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HomeMy WebLinkAbout2015-07-20 Elan Design Stomrwater Design Materials to BCWD D E S I G N 901 N 3rd St, Suite 120 Minneapolis, MN 55401 tel 612.260.7980 fax 612.260.7990 www.elanlab.com July 20, 2015 Eric Johnson City Administrator 14168 Oak Park Blvd. N. Oak Park Heights, MN 55082 Karen Kill Administrator Brown's Creek Watershed District 455 Hayward Ave. N. Oakdale, MN 55128 Range 082 Indoor Shooting,Oak Park Heights,MN RE:Stormwater Design Dear Ms. Kill and Mr.Johnson: We have recently submitted plans to Oak Park Heights for the Range 082 Indoor Shooting project located between Memorial Avenue and Stillwater Boulevard opposite the entrance to Stillwater High School. The development is served by a regional ponding basin located immediately south of our site. It is our understanding that this regional pond satisfies the City and Watershed requirements for rate control. However,since the developed site will have greater than 1 acres of new impervious we will need to provide volume control in the form of infiltration to meet State requirements. If this assumption is incorrect please let me know and we will adjust the plans. The plans show two infiltration basins in the southwest and southeast corners of the site. A very small area in the northwest corner of the site does not flow to an infiltration basin. The basins have been sized to store a volume equal to 1"of instantaneous runoff from the impervious areas of the site. The basins bounce 1.1'and 1.2',west and east respectively. Based on a HSG B soil rate(0.45 inches per hour)infiltration will occur in less than 48 hours. I am still waiting on geotechnical information to confirm the infiltration rates. An armored overflow to the regional pond is provided for greater rainfall events. We have analyzed the 2, 10 and 24 hour rainfall events with HydroCAD and have found that the overflows pass sufficient runoff to allow the basins to infiltrate well within 48 hours of the end of the rainfall event. Pretreatment is provided to the southwest infiltration basin by two Rain Guardian devices and short grass lined swales. Pretreatment for the southeastern basin is provided by an extended grass lined swale. Site Analysis& Planning I Civil Engineering I Landscape Architecture I Construction Services RE:Range 082 Indoor Shooting,Stormwater Management July 20,2015 I have attached a copy of our HydroCAD analysis and have summarized the results below. Southwest Basin Southeast Basin Impervious Area 24,530 SF 76,270 SF Required Extraction Volume(1") 2,044 CF 6,355 CF Bottom of Basin 933.0 933.0 Extraction Volume Achieved at Elevation 934.1 934.2 2 Year,24 Hour 934.3 934.4 10 Year,24 Hour 934.4 934.7 100 Year,24 Hour 934.5 934.9 The plans also provide temporary sedimentation basins during construction. In the southwest corner of the site a sedimentation basin is provided between the Rain Guardian inlets and the infiltration basin. In the southeast corner of the site a temporary sedimentation basin is created through the modification of the grass lined swale. In both cases the outlet is controlled with a perforated riser pipe that drains to ditches that flow to the adjacent regional pond. The sedimentation basins were sized for the 2 year hour event as modeled in HydroCAD using a non-vegetated site. The results are summarized below. Southwest Basin Southeast Basin Total Drainage Area 41,790 SF 98,560 SF Minimum Storage Volume(1800 CF/Acre) 1,730 CF 4,075 CF Storage Volume Provided to Overflow 2,040 CF 5,540 CF 2 Year,24 Hour 935.1 936.6 There are two major areas that drain through the site via ditches. The western most basin is approximately 122,000 SF in area and drains to the eastern Memorial Ave. N.ditch. The two entrance drives to the site cross this ditch, requiring culverts. We have sized these culverts for the 100 year event with an assumed runoff coefficient of 0.8 and a 15 minute time of concentration resulting in a flow of 16.1 CFS. The eastern basin is approximately 224,590 SF in area and drains to a ditch that bisects the site just to the east of the proposed parking lot. Again assuming C=0.8 and Tc= 15 minutes the peak flow equals 30.0 CFS. The proposed plan includes filling a portion of the ditch to allow site runoff to reach the infiltration area. Due to restricted headroom it is proposed use an array of three 15" culverts. The pipe sizing calculations are shown in the attached spreadsheet. ‘ tol,ter Page2of3 D E S I G N L A B RE:Range 082 Indoor Shooting,Stormwater Management July 20,2015 I will forward geotechnical information as soon as it becomes available. In the meantime, please feel free to contact me should you have questions on the enclosed submittal, 612-260-7982. Sincerely, Steve Johnston, PE Principal Engineer Cc: Élan File#OBA15001 Steve Erban,Out of the Box Architecture Encl: Digital Plans HydroCAD Analysis Pipe sizing spreadsheet III Page3of3 DESIGN LAB W I� zh qN m°� g �r O 00. a Z °a $ _ ibldZ� q gg oW x w e`�i Hw " O a— I! g Y `i i #ii6s°�,7 I'd C7 woyEUq Ox W3,rai ZOO az w � g$$ � a i a _ a ",°,;1!