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HomeMy WebLinkAboutStudies APPLICANT 7/12/2021 (2)A & O Engineering LLC Civil Engineering & Site Planning Drainage Memorandum Prepared Br. Lucas Becia, EIT Reviewed By. Scott Morris, PE Date: Re: 11/12/2020 0 Digitally signed by Scott Scott Morris, PE Data 2020.11.12 Morris, E14:41:23-08'00' Storm Drainage Design for Ridgeview Gardens Apartments, Springfield, Oregon Overview This storm analysis is for an apartment complex located at 5050 Main Street in Springfield, Oregon. The proposed 1.98 -acre development includes 3 multi -family residential apartment buildings, an office, and parking lot. The existing shared driveway is proposed to keep its natural drainage pattern. The roof drainage from the 3 apartments are proposed to be directed to individual rain gardens on the property. The main outlet of each rain garden is infiltration with overflow for the 2 -25 -year events being directed to the existing 42" storm line in Main Street. The rain gardens will provide some level of detention as well as filtration for the water quality storm event before stormwater enters the public drainage system. The existing 42' storm line in Main street is around 9 feet down allowing adequate depth for connection of overflows from the site. Site Soils The site is within the 99 -year time of travel wellhead zone and requires that the rain gardens have at least 12" of growing media for stonnwater entering ground. PBS Engineering performed two infiltration tests (open -hole, falling -head) at the site on September 9' , 2020. The infiltration rate for the test pit at the north end (TP -2) was used for Rain Gardens #1-3. The infiltration rate at the south end (TP -7) of the site was used for Rain Garden #4. Groundwater was encountered at 11 feet below ground surface. The northern test pit had an infiltration rate of 4.5 in/hr and the southern test pit was 2.1 in/hr. With a factor of safety of 2.0 being applied, infiltration rates of 2.25 and 1.05 in/hr were used respectively in rain garden design. Storm Design The rain gardens are designed to process drainage from the 3 apartment roofs, the office, and the main parking lot area, with rain garden #4 being for the surrounding parking lot only. All rain gardens are designed as infiltration and flow control facilities. The primary outlet is infiltration with an assumed infiltration rate of 2.25 in/hr for rain gardens 1-3, and 1.05 in/hr for rain garden #4 in the center of the parking area. All rain gardens have a 4" standpipe that is designed to convey stormwater overflow for larger storm events (2 -25 -year) to the existing public system within Main street. The small northern parking lot area (approx. 4500 SF) will be treated via dual chambered catch basin with fossil filter insert. All stormwater facilities direct flow to the existing public system in Main Street via a 8" pipe. The rain garden dimensions were designed with the following variables: Draina a Area Impervious Area (sq -ft) CN Parking lot 25,254 98 Apt #1 7758 98 Apt #2 7,758 98 Apt #3 7.758 98 North Parking 5,609 98 Existing Conditions: Description Area CN HydroCAD (Acres) Value Node Grassland HSG C 1.98 79 7S Water quality Storm = 0.83 inches in 24 hours 2 -Year Design storm = 3.3 inches in 24 hours 25 -Year Storm = 4.80 Inches in 24 hours. The analysis was completed utilizing HydroCAD software, the Santa Barbara Urban Hydrograph runoff method. The calculation sheets are attached, and the analysis results outlined in the table above. Rainfall Event Existing Flow Post Construction Peak Flow Top Bottom Max Water Drawdown 0.44 0.09 0.55 Elevation Elevation Elevation Time of of Rock during for Surface Area Side Chamber Chamber design Facility (Sq -ft) slope (ft) (ft) storm (k) (Hours) Rain 3:1 642 500.00 496.00 499.06 24.6 Garden #1 Rain 211 500.00 496.00 499.03 24.8 Garden #2 3:1 Rain 438 500.00 496.00 498.65 26.5 Garden #3 3:1 Rain Garden #4 1,544 3:1 498.83 494.53 497.96 30 The analysis was completed utilizing HydroCAD software, the Santa Barbara Urban Hydrograph runoff method. The calculation sheets are attached, and the analysis results outlined in the table above. Rainfall Event Existing Flow Post Construction Peak Flow Paved Area (cfs) (cfs) 2 -Year 0.44 0.09 0.55 25 -Year 0.93 Driveway Areas on Site Stormwater from the existing shared driveway will not change its existing drainage pattern and therefore was not included in the calculations. The north portion of the parking lot is being treated via dual chambered catch basin with oil filter insert. This meets the criteria of at least 50% of non -building impervious surfaces being treated vegetatively. Square Percentage Paved Area feet (q) Primary 25,254 84.85 North 15.15 4,509 Conclusion For the storm events analyzed, the rain gardens are adequately sized to fully infiltrate the water quality storm event. For storm events 2-25 year, the rain gardens will overflow and be conveyed to the existing 42" public storm line in Main Street. The storm line in Main street is approximately 9 feet deep, allowing the overflow from the site to be tied into it. The post construction peak flows are at or below the existing peak flows on site for all analyzed storm events. The analysis shows the storm system for the development is adequately sized for the water quality storm event, with a drawdown time that meets code and will not cause problems in the downstream system. Water surface levels in all facilities are below top of bank during analyzed storm events. Therefore, the proposed system does not create any safety concerns for property or persons. Attachments 1. HydroCAD Calculations 7$ Existing Conditions Npa#ment#1 NoM Rain Gahm kt A' Satan Subcat Reach Aw Link `8$ BlwagGPwe 145. Pa ""Ill sli 11 %1 S.\ Q�(� 16 12 Ppanmenl 93 NOM Rain GaNet 92 J/ PeAI�C Lol Rain Garden #3 Oue. hounder GB `4$ % vl naanmem z -P � Ran G�men I �\. c5 �t�j Q p Npa#ment#1 NoM Rain Gahm kt A' Satan Subcat Reach Aw Link Designed By: LAB Ridgeview Apartements Storm Analysis Type /A 24 -hr 2 Year Rainfall=3.30" Prepared by Olson & Morris Printed 11/12/2020 HydroCAD010.00-25 s/n 04993 Q2019 HydroCAD Software Solutions LLC Page 2 Summary for Subcatchment 1S: Parking Lot Runoff = 0.43 cis @ 7.98 hrs, Volume= 0.148 af, Depth= 3.07" Runoff by SBUH method, Split Pervious/Imperv., Time Span= 0.00-50.00 hrs, dt= 0.05 hrs Type IA 24 -hr 2 Year Rainfall=3.30" Tc Length Slope Velocity Capacity Description (min) (feet) (f /ft) (ft/sec) (cfs) 10.0 Direct Entry, Subcatchment 1S: Parking Lot Hydrograph 5 10 1 Time (hours) — Runoff 0.4. Type IA 24 -hr 0.35.2 Year Rainfall=3.30" Runoff Area=25,254 sf 0.3: w Runoff Volume=0.148 of 0.25: Runoff Depth=3.07" 3 0.2. Tc=10.0 min 0.15: - CN=0/98 0.1-1- 5 10 1 Time (hours) — Runoff Designed By: LAB Ridgeview Apartements Storm Analysis Type IA 24 -hr 2 Year Rainfall=3.30" Prepared by Olson & Morris Printed 11/12/2020 HydroCAD010.00-25 s/n 04993 02019 HydroCAD Software Solutions LLC Pane 3 Summary for Subcatchment 3S: Apartment #3 Runoff = 0.13 cfs @ 7.98 hrs, Volume= 0.046 af, Depth= 3.07' Runoff by SBUH method, Split Pervious/Imperv., Time Span= 0.00-50.00 hrs, dt= 0.05 hrs Type IA 24 -hr 2 Year Rainfall=3.30" Area (sf) CN Description 7,758 98 Unconnected roofs, HSG B 7,758 98 100.00% Impervious Area Tc Length Slope Velocity Capacity Description /minl /f..fl !ftlHl /R/.Pn1 lcfsl 10.0 Direct Entry, Subcatchment 3S: Apartment #3 Hydrograph 0.14 0.13 cfs —Runoff 0.12 Type lA 24 -hr 2 Year Rainfall=3.30" 0.1 _ Runoff Area=7,758 sf 0.08. Runoff Volume=0.046 of Runoff Depth=3.07" LL 0.06 Tc=10.0 min CN=0/98 0 5 10 15 20 25 30 35 40 45 50 Time (hours) Designed By: LAB Ridgeview Apartements Storm Analysis Type /A 24 -hr 2 Year Rainfall=3.30" Prepared by Olson & Morris Printed 11/12/2020 HydroCAD®10.00-25 s/n 04993 © 2019 HVdroCAD Software Solutions LLC page 4 Summary for Subcatchment 4S: Apartment #2 Runoff = 0.13 cfs @ 7.98 hrs, Volume= 0.046 af, Depth= 3.07" Runoff by SBUH method, Split Pervious/lmperv., Time Span= 0.00-50.00 hrs, dt= 0.05 hrs Type IA 24 -hr 2 Year Rainfall=3.30" Area (sf) CN Description 7,758 98 Unconnected roofs, HSG B 7,758 98 100.00% Impervious Area Tc Length Slope Velocity Capacity Description fminl lfpPtl /ff/ffl fftfccrl mel Direct Entry, Subcatchment 4S: Apartment #2 Hydrograph 0.14-1 1 0.13 cfs 0.12-- Type IA 24 -hr 2 Year Rainfal1=3.30" 0.1- Runoff - Area=7,758 sf ;-3I I Runoff Volume=0.046 of 0.08. Runoff De th=3.07" LL 0.06 - Tc=10.0 min CN=0/98 0 5 10 15 20 25 30 35 40 45 50 Time (hours) F --Runoff Designed By: LAB Ridgeview Apartements Storm Analysis Type /A 24 -hr 2 YearRainfall=3.30" Prepared by Olson & Morris Printed 11/12/2020 HydroCAD®10.00-25 s/n 04993 C2019 HydroCAD Software Solutions LLC Page 5 Summary for Subcatchment 5S: Apartment #1 Runoff = 0.13 cfs @ 7.98 hrs, Volume= 0.046 af, Depth= 3.07' Runoff by SBUH method, Split Pervious/lmperv., Time Span= 0.00-50.00 hrs, dt= 0.05 hrs Type IA 24 -hr 2 Year Rainfall=3.30" Area (sf) CN Description 7,758 98 Unconnected roofs, HSG B 7,758 98 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.0 Direct Entry, Subcatchment 5S: Apartment #1 Hydrograph 0.14- 0.13 cfs ULA Q 0.1 0.08 LL 0.061 11 0.02-1 Type IA 24 -hr 2 Year Rainfall=3.30" Runoff Area=7,758 sf Runoff Volume=0.046 of Runoff Depth=3.07" Tc=10.0 min CN=0/98 0 5 10 15 20 25 30 35 40 45 50 Time (hours) Designed By: LAB Ridgeview Apartements Storm Analysis Type IA 24 -hr 2 YearRainfall=3.30" Prepared by Olson & Morris Printed 11/12/2020 HydroCAD®10.00-25 s/n 04993 02019 HydroCAD Software Solutions LLC Paae 6 Summary for Subcatchment 7S: Existing Conditions Runoff = 0.44 cfs @ 8.07 hrs, Volume= 0.233 af, Depth= 1.41" Runoff by SBUH method, Split Pervious/Imperv., Time Span= 0.00-50.00 hrs, dt= 0.05 hrs Type IA 24 -hr 2 Year Rainfall=3.30" Tc Length Slope min) (feet) (ftift) 25.1 234 0.0100 Area Description 0.16 Sheet Flow, Grass:Short n=0.150 P2=3.30" Subcatchment 7S: Existing Conditions Hydrograph — Runoff 0 5 10 15 20 25 30 35 40 Time (hours) 0.4= Type IA 24 -hr 0.35 ' 2 Year Rainfall=3.30" Runoff 'Area=1.984 ac w 0.3 Runoff Volume=0.233 of u Runoff Depth=1.41" ri0.25- 0.2- - - - --Flow-Length=234' 0.15 Slope=0.0100 T 0.1: Tc=25.1 min CN=79/0 0.05' 0 5 10 15 20 25 30 35 40 Time (hours) Designed By: LAB Ridgeview Apartements Storm Analysis Type IA 24 -hr 2 YearRatnfall=3.30" Prepared by Olson & Morris Printed 11/12/2020 HydroCAD010.00-25 s/n 04993 @2019 HydroCAD Software Solutions LLC Pace 7 Summary for Subcatchment 8S: Storage/Office Runoff = 0.02 cfs @ 7.98 hrs, Volume= 0.008 af, Depth= 3.07' Runoff by SBUH method, Split Pervious/Imperv., Time Span= 0.00-50.00 hrs, dt= 0.05 hrs Type IA 24 -hr 2 Year Rainfall=3.30" 1,288 98 Unconnected roofs, HSG B 1,288 98 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (ofs) 10.0 Direct Entry, Subcatchment 8S: Storage/Office Hydrograph 0.022 UZII- 0..02 cfs 0.022—Runoff 0 5 10 15 20 25 30 35 40 45 50 Time (hours) 0.02 Type IA 24 -hr 0.018 2 Year Rainfall=3.30" 0.016 Runoff Area=1,288 sf Runoff Volume=0.008 of v 0.014- Runoff Depth=3.07' 0.012. Tc=10.0'min —°� 0.01 CN=0/98 0.008.- 0 5 10 15 20 25 30 35 40 45 50 Time (hours) Designed By: LAB RidgeviewApartements Storm Analysis Type /A 24 -hr 2 YearRainfall=3.30" Prepared by Olson & Morris Printed 11/12/2020 HydroCAD510.00-25 s/n 04993 © 2019 HydroCAD Software Solutions LLC Page 8 Summary for Subcatchment 145: Parking Lot North Runoff = 0.08 cfs @ 7.98 hrs, Volume= 0.026 af, Depth= 3.07" Runoff by SBUH method, Split Pervious/lmperv., Time Span= 0.00-50.00 hrs, dt= 0.05 hrs Type IA 24 -hr 2 Year Rainfall=3.30" Area (sf) CN Description 4,50 98 Paved parking HSG B 4,509 98 100.00% Impervious Area Tc Length Slope Velocity Capacity. Description (min) (feet) (ft/ft) (ft/sec) (cfs) Direct Entry, Subcatchment 145: Parking Lot North Hydrograph !Jmiiiiiiiiiiii .� 0.05: 3 0.04- -. 0 ` 0.03. JL 0.02-- .02-0.01 0.01= Type IA 24 -hr 2 Year Rainfall=3.30" Runoff Area=4,509 sf Runoff Volume=0.026 of Runoff Depth=3.07" Tc=10.0 min CN=0/98 0 5 10 15 20 25 30 35 40 Time (hours) — Runoff Designed By: LAB Ridgeview Apartements Storm Analysis Type /A 24 -hr 2 YearRainfall=3.30" Prepared by Olson & Morris Printed 11/12/2020 HydroCAD010.00-25 s/n 04993 02019 HydroCAD Software Solutions LLC Pace 9 Summary for Reach 13R: 8" Storm Inflow Area = 0.104 ac,100.00% Impervious, Inflow Depth = 3.58" for 2 Year event Inflow = 0.09 cfs @ 8.39 hrs, Volume= 0.031 of Outflow = 0.09 cfs @ 8.41 hrs, Volume= 0.031 af, Atten= 0%, Lag= 0.8 min Routing by Stor-Ind+Trans method, Time Span= 0.00-50.00 hrs, dt= 0.05 hrs Max. Velocity= 2.40 fps, Min. Travel Time= 0.3 min Avg. Velocity = 1.30 fps, Avg. Travel Time= 0.6 min Peak Storage= 2 cf @ 8.40 hrs Average Depth at Peak Storage= 0.10' Bank -Full Depth= 0.83' Flow Area= 0.5 sf, Capacity= 2.85 cfs 10.0" Round Pipe n= 0.010 Length= 50.0' Slope= 0.0100 7 Inlet Invert= 0.00% Outlet Invert= -0.50' O Reach 13R: 8" Storm Hydrograph —Inflow Inflow Area=0.104 ac —Outflow Avg. Flow Depth=0.10' Max Vel=2.40 fps —10.0 Round Pipe n=0;010 L=50.0' S=0.0100'1' Capacity=2.85 cfs 10 15 20 25 30 35 40 45 50 Time (hours) 0.1 0.09 cts 0.09 0.08 0.07 0.06 0.05 0 LL 0.04 0.03 0.02 n nil _. _. . —Inflow Inflow Area=0.104 ac —Outflow Avg. Flow Depth=0.10' Max Vel=2.40 fps —10.0 Round Pipe n=0;010 L=50.0' S=0.0100'1' Capacity=2.85 cfs 10 15 20 25 30 35 40 45 50 Time (hours) Designed By: LAB Ridgeview Apartements Storm Analysis Type /A 24 -hr 2 Year Rainfall=3.30" Prepared by Olson & Morris Printed 11/1212020 HydroCADO 10.00-25 s/n 04993 © 2019 HydroCAD Software Solutions LLC Page 10 Summary for Pond 2P: Rain Garden #4 Inflow Area = 0.580 ac,900.00% Impervious, Inflow Depth = 3.07" for 2 Year event Inflow = 0.43 cfs @ 7.98 hrs, Volume= 0.148 of Outflow = 0.10 cfs @ 9.89 hrs, Volume= 0.148 af, Atten= 76%, Lag= 114.8 min Discarded = 0.08 cfs @ 9.89 hrs, Volume= 0.146 of Secondary = 0.02 cfs @ 9.89 hrs, Volume= 0.002 of Routing by Stor-Ind method, Time Span= 0.00-50.00 hrs, dt= 0.05 hrs Peak Elev= 497.96'@ 9.89 hrs Surf.Area= 3,468 sf Storage= 1,732 cf Flood Elev= 498.53' Surf.Area= 3,678 sf Storage= 2,491 cf Plug -Flow detention time= 226.9 min calculated for 0.148 of (100% of inflow) Center -of -Mass det. time= 227.0 min ( 897.6 - 670.6 ) Volume Invert Avail.Storage Storage Description #1 496.53' 2,581 cf Open Area (Prismatic)Listed below (Recalc) #2 495.53' 112 cf Growing Media (Prismatic)Listed below (Recalc) 1,122 cf Overall x 10.0% Voids #3 494.53' 245 cf Rock Chamber (Prismatic)Listed below (Recalc) 700 cf Overall x 35.0% Voids 2,938 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubic -feet) (cubic -feet) 496.53 700 0 0 498.83 1,544 2,581 2,581 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubic -feet) (cubic -feet) 495.53 700 0 0 496.53 1,544 1,122 1,122 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubic -feet) (cubic -feet) 494.53 700 0 0 495.53 700 700 700 Device Routing Invert Outlet Devices #1 Discarded 494.53' 1.050 in/hr Exfiltration over Surface area #2 Secondary 497.93' 4.