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Stormwater Management Report
MAY 2 9 2MU"2 TOWN OF QUEENSBURY PLANNING OFFICE STORMWATER MANAGEMENT REPORT FOR BAYBROOK PROFESSIONAL PARK MEDICAL OFFICE BUILDING Town of Queensbury, New York Warren County Prepared by: NACE ENGINEERING, P.C. 169 HAVII.AND ROAD QUEENSBURY,NY 12804 o- Thomas W.Nace, P.E. May 2002 File: #47347 STORMWATER MANAGEMENT REPORT FOR BAYBROOK PROFESSIONAL PARK MEDICAL OFFICE BUILDING INTRODUCTION The site of the proposed Medical Office Building is on Lots #2, 3 & 4 of the recently approved Baybrook Professional Park Subdivision on the east side of Bay Road, in the Town of Queensbury,NY. The site is in the southwest comer of the subdivision and contains 5.2 acres. This report addresses drainage issues pertaining to the development of a 17,360 square foot medical office facility and associated roads, parking and site improvements on these lots. EXISTING CONDITIONS The site is a gently sloping meadow. There is an area of ACOE freshwater wetlands which have been flagged across the east edge and north side of the lot. The lots are bordered on the east by Old Maids Brook. Soils on this site are Raynham silt loams. One deep test pit was dug in a lower area in the north center portion of the site. The soils encountered were fine sandy loam over silty and clay subsoils. Evidence of seasonal high groundwater was present at a depth of approximately two and one half feet. The soils on the higher portions of the site are somewhat deeper and better drained. Groundcover on the existing site is predominantly overgrown meadow with some brush. All existing drainage from the site to be developed runs off into the wetland along the north and ease sides of the site. This wetland flows into the Old Maid Brook which eventually flows into Halfway Brook. DRAINAGE METHODOLOGY Due to the flat, low nature of the existing site, the building, roads and parking lots will be raised above the existing grades on imported fill. In the higher areas around the building infiltration trenches will be used to collect, store and infiltrate runoff from the building roof. Runoff from the parking and paved areas will be collected in catchbasins and piped to shallow detention basins. These basins will have a raised outlet so that the first-flush runoff is stored and treated in the basins. The primary outlet will be equipped with an orifice plate to control the rate of release. A secondary outlet will be provided higher in the basin to serve as an overflow if the primary orifice becomes plugged or during storms greater than the 50-year design storm. 1 The southwestern portion of the site currently drains to the recently constructed subdivision road. This drainage is collected in the catchbasins in the road and will be conveyed to stormwater basins to be constructed as part of the subdivision infrastructure. This portion of the developed site will continue to drain to the road and a detention pond on the site will serve to limit the peak runoff to predeveloped conditions which the subdivision infrastructure was designed for. CALCULATIONS The design of the eave trench is based upon an in-place percolation rate of 8 minutes per inch for the imported granular fill. The detention ponds have been sized to accommodate the storage required for a 50-year storm. All computations SCS TR-20 HydroCAD. 