Loading...
HomeMy WebLinkAboutCT 02-10; VILLA FRANCESCA; PRELIMINARY HYDROLOGY CALCULATIONS; 2002-05-07Conway & Associates, Inc. Civil Engineers/Surveyors/Gena-al-Engineering Contractors AB412412 2525 Pio Pico Drive • Carlsbad, CA 92008 • Telephone (760) 753-1453 « Fax (760) 635-0839 PRELIMINARY HYDROLOGY CALCULATIONS and HYDRAULIC ANALYSIS for VILLA FRANCESCA CT 02-10 / CP 02-05 / SDP 02-04 /CDP 02-15 A TENTATIVE MAP FOR CONDOMINIUM PURPOSES 2642, 44 & 46 JEFFERSON STREET CARLSBAD.CA APN 155-271-19, 20, 21 & 22 Prepared: May 7, 2002 Revision 1: July 9, 2002 Civil Enginecrs/Sur^eyoni/General-Engineering Conlractors AB412412 2525 Pio Pico Dnve • Carlsbad, CA 92008^elephone (760) 753-1453 • Fax (760) 635-0839 DATE: TO: LETTER OF TRANSMITTA July 10, 2002 Karnak Architecture & Planning Attn: Robert Richardson 2802 State Street Carlsbad, CA 92008 FROM: Trish Cox PROJECT: Villa Francesca SUBJECT: Tentative Map Submittal Enclosed please find the following items submitted for your review: Copies Date No. Description 2 07/09/02 2 Tentative Map (Rev. 2 - Vellum Originals) ** I 05/07/02 18 Hydrology Report (with red line comments) 2 07/09/02 23 Hydrology Report (Rev. 1) 2 07/10/02 1 Response to City Review Comments. NOTES: **Tentative Map was hand delivered to Robert Richardson on 07/09/02. Please call ifyou have any questions, (760) 753-1453. Thank You, Trish Cox Conway & Associates, Inc. cc: Anthony DeLeonardis with Hydrology Report p:\02-004 karnak\wordproc\karnak020710t.doc Conway & Associates, Inc. ^ivil Engineers/Surveyors/General-Engineering Contractors AB412412 2525 Pio Pico Drive • Carlsbad, CA 92008 • Telephone (760) 753-1453 • Fax (760) 635-0839 July 10, 2002 Response to City of Carlsbad Engineering Department Review Comments Dated June 6, 2002 Project: CT 02-10 / CP 02-05 / SDP 02-04 /CDP 02-15 - Villa Francesca Tentative Map for Condominium Purposes Responses submitted by Michael Pasko, Conway & Associates, Inc. Engnr'g Comment: Response: 1. Preliminary hydrology report comments addressed with hand-written responses on report check set - see revised hydrology report dated July 9, 2002. 2. See revised TM (sht 2) and revised hydrology map for amended topography 3. Project description was amended - see revised TM. 4. Trash enclosure area located at southwesterly comer of site - noted on TM (refer to Planning Dept. comment 2a). 5. Driveway grades modified to 20% maximum grade. Letter to city engineer to follow requesting this deviation form standard design criteria to follow. 6. Water service notes reviewed and omitted item tag "P" added. See item tags N, M, P & Q. 7. A detail of the project perimeter retaining wall / screen wall / barrier requirements was added to the architect's site plan. Additional information: a) As part of my counter meeting with John MaashofF, engineering staff, on June 21, 2002, a preliminary drainage basin analysis for the tributary drainage basin of the project was submitted for the city's review and comment in response to the city's request for a detailed hydrology report of the tributary basin and determination if the project warrants the construction of City master plan Facility AB in Jefferson Street. See page 3 of the "Discussion of City's Drarnage Master Plan Elements" section of the report for our response to the city's request for the drainage study. b) In response to verbal direction from Mr. MaashofF, we collected topographic mapping of the offsite area east of the project site to investigate sources of ponding complaints for this area. The results of this investigation are presented on page I in the "Basic Hydrology Overview" section of the report. \\fileserver\projects\02-004kamak\wordproc\revresp2.doc Qonway & Associates, Inc. ^Civil Engineers/Surveyots/General-Engineering Contractors AB412412 2525 Pio Pico Drive • Carlsbad, CA 92008 • Telephone (760) 753-1453 • Fax (760) 635-0839 July 10, 2002 Response to City of Carlsbad Engineering Department Review Comments Dated June 6, 2002 Project: CT 02-10 / CP 02-05 / SDP 02-04 /CDP 02-15 - Villa Francesca Tentative Map for Condominium Purposes Responses submitted by Michael Pasko, Conway & Associates, Inc. Engnr'g Comment: Response: 1. Preliminary hydrology report comments addressed with hand-written responses on report check set - see revised hydrology report dated July 9, 2002. 