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads �scarded OutFlow Max=0.08 cfs @ 9.89 hrs HW=497.96' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.08 cfs) Secondary OutFlow Max=0.02 cfs @ 9.69 hrs HW=497.96' (Free Discharge) 2=Orifice/Grate (Weir Controls 0.02 cfs @ 0.56 fps) Designed By: LAB Ridgeview Apartements Storm Analysis Type IA 24 -hr 2 YearRainfall=3.30" Prepared by Olson & Morris Printed 11/12/2020 HYdroCAD® 10.00-25 s/n 04993 ® 2019 HydroCAD Software Solutions LLC Page 11 Pond 2P: Rain Garden #4 Hydrograph U7 0.1E 0.1 5 10 15 20 25 30 35 40 45 50 Time (hours) Area=0.580 ac mInflow Peak Elev=497,96' Storage=1,732 cif 5 10 15 20 25 30 35 40 45 50 Time (hours) Designed By: LAB Ridgeview Apartements Storm Analysis Type /A 24 -hr 2 YearRainfall=3.30" Prepared by Olson & Morris Printed 11/1212020 HvdroCAD810.00-25 s/n 04993 © 2019 HvdroCAD Software Solutions LLC Page 12 Summary for Pond 11 P: North Rain Garden #2 Inflow Area = 0.030 ac,100.00% Impervious, Inflow Depth = 3.07" for 2 Year event Inflow = 0.02 cfs @ 7.98 hrs, Volume= 0.008 of Outflow = 0.02 cfs @ 8.17 hrs, Volume= 0.008 af, Atten= 23%, Lag= 11.6 min Discarded = 0.02 cfs @ 8.17 hrs, Volume= 0.008 of Secondary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-50.00 hrs, dt= 0.05 hrs Peak Elev= 498.03' @ 8.17 hrs Surf.Area= 322 sf Storage= 20 cf Flood Elev= 500.00' Surf.Area= 686 sf Storage= 362 cf Plug -Flow detention time= (not calculated: outflow precedes inflow) Center -of -Mass det. time= 18.4 min ( 688.9 - 670.6) #1 499.00' 211 of Open Area Above Rain Garden (Prismatic)-istei #2 498.00' 132 cf Open Area (Prismatic) Listed below (Recalc) #3 497.00' 13 cf Growing Media (Prismatic)Listed below (Recalc) 500.00 211 211 132 cf Overall x 10.0% Voids #4 496.00' 5 cf Rock Chamber (Prismatic)Listed below (Recalc) 362 cf Total Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubic -feet) (cubic -feet) 499.00 211 0 0 500.00 211 211 211 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubic -feet) (cubic -feet) 498.00 53 0 0 499.00 211 132 132 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubic -feet) (cubic -feet) 497.00 53 0 0 498.00 211 132 132 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubic feet) (cubic -feet) 496.00 53 0 0 497.00 53 53 53 Device Routing Invert Outlet Devices #1 Discarded 496.00' 2.250 in/hr Exfiltration over Surface area #2 Secondary 499.00' 4.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Designed By: LAB Ridgeview Apartements Storm Analysis Type IA 24 -hr 2 YearRainfall=3.30" Prepared by Olson & Morris Printed 11/12/2020 HydroCAD® 10.00-25 s/n 04993 02019 HydroCAD Software Solutions LLC Paoe 13 LN carded OutFlow Max=0.02 cfs @ 8.17 hrs HW=498.03' (Free Discharge) 1=Exfiltration (ExFltration Controls 0.02 cfs) Secondary OutFlow Max=0.00 cfs @ 0.00 hrs HW=496.00' (Free Discharge) 2=0rifice/Grate ( Controls 0.00 cfs) Pond 11 P: North Rain Garden #2 Hydrograph n r»e- 0 5 10 15 20 25 30 35 40 45 Time (hours) — Inflow — Outflow — Discarded — Secondary 0.02 Inflow Area=0.030-ac- 0.018. 0.02 cfs Peak- Elev=498.03'- 0.016- Storage=20 cf 0.014 3 0.012- - -O° 0.01 0.008 0.006z n MAI 0 5 10 15 20 25 30 35 40 45 Time (hours) — Inflow — Outflow — Discarded — Secondary Designed By: LAB Ridgeview Apartements Storm Analysis Type /A 24 -hr 2 Year Rainfall=3.30" Prepared by Olson & Morris Printed 11/12/2020 HydroCAD010.00-25 9/n04993 02019 HydroCAD Software Solutions LLC Page 14 Summary for Pond 12P: Rain Garden #3 Inflow Area = 0.178 ac,100.00% Impervious, Inflow Depth = 3.07" for 2 Year event Inflow = 0.13 cis @ 7.98 hrs, Volume= 0.046 of Outflow = 0.05 cis @ 8.76 hrs, Volume= 0.046 af, Atten= 60%, Lag= 47.2 min Discarded = 0.05 cis @ 8.76 hrs, Volume= 0.046 of Secondary = 0.00 cis @ 0.00 hrs, Volume= 0.000 of Routing by Star -Ind method, Time Span= 0.00-50.00 hrs, dt= 0.05 hrs Peak Elev= 498.65' @ 8.76 hrs Surf.Area= 997 sf Storage= 284 cf Flood Elev= 500.00' Surf.Area= 1,517 sf Storage= 862 cf Plug -Flow detention time= 64.2 min calculated for 0.046 of (100% of inflow) Center -of -Mass det. time= 64.3 min ( 734.9 - 670.6 ) #1 #2 #3 #4 499.00' 498.00' 497.00' 496.00' 438 cf Open Area Wall (Prismatic)Listed below (Recalc) 321 cf Open Area (Prismatic)Listed below (Recalc) 32 cf Growing Media (Prismatic)Listed below (Recalc) 321 cf Overall x 10.0% Voids 71 cf Rock Chamber (Prismatic)Listed below (Recalc) 203 cf Overall x 35.0% Voids 862 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubic -feet) (cubic -feet) 499.00 438 0 0 500.00 438 438 438 Elevation Surf.Area Inc.Store Cum.Store _ (feet) (sq -ft) (cubic -feet) (cubic -feet) 498.00 203 0 0 499.00 438 321 321 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubicfeet) (cubic -feet) 497.00 203 0 0 498.00 438 321 321 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubic -feet) (cubic -feet) 496.00 203 0 0 497.00 203 203 203 Device Routing Invert Outlet Devices #1 Discarded 496.00' 2.250 in/hr Exfiltration over Surface area #2 Secondary 499.00' 4.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Designed By: LAB Ridgeview Apartements Storm Analysis Type /A 24 -hr 2 Year Rainfall=3.30" Prepared by Olson & Morris Printed 11112/2020 HydroCAD010.00-25 s/n 04993 02019 HydroCAD Software Solutions LLC Page 15 Qlscarded OutFlow Max=0.05 cfs @ 8.76 hrs HW=498.65' (Free Discharge) T I=Exfiltration (Exfiltration Controls 0.05 cfs) Secondary OutFlow Max=0.00 cfs @ 0.00 hrs HW=496.00' (Free Discharge) 2=Orifice/Grate ( Controls 0.00 cfs) Pond 1213: Rain Garden #3 Hydrograph 0.14 0.13 cfs — Inflow — Outflow 0.12 Inflow Area=0.178 ac —Discarded PeakElev=498,65' —Secondary 0.1- Storage=284 cf a 0.08- 0.06- 0.05 cfs rL 0.04 O.O Ccfs 0 5 10 15 20 25 30 35 40 Time (hours) Designed By: LAB Ridgeview Apartements Storm Analysis Type /A 24 -hr 2 Year Rainfall=3.30" Prepared by Olson & Morris Printed 11/12/2020 HydroCAD® 10.00-25 s/n 04993 02019 HydroCAD Software Solutions LLC Page 16 Summary for Pond 1313: North Rain Garden #1 Inflow Area = 0.356 ac,100.00% Impervious, Inflow Depth = 3.07" for 2 Year event Inflow = 0.26 cfs @ 7.98 hrs, Volume= 0.091 of Outflow = 0.14 cfs @ 8.41 hrs, Volume= 0.090 at, Atten= 47%, Lag= 26.2 min Discarded = 0.09 cfs @ 8.25 hrs, Volume= 0.088 of Secondary = 0.05 cfs @ 8.41 hrs, Volume= 0.002 of Routing by Stor-Ind method, Time Span= 0.00-50.00 hrs, dt= 0.05 hrs Peak Elev= 499.06'@ 8.41 hrs Surf.Area= 2,033 sf Storage= 614 cf Flood Elev= 500.00' Surf.Area= 2,292 sf Storage= 1,095 cf Plug -Flow detention time= 74.8 min calculated for 0.090 of (99% of inflow) Center -of -Mass det. time= 67.8 min ( 738.4 - 670.6 ) Volume Invert Avail.Storage Storage Description #1 499.00' 504 cf Open Area (Prismatic)Listed below (Recalc) #2 498.00' 504 cf Open Area (Prismatic)Listed below (Recalc) #3 497.00' 50 cf Growing Media (Prismatic)Listed below (Recalc) 504 cf Overall x 10.0% Voids #4 496.00' 37 cf Rock Chamber (Prismatic)Listed below (Recalc) 366 cf Overall x 10.0% Voids 1,095 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubic -feet) (cubic -feet) 499.00 366 0 0 500.00 642 504 504 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubic -feet) (cubic -feet) 498.00 366 0 0 499.00 642 504 504 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubic -feet) (cubic -feet) 497.00 366 0 0 498.00 642 504 504 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubic -feet) (cubic -feet) 496.00 366 0 0 497.00 366 366 366 Device Routing Invert Outlet Devices #1 Discarded 496.00' 2.250 in/hr Exfiltration over Surface area from 496.00' - 499.00' Excluded Surface area = 366 sf #2 Secondary 499.00' 4.