50 year storm event—Type II rainfall=4.8"—for detention basin and storm sewer sizing Soil conditions —fine sands & silts— SCS soil group C for existing site & group B for imported fill. Runoff rate and volume computations for the 50 year storm event have been completed for both the pre-developed and developed conditions. Eave trench and detention basin has been sized to maintain adequate freeboard during a 50 year design storm. 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 Southwestern Drainage Area Peak runoff rate.- 1.98 cfs 0.89 cfs Runoff volume - 0.178 acre feet .124 acre feet Main Site Drainage Area Peak runoff rate- 3.23 cfs 3.28 cfs Runoff volume- 0.29 acre feet 0.55 acre feet During a 50 year storm the detention basins will serve to control the peak runoff to predeveloped levels without reaching the overflow elevations of the basins. 2 r r STORMWATER MANAGEMENT REPORT FOR BAYBROOK PROFESSIONAL PARK MEDICAL OFFICE BUILDING HydroCAD RESULTS SOUTHWESTERN DRAINAGE LN Z N N O Ny F 00 N W N 7 3 a F o a o LO N U t � LL W O Q E Q U C O C N W � � aco Y Ern K V � m } o co T Q r /1/ m O LL � O � O M 0 V N w TO E � o E v � A d ® o mQn (� m ° a � Oa A M co 0 O ;C'7 47347 BAYBROOK MEDICAL OFFICES SOUTHWEST DRAINAGIType 1124-hrRainfall=4.80" Prepared by {enter your company name here) Page 1 H droCAD®6 00 s/n 000768 01986-2001 Applied Microcomputer Systems 5/28/2002 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=4.80" Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment 3S: SOUTHWEST PORTION OF BUILDING ROOF Tc=0.2 min CN=98 Area=3,650 sf Runoff-- 0.64 cfs 0.029 of Subcatchment 6S: SOUTHWEST PORTION OF SITE Tc=2.5 min CN=72 Area=37,473 sf Runoff-- 3.44 cfs 0.134 of Subcatchment 10S: PREDEVELOPED SOUTHWEST PORTION OF SITE Tc=28.7 min CN=65 Area=68,440 sf Runoff-- 1.98 cfs 0.178 of Reach 3R: (new node) Inflow-- 0.54 cfs 0.004 of Outflow= 0.54 cfs 0.004 of Pond 3P: 100 LF INFILTRATION TRENCH Peak Storage= 360 cf Inflow=0.64 cfs 0.029 of Discarded= 0.05 cfs 0.025 of Primary=0.54 cfs 0.004 of Outflow-- 0.59 cfs 0.029 of Pond 5P: POND#5 Peak Storage=2,478 cf Inflow-- 3.95 cfs 0.139 of Primary=0.89 cfs 0.124 of Outflow=0.89 cfs 0.124 of Runoff Area = 2.515 ac Volume= 0.341 of Average Depth= 1.63" r 47347 BAYBROOK MEDICAL OFFICES SOUTHWEST DRAINAGEype 1124-hr Rainfall=4.80" Prepared by(enter your company name here) Page 2 HydroCADO 6.00 s/n 000768 @ 1986-2001 Applied Microcomputer Systems 5/28/2002 Subcatchment 3S: SOUTHWEST PORTION OF BUILDING ROOF Runoff = 0.64 cfs @ 11.89 hrs, Volume= 0.029 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=4.80" Area (sf) CN Description 3,650 98 ROOF Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.2 40 0.3300 3.0 Sheet Flow,ACROSS ROOF TO EAVE TRENCH Smooth surfaces n= 0.011 P2= 2.40" Subcatchment 6S: SOUTHWEST PORTION OF SITE Runoff = 3.44 cfs @ 11.93 hrs, Volume= 0.134 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=4.80" Area (sf) CN Description 11,524 98 PAVEMENT 25,949 61 LAWN 37,473 72 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ftfsec) (cfs) 