2. See revised TM (sht 2) and revised hydrology map for aniended topography 3. Project description was amended - see revised TM. 4. Trash enclosure area located at southwesterly comer of site - noted on TM (refer to Planning Dept. comment 2a). 5. Driveway grades modified to 20% maximiun grade. Letter to city engineer to follow requesting this deviation form standard design criteria to follow. 6. Water service notes reviewed and omitted item tag "P" added. See item tags N, M, P & Q. 7. A detail of the project perimeter retaining wall / screen wall / barrier requirements was added to the architect's site plan. Additional information: a) As part of my counter meeting with John Maashoff, engineering staff, on June 21, 2002, a preliminary drainage basin analysis for the tributary drainage basin of the project was submitted for the city's review and comment in response to the city's request for a detailed hydrology report of the tributary basin and determination if the project warrants the construction of City master plan Facility AB in Jefferson Street. See page 3 of the "Discussion of City's Drainage Master Plan Elements" section of the report for our response to the city's request for the drainage study. b) In response to verbal direction from Mr. Maashoff, we collected topographic mapping of the offsite area east ofthe project site to investigate sources of ponding complaints for this area. The results of this investigation are presented on page I in the "Basic Hydrology Overview" section of the report. \\filesefverAprojects\02-004 kamak\wordproc\revresp2.doc SNIPES-DYE ASSOCIATES Civil Engineers & Land Surveyors 8348 Center Drive Ste. G LA MESA, CALIFORNIA 91942-2910 (619) 697-9234 FAX (619) 460-2033 JOB SHEETNO.. CALCULATED BY_ CHECKED BY_ OF DATE. DATE. 7^ V0 15 ..-be,:.) *b'J^J. ^i^^im^t^... L At I % i PWDUa 204-1 (Single SliieGI iOS-1 (Paddtd) SNIPES-DYE ASSOCIATES Civil Engineers & Land Surveyors 8348 Center Drive Ste. G LA MESA, CALIFORNIA 91942-2910 (619) 697-9234 FAX (619) 460-2033 JOB. SHEETNO.. CALCULATED BY. 0F_ CHECKED BY_ SCALE DATE. DATE. n.s4 ^1 j /iJ M L.^.l IT V i ^ ; iMtJe hJM^l>m I jt)^^| fi^A iriiiT iifeif^ )PW6is -rvtcp'; sSi.^i.^?te ^il3)i^6v!rj,..,i^ PDODUa 204-1 (Single SMs) 20S-1 (Padileill Conway & Associates, Inc. Civil Engineers/Surveyors/General-Engineering Contractors AB412412 2525 Pio Pico Drive • Carlsbad, CA 92008 • Telephone (760) 753-1453 • Fax (760) 635-0839 PRELIMINARY HYDROLOGY REPORT for VILLA FRANCESCA July 9, 2002 Project: CT 02-10 / CP 02-05 / SDP 02-04 /CDP 02-15 - Villa Francesca Tentative Map for Condominium Purposes RE: City of Carlsbad Engineering Department Review Comments Dated March 29, 2002 and Review Comments Dated June 6, 2002 Introduction: This preliminary hydrology report for the Villa Francesca condominium project is presented in response to various City of Carlsbad Engineering Department review comments prepared by Mr. John Maashoff and to verbal comments received in project review meetings with Mr. Maashoff held on April 8, 2002 and June 21, 2002. This report addresses the following engineering issues: • Basic hydrology overview • Storm water detention feasibility study • Discussion of City's Drainage Master Plan elements • Preliminary SWPPP Elements: Storm water quality / preliminary BMP applications Basic Hydrology Overview The project site currently consists of three single family residential lots improved with various living units, garage stmctures and miscellaneous paved areas. Generally, the project site slopes moderately to the west towards the Jefferson Street curb line. The runoff that reaches the existing concrete gutter in Jefferson Street flows southerly to the existing storm drain curb inlet located near the northeast curb retum of the Jefferson Street-Lagtma Drive intersection, approximately 255 feet south of the project site. The grade of the easterly portion of the project site breaks to the east and drains toward a flat-cross sectioned natural «'Wi6fle^ocated approximately 80 feet east of the site. This offsite drain swale historically drained southerly from Knowles Road to Laguna Drive. The site grading for the Laguna Village project (City drawing 327-3A), located east of the subject site, raised the grade of the south half of the swale area and constmcted a sbc-foot tall masomy screen wall across the swale flowline, impeding the natural flow through this area. City drawing 327-3A shows offsite grading proposed north of the Laguna Village project to direct