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Designed By: LAB Ridgeview Apartements Storm Analysis Type IA 24 -hr 2 YearRainfall=3.30" Prepared by Olson & Morris Printed 11112/2020 HydroCAD010.00-25 sin 04993 02019 HydroCAD Software Solutions LLC Page 17 Discarded OutFlow Max=0.09 cfs @ 8.25 hrs HW=499.01' (Free Discharge) 1=Exfiltration (EAltration Controls 0.09 cfs) Secondary OutFlow Max=0.05 cfs @ 8.41 hrs HW=499.06' (Free Discharge) 2=OrificelGrate (Weir Controls 0.05 cfs @ 0.80 fps) Pond 13P: North Rain Garden #1 Hydrograph w11 0.15- 0.14 cfs 3 0 u 0.1- 0.09 cfs 0.05 cfs 0.05 0 0 5 10 15 20 25 30 35 40 45 Time (hours) — Inflow Inflow Area=0.356 ac `Outflow —Discarded Peak Elev=499.06' —Secondary Storage=614 cf w11 0.15- 0.14 cfs 3 0 u 0.1- 0.09 cfs 0.05 cfs 0.05 0 0 5 10 15 20 25 30 35 40 45 Time (hours) Designed By: LAB Ridgeview Apartements Storm Analysis Type /A 24 -hr 2 YearRatnfall=3.30" Prepared by Olson & Morris Printed 11/12/2020 HydroCAD010.00-25 s/n 04993 02019 HydroCAD Software Solutions LLC Page 18 Summary for Pond 16P: Dual Chamber CB Inflow Area = 0.104 ac,100.00% Impervious, Inflow Depth = 3.07" for 2 Year event Inflow = 0.08 cfs @ 7.98 hrs, Volume= 0.026 of Outflow = 0.08 cfs @ 7.98 hrs, Volume= 0.026 af, Atten= 0%, Lag= 0.0 min Primary = 0.08 cfs @ 7.98 hrs, Volume= 0.026 of Routing by Stor-Ind method, Time Span= 0.00-50.00 hrs, dt= 0.05 hrs Peak Elev= 497.19' @ 7.98 hrs Flood EIev=499.00' Device Routing Invert Outlet Devices #1 Primary 497.00' 4.0" Vert. Orifice/Grate C= 0.600 Lrimary OutFlow Max=0.08 cfs @ 7.98 hrs HW=497.19' (Free Discharge) 1=Orifice/Grate (Orifice Controls 0.08 cfs @ 1.48 fps) Pond 16P: Dual Chamber CB Hydrograph 1111YA 0.05 0 0.04= 0.01 0.08 cfs 0 5 10 15 — Inflow Inflow Area=0.104-ac- — Primary Peak EIev=497.19' !0 25 30 35 40 45 50 Time (hours) Designed By: LAB Ridgeview Apartements Storm Analysis Type /A 24 -hr 25 Year Rainfall=4.80" Prepared by Olson & Morris Printed 11/12/2020 HydroCADO 10.00-25 s/n 04993 © 2019 HVdroCAD Software Solutions LLC Paas 19 Summary for Subcatchment 1S: Parking Lot Runoff = 0.63 ds @ 7.98 hrs, Volume= 0.220 af, Depth= 4.56" Runoff by SBUH method, Split Pervious/Impew., Time Span= 0.00-50.00 hrs, dt= 0.05 hrs Type IA 24 -hr 25 Year Rainfall=4.80" LO.G04 UO raven parKina mOu u 25,254 98 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.0 Direct Entry, Subcatchment 1S: Parking Lot 0.7-1---- 7 Hydrograph 0.63 cfs —Runoff 0.5-1 1 11 0.4 o LL 0.3- 0.2 0.1 0 5 10 15 Type IA 24 -hr 25 Year Rainfall=4'.80" Runoff Area=25,254 sf Runoff Volume=0.220-af Runoff Depth=4.56" Tc --10.0 min CN=0/98 Time (hours) Designed By: LAB Ridgeview Apartements Storm Analysis Type /A 24 -hr 25 YearRainfall=4.80" Prepared by Olson & Morris Printed 11/12/2020 HydroCAD010.00-25 s/n 04993 02019 HydroCAD Software Solutions LLC Page 20 Summary for Subcatchment 3S: Apartment #3 Runoff = 0.19 ds @ 7.98 hrs, Volume= 0.068 at, Depth= 4.56" Runoff by SBUH method, Split Pervious/Imperv., Time Span= 0.00-50.00 hrs, dt= 0.05 hrs Type IA 24 -hr 25 Year Rainfal1=4.80" Area (st) CN Description 7.758 98 Unconnected roofs. HSG B 7,758 98 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (tuft) (ft/sec) (cfs) 10.0 Direct Entry, Subcatchment 3S: Apartment #3 Hydrograph 0.19 cfs —Runoff 0.2-. 0.18: Type iA 24 -hr 0.16 25YearRainfall=4.80" - 0.14- Runoff Area=7,758 sf 0.12= Runoff Volume=0.068 of 0 0 1' Runoff Depth=4.56" 0 08- Tc=10.0 min CN=0/98 Ana= __ Q 0 5 10 15 20 25 30 35 40 45 50 Time (hours) Designed By: LAB Ridgeview Apartements Storm Analysis Type /A 24 -hr 25 YearRainfall=4.80" Prepared by Olson & Morris Printed 11/12/2020 HydroCAD®10.00-25 s/n 04993 ® 2019 HydroCAD Software Solutions LLC Page 21 Summary for Subcatchment 4S: Apartment #2 Runoff = 0.19 GIs @ 7.98 hrs, Volume= 0.068 af, Depth= 4.56" Runoff by SBUH method, Split Pervious/Imperv., Time Span= 0.00-50.00 hrs, dt= 0.05 hrs Type IA 24 -hr 25 Year Rainfall=4.80" 7,758 98 100.00% Impervious Areay Tc Length Slope Velocity Capacity Description (min) (feet) (f /ft) (fUsec) (cfs) 10.0 Direct Entry, Subcatchment 4S: Apartment #2 Hydrograph —Runoff Type IA 24 -hr 25 Year Rainfall=4,80" Runoff Area=7,758sf Runoff Volume=0.068 of Runoff Depth=4.56" Tc=10.0 min CN=0/98 0 5 10 15 20 25 30 35 40 45 50 Time (hours) 0.18. 0.16' 0.14. N - 0.12= c 0.1 LL n r1Q Type IA 24 -hr 25 Year Rainfall=4,80" Runoff Area=7,758sf Runoff Volume=0.068 of Runoff Depth=4.56" Tc=10.0 min CN=0/98 0 5 10 15 20 25 30 35 40 45 50 Time (hours) Designed By: LAB Ridgeview Apartements Storm Analysis Type /A 24 -hr 25 Year Rainfall=4.80" Prepared by Olson & Morris Printed 11/12/2020 HydroCAD010 00-25 s/n 04993 02019 HydroCAD Software Solutions LLC Page 22 Summary for Subcatchment 5S: Apartment #1 Runoff = 0.19 cfs @ 7.98 hrs, Volume= 0.068 af, Depth= 4.56" Runoff by SBUH method, Split Pervious/lmperv., Time Span= 0.00-50.00 hrs, dt= 0.05 hrs Type IA 24 -hr 25 Year Rainfall=4.80" Area (sf) CN Description 7.758 98 Unconnected roofs, HSG B 7,758 98 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.0 Direct Entry, Subcatchment 5S: Apartment #1 Hydrograph 0.2: 0.19 Cfs —Runoff 0.18 Type iA 24 -hr 0.16 25YearRainfall=4.80"- 0.14 _ Runoff Area=7,758sf u 0.12 Runoff Volume=0.068 of c 0.1 Runoff Depth=4.56" Tc=10.0 min LL - 0.08CN=0198 0 5 10 15 20 25 30 35 Time (hours) Designed By: LAB Ridgeview Apartements Storm Analysis Type /A 24 -hr 25 YearRainfall=4.80" Prepared by Olson & Morris Printed 11/12/2020 HydroCAD010.00-25 s/n 04993 02019 HydroCAD Software Solutions LLC Pace 23 Summary for Subcatchment 7S: Existing Conditions Runoff = 0.93 cfs @ 8.05 hrs, Volume= 0.435 af, Depth= 2.63" Runoff by SBUH method, Split Pervious/Imperv., Time Span= 0.00-50.00 hrs, dt= 0.05 hrs Type IA 24 -hr 25 Year Rainfall=4.80" 1.984 79 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (f Ift) (f /sec) (ds) 25.1 234 0.0100 0.16 Sheet Flow, Grass: Short n= 0.150 P2= 3.30" Subcatchment 7S: Existing Conditions Hydrograph fs —Runoff 1- 3c Type IA 24 -hr 25 Year Rainfall=4'.80" Runoff Area=1.984 ac Runoff Volume=0.435 of Runoff Depth=2.63" Flow Length=234' Slope=0.0100 '/' Tc=25.1 min CN=79/0 0 5 10 15 20 25 30 35 40 45 50 Time (hours) Designed By: LAB Ridgeview Apartements Storm Analysis Type IA 24 -hr 25 Year Rainfall=4.80" Prepared by Olson & Morris Printed 11/12/2020 HvdroCADO 10.00-25 s/n 04993 m 2019 HvdroCAD Software Solutions LLC Pace 24 Summary for Subcatchment 8S: Storage/Office Runoff = 0.03 ds @ 7.98 hrs, Volume= 0.011 af, Depth= 4.56" Runoff by SBUH method, Split Pervioushmperv., Time Span= 0.00-50.00 hrs, dt= 0.05 hrs Type IA 24 -hr 25 Year Rainfall=4.80" 1,288 98 1 Tc Length Slope 0.035 0.025- 0.02-. .0250.02 _ 3 LL 0.015- 0.01- 0.005- I0- 0.03 cfs Description Direct Entry, Subcatchment 8S: Storage/Office Hydrograph Type IA 24 -hr 25 Year Rainfall=4.80" Runoff Area=11288 sf Runoff Volume=0.011 of Runoff Depth=4.56" Tc=10.0min CN=0/98 20 25 30 35 40 45 50 Time (hours) — Runoff Designed By: LAB Ridgeview Apartements Storm Analysis Type IA 24 -hr 25 Year Rainfall=4.80" Prepared by Olson & Morris Printed 11112/2020 HydfoCAD® 10.00-25 s/n 04993 © 2019 HydroCAD Software Solutions LLC Page 25 Summary for Subcatchment 14S: Parking Lot North Runoff = 0.11 cfs @ 7.98 hrs, Volume= 0.039 af, Depth= 4.56" Runoff by SBUH method, Split Pervious/Imperv., Time Span= 0.00-50.00 hrs, dt= 0.05 hrs Type IA 24 -hr 25 Year Rainfall=4.80" Area (so CN Description 4,509 98 Paved parking, HSG B 4,509 98 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (fUsec) (cfs) 10.0 Direct Entry, Subcatchment 14S: Parking Lot North Hydrograph 0.12' 0.11 cfs 0.11' 0.1 _ Type IA 24 -hr 0.09 25 Year Rainfall=4.80" 0.08 Runoff Area --4,509 sf le 0.07 Runoff Volume=0.039.af. 3 0.06 - Runoff Depth=4.56" LL 0.05- — Tc=10.0 min 0.04= _ CN=0/98 0.03 0.02 - 0.01- 10 15 20 25 30 35 40 45 50 Time (hours) Designed By: LAB Ridgeview Apartements Storm Analysis Type 1A 24 -hr 25 Year Rainfall=4. 