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Stormwater Management Report
STORMWATER MANAGEMENT REPORT FOR WARREN TIRE - COMBINED SITE LAFAYETTE STREET SITE Queensbury, New York Warren County Prepared by: NACE ENGINEERING, P.C. 169 HAVILAND ROAD QUEENSBURY,NY 12804 Thomas W.Nace, P.E. April 2003 File: #47362 STORMWATER MANAGEMENT REPORT FOR WARREN TIRE—LAFAYETTE STREET - COMBINED SITE INTRODUCTION The proposed site of the expansion for the Warren Tire Service Center is located just north of their existing facility on the northwest side of Lafayette Street in the Town of Queensbury,New York. The site is a portion of the previous Moores Lumber site. This report addresses drainage issues pertaining to the expansion of the existing Warren Tire site onto the adjacent vacant property just north of the existing service center. Since the two properties will be utilized as part of the same facility and the stormwater management facilities will function as a whole, this report addresses the entire combined site as one facility. EXISTING CONDITIONS As noted above, the existing site is a portion of the previous Moores Lumber (and before that Woodburry Lumber) site. As such the site was previously 100% developed with buildings and pavement. The site slopes gradually from southwest to northeast. All drainage from the site is collected in an existing storm drain which originates near Glen Street and traverses across the site to Lafayette Street. The storm drain then runs northeast along Lafayette Street to a point north of the fire house where it joins a storm drain flowing southwest from the intersection of Lafayette and Bank Streets. This combined storm sewer then crosses Lafayette and eventually outlets in Hovey Pond. Soils on the site are mixed fills. The site was once a sawmill and during previous development of the site sawdust and the native soils have been replaced by imported fills. The depth to groundwater in this area is generally 8 to 10 feet. DRAINAGE METHODOLOGY Since prior site development has resulted in a totally impervious site, it is obvious that the proposed Warren Tire development with its required 30% permeable area will reduce the amount of runoff from the site. However, to further improve drainage conditions, we are proposing the use of a closed drainage system which incorporates two detention areas to slow down the rate of runoff. Runoff from the entire rear portion of the property will be collected in a the existing rear parking catch basin and in an expanded grassy detention area to the rear of the property. The existing parking area catch basin with an 8 inch diameter orifice in the outlet will restrict the outlet and the detention I area will store peak storm flows which exceed the capacity of the orifice. An infiltration trench in the bottom of the detention area will allow infiltration and treatment for the runoff from the proposed new rear parking area which sheet flows into the basin. Runoff from the paved area in front of the expanded site will be collected in a detention area in front of the new building. The outlet from this basin will incorporate a 6 inch diameter orifice to regulate peak discharges. CALCULATIONS All computations SCS TR-20 HydroCAD. 