` �'d se =`�" U o �° ~� � w QZ=<� N=o ea =6e?? :RR E Z ° °g° g F �i �a N°3 z—vfo in -@e t= $ $ g a iiit m RR @�L I'!tf pg Ii1 1, ■ eR4 . . 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Pond Temp Pond 10S <20S> <30S> West Basin East asin CB H 1 A 31P 11P 21P West Infiltration Basin East Infiltration Basin CBMH 1 Subcat Reach 'on• Link Routing Diagram for 20150713_Range 082 Prepared by Elan Design Lab, Inc., Printed 7/15/2015 HydroCAD®10.00-13 s/n 07437 ©2014 HydroCAD Software Solutions LLC Range 082, Oak Park Heights 20150713_Range 082 Type 1124-hr 1"Rainfall=1.00" Prepared by Elan Design Lab, Inc. Printed 7/15/2015 HydroCAD®10.00-13 s/n 07437 ©2014 HydroCAD Software Solutions LLC Page 2 Summary for Subcatchment 10aS: West Basin THIS IS CONDITION DURING SITE DEVELOPMENT Runoff = 0.89 cfs @ 11.96 hrs, Volume= 0.044 af, Depth= 0.55" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/lmperv., Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type II 24-hr 1" Rainfall=1.00" Area (sf) CN Description 17,260 86 Fallow, bare soil, HSG B 24,530 98 Roofs, Paved parking, HSG C 41,790 93 Weighted Average 17,260 86 41.30% Pervious Area 24,530 98 58.70% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Range 082, Oak Park Heights 20150713_Range 082 Type 1124-hr 1"Rainfall=1.00" Prepared by Elan Design Lab, Inc. Printed 7/15/2015 HydroCAD®10.00-13 s/n 07437 ©2014 HydroCAD Software Solutions LLC Page 3 Summary for Subcatchment 10S: West Basin THIS IS THE CONDITION POST DEVELOPMENT Runoff = 0.76 cfs @ 11.96 hrs, Volume= 0.038 af, Depth= 0.47" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/lmperv., Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type II 24-hr 1" Rainfall=1.00" Area (sf) CN Description * 17,260 72 >75% Grass cover, Good, HSG C * 24,530 98 Roofs, Paved parking, HSG C X 1/12 = 2044 CF RFQI JIRFD VC)j UME 41,790 87 Weighted Average 17,260 72 41.30% Pervious Area 24,530 98 58.70% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Range 082, Oak Park Heights 20150713_Range 082 Type 1124-hr 1"Rainfall=1.00" Prepared by Elan Design Lab, Inc. Printed 7/15/2015 HydroCAD®10.00-13 s/n 07437 ©2014 HydroCAD Software Solutions LLC Page 4 Summary for Subcatchment 20aS: East Basin THIS IS THE CONDITION DURING SITE DEVELOPMENT Runoff = 2.53 cfs @ 11.96 hrs, Volume= 0.124 af, Depth= 0.66" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type II 24-hr 1" Rainfall=1.00" Area (sf) CN Description 22,290 86 Fallow, bare soil, HSG B 76,270 98 Roofs, Paved parking, HSG C 98,560 95 Weighted Average 22,290 86 22.62% Pervious Area 76,270 98 77.38% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Range 082, Oak Park Heights 20150713_Range 082 Type 1124-hr 1"Rainfall=1.00" Prepared by Elan Design Lab, Inc. Printed 7/15/2015 HydroCAD®10.00-13 s/n 07437 ©2014 HydroCAD Software Solutions LLC Page 5 Summa for Subcatchment 20S: East Basin THIS IS THE CONDITION POST DEVELOPMENT Runoff = 2.37 cfs @ 11.96 hrs, Volume= 0.116 af, Depth= 0.61" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type II 24-hr 1" Rainfall=1.00" Area (sf) CN Description * 22,290 72 >75% Grass cover, Good, HSG C * 76,270 98 Roofs, Paved parking, HSG C X 1/12 = 6.355 CF REQUIRE VOLUME 98,560 92 Weighted Average 22,290 72 22.62% Pervious Area 76,270 98 77.38% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Range 082, Oak Park Heights 20150713_Range 082 Type 1124-hr 1"Rainfall=1.00" Prepared by Elan Design Lab, Inc. Printed 7/15/2015 HydroCAD®10.00-13 s/n 07437 ©2014 HydroCAD Software Solutions LLC Page 6 Summary for Subcatchment 30S: CBMH 1 Runoff = 0.07 cfs @ 11.96 hrs, Volume= 0.003 af, Depth= 0.65" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type II 24-hr 1" Rainfall=1.00" Area (sf) CN Description * 500 72 >75% Grass cover, Good, HSG C * 2,250 98 Roofs, Paved parking, HSG C 2,750 93 Weighted Average 500 72 18.18% Pervious Area 2,250 98 81.82% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Range 082, Oak Park Heights 20150713_Range 082 Type /I 24-hr 1"Rainfall=1.00" Prepared by Elan Design Lab, Inc. Printed 7/15/2015 HydroCAD® 10.00-13 s/n 07437 ©2014 HydroCAD Software Solutions LLC Page 7 Summary for Pond 11P: West Infiltration Basin Inflow Area = 0.959 ac, 58.70% Impervious, Inflow Depth = 0.47" for 1"event Inflow = 0.76 cfs @ 11.96 hrs, Volume= 0.038 af Outflow = 0.02 cfs @ 14.07 hrs, Volume= 0.038 af, Allen= 97%, Lag= 126.9 min Discarded = 0.02 cfs @ 14.07 hrs, Volume= 0.038 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Peak Elev= 933.58' @ 14.07 hrs Surf.Area= 