80" Prepared by Olson & Morris Printed 11/12/2020 HydroCAD®10.00-25 s/n 04993 02019 HydroCAD Software Solutions LLC Paae 26 Summary for Reach 13R: 8" Storm Inflow Area = 0.104 ac,100.00% Impervious, Inflow Depth = 12.03" for 25 Year event Inflow = 0.55 cfs @ 8.15 hrs, Volume= 0.104 of Outflow = 0.55 cfs @ 8.16 hrs, Volume= 0.104 at, Atten= 0%, Lag= 0.7 min Routing by Stor-Ind+Trans method, Time Span= 0.00-50.00 hrs, dt= 0.05 hrs Max. Velocity= 4.04 fps, Min. Travel Time= 0.2 min Avg. Velocity = 1.66 fps, Avg. Travel Time= 0.5 min Peak Storage= 7 of @ 8.15 hrs Average Depth at Peak Storage= 0.25' Bank -Full Depth= 0.83' Flow Area= 0.5 sf, Capacity= 2.85 cfs 10.0" Round Pipe n= 0.010 Length= 50.0' Slope= 0.0100'f Inlet Invert=0.00', Outlet Invert= -0.50' i' Reach 13R: 8" Storm Hydrograph 0.6° 0.55 cfs - - Inflow 0.55 - Outflow 0.5' Inflow Area=0.104 ac 0.45_ Avg. Flow Pepth=0.25' 0.4= Max Vel=4.04 fps 0.35- 10.01. 0.3 RoundPipe -° 0.25. - -n=0.010 0.2 L=50.0' 0.15 S=0:0100'1' 0.1 Capacity=2:85 cfs A nr 0 5 10 15 20 25 3 Time (hours) Designed By: IAB Ridgeview Apartements Storm Analysis Type IA 24 -hr 25 YearRainfall=4.80" Prepared by Olson & Morris Printed 11/12/2020 HydroCAD010.00-25 s/n 04993 02019 HydroCAD Software Solutions LLC Pace 27 Summary for Pond 2P: Rain Garden #4 Inflow Area = 0.580 ag100.00% Impervious, Inflow Depth = 4.56" for 25 Year event Inflow = 0.63 ofs @ 7.98 hrs, Volume= 0.220 of Outflow = 0.33 cfs @ 8.40 hrs, Volume= 0.220 af, Atten= 47%, Lag= 25.6 min Discarded = 0.09 cfs @ 8.40 hrs, Volume= 0.175 of Secondary = 0.25 cfs @ 8.40 hrs, Volume= 0.045 of Routing by Stor-Ind method, Time Span= 0.00-50.00 hrs, dt= 0.05 hrs Peak Elev= 498.27'@ 8.40 hrs Surf.Area= 3,583 sf Storage= 2,132 cf Flood Elev= 498.53' Surf.Area= 3,678 sf Storage= 2,491 cf Plug -Flow detention time= 215.4 min calculated for 0.220 of (100% of inflow) Center -of -Mass det. time= 215.7 min ( 877.4 - 661.7 ) #1 496.53' #2 495.53' #3 494.53' 112 cf Area (Prismatic)Listed below (Recalc) ng Media (Prismatic) Listed below (Recalc) 1,122 cf Overall x 10.0% Voids 245 cf Rock Chamber below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feel) (sq -ft) (cubic -feet) (cubic -feet) 496.53 700 0 0 498.83 1,544 2,581 2,581 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubic -feet) (cubic -feet) 495.53 700 0 0 496.53 1,544 1,122 1,122 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubic -feet) (cubic -feet) 494.53 700 0 0 495.53 700 700 700 Device Routing Invert Outlet Devices #1 Discarded 494.53' 1.050 in/hr Exfiltration over Surface area #2 Secondary 497.93' 4.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads fSiscarded OutFlow Max=0.09 cfs @ 8.40 hrs HW=498.27' (Free Discharge) 1=Exfiltration (Exfitration Controls 0.09 cfs) Secondary OutFlow Max=0.25 cfs @ 8.40 hrs HW=498.27' (Free Discharge) 2=Orifice/Grate (Orifice Controls 0.25 cfs @ 2.81 fps) Designed By: LAB Ridgeview Apartements Storm Analysis Type IA 24 -hr 25 Year Rainfall=4. 80" Prepared by Olson & Morris Printed 11/12/2020 HydroCADE)10.00-25 s/n 04993 02019 HydroCAD Software Solutions LLC Paoe 28 Pond 2P: Rain Garden #4 Hydrograph 0.7 0.63 cfs — Inflow ow 0.6 Inflow Area=0.580 ac L—Discarded ' 0.5PeakElev=498.27' econdary Storage=2,132 cf u 0.4- 0.33 cfs LL 0.3 0.25 cfs n� 5 10 15 20 25 30 35 40 45 50 Time (hours) Designed By: LAB Ridgeview Apartements Storm Analysis Type IA 24 -hr 25 Year Rainfall=4.80" Prepared by Olson & Morris Printed 11/12/2020 HydroCAD010.00-25 s/n 04993 02019 HydroCAD Software Solutions LLC Page 29 Summary for Pond 11 P: North Rain Garden #2 Inflow Area = 0.030 ac,100.00% Impervious, Inflow Depth = 4.56" for 25 Year event Inflow = 0.03 cis @ 7.98 hrs, Volume= 0.011 of Outflow = 0.02 cis @ 8.34 hrs, Volume= 0.011 af, Atten= 41 %, Lag= 21.8 min Discarded = 0.02 cfs @ 8.34 hrs, Volume= 0.011 of Secondary = 0.00 cis @ 0.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-50.00 hrs, dt= 0.05 hrs Peak Elev= 498.26' @ 8.34 hrs Surf.Area= 359 sf Storage= 38 cf Flood Elev= 500.00' Surf.Area= 686 sf Storage= 362 cf Plug -Flow detention time= 20.5 min calculated for 0.011 of (100% of inflow) Center -of -Mass det. time= 20.6 min ( 682.3 - 661.7 ) Volume Invert Avail.Storage Storage Description #1 499.00' 211 cf Open Area Above Rain Garden (Prismatic)-isted below (Recalc) #2 498.00' 132 cf Open Area (Prismatic)Listed below (Recalc) #3 497.00' 13 cf Growing Media (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store 132 cf Overall x 10.0% Voids #4 496.00' 5 cf Rock Chamber (Prismatic)Listed below (Recalc) Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubio-feet) (cubic -feet) 499.00 211 0 0 500.00 211 211 211 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubiofeat) (cubic -feet) 498.00 53 0 0 499.00 211 132 132 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubic -feet) (cubic -feet) 497.00 53 0 0 498.00 211 132 132 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubic -feet) (cubic -feet) 496.00 53 0 0 497.00 53 53 53 Device Routing Invert Outlet Devices #1 Discarded 496.00' 2.250 in/hr Exfiltration over Surface area #2 Secondary 499.00' 4.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Designed By: LAB Ridgeview Apartements Storm Analysis Type IA 24 -hr 25 YearRainfall=4.80" Prepared by Olson & Morris Printed 11/12/2020 HydroCAD010 00-25 s/n 04993 02019 HydroCAD Software Solutions LLC Page 30 Discarded OutFlow Max=0.02 cfs @ 8.34 hrs HW=498.26' (Free Discharge) 11=Exfiltration (Exfiltration Controls 0.02 cfs) Secondary OutFlow Max=0.00 cfs @ 0.00 hrs HW=496.00' (Free Discharge) 2=Orifice/Grate ( Controls 0.00 cfs) Pond 11 P: North Rain Garden #2 Hydrograph 0.035. 0.03 cfs —Inflow —Outflow 0.03. Inflow Area=0.030 ac — Discarded Peak Elev=498'.26' —Secondary 0.025 _ Storage=38 cf » 0.02 cfs u 0.02 3 LL 0.015- 0.01 11111111111IMMI. 0 5 10 15 20 25 30 35 40 45 50 Time (hours) Designed By: LAB Ridgeview Apartements Storm Analysis Type IA 24 -hr 25 Year Rainfall=4. 80" Prepared by Olson & Morris Printed 11/12/2020 HydroCAD® 10.00-25 s/n 04993 02019 HvdroCAD Software Solutions LLC Page 31 Summary for Pond 12P: Rain Garden #3 Inflow Area = 0.178 ac,100.00% Impervious, Inflow Depth = 4.56" for 25 Year event Inflow = 0.19 ofs @ 7.98 hrs, Volume= 0.068 of Outflow = 0.10 cfs @ 8.41 hrs, Volume= 0.068 at, Atten= 47%, Lag= 26.0 min Discarded = 0.08 cfs @ 8.25 hrs, Volume= 0.067 of Secondary = 0.02 cfs @ 8.41 hrs, Volume= 0.001 of Routing by Stor-Ind method, Time Span= 0.00-50.00 hrs, dt= 0.05 hrs Peak Elev= 499.03'@ 8.41 hrs Surf.Area= 1,517 sf Storage= 438 cf Flood Elev= 500.00' Surf.Area= 1,517 sf Storage= 662 cf Plug -Flow detention time= 69.8 min calculated far 0.068 of (100% of inflow) Center -of -Mass det. time= 69.8 min ( 731.6 - 661.7 ) #1 #2 #3 #4 499.00' 498.00' 497.00' 496.00' 438 cf Open Area Wall (Prismatic)Listed below (Recalc) 321 cf Open Area (Prismatic)Listed below (Recalc) 32 cf Growing Media (Prismatic)Listed below (Recalc) 321 cf Overall x 10.0% Voids 71 of Rock Chamber (Prismatic)Listed below (Recalc) 203 cf Overall x 35.0% Voids 862 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubic -feet) (cubic -feet) 499.00 438 0 0 500.00 438 438 438 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubic -feet) (cubic -feet) 498.00 203 0 0 499.00 438 321 321 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubic -feet) (cubic -feet) 497.00 203 0 0 498.00 438 321 321 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubic -feet) (cubic -feet) 496.00 203 0 0 497.00 203 203 203 Device Routing Invert Outlet Devices #1 Discarded 496.00' 2.250 in/hr ExHitration over Surface area #2 Secondary 499.00' 4.