50 year storm event- Type II rainfall=4.9". Runoff rate and volume computations for the 50 year storm event have been completed for the entire developed site. See attached HydroCAD analysis for all computations. CONCLUSIONS Based upon the attached HydroCAD analysis, the proposed site development and stormwater management will reduce runoff from this site as follows: EXISTING CONDITIONS PROPOSED DEVELOPMENT Peak runoff rate - 15.45 efs 9.36 cfs Runoff volume - 1.002 acre feet 0.624 acre feet During a 50 year storm the rear detention basin will store water to a peak elevation of 335.19 feet which is just below the grate on the catch basin in rear parking lot. The peak elevation of the front detention basin will be 333.15 which is well below the top of the basin. 2 STORMWATER MANAGEMENT REPORT FOR WARREN TIRE - COMBINED SITE LAFAYETTE STREET SITE DRAINAGE AREA PLAN ,U. 17 a I IO '1 ,1 p II p II I - /�� ' 'I /�� `,' `� ♦ -� it v� I Q' �i It I • ♦ 4 O � ■ 0 �'' � i p I ' -- z i � i If0 ■ '�, O 11 A •�� F� rn H f IM I' I p i_,_..--------`-- r , ( ' �ESs'�s•Ja/��'i ____... �d --,�-Y I' I r � W p( ! Wy CY zoz ' 3 _ I � �I ■ L I I d •� ■ 1+.r' ■ I W �0 1 Z_ m J co W Q W 1I = W ' R■■ i i I z U tmD U' j9i Z I • Ili I ■ w.-� �� i ■ STORMWATER MANAGEMENT REPORT FOR WARREN TIRE - COMBINED SITE LAFAYETTE STREET SITE. HydroCAD RESULTS EXISTING CONDITIONS 1S 1R Subcat Reach O l Link 7HYdPr Diagramfor 47362-WARREN TIRE COMBINED-EXISTING SITE epared by{enter your company name here} 4/14/2003 CAD®6.00 s/n 000768 0 1986-2001 Applied Microcomputer Systems • • 47362 -WARREN TIRE COMBINED - EXISTING SITE Type //24-hr Rainfall=4.90" Prepared by{enter your company name here} Page 1 HydroCAD®6.00 s/n 000768 © 1986-2001 Applied Microcomputer Systems 4/14/2003 Time span=5.00-20.00 hrs, dt=0.05 hrs, 301 points Runoff by SCS TR-20 method, UH=SCS, Type II 24-hr Rainfall=4.90" Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment 1S: EXISTING SITE Tc=7.6 min CN=98 Area=122,353 sf Runoff= 18.35 cfs 1.002 of Reach 1 R: EXISTING STORM SEWER Inflow-- 18.35 cfs 1.002 of Length= 120.0' Max Vel= 5.1 fps Capacity= 14.00 cfs Outflow-- 15.45 cfs 1.001 of Runoff Area=2.809 ac Volume = 1.002 of Average Depth =4.28" 47362 -WARREN TIRE COMBINED - EXISTING SITE Type 11 24-hr Rainfall=4.90" Prepared by (enter your company name here) Page 2 HydroCADO 6.00 s/n 000768 © 1986-2001 Applied Microcomputer Systems 4/14/2003 Subcatchment 1S: EXISTING SITE Runoff = 18.35 cfs @ 11.98 hrs, Volume= 1.002 of Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr Rainfall=4.90" Area (sf) CN Description 122,353 98 EXISTING PAVEMENT & ROOFS Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.9 300 0.0050 0.9 Sheet Flow,ACROSS PAVEMENT Smooth surfaces n= 0.011 P2= 2.40" 1.7 150 0.0050 1.4 Shallow Concentrated Flow,ACROSS PAVEMENT Paved Kv= 20.3 fps 7.6 450 Total Reach 1R: EXISTING STORM SEWER Inflow = 18.35 cfs @ 11.98 hrs, Volume= 1.002 of Outflow = 15.45 cfs @ 12.08 hrs, Volume= 1.001 af, Atten= 16%, Lag= 5.8 min Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Max. Velocity= 