1,791 sf Storage= 916 cf Plug-Flow detention time= 460.6 min calculated for 0.038 af(100% of inflow) Center-of-Mass det. time= 460.5 min ( 1,247.9 - 787.4 ) Volume Invert Avail.Storage Storage Description #1 933.00' 4,468 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 933.00 1,385 0 0 REQUIRED VOLUME MET AT 934.1 934.00 2,090 1,738 1,738 ALLOW OVERFLOW AT THAT 935.00 3,370 2,730 4,468 ELEVATION Device Routing Invert Outlet Devices #1 Primary 934.10' 10.0' long x 1.00' rise Sharp-Crested Rectangular Weir 2 End Contraction(s) 1.0' Crest Height #2 Discarded 933.00' 0.450 in/hr Exfiltration over Surface area BASED ON B SOILS Conductivity to Groundwater Elevation = 928.00' 4iscarded OutFlow Max=0.02 cfs @ 14.07 hrs HW=933.58' (Free Discharge) 2=Exfiltration ( Controls 0.02 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=933.00' (Free Discharge) L1=Sharp-Crested Rectangular Weir( Controls 0.00 cfs) 20150713_Range 082 Type 1124-hr 1"Rainfall=1.00" Prepared by Elan Design Lab, Inc. Printed 7/20/2015 HydroCAD®10.00-13 s/n 07437 ©2014 HydroCAD Software Solutions LLC Page 8 Summary for Pond 12P: Temp. Pond Inflow Area = 0.959 ac, 58.70% Impervious, Inflow Depth = 0.55" for 1"event Inflow = 0.89 cfs @ 11.96 hrs, Volume= 0.044 af Outflow = 0.32 cfs @ 12.06 hrs, Volume= 0.040 af, Atten= 64%, Lag= 6.1 min Primary = 0.32 cfs @ 12.06 hrs, Volume= 0.040 af Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Peak Elev= 933.89' @ 12.06 hrs Surf.Area= 856 sf Storage= 706 cf Plug-Flow detention time= 98.1 min calculated for 0.040 of(91% of inflow) Center-of-Mass det. time= 49.9 min ( 849.2 - 799.4 ) Volume Invert Avail.Storage Storage Description #1 932.00' 2,963 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 932.00 0 0 0 933.00 345 173 173 934.00 920 633 805 935.00 1,550 1,235 2,040 935.50 2,140 923 2,963 Device Routing Invert Outlet Devices #1 Primary 933.00' 1.0"Vert. Orifice/Grate X 6.00 columns X 4 rows with 4.0" cc spacing C= 0.600 #2 Primary 935.00' 10.0' long x 1.00' rise Sharp-Crested Rectangular Weir 2 End Contraction(s) 1.0' Crest Height Primary OutFlow Max=0.32 cfs @ 12.06 hrs HW=933.89' (Free Discharge) 4E1=Orifice/Grate (Orifice Controls 0.32 cfs @ 3.31 fps) 2=Sharp-Crested Rectangular Weir( Controls 0.00 cfs) Range 082, Oak Park Heights 20150713_Range 082 Type 1124-hr 1"Rainfall=1.00" Prepared by Elan Design Lab, Inc. Printed 7/15/2015 HydroCAD®10.00-13 s/n 07437 ©2014 HydroCAD Software Solutions LLC Page 9 Summary for Pond 21P: East Infiltration Basin Inflow Area = 2.263 ac, 77.38% Impervious, Inflow Depth = 0.61" for 1"event Inflow = 2.37 cfs @ 11.96 hrs, Volume= 0.116 of Outflow = 0.06 cfs @ 14.30 hrs, Volume= 0.116 af, Atten= 97%, Lag= 140.5 min Discarded = 0.06 cfs @ 14.30 hrs, Volume= 0.116 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Peak Elev= 933.58' @ 14.30 hrs Surf.Area= 5,222 sf Storage= 2,891 cf Plug-Flow detention time= 484.2 min calculated for 0.116 af(100% of inflow) Center-of-Mass det. time= 484.1 min ( 1,269.3 - 785.2 ) Volume Invert Avail.Storage Storage Description #1 933.00' 12,397 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) REQUIRED VOLUME MET AT 933.00 4,740 0 0 g34.2 934.00 5,570 5,155 5,155 935.00 8,914 7,242 12,397 ALLOW OVERFLOW AT THAT Device Routing Invert Outlet Devices ELEVATION #1 Primary 934.20' 10.0' long x 2.00' rise Sharp-Crested Rectangular Weir 2 End Contraction(s) 2.0' Crest Height #2 Discarded 933.00' 0.450 in/hr Exfiltration over Surface area ASSUMED B SOILS Conductivity to Groundwater Elevation = 928.00' iscarded OutFlow Max=0.06 cfs @ 14.30 hrs HW=933.58' (Free Discharge) 2=Exfiltration ( Controls 0.06 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=933.00' (Free Discharge) t1=Sharp-Crested Rectangular Weir( Controls 0.00 cfs) Range 082, Oak Park Heights 20150713_Range 082 Type 1124-hr 1"Rainfall=1.00" Prepared by Elan Design Lab, Inc. Printed 7/15/2015 HydroCAD®10.00-13 s/n 07437 ©2014 HydroCAD Software Solutions LLC Page 10 Summary for Pond 22P: Temp Pond Inflow Area = 2.263 ac, 77.38% Impervious, Inflow Depth = 0.66" for 1"event Inflow = 2.53 cfs @ 11.96 hrs, Volume= 0.124 af Outflow = 0.51 cfs @ 12.10 hrs, Volume= 0.124 af, Atten=80%, Lag= 8.8 min Primary = 0.51 cfs @ 12.10 hrs, Volume= 0.124 af Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Peak Elev= 935.25' @ 12.10 hrs Surf.Area=2,238 sf Storage= 2,114 cf Plug-Flow detention time= 68.7 min calculated for 0.124 af(100% of inflow) Center-of-Mass det. time= 68.6 min (859.4- 790.8 ) Volume Invert Avail.Storage Storage Description #1 934.00' 7,758 cf Custom Stage Data(Prismatic)Listed below(Recaic) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 934.00 1,170 0 0 935.00 1,990 1,580 1,580 936.00 2,970 2,480 4,060 937.00 4,425 3,698 7,758 Device Routing Invert Outlet Devices #1 Primary 934.00' 