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Designed By: LAB Ridgeview Apartements Storm Analysis Type /A 24 -hr 25 Year Rainfal1=4.80" Prepared by Olson & Morris Printed 11/12/2020 HydroCAD010.00-25 s/n 04993 02019 HydroCAD Software Solutions LLC Page 32 Sscarded OutFlow Max=0.08 cfs @ 8.25 hrs HW=499.01' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.08 cfs) Secondary OutFlow Max=0.02 cfs @ 8.41 hrs HW=499.03' (Free Discharge) 2=Orifice/Grate (Weir Controls 0.02 cfs @ 0.59 fps) Pond 12P: Rain Garden #3 Hydrograph 0 5 10 15 20 25 30 35 Time (hours) — Inflow 0.18- .18:0.16 0. 16 Inflow Area=0.178 ac 0.14 — —Discarded 0.12 0.10 cfs c 0.1I u.0.08. 0.06 0.04 n no 0 5 10 15 20 25 30 35 Time (hours) — Inflow Outflow Inflow Area=0.178 ac — —Discarded PeakElev=499.03' —Secondary Storage=438 cf 0 5 10 15 20 25 30 35 Time (hours) Designed By: LAB Ridgeview Apartements Storm Analysis Type IA 24 -hr 25 Year Rainfall=4. 80" Prepared by Olson & Morris Printed 11/12/2020 HydroCAD® 10.00-25 s/n 04993 © 2019 HydroCAD Software Solutions LLC Page 33 Summary for Pond 13P: North Rain Garden #1 Inflow Area = 0.356 ac,100.00% Impervious, Inflow Depth = 4.56" for 25 Year event Inflow = 0.38 cis @ 7.98 hrs, Volume= 0.135 of Outflow = 0.33 cis @ 8.12 hrs, Volume= 0.135 af, Atten= 15%, Lag= 8.4 min Discarded = 0.09 cfs @ 7.75 hrs, Volume= 0.116 of Secondary = 0.24 cis @ 8.12 hrs, Volume= 0.019 of Routing by Stor-Ind method, Time Span= 0.00-50.00 hrs, dt= 0.05 hrs Peak Elev= 499.33'@ 8.12 hrs Surf.Area= 2,106 sf Storage= 725 cf Flood Elev= 500.00' Surf.Area= 2,292 sf Storage= 1,095 cf Plug -Flow detention time= 82.7 min calculated for 0.135 of (99% of inflow) Center -of -Mass det. time= 77.9 min ( 739.6 - 661.7 ) #1 #2 #3 #4 499.00' 498.00' 497.00' 496.00' 504 cf Open Area (Prismatic)Listed below (Recalc) 504 cf Open Area (Prismatic)Listed below (Recalc) 50 cf Growing Media (Prismatic)Listed below (Recalc) 504 cf Overall x 10.0% Voids 37 cf Rock Chamber (Prismatic)Listed below (Recalc) 366 cf Overall x 10.0% Voids 1,095 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubic -feet) (cubic -feet) 499.00 366 0 0 500.00 642 504 504 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubic -feet) (cubic -feet) 498.00 366 0 0 499.00 642 504 504 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubic -feet) (cubic -feet) 497.00 366 0 0 498.00 642 504 504 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubic -feet) (cubic -feet) 496.00 366 0 0 497.00 366 366 366 Device Routing Invert Outlet Devices #1 Discarded 496.00' 2.250 in/hr Exi'lltration over Surface area from 496.00'- 499.00' Excluded Surface area = 366 sf #2 Secondary 499.00' 4.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Designed By: LAB Ridgeview Apartements Storm Analysis Type IA 24 -hr 25 Year Rainfall=4.80" Prepared by Olson & Morris Printed 11/12/2020 HydroCAD@ 10.00-25 s/n 04993 02019 HydroCAD Software Solutions LLC Page 34 Sscarded OutFlow Max=0.09 cfs @ 7.75 hrs HW=499.08' (Free Discharge) 1=Exfiltration (Exfltration Controls 0.09 cfs) Secondary OutFlow Max=0.24 cfs @ 8.12 hrs HW=499.32' (Free Discharge) 2=0rifice/Grate (Orifice Controls 0.24 cfs @ 2.74 fps) Pond 1313: North Rain Garden #1 Hydrograph cfs fs 0.25= 0.24 c 0 0.2. LL 0.15 0.1 0.0 fs 0 15 20 25 30 35 40 45 50 Time (hours) —Inflow Inflow Area=0.356 ac — OutFlow —Discarded Peak Elev=499.33' —Secondary Storage=725 cf 0 15 20 25 30 35 40 45 50 Time (hours) 0.01-1 / 10 15 20 25 30 35 40 45 50 Time (hours) Designed By: IAB Ridgeview Apartements Storm Analysis Type IA 24 -hr 25 YearRainfall=4.80" Prepared by Olson & Morris Printed 11/12/2020 HydroCAD®10 00-25 sin 04993 © 2019 HydroCAD Software Solutions LLC Page 35 Summary for Pond 16P: Dual Chamber CB Inflow Area = 0.104 ac,100.00% Impervious, Inflow Depth = 4.56" for 25 Year event Inflow = 0.11 cfs @ 7.98 hrs, Volume= 0.039 of Outflow = 0.11 cfs @ 7.98 hrs, Volume= 0.039 af, Atten= 0%, Lag= 0.0 min Primary = 0.11 cfs @ 7.98 hrs, Volume= 0.039 of Routing by Stor-Ind method, Time Span= 0.00-50.00 hrs, dt= 0.05 hrs Peak Elev= 497.24'@ 7.98 hrs Flood Elev= 499.00' Device Routing Invert Outlet Devices #1 Primary 497.00' 4.0" Vert. Orifice/Grate C= 0.600 rimary OutFlow Max=0.11 cfs @ 7.98 hrs HW=497.24' (Free Discharge) 1=Orifice/Grate (Orifice Controls 0.11 cfs @ 1.66 fps) Pond 16P: Dual Chamber CB Hydrograph 0.12: 0.11 cfs — — Inflow 0.11- —Primary Inflow Area=0.104 ac 0.1- Peak Elev=497.24' 0.09: 0.08- `u 0.07 3 0.06- 0 0.05' 0.04 0.03 0.01-1 / 10 15 20 25 30 35 40 45 50 Time (hours) Designed By: LAB Ridgeview Apartements Storm Analysis Type IA 24 -hr WQ Rainfall=0.83" Prepared by Olson & Morris Printed 11/12/2020 HydroCAD010 00-25 s/n 04993 02019 HydroCAD Software Solutions LLC Page 36 Summary for Subcatchment 1S: Parking Lot Runoff = 0.09 cfs @ 7.98 hrs, Volume= 0.030 at, Depth= 0.63" Runoff by SBUH method, Split Pervious/Imperv., Time Span= 0.00-50.00 hrs, dt= 0.05 hrs Type IA 24 -hr WQ Rainfall=0.83" 25,254 98 Paved parking HSG B 25,254 98 100.00% Impervious Area To Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (ds) 10.0 Direct Entry, Subcatchment 1S: Parking Lot Hydrograph 0.1 0.09 cfs —Runoff 0.092 Type IA 24 -hr 0.08 WQ Rainfall=0.83" 0.07 Runoff Area=25,254 sf w 0.06 Runoff Volume=0:030 of 0.05_ Runoff Depth=0.63" 0 0.04 Tc=10.0;min CN=0/98 0.03 0.02 0.01- 10 15 20 25 30 35 40 Time (hours) Designed By: LAB Ridgeview Apartements Storm Analysis Type IA 24 -hr WQ Rainfa/1=0.83" Prepared by Olson & Morris Printed 11/12/2020 HydfoCAD®10.00-25 s/n 04993 02019 HydroCAD Software Solutions LLC Page 37 Summary for Subcatchment 3S: Apartment #3 Runoff = 0.03 ds @ 7.98 hrs, Volume= 0.009 af, Depth= 0.63" Runoff by SBUH method, Split Pervious/Imperv., Time Span= 0.00-50.00 hrs, dt= 0.05 hrs Type IA24-hr WQ Rainfall=0.83" Area (sf) CN Description 7,758 98 Unconnected roofs, HSG B 7,758 98 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (fUft) (ft/sec) (cfs) 10.0 Direct Entry, 0.015 0 LL 0.01 Subcatchment 3S: Apartment #3 Hydrograph —Runoff Type IA 24 -hr WQ Rainfall=0.83" Runoff Area=7,758 sf Runoff Volume=0.009 of Runoff Depth=0.63" Tc=10.0`min CN=0/98 0 5 10 15 20 25 30 35 40 45 50 Time (hours) Designed By: LAB Ridgeview Apartements Storm Analysis Type IA 24 -hr WQ Rainfall=0.83" Prepared by Olson & Morris Printed 11/12/2020 HydroCAD010.00-25 s/n 04993 02019 HydroCAD Software Solutions LLC Paoe 38 Summary for Subcatchment 4S: Apartment #2 Runoff = 0.03 cfs @ 7.98 hrs, Volume= 0.009 af, Depth= 0.63" Runoff by SBUH method, Split Pervious/Imperv., Time Span= 0.00-50.00 hrs, dt= 0.05 hrs Type IA 24 -hr WQ Rainfall=0.83" r.rao as unconneccea mors HJIi is 7,758 98 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) Wit) (ft/sec) (cfs) 10.0 Direct Entry, Subcatchment 4S: Apartment #2 Hydrograph cfs 0.025-1 1 0.02- 0.015, 0 LL 0.01 — Runoff Type IA 24 -hr WQ Rainfall=0.83" Runoff