5.1 fps, Min. Travel Time= 0.4 min Avg. Velocity = 2.1 fps, Avg. Travel Time= 1.0 min Peak Depth= 2.00' Capacity at bank full= 14.00 cfs 24.0" Diameter Pipe n= 0.021 Length= 120.0' Slope= 0.01007 ST(}EdMWATEIR MANAGEMENT REPORT FOR WARREN TIRE - COMBINED SITE LAFAYETTE STREET SITE HydroCAD RESULTS DEVELOPED CONDITIONS LU co E f' O n y O T N � LIJ ❑ a N (n z n coo N 1O ou U m.0 W 2b Q s a) H E 'Q Wn M Q C() a �o O Qm r. n E rn M Fo,� CCD OU M � � h 7 c0 O CD w N O O E C C V V N v) O Y J N a O cn -pa p O U 47362 -WARREN TIRE-COMBINED SITES Type lI 24-hrRainfall=4.90" Prepared by {enter your company name here} Page 1 HydroCADO 6.00 s/n 000768 © 1986-2001 Applied Microcomputer Systems 4/14/2003 Time span=5.00-20.00 hrs, dt=0.05 hrs. 301 points Runoff by SCS TR-20 method, UH=SCS, Type II 24-hr Rainfall=4.90" Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment 1S: AREA TO REAR OF BUILDINGS Tc=1.7 min CN=63 Area=44,171 sf Runoff= 2.85 cfs 0.110 of Subcatchment 2S: ROOF OF SOUTHERN BUILDING Tc=1.5 min CN=98 Area=6,313 sf Runoff= 1.09 cfs 0.052 of Subcatchment 3S: SOUTH & CENTRAL PORTION OF FRONT AREA Tc=1.7 min CN=89 Area=18,913 sf Runoff= 2.88 cfs 0.125 of Subcatchment 4S: CENTER BETWEEN BUILDINGS Tc=1.2 min CN=92 Area=4,901 sf Runoff= 0.81 cfs 0.035 of Subcatchment 5S: OFF SITE AREA TRIBUTARY TO STORM DRAIN Tc=0.0 min CN=98 Area=24,000 sf Runoff=4.32 cfs 0.196 of Subcatchment 6S: ROOF OF NORTH BUILDING Tc=1.0 min CN=98 Area=6,360 sf Runoff= 1.13 cfs 0.052 of Subcatchment 7S: FRONT PARKING ADJACENT TO NORTH BUILDING Tc=0.9 min CN=98 Area=2,008 sf Runoff= 0.36 cfs 0.016 of Subcatchment 8S: AREA TO NORTH OF NORTH BUILDING Tc=1.3 min CN=85 Area=4,619 sf Runoff= 0.66 cfs 0.027 of Subcatchment 9S: EAST PORTION PAVEMENT NORTH OF NOTRH BLDG. Tc=1.1 min CN=98 Area=1,825 sf Runoff= 0.32 cfs 0.015 of Subcatchment 10S: LAWN AREA NORTHEAST OF NORTH BUILDING Tc=1.8 min CN=41 Area=9,243 sf Runoff= 0.02 cfs 0,003 of Reach 1 R: EXISTING 12" STORM Inflow= 0.65 cfs 0.105 of Length= 40.0' Max Vel= 3.2 fps Capacity= 3.28 cfs Outflow= 0.65 cfs 0.105 of Reach 2R: EXISTING 24" STORM DRAIN Inflow= 5.76 cfs 0,354 of Length= 90.0' Max Vel= 5.2 fps Capacity= 18.60 cfs Outflow= 5.60 cfs 0.353 of Reach 3R: EXISTING 24" STORM DRAIN Inflow= 6.40 cfs 0.388 of Length= 135.0' Max Vel= 5.4 fps Capacity= 18.60 cfs Outflow=6.16 cfs 0.388 of Reach 4R: EXISTING 24" STORM Inflow= 9.04 cfs 0.513 of Length= 155.0' Max Vel= 3.3 fps Capacity= 9.21 cfs Outflow= 8.69 cfs 0.512 of Reach 5R: EXISTING 24" STORM OFF SITE Inflow= 9.55 cfs 0.624 of Length= 120.0' Max Vel=4.8 fps Capacity= 14.00 cfs Outflow= 9.36 cfs 0.624 of 47362 -WARREN TIRE-COMBINED SITES Type 11 24-hr Rainfall=4.90" Prepared by {enter your company name here} Page 2 HydroCADO 6.00 s/n 000768 © 1986-2001 Applied Microcomputer Systems 4/14/2003 Reach 6R: NEW 12" STORM FROM CB4 TO CB5 Inflow= 1.78 cfs 0.079 of Length= 60.0' Max Vel= 4.2 fps Capacity= 3.28 cfs Outflow= 1.74 cfs 0.079 of Reach 7R: NEW 12" STORM FROM CB5 TO CB7 Inflow= 2.06 cfs 0.094 of Length=48.0' Max Vel= 11.0 fps Capacity= 11.35 cfs Outflow= 2.04 cfs 0.094 of Pond 1 P: DETENTION BASIN IN GRASS