2.5 200 0.0180 1.3 Sheet Flow,ACROSS PARKING AREA TO POND Smooth surfaces n= 0.011 P2= 2.40" Subcatchment 10S: PREDEVELOPED SOUTHWEST PORTION OF SITE Runoff = 1.98 cfs @ 12.25 hrs, Volume= 0.178 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=4.80" Area (sf) CN Description 68,440 65 MEADOW/ BRUSH Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 28.7 200 0.0200 0.1 Sheet Flow,ACROSS MEADOW TO ROAD Grass: Dense n= 0.240 P2=2.40" 47347 BAYBROOK MEDICAL OFFICES SOUTHWEST DRAINAGEype 1124-hr Rainfall=4.80" Prepared by{enter your company name here) Page 3 HydroCAD®6.00 s/n 000768 01986-2001 Applied Microcomputer Systems 6/28/2002 Reach 3R: (new node) Inflow = 0.54 cfs @ 11.92 hrs, Volume= 0.004 of Outflow = 0.54 cfs @ 11.92 hrs, Volume= 0.004 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Pond 3P: 100 LF INFILTRATION TRENCH Inflow = 0.64 cfs @ 11.89 hrs, Volume= 0.029 of Outflow = 0.59 cfs @ 11.92 hrs, Volume= 0.029 af, Atten= 8%, Lag= 1.8 min Discarded = 0.05 cfs @ 11.90 hrs, Volume= 0.025 of Primary = 0.54 cfs @ 11.92 hrs, Volume= 0.004 of Routing by Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 3.01' Storage= 360 cf Plug-Flow detention time= 55.7 min calculated for 0.029 of(100% of inflow) Elevation Cum.Store (feet) (cubic-feet) 0.00 0 1.00 120 2.00 240 3.00 360 3.50 365 Discarded OutFlow (Free Discharge) L1=INFILTRATION Primary OutFlow (Free Discharge) t2=OVERFLOW FROM TRENCH # Routing Invert Outlet Devices 1 Discarded 0.00' INFILTRATION Elev. (feet) 0.00 0.10 1.00 2.00 3.00 Disch. (cfs) 0.00 0.02 0.03 0.04 0.05 2 Primary 3.00' 100.0' long x 10.0' breadth OVERFLOW FROM TRENCH Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 Pond 5P: POND #5 Inflow = 3.95 cfs @ 11.93 hrs, Volume= 0.139 of Outflow = 0.89 cfs @ 12.06 hrs, Volume= 0.124 af, Atten=77%, Lag= 7.7 min Primary = 0.89 cfs @ 12.06 hrs, Volume= 0.124 of Routing by Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs 47347 BAYBROOK MEDICAL OFFICES SOUTHWEST DRAINAGIType II 24-hr Rainfall=4.80" Prepared by{enter your company name here} Page 4 HydroCADO 6.00 s/n 000768 © 1986-2001 Applied Microcomputer Systems 5/28/2002 Peak Elev= 312.14' Storage= 2,478 cf Plug-Flow detention time= 70.5 min calculated for 0.123 of(89% of inflow) Storage and wetted areas determined by Prismatic sections Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 310.00 0 0 0 310.50 306 77 77 311.00 1,211 379 456 312.00 2,023 1,617 2,073 31$.00 3,667 2,845 4,918 Primary OutFlow (Free Discharge) �1=Orifice/Grate 2=Orifice/Grate # Routing Invert Outlet Devices 1 Primary 311.00' 6.0"Vert. Orifice/Grate C= 0.600 2 Primary 312.80' 2.00' x 1.00' Horiz. Orifice/Grate Limited to weir flow C= 0.600 STORMWATER MANAGEMENT REPORT FOR BAYBROOK PROFESSIONAL PARK MEDICAL OFFICE BUILDING HydroCAD RESULTS MAIN SITE W y O in O T N O ? Lo a E W O r LL LL o L N U N Q (n W C c o c I� O co O n LL' E rn ado a o m =3co co �l T 0 v « o ` C C w �h C < tm � IL A a O N V N o a 0 C N c J 0 0 U N C a 0 47347 BAYBROOK MEDICAL OFFICES MAIN DRAINAGE Type 1124-hrRainfall=4.80" Prepared by{enter your company name here} Page 1 HydroCAD®6.00 sln 000768 01986-2001 Applied Microcomputer Systems 5/28/2002 