1.0"Vert. Orifice/Grate X 6.00 columns X 4 rows with 4.0"cc spacing C= 0.600 #2 Primary 936.40' 16.0' long x 1.00' rise Sharp-Crested Rectangular Weir 2 End Contraction(s) 1.0' Crest Height Primary OutFlow Max=0.51 cfs @ 12.10 hrs HW=935.25' (Free Discharge) t1=Orifice/Grate (Orifice Controls 0.51 cfs @ 3.89 fps) 2=Sharp-Crested Rectangular Weir( Controls 0.00 cfs) Range 082, Oak Park Heights 20150713_Range 082 Type 1124-hr 1"Rainfall=1.00" Prepared by Élan Design Lab, Inc. Printed 7/15/2015 HydroCAD®10.00-13 s/n 07437 ©2014 HydroCAD Software Solutions LLC Page 11 Summary for Pond 31P: CBMH 1 [57] Hint: Peaked at 938.27'(Flood elevation advised) Inflow Area = 0.063 ac, 81.82% Impervious, Inflow Depth = 0.65" for 1"event Inflow = 0.07 cfs @ 11.96 hrs, Volume= 0.003 af Outflow = 0.07 cfs @ 11.96 hrs, Volume= 0.003 af, Atten= 0%, Lag= 0.0 min Primary = 0.07 cfs @ 11.96 hrs, Volume= 0.003 af Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt=0.01 hrs Peak Elev=938.27' @ 11.96 hrs Device Routing Invert Outlet Devices #1 Primary 938.17' 24.0"Vert. Orifice/Grate C= 0.600 Primary OutFlow Max=0.07 cfs @ 11.96 hrs HW=938.27' (Free Discharge) L1=Orifice/Grate (Orifice Controls 0.07 cfs @ 1.10 fps) • Range 082, Oak Park Heights 20150713_Range 082 Type 1124-hr 2 Yr. Rainfall=2.80" Prepared by Elan Design Lab, Inc. Printed 7/15/2015 HydroCAD®10.00-13 s/n 07437 ©2014 HydroCAD Software Solutions LLC Paae 12 Summary for Subcatchment 10aS: West Basin Runoff = 3.38 cfs @ 11.96 hrs, Volume= 0.170 af, Depth= 2.12" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/lmperv.,Time Span= 0.00-72.00 hrs, dt=0.01 hrs Type II 24-hr 2 Yr. Rainfall=2.80" Area (sf) CN Description 17,260 86 Fallow, bare soil, HSG B 24,530 98 Roofs, Paved parking, HSG C 41,790 93 Weighted Average 17,260 86 41.30% Pervious Area 24,530 98 58.70% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Range 082, Oak Park Heights 20150713_Range 082 Type 1124-hr 2 Yr. Rainfall=2.80" Prepared by Elan Design Lab, Inc. Printed 7/15/2015 HydroCAD®10.00-13 s/n 07437 ©2014 HydroCAD Software Solutions LLC Pape 13 Summary for Subcatchment 10S: West Basin Runoff = 2.77 cfs @ 11.96 hrs, Volume= 0.143 af, Depth= 1.79" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/lmperv., Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type II 24-hr 2 Yr. Rainfall=2.80" Area (sf) CN Description * 17,260 72 >75% Grass cover, Good, HSG C * 24,530 98 Roofs, Paved parking, HSG C 41,790 87 Weighted Average 17,260 72 41.30% Pervious Area 24,530 98 58.70% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Range 082, Oak Park Heights 20150713_Range 082 Type 1124-hr 2 Yr. Rainfall=2.80" Prepared by Élan Design Lab, Inc. Printed 7/15/2015 HydroCAD®10.00-13 s/n 07437 ©2014 HydroCAD Software Solutions LLC Page 14 Summary for Subcatchment 20aS: East Basin Runoff = 8.54 cfs @ 11.96 hrs, Volume= 0.439 af, Depth= 2.33" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type II 24-hr 2 Yr. Rainfall=2.80" Area (sf) CN Description 22,290 86 Fallow, bare soil, HSG B 76,270 98 Roofs, Paved parking, HSG C 98,560 95 Weighted Average 22,290 86 22.62% Pervious Area 76,270 98 77.38% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Range 082, Oak Park Heights 20150713_Range 082 Type 1124-hr 2 Yr. Rainfall=2.80" Prepared by Élan Design Lab, Inc. Printed 7/15/2015 HydroCAD®10.00-13 s/n 07437 ©2014 HydroCAD Software Solutions LLC Page 15 Summary for Subcatchment 20S: East Basin Runoff = 7.75 cfs @ 11.96 hrs, Volume= 0.404 af, Depth= 2.14" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-72.00 hrs, dt=0.01 hrs Type II 24-hr 2 Yr. Rainfall=2.80" Area (sf) CN Description 22,290 72 >75% Grass cover, Good, HSG C 76,270 98 Roofs, Paved parking, HSG C 98,560 92 Weighted Average 22,290 72 22.62% Pervious Area 76,270 98 77.38% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Range 082, Oak Park Heights 20150713_Range 082 Type 1124-hr 2 Yr. Rainfall=2.80" Prepared by Élan Design Lab, Inc. Printed 7/15/2015 HydroCAD®10.00-13 s/n 07437 ©2014 HydroCAD Software Solutions LLC Page 16 Summary for Subcatchment 30S: CBMH 1 Runoff = 0.22 cfs @ 11.96 hrs, Volume= 0.012 af, Depth= 2.23" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/lmperv., Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type II 24-hr 2 Yr. Rainfall=2.80" Area (sf) CN Description 500 72 >75% Grass cover, Good, HSG C 2,250 98 Roofs, Paved parking, HSG C 2,750 93 Weighted Average 500 72 18.18% Pervious Area 2,250 98 81.82% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Range 082, Oak Park Heights 20150713_Range 082 Type 1124-hr 2 Yr. Rainfall=2.80" Prepared by Elan Design Lab, Inc. Printed 7/15/2015 HydroCAD®10.00-13 s/n 07437 ©2014 HydroCAD Software Solutions LLC Page 17 Summary for Pond 11P: West Infiltration Basin Inflow Area = 0.959 ac, 58.70% Impervious, Inflow