment of urban runoff for the protection of groundwater beneficial 16 March 2008 EXHIBIT K r ' •» (ScR'-i' AID?. >0 A1E.2T) EXHIBIT L EXHIBIT M San Diego County Hydrology Manual Date: June 2003 Section: Page: 3 6 of 26 Table 3-1 RUNOFF COEFFICIENTS FOR URBAN AREAS L NRCS Elements Undisturbed Natural Terrain (Natural) Low Density Residential (LDR) Low Density Residential (LDR) Low Density Residential (LDR) Medium Density Residential (MDR) Medium Density Residential (MDR) Medium Density Residential (MDR) Medium Density Residential (MDR) High Density Residential (HDR) High Density Residential (HDR) Commercial/Industrial (N. Com) Commercial/Industrial (G. Com) Commercial/Industrial (O.P. Com) Commercial/Industrial (Limited I.) Commercial/Industrial (General I.) *The values associated with 0% imner coefficient, Cp, for the soil type), or for .and Use County Elements Permanent Open Space Residential, 1.0 DU/A or less Residential, 2.0 DU/A or less Residential, 2.9 DU/A or less Residential, 43 DU/A or less Residential, 7.3 DU/A or less Residential, 10.9 DU/A or less Residential, 14 5 DU/A or less Residential, 24.0 DU/A or less Residential, 43.0 DU/A or less Neighborhood Commercial General Commercial Office Professional/Commercial Limited Industrial General Industrial Runoff Coefficient "C" ' %IMPER. 0* 10 20 25 30 40 45 50 65 80 80 85 90 90 95 nous may be used for direct calculation of the runoff coefficient as VMS that wi" p"7J7ain undisturbed in perpetuity Justification must IN A 0.20 0.27 0.34 038 0.41 0.48 0.52 0.55 0.66 0.76 0.76 0.80 0.83 0.83 0.87 Soil Type B ^ 0.25 0.32 0.38 0.41 0.45 0.51 0.54 0.58 0.67 0.77 0.77 0.80 0.84 0.84 0.87 C 0.30 0.36 0.42 0.45 0.48 0.54 0.57 0.60 0.69 0.?8 0.78 0.81 0.84 0.84 0.87 described in Section 3.12 (representing * given that the wen will remain natural ft D 0.35 < — 0.41 0.46 0.49 0.52 0.57 0.60 0.63 0.7 l<f— 0.79 0.79 0.82 0.85 0.85 0.87 the pervious runoff never (e.g.. the areais located in Cleveland National Forest). DU/A - dwelling units per acre NRCS * National Resources Conservation Service cn 3-6 CP EXHIBIT N 100L"NJ.Tsl SFffl 9f\ J *ttA «L» Jar 04 n JE A 9 A9 J N ^ n> ^~ . ^ I 11 1111 11 Ililllllllilllllllllll III! Illllfllillllllll I I I 111! 111 Illiilll (1) From precipitation maps etotormin* 6 hr and 24 hr amounts far th« wtoctod itaqumcy. The» mapg are inctuctod In the 0,1 EQUATION 64tourPn>dptotk3n(in} Duration (rmn) .........•..!•!.ii.•..•isiiiaiiiiijjiiintiiui • •••IIIIVIIllMIIIMIBMBlllllllllHMIIIIItlllfl • ••••Illllllllllllllllllllllllllllllllllllllllllll • •••••IIIIIIMIMIIIIIIKIIIIIIIItllllllliinilNI • •••••III Mill III Illlllllllll Illll Illlllllllll III !1 • •••IIIIIIIIIIIIIIHIIIIIIIIllllIllllimimilll il.•••••••iiiiiiiiiiiiiiniiiiiiiiiiiiiiiniiiiiiiiini ••••lllilllllllllMllllllflllllllilllllllllllllillll In ttw DMign and Prooadun Manual). (2) Adjust 6 hr predpttatton (if necessary) so that it is w«iin the rang* of 46% ID 65% of the 24 hr precipitation {not apptoaptotoOwart). (3) Ptot6 hr predpttatton on the right side of the chart. (4) Draw a Una through the point paraUel to the plotted lines. (5) TN» one to the Intensity-duration curve for the location Doing analyzed. !<li!i|i:!ii.!!i.''h:iii,.';n,Mi,i'ih."ii.lltiilittuii! \l\X\ Application Forai: (a) Selected frequency <b) PB - - *n.. P24 « (c) Adjusted P6® « _ _ in. d)« mfci. year ^24 (e)l inJhr. •&0 Note: Thte chart replaces the Intenstty-Ouraton-Frequency curves usadaince 1965. • •••Illllill <llll 1ma ••••••in in nit. MI i Itfllllllf till. '• •••••••iiiiiiiiiiini• •••••••IIIIIHIIIIIIII-••••Illlillllllllllll • •••lllillllUlllilH -10) •••••••••lllllllllllllllllllllllllllllilllfllljillllllllllHHalllllllllllilllllllilll 8 e IN S3S.0.79 \M 0.87 9.73a 10 240 149 132 A»_ 4.1S 3.4S 1.70 1.47 \S\ 1.0B S.13 ^x^1.62 1^4 1.19 &«0 4.13 158atw. 2M 178 147 1.13 F I G P R E Intanaity-Duration Design Chart-Tamplate 3-1 EXHIBIT 0 100 tDui oI Q £ IUJ I 2.50% slope 2.01.5 EXAMPLE: Given: Watercourse Distance (0) = 70 Feet Slope (s)= 1.3% Runoff Coefficient (C) = 0.41 Overland Flow Time (T) - 9.5 Minutes SOURCE: Airport Drainage, Federal Aviation Administration, 1965 T . FIGURE Rational Formula - Overland Time of Flow Nomograph 3-3 9 O EXHIBIT P fspaff f*f l-H-t! ; H*hf>Ji±!iH-;-niJEK County of San Diego Hydrology Manual Rainfall Isoplwials 10 Year Rainfall Event - 6 Hours Isopfcjvlol (Indies) DEW ^me-y^TC1iGIiWe Havi: S«\ l>tp(i O'vctrd.1 H County of San Diego Hydrology Manual Rainfall Isopluviak 10 Year Rainfall Event - 24 Hours j-f •!-.-T-4-)-:-i ri-t- ' ' j r:rrti • :njl 4JJ.:', L.i.1 SaEGIS EXHIBIT Q Hydrology Manual r-*_ s County of San Diego Hydrology Manual wX EXHIBIT R EXHIBITS