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=4.80" Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment 1S: NORTHWEST BLDG. ROOF Tc=0.2 min CN=98 Area=4,875 sf Runoff-- 0.86 cfs 0.039 of Subcatchment 2S: NORTH ROOF HIP Tc=0.2 min CN=98 Area=1,700 sf Runoff= 0.30 cfs 0.014 of Subcatchment 4S: EAST BUILDING ROOF Tc=0.2 min CN=98 Area=6,825 sf Runoff= 1.20 cfs 0.055 of Subcatchment 5S: NORTHWEST PORTION OF SITE Tc=4.5 min CN=61 Area=21,866 sf Runoff-- 1.12 cfs 0.047 of Subcatchment 7S: SOUTHEAST CORNER OF SITE Tc=1.8 min CN=80 Area=30,645 sf Runoff--3.62 cfs 0.148 of Subcatchment 8S: EAST SIDE OF SITE Tc=2.0 min CN=85 Area=46,348 sf Runoff--6.22 cfs 0.264 of Subcatchment 9S: NORTH EAST CORNER OF SITE Tc=1.7 min CN=82 Area=26,829 sf Runoff-- 3.38 cfs 0.138 of Subcatchment 11S: PREDEVELOPED CONDITIONS MAIN SITE Tc=28.7 min CN=65 Area=111,771 sf Runoff--3.23 cfs 0.290 of Reach 1 R: SWALE Inflow= 1.14 cfs 0.005 of Length= 180.0' Max Vet= 0.3 fps Capacity= 125.52 cfs Outflow=0.29 cfs 0.005 of Reach 2R:TOTAL FLOW TO OFF SITE Inflow=3.28 cfs 0.558 of Length= 50.0' Max Vel=0.1 fps Capacity=42.26 cfs Outflow=2.88 cfs 0.553 of Reach 4R: EAVE TRENCH OVERFLOW ACROSS PARKING Inflow=0.32 cfs 0.002 of Length= 110.0' Max Vel= 0.5 fps Capacity--438.64 cfs Outflow=0.14 cfs 0.002 of Reach 5R: EAVE TRENCH OVERFLOW ACROSS PAVEMENT Inflow= 1.29 cfs 0.009 of Length= 150.0' Max Vel= 0.7 fps Capacity=911.36 cfs Outflow--0.64 cfs 0.009 of Pond 1P: 160 LF EAVE TRENCH Peak Storage=540 cf Inflow=0.86 cfs 0.039 of Discarded= 0.08 cfs 0.034 of Primary= 1.14 cfs 0.005 of Outflow= 1.22 cfs 0.039 of Pond 2P: 50 LF EAVE TRENCH Peak Storage= 180 cf Inflow=0.30 cfs 0.014 of Discarded=0.03 cfs 0.012 of Primary= 0.32 cfs 0.002 of Outflow=0.35 cfs 0.014 of Pond 4P: 185 LF INFILTRATION TRENCH Peak Storage=666 cf Inflow= 1.20 cfs 0.055 of Discarded= 0.10 cfs 0.046 of Primary= 1.29 cfs 0.009 of Outflow-- 1.39 cfs 0.055 of 47347 BAYBROOK MEDICAL OFFICES MAIN DRAINAGE Type 1124-hr Rainfall=4.80" Prepared by{enter your company name here} Page 2 HydroCADO 6.00 s/n 000768 01986-2001 Applied Microcomputer Systems 5/28/2002 Pond 6P: POND#6 Peak Storage= 3,021 cf Inflow-- 3.62 cfs 0.148 of Primary=0.70 cfs 0.127 of Outflow-- 0.70 cfs 0.127 of Pond 7P: POND#7 Peak Storage= 5,971 cf Inflow--6.29 cfs 0.272 of Primary= 0.85 cfs 0.250 of Outflow-- 0.85 cfs 0.250 of Pond 8P: (new node) Peak Storage=2,612 cf Inflow=3.38 cfs 0.140 of Primary=0.76 cfs 0.130 of Outflow--0.76 cfs 0.130 of Runoff Area= 6.769 ac Volume= 0.994 of Average Depth=2.07" 47347 BAYBROOK MEDICAL OFFICES MAIN DRAINAGE Type 1124-hr Rainfall=4.80" Prepared by tenter your company name here) Page 3 HydroCAD®6.00 s/n 000768 © 1986-2001 Applied Microcomputer Systems 5/28/2002 Subcatchment 1S: NORTHWEST BLDG. ROOF Runoff = 0.86 cfs @ 11.89 hrs, Volume= 0.039 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=4.80" Area (sf) CN Description 4,875 98 ROOF Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.2 40 0.3300 3.0 Sheet Flow,ACROSS ROOF TO EAVE TRENCH Smooth surfaces n= 0.011 P2=2.40" Subcatchment 2S: NORTH ROOF HIP Runoff = 0.30 cfs @ 11.89 hrs, Volume= 0.014 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=4.80" Area (sf) CN Description 