Depth = 1.79" for 2 Yr. event Inflow = 2.77 cfs @ 11.96 hrs, Volume= 0.143 af Outflow = 2.25 cfs @ 12.00 hrs, Volume= 0.143 af, Atten= 19%, Lag=2.7 min Discarded = 0.03 cfs @ 12.00 hrs, Volume= 0.083 af Primary = 2.22 cfs @ 12.00 hrs, Volume= 0.060 af Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Peak Elev= 934.26' @ 12.00 hrs Surf.Area=2,429 sf Storage= 2,335 cf Plug-Flow detention time= 471.1 min calculated for 0.143 af(100%of inflow) Center-of-Mass det. time= 471.2 min ( 1,244.9-773.7 ) Volume Invert Avail.Storage Storage Description #1 933.00' 4,468 cf Custom Stage Data(Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Gum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 933.00 1,385 0 0 934.00 2,090 1,738 1,738 935.00 3,370 2,730 4,468 Device Routing Invert Outlet Devices #1 Primary 934.10' 10.0' long x 1.00' rise Sharp-Crested Rectangular Weir 2 End Contraction(s) 1.0' Crest Height #2 Discarded 933.00' 0.450 in/hr Exfiltration over Surface area Conductivity to Groundwater Elevation = 928.00' Qiscarded OutFlow Max=0.03 cfs @ 12.00 hrs HW=934.26' (Free Discharge) 2=Exfiltration ( Controls 0.03 cfs) Primary OutFlow Max=2.21 cfs @ 12.00 hrs HW=934.26' (Free Discharge) 'L1=Sharp-Crested Rectangular Weir(Weir Controls 2.21 cfs @ 1.35 fps) 20150713_Range 082 Type 1124-hr 2 Yr. Rainfall=2.80" Prepared by Elan Design Lab, Inc. Printed 7/20/2015 HydroCAD®10.00-13 s/n 07437 ©2014 HydroCAD Software Solutions LLC Page 18 Summary for Pond 12P: Temp. Pond Inflow Area = 0.959 ac, 58.70% Impervious, Inflow Depth = 2.12" for 2 Yr. event Inflow = 3.38 cfs @ 11.96 hrs, Volume= 0.170 af Outflow = 2.25 cfs @ 12.02 hrs, Volume= 0.166 af, Atten= 33%, Lag= 3.9 min Primary = 2.25 cfs @ 12.02 hrs, Volume= 0.166 af Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Peak Elev= 935.12' @ 12.02 hrs Surf.Area= 1,697 sf Storage= 2,242 cf Plug-Flow detention time= 53.4 min calculated for 0.166 af(98% of inflow) Center-of-Mass det.time= 38.6 min ( 813.5-774.8 ) Volume Invert Avail.Storage Storage Description #1 932.00' 2,963 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 932.00 0 0 0 933.00 345 173 173 934.00 920 633 805 935.00 1,550 1,235 2,040 935.50 2,140 923 2,963 Device Routing Invert Outlet Devices #1 Primary 933.00' 1.0"Vert. Orifice/Grate X 6.00 columns X 4 rows with 4.0" cc spacing C= 0.600 #2 Primary 935.00' 10.0' long x 1.00' rise Sharp-Crested Rectangular Weir 2 End Contraction(s) 1.0' Crest Height Primary OutFlow Max=2.23 cfs @ 12.02 hrs HW=935.12' (Free Discharge) -1=Orifice/Grate (Orifice Controls 0.79 cfs @ 6.01 fps) 2=Sharp-Crested Rectangular Weir(Weir Controls 1.44 cfs @ 1.17 fps) Range 082, Oak Park Heights 20150713_Range 082 Type 1124-hr 2 Yr. Rainfall=2.80" Prepared by Elan Design Lab, Inc. Printed 7/15/2015 HydroCAD®10.00-13 s/n 07437 ©2014 HydroCAD Software Solutions LLC Page 19 Summary for Pond 21 P: East Infiltration Basin Inflow Area = 2.263 ac, 77.38% Impervious, Inflow Depth = 2.14" for 2 Yr. event Inflow = 7.75 cfs @ 11.96 hrs, Volume= 0.404 af Outflow = 3.90 cfs @ 12.04 hrs, Volume= 0.404 af, Atten= 50%, Lag= 5.0 min Discarded = 0.09 cfs @ 12.04 hrs, Volume= 0.256 af Primary = 3.81 cfs @ 12.04 hrs, Volume= 0.148 af Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Peak Elev= 934.44' @ 12.04 hrs Surf.Area= 7,031 sf Storage= 7,908 cf Plug-Flow detention time= 565.4 min calculated for 0.404 af(100% of inflow) Center-of-Mass det. time= 565.4 min ( 1,328.7-763.3 ) Volume Invert Avail.Storage Storage Description #1 933.00' 12,397 cf Custom Stage Data(Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 933.00 4,740 0 0 934.00 5,570 5,155 5,155 935.00 8,914 7,242 12,397 Device Routing Invert Outlet Devices #1 Primary 934.20' 10.0' long x 2.00' rise Sharp-Crested Rectangular Weir 2 End Contraction(s) 2.0' Crest Height #2 Discarded 933.00' 0.450 in/hr Exfiltration over Surface area Conductivity to Groundwater Elevation = 928.00' Qiscarded OutFlow Max=0.09 cfs @ 12.04 hrs HW=934.44' (Free Discharge) 2=Exfiltration ( Controls 0.09 cfs) Primary OutFlow Max=3.80 cfs @ 12.04 hrs HW=934.44' (Free Discharge) L1=Sharp-Crested Rectangular Weir(Weir Controls 3.80 cfs @ 1.61 fps) Range 082, Oak Park Heights 20150713_Range 082 Type 1124-hr 2 Yr. Rainfall=2.80" Prepared by Elan Design Lab, Inc. Printed 7/15/2015 HydroCAD®10.00-13 s/n 07437 ©2014 HydroCAD Software Solutions LLC Page 20 Summary for Pond 22P: Temp Pond Inflow Area = 2.263 ac, 77.38% Impervious, Inflow Depth = 2.33" for 2 Yr. event Inflow = 8.54 cfs @ 11.96 hrs, Volume= 0.439 af Outflow = 6.59 cfs @ 12.01 hrs, Volume= 0.439 af, Atten= 23%, Lag= 3.1 min Primary = 6.59 cfs @ 12.01 hrs, Volume= 0.439 af Routing by Stor-Ind method, Time Span=0.00-72.00 hrs, dt= 0.01 hrs Peak Elev= 936.62' @ 12.01 hrs Surf.Area=3,878 sf Storage=6,196 cf Plug-Flow detention time= 