runoff from the north half of the offeite swale to a type F catch basin located wdthin the Laguna Village project limits. The topography of this area (see enclosed hydrology map) shows a sump area north of the existing catch basin that prevents a free flow of the area runoff to the inlet without some localized ponding. The proposed development wdll elevate the project site's existing grade between zero and three feet using retaining walls along the project perimeter. The addition of the site perimeter retaining walls wdll lessen the runoff impact to the offsite drain swale by redirecting the runoff from the easterly portion of the project site towards the Jefferson Street right of way, away from the offsite sump area. The proposed block screen wall along the northerly property line of the proposed Villa Francesca project vsdll not interfere with the site Page 1 of 5 Pages p:\02-004 karnak\hydro\02-004_hydrpt.doc Conway & Associates, Inc. Civil Engineers/Surveyors/General-Engineering Contractors AB412412 2525 Pio Pico Drive • Carlsbad, CA 92008 • Telephone (760) 753-1453 • Fax (760) 635-0839 drainage from the abutting residential lot. Site nmoff from the north will flow westerly along the north side of the perimeter wall to the Jefferson Street right of way. Storm Water Detention Feasibility Studv Discussion: A storm water detention study was performed to investigate placing a storm water detention system on the Villa Francesca project site as it is currently designed. The storm water detention system presented herein consists ofa series of subsurface storage tanks (precast concrete vaults) and a storm water pumping system. The tank-stored storm water would be pimiped to the Jefferson Street curb flowline at the southwest comer ofthe project site by submersible pump. The storm water pumped to the existing Jefferson Street gutter would then flow southerly to the existing storm drain curb inlet located near the northeast curb retum of the Jefferson Street-Laguna Drive intersection. Adequate space exists on the site to greatly increase the number of storage tanks if the final design analysis requires it. A proposed 8-inch diameter private storm drain surroimding the building exterior will act as a backbone drain system for the exterior yards, center courtyard, and roof areas. This 8-inch pipe system drains to the storage tanks located in the south side yard area. Electronic level monitoring of the storage tanks wdll provide input to the pump controller to limit the pump's startup frequency. Practically all drainage from the project site is directed to the storm water detention tanks. An exception is the runoff collected on the underground parking approach ramp. A trench drain at the base of the approach ramp will collect the ramp runoff where it is directed to a separate sump pump system located in the paridng garage. This garage area pumping system is for nuisance water from the garage floor area (spillage, wash down, etc.) and would not be part of the detention and pumping system previously described. The City's design criteria for a storm water detention system requires a project to limit its post-development peak storm water nmoff rate to no more than its pre-development peak storm water runoff rate for a 10-year, 6-hoiir storm event. The pump selection during the final design phase is critical to ensure that the pumping discharge rate does not exceed the pre-development peak storm water runoff rate for the project site. Storm water runoff flows exceeding the capacity of the Qio detention/pumping system flows will bypass the pumping system by overtopping the storage tank. This bypass flow will be conveyed by two sk-inch diameter gravity drain lines that outlet into Jefferson Street right of way via a sidewalk underdrain stmcture. The following sections of this report contain the backup data and computations for the storm water detention feasibility study: - Tributarv Basin Hydrology Computations: rational method hydrology computations quantifying the project's pre-development and post-development peak runoff conditions; - Preliminarv Storm Water Detention Design: hydrology inflow modeling, pump system modeling , and storage tank sizing computations; - Hydrology Map: A 1 "=30 scale, map (24"X36") showing the pre-development and post-development runoff conditions for the project site. The results ofthis study demonstrate that it is feasible to incorporate