1,700 98 ROOF Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.2 40 0.3300 3.0 Sheet Flow,ACROSS ROOF TO EAVE TRENCH Smooth surfaces n= 0.011 P2= 2.40" Subcatchment 4S: EAST BUILDING ROOF Runoff = 1.20 cfs @ 11.89 hrs, Volume= 0.055 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=4.80" Area (sf) CN Description 6,825 98 ROOF Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.2 40 0.3300 3.0 Sheet Flow,ACROSS ROOF TO EAVE TRENCH Smooth surfaces n= 0.011 P2= 2.40" 47347 BAYBROOK MEDICAL OFFICES MAIN DRAINAGE Type II 24-hr Rainfall=4.80" Prepared by (enter your company name here) Page 4 HydroCAD®6 00 s/n 000768 01986-2001 Applied Microcomputer Systems 5/28/2002 Subcatchment 5S: NORTHWEST PORTION OF SITE Runoff = 1.12 cfs @ 11.96 hrs, Volume= 0.047 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=4.80" Area (sf) CN Description 21,866 61 LAWNS AND PLANTING AREAS Tc Length Slope Velocity Capacity Description (min) (feet) (ftift) (ft/sec) (cfs) 4.5 40 0.0800 0.1 Sheet Flow,ACROSS GRASS TO SWALE Grass: Dense n= 0.240 P2= 2.40" Subcatchment 7S: SOUTHEAST CORNER OF SITE Runoff = 3.62 cfs @ 11.92 hrs, Volume= 0.148 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=4.80" Areas CN Description 16,002 98 PAVEMENT 14,643 61 LAWN 30,645 80 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.8 150 0.0250 1.4 Sheet Flow,ACROSS PAVEMENT TO INLET Smooth surfaces n= 0.011 P2= 2.40" Subcatchment 8S: EAST SIDE OF SITE Runoff = 6.22 cfs @ 11.92 hrs, Volume= 0.264 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=4.80" Areas CN Description 30,321 98 PAVEMENT 16,027 61 LAWN 46,348 85 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 2.0 170 0.0250 1.4 Sheet Flow,ACROSS PAVEMENT TO INLET Smooth surfaces n= 0.011 P2= 2.40" 47347 BAYBROOK MEDICAL OFFICES MAIN DRAINAGE Type 1124-hr Rainfall=4.80" Prepared by{enter your company name here) Page 5 HydroCAD®6.00 s/n 000768 01986-2001 Applied Microcomputer Systems 5/28/2002 Subcatchment 9S: NORTH EAST CORNER OF SITE Runoff = 3.38 cfs @ 11.91 hrs, Volume= 0.138 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=4.80" Area (sf) CN Description 15,422 98 PAVEMENT 11,407 61 LAWN 26,829 82 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.7 130 0.0200 1.3 Sheet Flow,ACROSS PAVEMENT TO INLET Smooth surfaces n= 0.011 P2= 2.40" Subcatchment 11S: PREDEVELOPED CONDITIONS MAIN SITE Runoff = 3.23 cfs @ 12.25 hrs, Volume= 0.290 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=4.80" Area (sf) CN Description 111,771 65 MEADOW/BRUSH Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 28.7 200 0.0200 0.1 Sheet Flow,ACROSS MEADOW TO STREAM Grass: Dense n= 0.240 P2= 2.40" Reach 1R: SWALE Inflow = 1.14 cfs @ 11.95 hrs, Volume= 0.005 of Outflow = 0.29 cfs @ 12.16 hrs, Volume= 0.005 af, Atten= 75%, Lag= 12.3 min Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Max. Velocity= 0.3 fps, Min. Travel Time= 9.1 min Avg. Velocity = 0.1 fps, Avg. Travel Time=20.5 min Peak Depth= 0.08' Capacity at bank full= 125.52 cfs 10.00' x 2.00' deep channel, n=0.080 Length= 180.0' Slope= 0.01007 Side Slope Z-value= 10.0 7' 47347 BAYBROOK MEDICAL OFFICES MAIN DRAINAGE Type 1124-hr Rainfall=4.80" Prepared by {enter your company name