70.1 min calculated for 0.438 af(100% of inflow) Center-of-Mass det. time= 70.1 min ( 834.8- 764.7 ) Volume Invert Avail.Storage Storage Description #1 934.00' 7,758 cf Custom Stage Data (Prismatic)Listed below(Recalc) Elevation Surf.Area Inc.Store Gum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 934.00 1,170 0 0 935.00 1,990 1,580 1,580 936.00 2,970 2,480 4,060 937.00 4,425 3,698 7,758 Device Routing Invert Outlet Devices #1 Primary 934.00' 1.0"Vert. Orifice/Grate X 6.00 columns X 4 rows with 4.0"cc spacing C= 0.600 #2 Primary 936.40' 16.0' long x 1.00' rise Sharp-Crested Rectangular Weir 2 End Contraction(s) 1.0' Crest Height Primary OutFlow Max=6.57 cfs @ 12.01 hrs HW=936.62' (Free Discharge) 11=Orifice/Grate (Orifice Controls 0.91 cfs @ 6.92 fps) 2=Sharp-Crested Rectangular Weir(Weir Controls 5.66 cfs @ 1.59 fps) Range 082, Oak Park Heights 20150713_Range 082 Type 1124-hr 2 Yr. Rainfall=2.80" Prepared by Elan Design Lab, Inc. Printed 7/15/2015 HydroCAD®10.00-13 s/n 07437 ©2014 HydroCAD Software Solutions LLC Page 21 Summary for Pond 31P: CBMH 1 [57] Hint: Peaked at 938.36' (Flood elevation advised) Inflow Area = 0.063 ac, 81.82% Impervious, Inflow Depth = 2.23" for 2 Yr. event Inflow = 0.22 cfs @ 11.96 hrs, Volume= 0.012 af Outflow = 0.22 cfs @ 11.96 hrs, Volume= 0.012 af, Atten=0%, Lag= 0.0 min Primary = 0.22 cfs @ 11.96 hrs, Volume= 0.012 af Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Peak Elev= 938.36' @ 11.96 hrs Device Routing Invert Outlet Devices #1 Primary 938.17' 24.0"Veil. Orifice/Grate C= 0.600 Primary OutFlow Max=0.22 cfs @ 11.96 hrs HW=938.36' (Free Discharge) t1=Orifice/Grate (Orifice Controls 0.22 cfs @ 1.48 fps) Range 082, Oak Park Heights 20150713_Range 082 Type 1124-hr 10 Yr. Rainfall=4.20" Prepared by Elan Design Lab, Inc. Printed 7/15/2015 HydroCAD®10.00-13 s/n 07437 ©2014 HydroCAD Software Solutions LLC Page 23 Summary for Subcatchment 10S: West Basin Runoff = 4.64 cfs @ 11.96 hrs, Volume= 0.239 af, Depth= 2.99" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span=0.00-72.00 hrs, dt= 0.01 hrs Type II 24-hr 10 Yr. Rainfall=4.20" Area (sf) CN Description 17,260 72 >75% Grass cover, Good, HSG C 24,530 98 Roofs, Paved parking, HSG C 41,790 87 Weighted Average 17,260 72 41.30% Pervious Area 24,530 98 58.70% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, • Range 082, Oak Park Heights 20150713_Range 082 Type 1124-hr 10 Yr. Rainfall=4.20" Prepared by Elan Design Lab, Inc. Printed 7/15/2015 HydroCAD®10.00-13 s/n 07437 ©2014 HydroCAD Software Solutions LLC Page 25 Summary for Subcatchment 20S: East Basin Runoff = 12.29 cfs @ 11.96 hrs, Volume= 0.647 af, Depth= 3.43" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type II 24-hr 10 Yr. Rainfall=4.20" Area (sf) CN Description 22,290 72 >75% Grass cover, Good, HSG C 76,270 98 Roofs, Paved parking, HSG C 98,560 92 Weighted Average 22,290 72 22.62% Pervious Area 76,270 98 77.38% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Range 082, Oak Park Heights 20150713_Range 082 Type 1124-hr 10 Yr. Rainfall=4.20" Prepared by Elan Design Lab, Inc. Printed 7/15/2015 HydroCAD®10.00-13 s/n 07437 ©2014 HydroCAD Software Solutions LLC Page 26 Summary for Subcatchment 30S: CBMH 1 Runoff = 0.35 cfs @ 11.96 hrs, Volume= 0.019 af, Depth= 3.54" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type II 24-hr 10 Yr. Rainfall=4.20" Area (sf) CN Description 500 72 >75% Grass cover, Good, HSG C 2,250 98 Roofs, Paved parking, HSG C 2,750 93 Weighted Average 500 72 18.18% Pervious Area 2,250 98 81.82% Impervious Area Tc Length Slope Velocity Capacity Description (mint (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Range 082, Oak Park Heights 20150713_Range 082 Type 1124-hr 10 Yr. Rainfall=4.20" Prepared by Elan Design Lab, Inc. Printed 7/15/2015 HydroCAD®10.00-13 s/n 07437 ©2014 HydroCAD Software Solutions LLC Page 27 Summary for Pond 11P: West Infiltration Basin Inflow Area = 0.959 ac, 58.70% Impervious, Inflow Depth = 2.99" for 10 Yr. event Inflow = 4.64 cfs @ 11.96 hrs, Volume= 0.239 af Outflow = 4.41 cfs @ 11.98 hrs, Volume= 0.239 af, Atten= 5%, Lag= 1.3 min Discarded = 0.03 cfs @ 11.98 hrs, Volume= 0.086 af Primary = 4.38 cfs @ 11.98 hrs, Volume= 0.153 af Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt=0.01 hrs Peak Elev= 934.36' @ 11.98 hrs Surf.Area= 2,547 sf Storage= 2,565 cf Plug-Flow detention time= 298.5 min calculated for 0.239 af(100% of inflow) Center-of-Mass det. time= 298.7 min ( 1,067.3-768.6 ) Volume Invert Avail.Storage Storage Description #1 933.00' 4,468 cf Custom Stage Data(Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 933.00 1,385 0 0 934.00 2,090 1,738 1,738 935.00 3,370 2,730 4,468 Device Routing Invert Outlet Devices #1 Primary 934.10' 10.0' long x 1.00' rise Sharp-Crested Rectangular Weir 2 End Contraction(s) 