a storm water detention system onto the Villa Francesca project site as it is currently designed. Other detention systems will be investigated and may be selected as part of the project's final design phase pending City review and approval. Storm Water Detention Calculation Methodology: Page 2 of 5 Pages p:\02-004 karnak\hydro\02-004_hydrpt.doc Conway & Associates, Inc. Civil Engineers/Surveyors/General-Engineering Contractors AB412412 2525 Pio Pico Drive • Carlsbad, CA 92008 • Telephone (760) 753-1453 • Fax (760) 635-0839 The storm water detention calculations included in this report compare the storm water inflow volume with the pump discharge volume over a given time interval. This detention analysis assesses tank storage requirements at one-minute time increments over the site's theoretical 51-minute duration storm event. In the imtial stages ofthe analysis, the pump discharge volume is compared to the storm water inflow volume for the selected time interval. Ifthe pump discharge volume exceeds the storm water inflow volume, the net stored storm water volume is recorded as a zero value. Once the storm water inflow volume exceeds the pump discharge volume, the excess storm water volume is considered tank storage and the depth ofthe stored volume is computed and stored. After the hydrograph peaks and the storm water inflow rate falls under the pump discharge rate (at approximately T=17 minutes, Tc for the project site), the pumping system begins to reduce the level ofthe stored runoff. As the storm water inflow rate continues to fall, the stored storm water volume is eventually reduced to zero. The peak pre-development storm water runoff rate was computed at 0.9 cfs (52 cfin). The peak post- development storm water runoff rate was computed at 1.4 cfs (85 cfin). These estimated peak flows are based on a I O-year, 6-hour storm event. This detention study analysis models the inflow hydrograph as a straight-lined triangular shape while maintaining the numerical value of the peak post-development inflow rate. This simplification ofthe inflow hydrograph yields a storm water volume approximately 30% greater than the storm water volume computed using the County Hydrology Manual IDD nomographs. A constant pump discharge rate of 50 cfin was used in the detention analysis when in fact the pump discharge rate would be less than the maximum pumping rate at the higher head lift conditions. For the purposes ofthis analysis, these two simplifications are generally expected to offset each other. 1 OO-year Return Event Peak Flow Computations: Estimate peak flows for 1 OO-year, 6-hour storm event were computed for the project site. The peak pre- development storm water runoff rate was computed at 1.3 cfs. The peak post-development storm water runoff rate was computed at 2.2 cfs, an increase of 0.9 cfs. Discussion of City*s Drainage Master Plan Elements The project site is located within the limits of Basin A, the Buena Vista watershed, as defined by the City's Master Drainage and Storm Water Quality Management Plan dated March 1994. Basin A is depicted on the Plate I fold-out (sheet 1 of 4, City drawdng 296-5 - a modified portion is shown at right). A review of city record drawings around the project area and a field review did not reveal the presence of existing storm drain lines in the immediate project area. Plate I of the drainage master plan shows a proposed 33-inch diameter RCP storm drain Une (Facility AB) in Jefferson Street is required to convey the tributary basin runoff along the project frontage. The tributary drainage basin where the project site is located is roughly bounded by Las Flores Drive to the North, Jefferson Street to the West and Interstate 5 to the East, depicted on the graphic at right. The project site encompasses less than 3% of the tributary basin area, discharges less than 1 cfs of additional flow in the after-development Page 3 of 5 Pages p:\02-004 kamak\hydro\02-004_hydrpt.doc Conway & Associates, Inc. Civil Engineers/Survevors/General-Engineering Contractors AB412412 _ •— 2525 Pio Pico Drive • Carlsbad, CA 92008 • Telephone (760) 753-1453 • Fax (760) 635-0839 condition (Qioo), and is located near the low point of the basin. Considering this data, it is our opinion that the proposed project is not a major contributor to the need for the FaciUty AB master plan storm drain system. Preliminary SWPPP Elements: Storm Water Quality / Preliminary BMP Applications Potential effects to the water aualitv environment: The County of San Diego Stormwater Standards Manual (Ordinance No. 9426) contains Attachment G-L Table I- Pollutants from the Project Area. This table suggests that pollutants that are possible from various types of developments. The potential pollutants Usted for Residential Development and Parking Lots are as foUows: • Sediment • Nutrients • Trash & Debris • Oxygen Demanding Substances • Oil & Grease • Bacteria & Vimses • Pesticides Table I makes no distinction between urban, suburban or rural types of development. The potential for these poUutants in storm water is a fimction of many factors that include development density, the physical design of the project site, location ofthe project, the presence or absence of off-site discharges through the property and the Uke. The primary constituents of concem in Hydrologic Unit 904.21, Buena Vista Lagoon, of which this project site is a contributor, are coUfonn bacteria, TDS, nutrients, petroleum chemicals, toxics and trash. The source/activity that this project would contribute would be urban runoff. Considering the specifics ofthe subject project, the foUowing Usts the potential poUutants and how they wUl be mitigated in the final design: • Sediments - Proposed slopes and graded areas wUl be planted and irrigated. Parking lots wUl be swept periodicaUy. Catch basin filter inserts wiU be used to treat aU catch basin inflow. • Nutrients - FertUizers shaU be appUed according to aU federaL state and local regulations. Slope and landscape areas shaU be monitored and maintained to reduce bare soU areas. • Trash & Debris - AU trash containers shaU have attached Uds. Trash containers shall be located in enclosure areas having sloped concrete pavement with waUs or curbs on three sides to prevent runoff from adjoining areas and gated in front. The enclosure, parking lot, drive aisles shaU be swept periodicaUy. Visible surface trash shaU be picked up on a weekly basis. Landscape vegetation wUl be disposed of in the trash or taken off-site to a recycUng center. • Oxygen Demanding Substances - See the "Trash & Debris" section Usted above. • Oil & Grease - The parking garage is the expected oil & grease source. The Ukely source of oUs and greases expected to be present would be from automobiles and deUvery vehicles. An emergency spUl kit shaU be kept on-site. Parking areas wUl be swept periodicaUy. Catch basin filter inserts wUl be instaUed in aU parking area catch basins. • Bacteria & Vimses - These are not expected to be a constituent from this project. Page 4 of 5 Pages p:\02-004 kamak\hydro\02-004_hydrpt.doc Conway & Associates, Inc. Civil Eneineeis/Surveyors/General-Engineering Contractors AB412412 ^ 2525 Pio Pico Drive • Carisbad, CA 92008 • Telephone (760) 753-1453 • Fax (760) 635-0839 • Pesticides - Pesticides wUl be appUed in accordance with aU federal, state and local regulations. Pesticide use shaU be kept to a minimum and shaU be used only when absolutely necessary. Surface Water Qualitv Obiectives: The stated purpose ofthe discharge requirements (as stated by the San Diego Regional Water QuaUty Control Board) is to "reduce the negative impacts to receiving waters resulting from urban runoff from development." This general objective is then implemented by the use of Best Management Practices (BMPs) for both the constmction period and the post-constmction period. See Appendbc G for existing water quaUty standards database for Buena Vista Lagoon. There are no water quaUty objectives for this water body reach. Anticipated cnrntruction Best Management Practices (BMP's) for the proiect site: Standard water pollution control measures (constmction BMP's) wUl be used in the project's constmction phase. References to BMP's standard drawings (example: TC-1) are from the Caltrans Constmction Best Management Practices manual dated November 2000. Anticipated BMP detaUs include, but are not Umited to: a stabiUzed constmction entrance per TC-1; storm drain inlet protection (sUt fence barrier & desUting basin) per SC-10; use of storm water filter catch basin inserts ("FossU FUter" system or equivalent); designated material deUvery and storage areas per WM-1; concrete waste management per WM-8; and sanitary waste management per WM-9. As the site grading wdU create a large sump, manual operation of submersible pumps to drain the site