here} Page 6 HydroCAD@)6.00 s/n 000768 01986-2001 Applied Microcomputer Systems 5/28/2002 Reach 2R: TOTAL FLOW TO OFF SITE Inflow = 3.28 cfs @ 11.98 hrs, Volume= 0.558 of Outflow = 2.88 cfs @ 12.16 hrs, Volume= 0.553 af, Atten= 12%, Lag= 11.1 min Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Max. Velocity-- 0.1 fps, Min. Travel Time=6.3 min Avg. Velocity = 0.1 fps, Avg. Travel Time= 11.4 min Peak Depth= 0.78' Capacity at bank full=42.26 cfs 20.00' x 3.00' deep channel, n= 0.800 Length= 50.0' Slope= 0.01007 Side Slope Z-value= 10.0 7' Reach 4R: EAVE TRENCH OVERFLOW ACROSS PARKING Inflow = 0.32 cfs @ 11.95 hrs, Volume= 0.002 of Outflow = 0.14 cfs @ 12.05 hrs, Volume= 0.002 af, Atten= 56%, Lag= 6.1 min Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt=0.05 hrs Max. Velocity= 0.5 fps, Min. Travel Time= 3.9 min Avg. Velocity = 0.5 fps, Avg. Travel Time= 3.9 min Peak Depth= 0.00' Capacity at bank full=438.64 cfs 80.00' x 0.50' deep channel, n= 0.013 Length= 110.0' Slope= 0.0200'P Side Slope Z-value= 30.0 'P Reach 5R: EAVE TRENCH OVERFLOW ACROSS PAVEMENT Inflow = 1.29 cfs @ 11.91 hrs, Volume= 0.009 of Outflow = 0.64 cfs @ 12.01 hrs, Volume= 0.009 af, Atten= 50%, Lag= 6.5 min Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Max. Velocity= 0.7 fps, Min. Travel Time= 3.6 min Avg. Velocity = 0.5 fps, Avg. Travel Time=4.6 min Peak Depth= 0.01' Capacity at bank full= 911.36 cfs 150.00' x 0.50' deep channel, n= 0.013 Length= 150.0' Slope= 0.0250 'P Side Slope Z-value= 50.0 '/' Pond 1 P: 150 LF EAVE TRENCH Inflow = 0.86 cfs @ 11.89 hrs, Volume= 0.039 of Outflow = 1.22 cfs @ 11.95 hrs, Volume= 0.039 af, Atten= 0%, Lag= 3.6 min Discarded = 0.08 cfs @ 11.93 hrs, Volume= 0.034 of Primary = 1.14 cfs @ 11.95 hrs, Volume= 0.005 of Routing by Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs 47347 BAYBROOK MEDICAL OFFICES MAIN DRAINAGE Type Il 24-hr Rainfall=4.80" Prepared by{enter your company name here} Page 7 HydroCAD®6.00 s/n 000768 © 1986-2001 Applied Microcomputer Systems 5/28/2002 Peak Elev= 3.04' Storage= 540 cf Plug-Flow detention time= 56.1 min calculated for 0.039 of(99% of inflow) Elevation Cum.Store (feet) (cubic-feet) 0.00 0 1.00 180 2.00 360 3.00 540 3.50 545 Discarded OutFlow (Free Discharge) t-1=INFILTRATION Primary OutFlow (Free Discharge) t-2=OVERFLOW FROM EAVE TRENCH # Routing Invert Outlet Devices 1 Discarded 0.00' INFILTRATION Elev. (feet) 0.00 0.10 1.00 2.00 3.00 Disch. (cfs) 0.00 0.03 0.04 0.06 0.08 2 Primary 3.00' 150.0' long x 10.0' breadth OVERFLOW FROM EAVE TRENCH Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 Pond 2P: 50 LF EAVE TRENCH Inflow = 0.30 cfs @ 11.89 hrs, Volume= 0.014 of Outflow = 0.35 cfs @ 11.94 hrs, Volume= 0.014 af, Atten= 0%, Lag= 3.3 min Discarded = 0.03 cfs @ 11.93 hrs, Volume= 0.012 of Primary = 0.32 cfs @ 11.95 hrs, Volume= 0.002 of Routing by Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 3.04' Storage= 180 cf Plug-Flow detention time= 59.2 min calculated for 0.014 of(100% of inflow) Elevation Cum.Store (feet) (cubic-feet) 0.00 0 1.00 60 2.00 120 3.00 180 3.50 185 Discarded OutFlow (Free Discharge) t-1=INFILTRATION Primary OutFlow (Free Discharge) t-2=OVERFLOW FROM EAVE TRENCH 47347 BAYBROOK MEDICAL