1.0'Crest Height #2 Discarded 933.00' 0.450 in/hr Exfiltration over Surface area Conductivity to Groundwater Elevation = 928.00' Qiscarded OutFlow Max=0.03 cfs @ 11.98 hrs HW=934.36' (Free Discharge) 2=Exfiltration ( Controls 0.03 cfs) Primary OutFlow Max=4.37 cfs @ 11.98 hrs HW=934.36' (Free Discharge) t-1=Sharp-Crested Rectangular Weir(Weir Controls 4.37 cfs @ 1.71 fps) Range 082, Oak Park Heights 20150713_Range 082 Type 1124-hr 10 Yr. Rainfall=4.20" Prepared by Elan Design Lab, Inc. Printed 7/15/2015 HydroCAD®10.00-13 s/n 07437 ©2014 HydroCAD Software Solutions LLC Page 29 Summary for Pond 21P: East Infiltration Basin Inflow Area = 2.263 ac, 77.38% Impervious, Inflow Depth = 3.43" for 10 Yr. event Inflow = 12.29 cfs @ 11.96 hrs, Volume= 0.647 af Outflow = 10.20 cfs @ 12.00 hrs, Volume= 0.647 af, Atten= 17%, Lag=2.6 min Discarded = 0.10 cfs @ 12.00 hrs, Volume= 0.268 af Primary = 10.10 cfs @ 12.00 hrs, Volume= 0.378 af Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Peak Elev= 934.65' @ 12.00 hrs Surf.Area= 7,747 sf Storage= 9,491 cf Plug-Flow detention time= 378.2 min calculated for 0.647 af(100%of inflow) Center-of-Mass det. time= 378.2 min ( 1,135.0 -756.8 ) Volume Invert Avail.Storage Storage Description #1 933.00' 12,397 cf Custom Stage Data(Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 933.00 4,740 0 0 934.00 5,570 5,155 5,155 935.00 8,914 7,242 12,397 Device Routing Invert Outlet Devices #1 Primary 934.20' 10.0' long x 2.00' rise Sharp-Crested Rectangular Weir 2 End Contraction(s) 2.0' Crest Height #2 Discarded 933.00' 0.450 in/hr Exfiltration over Surface area Conductivity to Groundwater Elevation = 928.00' 4iscarded OutFlow Max=0.10 cfs @ 12.00 hrs HW=934.65' (Free Discharge) 2=Exfiltration ( Controls 0.10 cfs) Primary OutFlow Max=10.09 cfs @ 12.00 hrs HW=934.65' (Free Discharge) L1=Sharp-Crested Rectangular Weir(Weir Controls 10.09 cfs @ 2.26 fps) Range 082, Oak Park Heights 20150713_Range 082 Type 1124-hr 10 Yr. Rainfall=4.20" Prepared by Elan Design Lab, Inc. Printed 7/15/2015 HydroCAD®10.00-13 s/n 07437 ©2014 HydroCAD Software Solutions LLC Page 31 Summary for Pond 31P: CBMH 1 [57] Hint: Peaked at 938.41' (Flood elevation advised) Inflow Area = 0.063 ac, 81.82% Impervious, Inflow Depth = 3.54" for 10 Yr. event Inflow = 0.35 cfs @ 11.96 hrs, Volume= 0.019 af Outflow = 0.35 cfs @ 11.96 hrs, Volume= 0.019 af, Atten= 0%, Lag= 0.0 min Primary = 0.35 cfs @ 11.96 hrs, Volume= 0.019 af Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Peak Elev= 938.41' @ 11.96 hrs Device Routing Invert Outlet Devices #1 Primary 938.17' 24.0"Vert. Orifice/Grate C= 0.600 Primary OutFlow Max=0.35 cfs @ 11.96 hrs HW=938.41' (Free Discharge) L1=Orifice/Grate (Orifice Controls 0.35 cfs @ 1.66 fps) Range 082, Oak Park Heights 20150713_Range 082 Type 1124-hr 100 Yr. Rainfall=7.20" Prepared by Élan Design Lab, Inc. Printed 7/15/2015 HydroCAD®10.00-13 s/n 07437 ©2014 HydroCAD Software Solutions LLC Page 32 Summary for Subcatchment 10aS: West Basin Runoff = 9.77 cfs @ 11.96 hrs, Volume= 0.510 af, Depth= 6.38" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type II 24-hr 100 Yr. Rainfall=7.20" Area (sf) CN Description 17,260 86 Fallow, bare soil, HSG B 24,530 98 Roofs, Paved parking, HSG C 41,790 93 Weighted Average 17,260 86 41.30% Pervious Area 24,530 98 58.70% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Range 082, Oak Park Heights 20150713_Range 082 Type 1124-hr 100 Yr. Rainfall=7.20" Prepared by Elan Design Lab, Inc. Printed 7/15/2015 HydroCAD®10.00-13 s/n 07437 ©2014 HydroCAD Software Solutions LLC Page 33 Summary for Subcatchment 10S: West Basin Runoff = 8.88 cfs @ 11.96 hrs, Volume= 0.459 af, Depth= 5.74" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/lmperv., Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type II 24-hr 100 Yr. Rainfall=7.20" Area (sf) CN Description * 17,260 72 >75% Grass cover, Good, HSG C * 24,530 98 Roofs, Paved parking, HSG C 41,790 87 Weighted Average 17,260 72 41.30% Pervious Area 24,530 98 58.70% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Range 082, Oak Park Heights 20150713_Range 082 Type 1124-hr 100 Yr. Rainfall=7.20" Prepared by Elan Design Lab, Inc. Printed 7/15/2015 HydroCAD®10.00-13 s/n 07437 ©2014 HydroCAD Software Solutions LLC Page 35 Summary for Subcatchment 20S: East Basin Runoff = 22.32 cfs @ 11.96 hrs, Volume= 1.186 af, Depth= 6.29" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Type II 24-hr 100 Yr. Rainfall=7.20" Area (sf) CN Description 22,290 72 >75% Grass cover, Good, HSG C 76,270 98 Roofs, Paved parking, HSG C 98,560 92 Weighted Average 22,290 72 22.62% Pervious Area 76,270 98 77.38% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, II Range 082, Oak Park Heights 20150713_Range 082 Type 1124-hr 100 Yr. Rainfall=7.20" Prepared by Elan Design Lab, Inc. Printed 