can ensure that coUected runoff heavUy laden with sUt is not discharged to the Jefferson Street gutter. Anticipatedpo.st-construction BMP's for the proiect site: Garage-Area Drain Svstem (sumo pump discharge to Jefferson Street - no detention svstem): Catchbasin filter inserts ("FossU FUter" system or equivalent) wUl be instaUed in the trench drain and garage floor catch basins to capture Utter, debris and oU contaminants. The catch basin inserts shaU meet the San Diego Regional Water QuaUty Control Board's "Standard Urban Storm Water Mitigation Plan" (SUSMP) requirements. Site drainape - roof runoff and general proiect site drainage (storage tank detention and pumping system): Storm water runoff coUected from the roof area wUl be discharged at grade in landscaped planters and turf areas and aUowed to flow along these areas to the greatest extent practical to provide bio-filtration ofthe roof runoff before it enters the on-site storm drain coUection system. Where possible, waUcways and flatwork wdU simUarly direct runoff through landscape strips to aUow filtering ofthe runoff before it enters the on-site storm drain coUection system. Storm drain catch basins wUl be equipped wdth storm water filter inserts ("FossU FUter" system or equivalent). The catch basin inserts shaU meet the San Diego Regional Water QuaUty Control Board's "Standard Urban Storm Water Mitigation Plan" (SUSMP) requirements. Page 5 of 5 Pages p:\02-004 karnak\hydro\02-004_hydrpt.doc Conway & Associates, Inc. Civil Engineers/Surveyors/Geno-al-Eiigineering Contractors AB412412 2525 Pio Pico Drive • Carlsbad, CA 92008 • Telqjhone (760) 753-1453 • Fax (760) 635-0839 TRIBUTARY BASIN HYDROLOGY COMPUTATIONS Contents: - PreUminary Storage Volume Calculations - Time Of Concentration Calculations - Peak Storm Water Runoff Calculations • Pre-Development Condition (Qio & Qioo) • Post-Development Condition (Qio & Qioo) • IDD Chart Reference (Qio & Qioo) • 10-Year, 6-Hour Storm Isopluvial Map • 100-Year, 6-Hour & 24-Hour Storm Isopluvial Maps '^I^'y, /gf^? -hrra. . .S^xJ/ ^-^ BeJ^-rc (l^dAdn Qyo ^ drKL c-fs (SLU ) - 72 - llyr^in .cJ.M^^^ Il^/^J -^.-^^^'k- ^ I7ZO ^-f 72^7^ CU,9?><fJ) Conway & Associates, Inc. civil EngineCTs/Surveyors/General-EflgineaTng Contractors AB412412 iQ m a I > a Ml ^ 2 S 2. I S 4 rt o o O ui > 00 4^ O O u u I rj o II II t-O n II II ?. •-3 waow 2 o si n SD IB OVERLAND TRAVEL DISTANCE, IN METERS o o ro o o O o OVERLAND TIME OF TRAVEL, IN MINUTES Conway & Associates, Inc. Civil Engineers/Surveyors/General-Engineering Contractors AB412412 2525 Pio Pico Drive • Carlbad, CA 92008 • Telephone (760) 753-1453 • Fax (760) 635-0839 SITE DRAINAGE WORKSHEET Villa Francesca City of Carlsbad CT 02-10 ON-SITE STORM DRAIN DESIGN DATA 10 YEAR EVENT tc(min) 17 min. Pe (10 YR Return) 1.7 in. I, intensity (in/hr) 2.0 In./hr. 100 YEAR EVENT tc (min) Ps (100 YR Retum) I, intensity (in/hr) 17 min. 2.6 in. 3.1 in./hr. 06/28/02 PRE-DEVELOPMENT CONDITION "A" SUB AREA AREA "C" Qio Qioo BASIN (SF) (ACRES) FACTOR (CFS) (CFS) Al 3,064 0.07 0.90 0.13 0.20 Bl 550 0.01 0.90 0.02 0.04 Cl 2,518 0.06 0.90 0.11 0.16 Dl 3,954 0.09 0.90 0.17 0.25 El 26,694 0.61 0.35 0.44 0.67 36,780 0.84 0.86 cfs 1.32 North house North garage Center house South house 51.6 cfm 78.9 cfm Printed 7/9/02 Page 1 of 2 02-004 DiLeonardis\hydro\hydro-3.xls Hydrology Conway & Associates, Inc. Civil Engineers/Surveyors/General-Engineering Contractors AB412412 2525 Pio Pico Drive • Carlbad, CA 92008 • Telephone (760) 753-1453 • Fax (760) 635-0839 POST-DEVELOPMENT CONDITION SUB BASIN "A" AREA (SF) AREA (ACRES) "C" FACTOR QIC (CFS) Qioo (CFS) A2 1,405 0.03 0.90 0.06 0.09 North sidewalk B2 252 0.01 0.90 0.01 0.02 Entry C2 584 0.01 0.90 0.02 0.04 Drive D2 2,665 0.06 0.90 0.11 0.17 South sidewalk E2 26,950 0.62 0.90 1.13 1.73 Building, East sidewalk F2 4,924 0.11 0.35 0.08 0.12 Yard 36,780 0.84 1.42 cfs 2.17 cfs 85.2 cfm 130.2 cfm Pre-Development Q v. Post-Development Q: 0.56 cfs 0.86 cfs Printed 7/9/02 Page 2 of 2 02-004 DILeonardis\hydro\hydro-3.xls Hydrology INTENSITYrDUMTION DESIGM CHART niihrii Directions for Application: \) From precipitation naps determine 6 hr. and 24 hr. amounts for the selected frequency. These maps are printed in the County Hydrology Manual (10, 50 and 100 yr. maps included in the Design and Procedure Manual). 2) Adjust 6 hr. precipitation (if necessary) so that it is within the ranne of 45X to 65% of the 24 hr. preciplUtion. (Not nppl Icable to Desert) 3) Plot 6 hr. precipitation on the right side of the chart. 