OFFICES MAIN DRAINAGE Type // 24-hr Rainfall=4.80" Prepared by{enter your company name here) Page 8 HydroCAD®6.00 s/n 000768 01986-2001 Applied Microcomputer Systems 5/28/2002 # Routing Invert Outlet Devices 1 Discarded 0,00' INFILTRATION Elev. (feet) 0.00 0.10 1.00 2.00 3.00 Disch. (cfs) 0.00 0.01 0.01 0.02 0.03 2 Primary 3.00' 50.0' long x 50.0' breadth OVERFLOW FROM EAVE TRENCH Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.68 2.70 2.70 2.64 2.63 2.64 2.64 2.63 Pond 4P: 185 LF INFILTRATION TRENCH Inflow = 1.20 cfs @ 11.89 hrs, Volume= 0.055 of Outflow = 1.39 cfs @ 11.91 hrs, Volume= 0.055 af, Atten= 0%, Lag= 1.0 min Discarded = 0.10 cfs @ 11.90 hrs, Volume= 0.046 of Primary = 1.29 cfs @ 11.91 hrs, Volume= 0.009 of Routing by Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 3.02' Storage= 666 cf Plug-Flow detention time= 55.6 min calculated for 0.055 of(100% of inflow) Elevation Cum.Store (feet) (cubic-feet) 0.00 0 1.00 222 2.00 444 3.00 666 3.50 675 Discarded OutFlow (Free Discharge) t1=INFILTRATION Primary OutFlow (Free Discharge) t-2=OVERFLOW FROM EAVE TRENCH # Routing Invert Outlet Devices 1 Discarded 0.00' INFILTRATION Elev. (feet) 0.00 0.10 1.00 2.00 3.00 Disch. (cfs) 0.00 0.03 0.05 0.08 0.10 2 Primary 3.00' 185.0' long x 10.0' breadth OVERFLOW FROM EAVE TRENCH Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 Pond 6P: POND #6 Inflow = 3.62 cfs @ 11.92 hrs, Volume= 0.148 of Outflow = 0.70 cfs @ 12.06 hrs, Volume= 0.127 af, Atten= 81%, Lag= 8.7 min Primary = 0.70 cfs @ 12.06 hrs, Volume= 0.127 of Routing by Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs 47347 BAYBROOK MEDICAL OFFICES MAIN DRAINAGE Type 11 24-hr Rainfall=4.80" Prepared by(enter your company name here) Page 9 HydroCAD®6.00 s/n 000768 © 1986-2001 Applied Microcomputer Systems 5/28/2002 Peak Elev= 310.54' Storage= 3,021 cf Plug-Flow detention time= 93.2 min calculated for 0.126 of(86% of inflow) Storage and wetted areas determined by Prismatic sections Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 308.00 0 0 0 308.50 306 77 77 309.00 1,172 370 446 310.00 1,678 1,425 1,871 311.00 2,605 2,142 4,013 311.50 2,937 1,386 5,398 Primary OutFlow, (Free Discharge) L1=0RIFACE 2=0rifice/Grate # Routing Invert Outlet Devices 1 Primary 309.20' 5.0"Vert. ORIFACE C= 0.600 2 Primary 311.20' 2.00'x 1.00' Horiz. Orifice/Grate Limited to weir flow C= 0.600 Pond 7P: POND#7 Inflow = 6.29 cfs @ 11.92 hrs, Volume= 0.272 of Outflow = 0.85 cfs @ 12.19 hrs, Volume= 0.250 af, Atten= 87%, Lag= 16.0 min Primary = 0.85 cfs @ 12.19 hrs, Volume= 0.250 of Routing by Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 309.87' Storage= 5,971 cf Plug-Flow detention time= 105.0 min calculated for 0.249 of(92% of inflow) Storage and wetted areas determined by Prismatic sections Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 307.50 352 0 0 308.00 1,890 561 561 309.00 2,882 2,386 2,947 310.00 4,035 3,459 6,405 311.00 5,222 4,629 11,034 311.50 5,689 2,728 13,761 Primary OutFlow (Free Discharge) L1=0rifice/Grate 2=Orifice/Grate # Routing Invert Outlet Devices 1 Primary 308.00' 5.0" Vert. Orifice/Grate C= 0.600 2 Primary 310.80' 2.00' x 1.00' Horiz. Orifice/Grate Limited to weir flow C= 0.600