AREA + ON PAVEMEE"rage= 1,593 cf Inflow= 2.85 cfs 0.110 of Primary= 0.65 cfs 0.105 of Outflow= 0.65 cfs 0.105 of Pond 2P: FRONT DETENTION BASIN Peak Storage= 1,432 cf Inflow=2.40 cfs 0.114 of Primary= 0.90 cfs 0.112 of Outflow= 0.90 cfs 0.112 of Runoff Area = 2.809 ac Volume = 0.632 of Average Depth = 2.70" 47362 -WARREN TIRE-COMBINED SITES Type l/ 24-hr Rainfall=4.90" Prepared by{enter your company name here) Page 3 HydroCAD®6.00 s/n 000768 © 1986-2001 Applied Microcomputer Systems 4/14/2003 Subcatchment 1S: AREA TO REAR OF BUILDINGs Runoff = 2.85 cfs @ 11.93 hrs, Volume= 0.110 of Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr Rainfall=4.90" Area (so CN Description 25,835 39 GRASS 18,336 98 PAVEMENT 44,171 63 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.7 110 0.0150 1.1 Sheet Flow,ACROSS PAVEMENT TO INLET Smooth surfaces n= 0.011 P2= 2.40" Subcatchment 2S: ROOF OF SOUTHERN BUILDING Runoff = 1.09 cfs @ 11.90 hrs, Volume= 0.052 of Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr Rainfall=4.90" Area (so CN Description 6,313 98 ROOF Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.5 80 0.0100 0.9 Sheet Flow,ACROSS ROOF TO LEADER Smooth surfaces n= 0.011 P2= 2.40" Subcatchment 3S: SOUTH & CENTRAL PORTION OF FRONT AREA Runoff = 2.88 cfs @ 11.91 hrs, Volume= 0.125 of Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr Rainfall=4.90" Area (sf) CN Description 2,955 39 GRASS 15958 98 PAVEMENT 18,913 89 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.7 90 0.0100 0.9 Sheet Flow, ACROSS PAVEMENT TO INLET Smooth surfaces n= 0.011 P2= 2.40" 47362 -WARREN TIRE-COMBINED SITES Type 1124-hr Rainfaff=4.90" Prepared by {enter your company name here} Page 4 HydroCAD®6.00 s/n 000768 @ 1986-2001 Applied Microcomputer Systems 4/14/2003 Subcatchment 4S: CENTER BETWEEN BUILDINGS Runoff = 0,81 cfs @ 11.90 hrs, Volume= 0.035 of Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr Rainfall=4.90" Area (sf) CN Description 478 39 GRASS 4,423 98 PAVEMENT 4,901 92 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.2 60 0.0100 0.8 Sheet Flow, ACROSS PAVEMENT TO INLET Smooth surfaces n= 0.011 P2= 2.40" Subcatchment 5S: OFF SITE AREA TRIBUTARY TO STORM DRAIN Runoff = 4.32 cfs @ 11.89 hrs, Volume= 0.196 of Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr Rainfall=4.90" Area (sf) CN Description 24,000 98 PAVEMENT AND ROOFS Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.0 Direct Entry, 5 Subcatchment 6S: ROOF OF NORTH BUILDING Runoff = 1.13 cfs @ 11.90 hrs, Volume= 0.052 of Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr Rainfall=4.90" Area (sf) CN Description 6,360 98 ROOF Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.0 Direct Entry, ACROSS ROOF TO DRAIN 47362 -WARREN TIRE-COMBINED SITES Type Il 24-hr Rainfall=4.90" Prepared by {enter your company name here) Page 5 HydroCAD®6.00 s/n 000768 © 1986-2001 Applied Microcomputer Svstems 4/14/2003 Subcatchment 7S: FRONT PARKING ADJACENT TO NORTH BUILDING Runoff = 0.36 cfs @ 11.90 hrs, Volume= 0.016 of Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr Rainfall=4.90" Area (sf) CN Description 2,008 98 