4) Draw a line through the point parallel to the plotted lines. 5) This line Is the Intensity-duration curve for the location being analyzed. Application Form: 0) Selected Frequency yr. /' ^ In.. P24» 2) Adjusted *P^* 3) t,. /7 4) A 7 "^4 6 Zt In. min. I • In/hr. *Not Applicable to Desert Region 15:^20 Minutes n Revised 1/8S APPRNDIX XI-A iQ m H <S. ^ I > O n> O CO ^ S. ^ m rt !B D §• P o o 3 o > TO < M <» 00 "0 H X t-l COUNTY OF SAN DIEGO OEPARTMENT OF SANITATION <• FLOOO CONTROL 10-YEAR 6-HOUljt PRECIPITATIOM 16- ISOPLUVIALS OF 10-YEAR G-H3Un PRECIPITATIOH IN TEflTIIS OF AN INCII 30' 15' 33* Prtpi U.S. DEPARTMENT OP COMMERCE NATIONAL OCBANtC AND AT .iOSPIIEmC ADWN UTR AUON SPKCIAL ITUOIBS ailANCII. OPFICC OP l{rDIIOLOOY. NATIONAL VKATHIR MNVieB 30' 118' 45' 30' Revised 1/85 15' 116* APPENDIX XI-C IHTENSITY-DUMTION DESIGN CHART nithrii Directions for Application: 1) From precipitation mps detemitne 6 hr. and 24 hr. amounts for the selected frequency. These maps are printed In the County Hydrology ManuaT (10» 50 and 100 yr. maps Included in the Design end Procedure Manual). 2) Adjust 6 hr. precipitation (If necessary) so that It is within the range of 45« to 65« of the 24 hr. precipitation. (Not applicable to Desert) 3) Plot 6 hr. precipitation on the right side of the chart. 4) Draw a line through the point parallel to the plotted lines. 5) This line is the intensity-duration curve for the location being analyzed. Application Form: 0) Selected Frequency yr. 1) Pg • In.. P24- .^'^ . \ ' 1^** 2) Adjusted *P^'' t • min. 6 In. "Pl4 3) 4) c 3.1 In/hr. *Not Applicable to Desert Region 15^20 Minutes r. X J - Revised 1/85 APPKNDIX XI-A m B <S. ^ I > ^ v> ^ 2 i 5' m •* I' !B B i- P (O O o 3 o o > courrTY OP SAN OIEGO DEPARTMENT OF SANITATION S FLOOD CONTROL 100-YEAR 6-HOU^ PRECIPITATIO?! ^Z0> ISOPLUVIALS OF lOO-YEAR 6-IIOUR PRECIPITATIOn IN EsiTMS or AN i::cii \o /Wl Zb' 33* U.S. DEPARTMEN T OF COMMERCE NATWHAL OCEANIC ANO AT! USrilKKIC AOUmitTIIATION • PKCIAL tTVOIBI BRANCH. OrPICC Of ti DROLOOT. NATIONAL NBATHBR IKRVICB 30 APPPMntY YT-P 19 to ^ 1'.ft? 2. c 3 (D •< ^ 2 3 2. fl> ^ m rt a' % B §• P to o o 3 o > CD COUNTY OF SAM OIEGO OEPARTMENT OF SANITATIOM * FLOOD CONTROL 30' •^3' {6 //n 2-0 15' 33' fnpa '4 by lOO-YEAR 24-H0l|R PRECIPITATION '-2fl-^IS0PLUVIALS 07 100 -YEAR 24-HOUR PRECIPITATION Itt ENTHS OF AN INCH U.S. DEPARTMEN NATIONAL OCEANIC AMO AT^Oiil'llEHlC ADMINMTRATION SPECIAL tTuoies BKA:4CII, orricic or ii 30' - IK," APPENDIX XI-ll Conway & Associates, Inc. Civil Engineers/Surveyors/General-EngineaTng Contractors AB412412 2525 Pio Pico Drive • Carlsbad, CA 92008 • Telqjhone (760) 753-1453 • Fax (760) 635-0839 PRELIMINARY STORM WATER DETENTION DESIGN Contents: - Graphic Result Of Storm Water Detention Study - Graphing Computation & Detention Study Worksheet - Typical Storage Tank Data Sheet Conway & Associates, Inc. Civil Engineers/Surveyors/General-Engineering-HAZ Contractors AB412412 Villa Francesca CT 02-10 ~ Site Hydrograph & On-Site Detention Calculations 2525 Pio Pico Drive • Carlsbad, CA 92008 • Telephone (760) 753-1453 • Fax (760) 635-0839 06/28/02 Villa Francesca ~ Site Hydrograph POST-DEVELOPMENT HYDROGRAPH (STORM WATER INFLOW) - CFM PUMP DISCHARGE - CFM —•— Q out (cfm) —-— Q In (cfm) - - -X- • - DEPTH (ft) Time (min) Printed 7/9/02 Page 1 of 1 02-004 DiLeonardis\tiydro\tiydro-3.xls Hydrograph Conway & Associates, Inc. Civil Engineers/Surveyors/General-EngineaTng-HAZ Contractors AB412412 2525 Pio Pico Drive • Carisbad, CA 92008 • Telephone (760) 753-1453 • Fax (760) 635-0839 Villa Francesca CT 02-10 ~ Site Hydrograph & On-Site Detention Calculations 06/28/02 AFTER-CONDITION INFLOW HYDROGRAPH (6-HOUR STORM, PEAK AT Tc -17 minutes) PUMP DATA 50.0 cfm Assumed steady pump outflow UP PEAK: DN PEAK: 85.2 cfm 85.2 cfm L up = L dn = 17 34 minutes minutes TANK AREA Q b = Inflow rate at beginning of time incren Q e = Inflow rate at end of time increment L Total: 51 minutes 119 sf IN-FLOW OUT-FLOW STORAGE TIME (min) VOL total (CF) Qb (CFM) Qe (CFM) Qin (CFM) VOL in (CF) Q ave (CFM) VOL net (CF) Dnet (ft) 0 0 0.0 0 0.0 0.0' 1 2.5 0.00 5.01 2.51 2.5 2.5 0.0 0.0' 2 10.0 5.01 10.02 7.52 7.5 7.5 0.0 0.0' 3 22.6 10.02 15.04 12.53 12.5 12.5 0.0 0.0' 4 40.1 15.04 20.05 17.54 17.5 17.5 0.0 0.0' 5 62.6 20.05 25.06 22.55 22.6 22.6 0.0 0.0' 6 90.2 25.06 30.07 