Area=7,758 sf Runoff Volume=0.009 of Runoff Depth=0.63" Tc=10.0`min CN=0198 0 5 10 15 20 25 30 35 40 45 50 Time (hours) Designed By: LAB Ridgeview Apartements Storm Analysis Type IA 24 -hr WQ Rainfall=0.83" Prepared by Olson & Morris Printed 11/12/2020 HydroCAD® 10.00-25 s/n 04993 @2019 HydroCAD Software Solutions LLC Page 39 Summary for Subcatchment 5S: Apartment #1 Runoff = 0.03 cfs @ 7.98 hrs, Volume= 0.009 af, Depth= 0.63" Runoff by SBUH method, Split Pervious/Imperv., Time Span= 0.00-50.00 hrs, dt= 0.05 hrs Type IA 24 -hr WQ Rainfall=0.83" Area (sf) CN Description 7,758 98 Unconnected roofs. HSG B 7,758 98 100.00% Impervious Area To Length Slope Velocity Capacity Description _(min) (feet) (ft/ft) (ft/sec) (cfs) 10.0 Direct Entry, Subcatchment 5S: Apartment #1 Hydrograph 0.03- 0.03 cfs 0 5 10 15 20 25 30 35 40 45 50 Time (hours) — Runoff 0.025- — Type IA 24 -hr WQ Rainfall=0.83" Runoff Area=7,758 sf w 0'02 Runoff Volume=0.009 of Runoff Depth=0.63" 0 0.015-.Tc=10.0'min LL C N=0/98 0.01- 0.005- 0 5 10 15 20 25 30 35 40 45 50 Time (hours) — Runoff Designed By: LAB Ridgeview Apartements Storm Analysis Type IA 24 -hr WQ Rainfall=0.63" Prepared by Olson & Morris Printed 11/12/2020 HydroCAD®10 00-25 s/n 04993 O 2019 HydroCAD Software Solutions LLC Pace 40 Summary for Subcatchment 7S: Existing Conditions Runoff = 0.01 cfs @ 21.72 hrs, Volume= 0.005 af, Depth= 0.03" Runoff by SBUH method, Split Pervious/Imperv., Time Span= 0.00-50.00 hrs, dt= 0.05 hrs Type IA 24 -hr WQ Rainfall=0.83" 1.U04 Ia rastureigrasslanu/range ran 1.984 79 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ff/ft) (ft/sec) (cfs) 0.0100 0.16 Sheet Flow, Grass: Short n=0.150 P2=3.30" Subcatchment 7S: Existing Conditions Hydrograph —Runoff 0 5 10 15 20 25 30 35 40 45 50 Time (hours) 0.006- 1 Type IA 24 -hr WQ Rainfall=0.83" 0.005 Runoff Area=1.984 ac ^ Runoff Volume=0.005 of 0.004: Runoff Depth=0.03" 3 Flow Length=234' LL 0.003-Slope=0.0100'/' 0.0021 Tc=25,1 min CN=79/0 0.001 0 5 10 15 20 25 30 35 40 45 50 Time (hours) Designed By: LAB Ridgeview Apartements Storm Analysis Type IA 24 -hr WQ Rainfall=0.83" Prepared by Olson & Morris Printed 11/12/2020 HydroCAD010.00-25 stn 04993 02019 HydroCAD Software Solutions LLC Pace 41 Summary for Subcatchment 8S: Storage/Office Runoff = 0.00 cfs @ 7.98 hrs, Volume= 0.002 af, Depth= 0.63" Runoff by SBUH method, Split Pervious/Imperv., Time Span= 0.00-50.00 hrs, dt= 0.05 hrs Type IA 24 -hr WQ Rainfall=0.83" u,CQICV IVVIJ. noo 0 1,288 98 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.0 Direct Entry, Subcatchment 8S: Storage/Office Hydrograph 0.005-.0.00 cfs —Runoff 0.005- - Type IA 24 -hr 0.004 WQ Rainfall=0.83" 0.004= Runoff Area=1,288-sf 0.003 Runoff Volume=0.002 of Runoff Depth=0.63" 0.003. Tc=10.0: m in 0 LL 0.002= CN=0/98 0.002 0.001 0.001- 0 5 10 15 20 25 30 35 40 45 50 Time (hours) Designed By: LAB Ridgeview Apartements Storm Analysis Type IA 24 -hr WQ Rainfall=0.83" Prepared by Olson & Morris Printed 11/12/2020 HydmCAD010.00-25 s/n 04993 02019 HydroCAD Software Solutions LLC Page 42 Summary for Subcatchment 14S: Parking Lot North Runoff = 0.02 cfs @ 7.98 hrs, Volume= 0.005 af, Depth= 0.63" Runoff by SBUH method, Split Pervious/Imperv., Time Span= 0.00-50.00 hrs, dt= 0.05 hrs Type IA 24 -hr WQ Rainfall=0.83" Area (sf) CN Description 4,509 98 Paved parking HSG B 4,509 98 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ff/ft) (ft/sec) (cfs) direct entry, Subcatchment 14S: Parking Lot North Hydrograph —Runoff 0.004:1 \ 0.002-- 0 5 10 15 20 25 30 35 40 Time (hours) Type IA 24 -hr 0.014' WQ Rainfall=0.83" 0.012- Runoff Area=4,509 sf Runoff Volume=0.005 of 0.01-_ Runoff Depth=0.63" 0 0.008 Tc=10.0'min w CN=0/98 0.004:1 \ 0.002-- 0 5 10 15 20 25 30 35 40 Time (hours) Designed By: LAB Ridgeview Apartements Storm Analysis Type IA 24 -hr WQ Rainfall=0.83" Prepared by Olson & Morris Printed 11/12/2020 HydroCADV 10 00-25 s/n 04993 02019 HydroCAD Software Solutions LLC Paae 43 Summary for Reach 13R: 8" Storm Inflow Area = 0.104 ac,100.00% Impervious, Inflow Depth = 0.63" for WQ event Inflow = 0.02 cfs @ 7.98 hrs, Volume= 0.005 of Outflow = 0.02 cfs @ 7.99 hrs, Volume= 0.005 af, Atten= 0%, Lag= 0.6 min Routing by Stor-Ind+Trans method, Time Span= 0.00-50.00 hrs, dt= 0.05 hrs Max. Velocity= 1.41 fps, Min. Travel Time= 0.6 min Avg. Velocity = 0.81 fps, Avg. Travel Time= 1.0 min Peak Storage= 1 cf @ 7.99 hrs Average Depth at Peak Storage= 0.04' Bank -Full Depth= 0.83' Flow Area= 0.5 sf, Capacity= 2.85 cls 10.0" Round Pipe n= 0.010 Length= 50.0' Slope= 0.01007 Inlet Invert=0.00', Outlet Invert= -0.50' 0 Reach 13R: 8" Storm 5 10 15 20 25 30 35 40 45 50 Time (hours) Hydrograph 0.02 cfs_ Inflow 0.016. Outflow Inflow Area=0.104 ac 0.014 Avg. Flow Depth=0.04' 0.012 - -Max Vel'' =1.41; fps 0.01 10.0" Round Pipe 0 0.008- n=0.010 u 0.006 L=50.0' S=0.01007' 0.004 cfs n nn2lCapacity=2.85 n nn2- 5 10 15 20 25 30 35 40 45 50 Time (hours) Designed By: LAB Ridgeview Apartements Storm Analysis Type /A 24 -hr WQ Rainfall=0.83" Prepared by Olson & Morris Printed 11/12/2020 HydroCAD® 10.00-25 s/n 04993 @2019 HydMCAD Software Solutions LLC Pane 44 Summary for Pond 2P: Rain Garden #4 Inflow Area = 0.580 ac,100.00% Impervious, Inflow Depth = 0.63" for WQ event Inflow = 0.09 cfs @ 7.98 hrs, Volume= 0.030 of Outflow = 0.03 cfs @ 9.02 hrs, Volume= 0.030 af, Atten= 63%, Lag= 62.4 min Discarded = 0.03 ds @ 9.02 hrs, Volume= 0.030 of Secondary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-50.00 hrs, dt= 0.05 hrs Peak Elev= 495.53' @ 9.02 hrs Surf.Area= 700 sf Storage= 245 cf Flood Elev= 498.53' Surf.Area= 3,678 sf Storage= 2,491 d Plug -Flow detention time= 147.5 min calculated for 0.030 of (100% of inflow) Center -of -Mass det. time= 147.4 min ( 877.3 - 729.9) #1 496.53' #2 495.53' #3 494.53' 2,581 cf 112 cf Area (Prismatic) Listed below (Recalc) ng Media (Prismatic)Listed below (Recalc) 1,122 cf Overall x 10.0% Voids 245 cf Rock Chamber 2,938 of Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubic -feet) (cubic -feet) 496.53 700 0 0 498.83 1,544 2,581 2,581 Elevation Surf.Area Inc.Store Cum.Store (feet) (so -ft) (cubic -feet) (cubic -feet) 495.53 700 0 0 496.53 1,544 1,122 1,122 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubic -feet) (cubic -feet) 494.53 700 0 0 495.53 700 700 700 below (Recalc) Device Routing Invert Outlet Devices #1 Discarded 494.53' 1.050 in/hr Exfiltration over Surface area #2 Secondary 497.93' 4.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads �scarded OutFlow Max=0.02 cfs @ 9.02 hrs HW=495.53' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.02 ds) Secondary OutFlow Max=0.00 cfs @ 0.00 hrs HW=494.53' (Free Discharge) 2=Orifice/Grate ( Controls 0.00 cfs) Designed By: LAB Ridgeview Apartements Storm Analysis Type IA 24 -hr WQ Rainfall=0.83" Prepared by Olson & Morris Printed 11/12/2020 HydroCAD®10 00-25 s/n 04993 02019 HydroCAD Software Solutions LLC Page 45 Pond 2P: Rain Garden #4 Hydrograph 0 5 10 15 20 25 30 35 40 45 50 Time (hours) 0.1 0.09 cfs —Inflow 0 Inflow Area=0.580 ac — D scarded 0.08- .08 Peak Elev=495'.53' —Secondary 0.07 Storage=245 cf a `o 0.06 0.05 a 0.04 0.03 cfs 0.03 . 