PAVEMENT Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.9 60 0.0200 1.1 Sheet Flow,ACROSS PAVEMENT TO INLET Smooth surfaces n= 0.011 P2= 2.40" Subcatchment 8S: AREA TO NORTH OF NORTH BUILDING Runoff = 0.66 cfs @ 11.90 hrs, Volume= 0.027 of Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr Rainfall=4.90" Area (so CN Description 1,046 39 GRASS 3,573 98 PAVEMENT 4,619 85 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.3 80 0.0150 1.0 Sheet Flow, ACROSS PAVEMENT TO INLET Smooth surfaces n= 0.011 P2= 2.40" Subcatchment 9S: EAST PORTION PAVEMENT NORTH OF NOTRH BLDG. Runoff = 0.32 cfs @ 11.90 hrs, Volume= 0.015 of Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr Rainfall=4.90" Area (sf) CN Description 1,825 98 PAVEMENT Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.1 50 0.0100 0.8 Sheet Flow, ACROSS PAVEMENT TO INLET Smooth surfaces n= 0.011 P2= 2.40" 47362 -WARREN TIRE-COMBINED SITES Type /I24-hrRainfall=4.90" Prepared by {enter your company name here} Page 6 HydroCADO 6.00 s/n 000768 01986-2001 Applied Microcomputer Systems 4/14/2003 Subcatchment 10S: LAWN AREA NORTHEAST OF NORTH BUILDING Runoff = 0.02 cfs @ 12.00 hrs, Volume= 0.003 of Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr Rainfall=4.90" Area (sf) CN Description 8,872 39 GRASS 371 98 PAVEMENT 9,243 41 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.8 25 0.3300 0.2 Sheet Flow,ACROSS GRASS INTO BASIN Grass: Dense n= 0.240 P2= 2.40" Reach 1R: EXISTING 12" STORM Inflow = 0.65 cfs @ 12.05 hrs, Volume= 0.105 of Outflow = 0.65 cfs @ 12.07 hrs, Volume= 0.105 af, Atten= 0%, Lag= 0.7 min Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Max. Velocity= 3.2 fps, Min. Travel Time= 0.2 min Avg. Velocity = 1.9 fps, Avg. Travel Time= 0.4 min Peak Depth= 0.30' Capacity at bank full= 3.28 cfs 12.0" Diameter Pipe n= 0.010 Length=40.0' Slope= 0.0050 'P Reach 2R: EXISTING 24" STORM DRAIN Inflow = 5.76 cfs @ 11.89 hrs, Volume= 0.354 of Outflow = 5.60 cfs @ 11.90 hrs, Volume= 0.353 af, Atten= 3%, Lag= 0.3 min Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Max. Velocity= 5.2 fps, Min. Travel Time= 0.3 min Avg. Velocity = 1.9 fps, Avg. Travel Time= 0.8 min Peak Depth= 0.76' Capacity at bank full= 18.60 cfs 24.0" Diameter Pipe n= 0.010 Length= 90.0' Slope= 0.0040'P Reach 3R: EXISTING 24" STORM DRAIN Inflow = 6.40 cfs @ 11.90 hrs, Volume= 0.388 of Outflow = 6.16 cfs @ 11.91 hrs, Volume= 0.388 af, Atten=4%, Lag= 0.6 min 47362 -WARREN TIRE-COMBINED SITES Type 1124-hrRainfall=4.90" Prepared by{enter your company name here} Page 7 HydroCADO 6.00 s/n 000768 © 1986-2001 Applied Microcomputer Systems 4/14/2003 Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Max. Velocity= 5.4 fps, Min. Travel Time= 0.4 min Avg. Velocity = 1.9 fps, Avg. Travel Time= 1.2 min Peak Depth= 0.80' Capacity at bank full= 18.60 cfs 24.0" Diameter Pipe n= 0.010 Length= 135.0' Slope= 0.0040 '/' Reach 4R: EXISTING 24" STORM Inflow = 9.04 cfs @ 11.91 hrs, Volume= 0.513 of Outflow = 8.69 cfs @ 11.93 hrs, Volume= 0.512 af, Atten=4%, Lag= 1.5 min Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Max. Velocity= 3.3 fps, Min. Travel Time= 0.8 min Avg. Velocity = 1.3 fps, Avg. Travel