27.56 27.6 27.6 0.0 0.0' 7 122.8 30.07 35.08 32.58 32.6 32.6 0.0 0.0' 8 160.4 35.08 40.09 37.59 37.6 37.6 0.0 0.0' 9 203.0 40.09 45.11 42.60 42.6 42.6 0.0 0.0' 10 250.6 45.11 50.12 47.61 47.6 47.6 0.0 0.0' 11 303.2 50.12 55.13 52.62 52.6 50.0 2.6 0.0' 12 360.8 55.13 60.14 57.64 57.6 50.0 10.3 o.r 13 423.5 60.14 65.15 62.65 62.6 50.0 22.9 0.2' 14 491.2 65.15 70.16 67.66 67.7 50.0 40.6 0.3' 15 563.8 70.16 75.18 72.67 72.7 50.0 63.2 0.5' 16 641.5 75.18 80.19 77.68 77.7 50.0 90.9 0.8" 17 724.2 80.19 85.20 82.69 82.7 50.0 123.6 1.0' 18 808.1 85.20 82.69 83.95 83.9 50.0 157.6 1.3' 19 889.6 82.69 80.19 81.44 81.4 50.0 189.0 1.6' 20 968.5 80.19 77.68 78.94 78.9 50.0 217.9 1.8" 21 1045.0 77.68 75.18 76.43 76.4 50.0 244.4 2.1' 22 1118.9 75.18 72.67 73.92 73.9 50.0 268.3 2.3' 23 1190.3 72.67 70.16 71.42 71.4 50.0 289.7 2.4' 24 1259.2 70.16 67.66 68.91 68.9 50.0 308.6 2.6' 25 1325.6 67.66 65.15 66.41 66.4 50.0 325.0 2.7' 26 1389.5 65.15 62.65 63.90 63.9 50.0 338.9 2.8' 27 1450.9 62.65 60.14 61.39 61.4 50.0 350.3 2.9' Printed 7/9/02 Page 1 of 2 02-004 DiLeonardis\hydro\tiydro-3.xls Dentention Conway & Associates, Inc. Civil Engineers/Surveyors/General-Engineering-HAZ Contractors AB412412 2525 Pio Pico Drive • Carlsbad, CA 92008 • Telephone (760) 753-1453 • Fax (760) 635-0839 Villa Francesca CT 02-10 ~ Site Hydrograph & On-Site Detention Calculations 06/28/02 AFTER-CONDITION INFLOW HYDROGRAPH (6-HOUR STORM, PEAK AT Tc -17 minutes) PUMP DATA 50.0 cfm Assumed steady pump outflow UP PEAK: DN PEAK: 85.2 cfm 85.2 cfm L up = L dn = 17 34 minutes minutes TANK AREA Q b = Inflow rate at beginning of time incren Q e = Inflow rate at end of time increment L Total: 51 minutes 119 sf IN-FLOW OUT-FLOW STORAGE TIME (min) VOL total (CF) Qb (CFM) Qe (CFM) Qln (CFM) VOL in (CF) Q ave (CFM) VOL net (CF) Dnet (ft) 28 1509.8 60.14 57.64 58.89 58.9 50.0 359.2 3.0' 29 1566.2 57.64 55.13 56.38 56.4 50.0 365.6 3.1' 30 1620.1 55.13 52.62 53.88 53.9 50.0 369.5 3.1' 31 1671.4 52.62 50.12 51.37 51.4 50.0 370.8 3.1' 32 1720.3 50.12 47.61 48.86 48.9 50.0 369.7 3.1' 33 1766.6 47.61 45.11 46.36 46.4 50.0 366.1 3.1' 34 1810.5 45.11 42.60 43.85 43.9 50.0 359.9 3.0' 35 1851.8 42.60 40.09 41.35 41.3 50.0 351.3 3.0' 36 1890.7 40.09 37.59 38.84 38.8 50.0 340.1 2.9' 37 1927.0 37.59 35.08 36.34 36.3 50.0 326.4 2.7' 38 1960.9 35.08 32.58 33.83 33.8 50.0 310.3 2.6' 39 1992.2 32.58 30.07 31.32 31.3 50.0 291.6 2.5' 40 2021.0 30.07 27.56 28.82 28.8 50.0 270.4 2.3' 41 2047.3 27.56 25.06 26.31 26.3 50.0 246.7 2.1' 42 2071.1 25.06 22.55 23.81 23.8 50.0 220.5 1.9' 43 2092.4 22.55 20.05 21.30 21.3 50.0 191.8 1.6' 44 2111.2 20.05 17.54 18.79 18.8 50.0 160.6 1.3' 45 2127.5 17.54 15.04 16.29 16.3 50.0 126.9 I.r 46 2141.3 15.04 12.53 13.78 13.8 50.0 90.7 0.8' 47 2152.6 12.53 10.02 11.28 11.3 50.0 52.0 0.4' 48 2161.3 10.02 7.52 8.77 8.8 50.0 10.7 O.r 49 2167.6 7.52 5.01 6.26 6.3 6.3 0.0 0.0' 50 2171.3 5.01 2.51 3.76 3.8 3.8 0.0 0.0' 51 2172.6 2.51 0.00 1.25 1.3 1.3 0.0 0.0' MAXIMUM STORAGE DEPTH: 3.1' Printed 7/9/02 Page 2 of 2 02-004 DiLeonardis\hydro\hydro-3.xis Dentention AS REOUIRED (AT EXTRA COST) 24" CAST IRON FRAME & COVER AS REQUIRED AT EXTRA COST HOLDING TANKS 4" IN^yERT I BOX DESIGN LOAD: H-20 TRAFFIC. FOR COMPLETE DESIGN AND PRODUCT INFORMATION, CONTACT JENSEN PRECAST. VARIABLE 5" MINIMUM MOOEL NUMBB) LIOUID CAPACITY QAUONS TOTAL TANK VOLUME DIMENSION A DIMENSION B DIMENSION C DIMENSION D MMIMUM EXCAVATION WCTH MNMUM EXCAVATION LENQTH HP-750 750 924 4'-0" 8'-r 6'-3" 5'-0" 5'-0" 9'-1" HP-1000 1000 1240 5'-1" 8-2" 6-3" 5'-0" 6-1" 9'-2" HP-1200 1200 1485 5'-9" 8-6" 6'-6" 5'-0" 6'-9" 9-6" HP-1500 1500 1870 5-7" 10'-8" 6-3" 5'-0" 6'-7" 11-8" HP-2000 2000 2424 4'-ir 15'-ir 6'-0" 5'-0" 5"-11" i6*-ir HZ-2500 2500 3066 5'-9" 16'-10" 6'-0" 5'-0" 6'-9" ir-io" HZ-3000 3000 3526 5-9" 16'-10" 6'-9" 5*-9" 6-9" ir-io" HZ-4000 4000 4851 r-8" 16'-7" 6'-9" 5-6" 8'-8" ir-r HZ-5000 5000 5750 r-8" 16'-7" r-n" 6'-9" 8*-8" ir-r LARGER SIZES AVAILABLE UPON REQUEST. CONTACT JENSEN PRECAST FOR DETAILS. NOTE: NOT RECOMMENDED FOR POTABLE WATER OR ABOVE GROUND USE. NO WARRANTIES EXPRESSED OR IMPUED FOR MERCHANTIBILITY OR FITNESS FOR ANY PARTICULAR PURPOSE. 4/2/97 ©1997 Jensen Precost PRECAST Since 1968 Conway & Associates, Inc. Civil Enginea-s/Surveyors/General-Ejigineering Contractors AB412412 2525 Pio Pico Drive • Carisbad, CA 92008 • Telephone (760) 753-1453 • Fax (760) 635-0839 HYDROLOGY MAP (1"=30,24"x36") INSERT DRAWINGS HERE