7/15/2015 HydroCAD®10.00-13 s/n 07437 ©2014 HydroCAD Software Solutions LLC Page 36 Summary for Subcatchment 30S: CBMH 1 Runoff = 0.63 cfs @ 11.96 hrs, Volume= 0.034 af, Depth= 6.42" Runoff by SCS TR-20 method, UH=SCS, Split Pervious/Imperv., Time Span=0.00-72.00 hrs, dt= 0.01 hrs Type II 24-hr 100 Yr. Rainfall=7.20" Area (sf) CN Description * 500 72 >75% Grass cover, Good, HSG C * 2,250 98 Roofs, Paved parking, HSG C 2,750 93 Weighted Average 500 72 18.18% Pervious Area 2,250 98 81.82% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Range 082, Oak Park Heights 20150713_Range 082 Type 1124-hr 100 Yr. Rainfall=7.20" Prepared by Elan Design Lab, Inc. Printed 7/15/2015 HydroCAD®10.00-13 s/n 07437 ©2014 HydroCAD Software Solutions LLC Page 37 Summary for Pond 11P: West Infiltration Basin Inflow Area = 0.959 ac, 58.70% Impervious, Inflow Depth = 5.74" for 100 Yr. event Inflow = 8.88 cfs @ 11.96 hrs, Volume= 0.459 af Outflow = 8.55 cfs @ 11.98 hrs, Volume= 0.459 af, Atten= 4%, Lag= 1.2 min Discarded = 0.03 cfs @ 11.98 hrs, Volume= 0.091 af Primary = 8.51 cfs @ 11.98 hrs, Volume= 0.368 af ELEVATION DROPS TO 934.1 Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs pT THE END OF STORM Peak Elev= 934.50' @ 11.98 hrs Surf.Area= 2,726 sf Storage= 2,935 c1' (HOUR 24) AND DRAINS DRY Plug-Flow detention time= 172.1 min calculated for 0.459 af(100% of in �v�)HOUR 52 28 HOURS Center-of-Mass det. time= 172.1 min ( 933.6 - 761.5 ) ) Volume Invert Avail.Storage Storage Description #1 933.00' 4,468 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 933.00 1,385 0 0 934.00 2.090 1,738 1,738 935.00 3.370 2,730 4,468 Device Routing Invert Outlet Devices #1 Primary 934.10' 10.0' long x 1.00' rise Sharp-Crested Rectangular Weir 2 End Contraction(s) 1.0' Crest Height #2 Discarded 933.00' 0.450 in/hr Exfiltration over Surface area Conductivity to Groundwater Elevation = 928.00' 4iscarded OutFlow Max=0.03 cfs @ 11.98 hrs HW=934.50' (Free Discharge) '-2=Exfiltration ( Controls 0.03 cfs) Primary OutFlow Max=8.50 cfs @ 11.98 hrs HW=934.50' (Free Discharge) L1=Sharp-Crested Rectangular Weir(Weir Controls 8.50 cfs @ 2.16 fps) Range 082, Oak Park Heights 20150713_Range 082 Type II 24-hr 100 Yr. Rainfall=7.20" Prepared by Elan Design Lab, Inc. Printed 7/15/2015 HydroCAD®10.00-13 s/n 07437 ©2014 HydroCAD Software Solutions LLC Page 39 Summary for Pond 21P: East Infiltration Basin Inflow Area = 2.263 ac, 77.38% Impervious, Inflow Depth = 6.29" for 100 Yr. event Inflow = 22.32 cfs @ 11.96 hrs, Volume= 1.186 of Outflow = 19.52 cfs @ 11.99 hrs, Volume= 1.186 af, Atten= 13%, Lag= 2.2 min Discarded = 0.11 cfs @ 11.99 hrs, Volume= 0.281 af ELEVATION DROPS TO 934.2 Primary = 19.41 cfs @ 11.99 hrs, Volume= 0.905 af AT THE END OF STORM Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs HOUR 24) AND DRAINS DRY Peak Elev= 934.89' @ 11.99 hrs Surf.Area= 8,557 sf Storage= 11,466 c AT HOUR 52 (30 HOURS) Plug-Flow detention time= 228.4 min calculated for 1.186 af(100% of inflow) Center-of-Mass det. time= 228.3 min ( 977.8- 749.5 ) Volume Invert Avail.Storage Storage Description #1 933.00' 12,397 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 933.00 4,740 0 0 934.00 5,570 5,155 5,155 935.00 8,914 7,242 12,397 Device Routing Invert Outlet Devices #1 Primary 934.20' 10.0' long x 2.00' rise Sharp-Crested Rectangular Weir 2 End Contraction(s) 2.0' Crest Height #2 Discarded 933.00' 0.450 in/hr Exfiltration over Surface area Conductivity to Groundwater Elevation = 928.00' 4iscarded OutFlow Max=0.11 cfs @ 11.99 hrs HW=934.89' (Free Discharge) 2=Exfiltration ( Controls 0.11 cfs) Primary OutFlow Max=19.38 cfs @ 11.99 hrs HW=934.89' (Free Discharge) L1=Sharp-Crested Rectangular Weir(Weir Controls 19.38 cfs @ 2.84 fps) Range 082, Oak Park Heights 20150713_Range 082 Type 1124-hr 100 Yr. Rainfall=7.20" Prepared by Elan Design Lab, Inc. Printed 7/15/2015 HydroCAD®10.00-13 s/n 07437 ©2014 HydroCAD Software Solutions LLC Page 41 Summary for Pond 31P: CBMH 1 [57] Hint: Peaked at 938.49'(Flood elevation advised) Inflow Area = 0.063 ac, 81.82% Impervious, Inflow Depth = 6.42" for 100 Yr. event Inflow = 0.63 cfs @ 11.96 hrs, Volume= 0.034 af Outflow = 0.63 cfs @ 11.96 hrs, Volume= 0.034 af, Atten= 0%, Lag= 0.0 min Primary = 0.63 cfs @ 11.96 hrs, Volume= 0.034 af Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs Peak Elev= 938.49' @ 11.96 hrs Device Routing Invert Outlet Devices #1 Primary 938.17' 24.0"Vert. Orifice/Grate C= 0.600 Primary OutFlow Max=0.63 cfs @ 11.96 hrs HW=938.49' (Free Discharge) ,Primary (Orifice Controls 0.63 cfs @ 1.93 fps) u, aI 1 1 1 1 ' '- Y &IYZw xw N J 1 �i, e !L ii - e $L- m� 1+�.10 �O cc 9 Z Qr 11 I • a e.vaa„2yO 1 i d w'u3"�� �w ^_k' 08 In aFc� o 5 ■ as€-t 7, a d g Z0-4`a3_ F2 f=i O0Oii WLr.r. 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