Time= 2.1 min Peak Depth= 1.56' Capacity at bank full= 9.21 cfs 24.0" Diameter Pipe n= 0.021 Length= 155.0' Slope= 0.0043 T Reach 5R: EXISTING 24" STORM OFF SITE Inflow = 9.55 cfs @ 11.93 hrs, Volume= 0.624 of Outflow = 9.36 cfs @ 11.94 hrs, Volume= 0.624 af, Atten= 2%, Lag= 0.6 min Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Max. Velocity= 4.8 fps, Min. Travel Time= 0.4 min Avg. Velocity = 1.8 fps, Avg. Travel Time= 1.1 min Peak Depth= 1.21' Capacity at bank full= 14.00 cfs 24.0" Diameter Pipe n= 0.021 Length= 120.0' Slope= 0.0100 T Reach 6R: NEW 12" STORM FROM CB4 TO CB5 Inflow = 1.78 cfs @ 11.90 hrs, Volume= 0.079 of Outflow = 1.74 cfs @ 11.90 hrs, Volume= 0.079 af, Atten= 3%, Lag= 0.3 min Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Max. Velocity=4.2 fps, Min. Travel Time= 0.2 min Avg. Velocity = 1.4 fps, Avg. Travel Time= 0.7 min Peak Depth= 0.52' Capacity at bank full= 3.28 cfs 12.0" Diameter Pipe n= 0.010 Length= 60.0' Slope= 0.0050 T 47362 -WARREN TIRE-COMBINED SITES Type 1124-hr Rainfall=4.90" Prepared by{enter your company name here) Page 8 HydroCAD®6.00 sln 000768 01986-2001 Applied Microcomputer Systems 4/14/2003 Reach 7R: NEW 12" STORM FROM CB5 TO CB7 Inflow = 2.06 cfs @ 11.90 hrs, Volume= 0.094 of Outflow = 2.04 cfs @ 11.91 hrs, Volume= 0.094 af, Atten= 1%, Lag= 0.1 min Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Max. Velocity= 11.0 fps, Min. Travel Time= 0.1 min Avg. Velocity = 3.5 fps, Avg. Travel Time= 0.2 min Peak-Depth 0.29' Capacity at bank full= 11.35 cfs 12.0" Diameter Pipe n= 0.010 Length=48.0' Slope= 0.0600 '/' Pond 1 P: DETENTION BASIN IN GRASS AREA + ON PAVEMENT Inflow = 2.85 cfs @ 11.93 hrs, Volume= 0.110 of Outflow = 0.65 cfs @ 12.05 hrs, Volume= 0.105 af, Atten= 77%, Lag= 7.7 min Primary = 0.65 cfs @ 12.05 hrs, Volume= 0.105 of Routing by Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 335.19' Storage= 1,593 cf Plug-Flow detention time=43.5 min calculated for 0.105 of(96% of inflow) Storage and wetted areas determined by Prismatic sections Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 334.70 100 0 0 335.00 3,442 531 531 336.00 7,855 5,649 6,180 Primary OutFlow (Free Discharge) L1=Orifice/Grate # Routing Invert Outlet Devices 1 Primary 334.70' 8.0"Vert. Orifice/Grate C= 0.600 Pond 2P: FRONT DETENTION BASIN Inflow = 2.40 cfs @ 11.90 hrs, Volume= 0.114 of Outflow = 0.90 cfs @ 12.01 hrs, Volume= 0.112 af, Atten= 63%, Lag= 6.4 min Primary = 0.90 cfs @ 12.01 hrs, Volume= 0.112 of Routing by Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 333.15' Storage= 1,432 cf Plug-Flow detention time= 32.9 min calculated for 0.112 of(98% of inflow) Storage and wetted areas determined by Prismatic sections 47362 -WARREN TIRE-COMBINED SITES Type 1124-hr Rainfall=4.90" Prepared by (enter your company name here) Page 9 HydroCADS 6.00 s/n 000768 ©1986-2001 Applied Microcomputer Systems 4/14/2003 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 332.00 300 0 0 333.00 1,907 1,104 1,104 333.50 2,532 1,110 2,213 Primary OutFlow (Free Discharge) L1=Orifice/Grate # -Routing Invert Outlet Devices 1 Primary 332.00' 6.0"Vert. Orifice/Grate C= 0.600