0.02- 0 5 10 15 20 25 30 35 40 45 50 Time (hours) Designed By: LAB Ridgeview Apartements Storm Analysis Type IA 24 -hr WQ Rainfall=0.83" Prepared by Olson & Morris Printed 11/12/2020 HydroCAD810.00-25 s/n 04993 02019 HVdroCAD Software Solutions LLC Paae 46 Summary for Pond 11 P: North Rain Garden #2 Inflow Area = 0.030 ac,100.00% Impervious, Inflow Depth= 0.63" for WQ event Inflow = 0.00 cfs @ 7.98 hrs, Volume= 0.002 of Outflow = 0.00 cfs @ 7.65 hrs, Volume= 0.002 af, Atten= 39%, Lag= 0.0 min Discarded = 0.00 cfs @ 7.65 hrs, Volume= 0.002 of Secondary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-50.00 hrs, dt= 0.05 hrs Peak Elev= 496.54' @ 8.34 hrs Surf.Area= 53 sf Storage= 3 cf Flood Elev= 500.00' Surf.Area= 686 sf Storage= 362 cf Plug -Flow detention time= 3.5 min calculated for 0.002 of (100% of inflow) Center -of -Mass det. time= 3.5 min ( 733.3 - 729.9) Volume Invert Avail.Storage Storage Description #1 499.00' 211 cf Open Area Above Rain Garden (Prismatic)Listed below (Recalc) #2 498.00' 132 cf Open Area (Prismatic) Listed below (Recalc) #3 497.00' 13 cf Growing Media (Prismatic)Listed below (Recalc) 132 cf Overall x 10.0% Voids #4 496.00' 5 of Rock Chamber (Prismatic)Listed below (Recalc) 362 cf Total Available Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubic -feet) (cubic -feet) 499.00 211 0 0 500.00 211 211 211 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubic -feet) (cubic -feet) 498.00 53 0 0 499.00 211 132 132 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubic feet) (cubic -feet) 497.00 53 0 0 498.00 211 132 132 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubic -feet) (cubic -feet) 496.00 53 0 0 497.00 53 53 53 Device Routing Invert Outlet Devices #1 Discarded 496.00' 2.250 in/hr Exfiltration over Surface area #2 Secondary 499.00' 4.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Designed By: LAB Ridgeview Apartements Storm Analysis Type IA 24 -hr WQ Rainfall=0.83" Prepared by Olson & Morris Printed 11/12/2020 HydroCAD®10.00-25 s/n 04993 © 2019 HydroCAD Software Solutions LLC Paae 47 Sscarded OutFlow Max=0.00 cfs @ 7.65 hrs HW=496.04' (Free Discharge) 1=Exfiltration (ExFltration Controls 0.00 cfs) Secondary OutFlow Max=0.00 cfs @ 0.00 hrs HW=496.00' (Free Discharge) 2=Orifice/Grate ( Controls 0.00 cfs) Pond 11 P: North Rain Garden #2 Hydrograph 0.005- 0.00 cfs —I fl 0.003-10.00 cfs 0.003' 0 r n nm 0.002- 0.001 Inflow Area=0.030 ac LL wded PeakElev=496.54' dary Storage=3 cf 20 25 30 35 40 45 50 Time (hours) Designed By: LAB Ridgeview Apartements Storm Analysis Type IA 24 -hr WQ Rainfall=0.83" Prepared by Olson & Morris Printed 11/12/2020 HydmCAD® 10.00-25 s/n 04993 © 2019 HydroCAD Software Solutions LLC Page 48 Summary for Pond 12P: Rain Garden #3 Inflow Area = 0.178 ac,100.00% Impervious, Inflow Depth = 0.63" for WQ event Inflow = 0.03 cfs @ 7.98 hrs, Volume= 0.009 of Outflow = 0.01 cfs @ 7.60 hrs, Volume= 0.009 af, Atten= 61 %, Lag= 0.0 min Discarded = 0.01 cfs @ 7.60 hrs, Volume= 0.009 of Secondary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-50.00 hrs, dt= 0.05 hrs Peak Elev= 496.56'@ 8.91 hrs Surf.Area= 203 sf Storage= 40 cf Flood Elev= 500.00' Surf.Area= 1,517 sf Storage= 862 cf Plug -Flow detention time= 18.6 min calculated for 0.009 of (100% of inflow) Center -of -Mass det. time= 18.6 min ( 748.4 - 729.9 ) #1 #2 #3 #4 499.00' 498.00' 497.00' 496.00' 438 of Open Area Wall (Prlsmatic)Llsted below (Recalc) 321 cf Open Area (Prismatic)Listed below (Recalc) 32 cf Growing Media (Prismatic)Listed below (Recalc) 321 cf Overall x 10.0% Voids 71 cf Rock Chamber (Prismatic)Listed below (Recalc) 203 cf Overall x 35.0% Voids 862 of Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubic feet) (cubic -feet) 499.00 438 0 0 500.00 438 438 438 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubic -feet) (cubic -feet) 498.00 203 0 0 499.00 438 321 321 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubic -feet) (cubic -feet) 497.00 203 0 0 498.00 438 321 321 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubic -feet) (cubic -feet) 496.00 203 0 0 497.00 203 203 203 Device Routing Invert Outlet Devices #1 Discarded 496.00' 2.250 in/hr Exfiltration over Surface area #2 Secondary 499.00' 4.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Designed By: LAB Ridgeview Apartements Storm Analysis Type IA 24 -hr WQ Rainfall=0.83" Prepared by Olson & Morris Printed 11/12/2020 HydroCAD® 10.00-25 s/n 04993 02019 HydroCAD Software Solutions LLC Page 49 iscarded OutFlow Max=0.01 cfs @ 7.60 hrs HW=496.05' (Free Discharge) =Exfiltration (Exfiltration Controls 0.01 cfs) Secondary OutFlow Max=0.00 cfs @ 0.00 hrs HW=496.00' (Free Discharge) 2=Orifice/Grate ( Controls 0.00 cfs) Pond 12P: Rain Garden #3 Hydrograph 0.03 0.03 cfs 0.025 Inflow Area=0.178 ac Peak! E lev=496.56' 0.02 Storage=40 cf 0 0.015- .2 0.01 cfs 0.01- 0.005 0.00 cfs 0 0 5 10 15 20 25 30 35 40 45 50 Time (hours) —Inflow —Outflow —Discarded —Secondary Designed By: LAB Ridgeview Apartements Storm Analysis Type IA 24 -hr WQ Rainfall=(). 83" Prepared by Olson & Morris Printed 11/12/2020 HydroCAD010.00-25 s/n 04993 O 2019 HydroCAD Software Solutions LLC Page 50 Summary for Pond 1313: North Rain Garden #1 Inflow Area = 0.356 ac,100.00% Impervious, Inflow Depth= 0.63" for WQ event Inflow = 0.05 ofs @ 7.98 hrs, Volume= 0.019 of Outflow = 0.03 cfs @ 8.34 hrs, Volume= 0.018 af, Atten= 38%, Lag= 21.4 min Discarded = 0.03 cfs @ 8.34 hrs, Volume= 0.018 of Secondary= 0.00 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-50.00 hrs, dt= 0.05 hrs Peak Elev= 497.96' @ 8.33 hrs Surf.Area= 998 sf Storage= 85 cf Flood Elev= 500.00' Surf.Area= 2,292 sf Storage= 1,095 cf Plug -Flow detention time= 58.1 min calculated for 0.018 of (96% of inflow) Center -of -Mass det. time= 27.9 min ( 757.7 - 729.9 ) Volume Invert Avail.Storage Storage Description #1 499.00' 504 cf Open Area (Prismatic)Listed below (Recalc) #2 498.00' 504 cf Open Area (Prismatic)Listed below (Recalc) #3 497.00' 50 cf Growing Media (Prismatic)Listed below (Recalc) 504 cf Overall x 10.0% Voids #4 496.00' 37 cf Rock Chamber (Prismatic)Listed below (Recalc) 1,095 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubic -feet) (cubic -feet) 499.00 366 0 0 500.00 642 504 504 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubic -feet) (cubic -feet) 498.00 366 0 0 499.00 642 504 504 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubic -feet) (cubic -feet) 497.00 366 0 0 498.00 642 504 504 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq -ft) (cubic -feel) (cubic -feet) 496.00 366 0 0 497.00 366 366 366 Device Routing Invert Outlet Devices #1 Discarded 496.00' 2.250 in/hr Exfiltration over Surface area from 496.00' - 499.00' Excluded Surface area = 366 sf #2 Secondary 499.00' 4.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Designed By: LAB Ridgeview Apartements Storm Analysis Type IA 24 -hr WQ Rainfall=0.83" Prepared by Olson & Morris Printed 11/12/2020 HydroCAD010.00-25 stn 04993 02019 HydroCAD Software Solutions LLC Page 51 Discarded OutFlow Max=0.03 cfs @ 8.34 hrs HW=497.96' (Free Discharge) 1=Exfiltration (EAllration Controls 0.03 cfs) Secondary OutFlow Max=0.00 cfs @ 0.00 hrs HW=496.00' (Free Discharge) 2=0rifice/Grate ( Controls 0.00 cfs) Pond UP: North Rain Garden #1 Hydrograph 0 06'- 0 05 cfs 0.01A I 0 5 10 15 20 25 30 35 40 Time (hours) — Inflow — Outflow — Discarded — Secondary 0.055- 0.05- Inflow Area=0.356 ac 0.045- Peak'Elev=49T.96' 0.04= Storage=85 cf 0.03 cfs 0.035 0.03 LL 0.025 0.02 0.01A I 0 5 10 15 20 25 30 35 40 Time (hours) — Inflow — Outflow — Discarded — Secondary Designed By: LAB Ridgeview Apartements Storm Analysis Type lA 24 -hr WQ Rainfall=0.83" Prepared by Olson & Morris Printed 11/12/2020 HydroCAD®10.00-25 s/n 04993 02019 HydroCAD Software Solutions LLC Pace 52 Summary for Pond 16P: Dual Chamber CB Inflow Area = 0.104 ac,100.00% Impervious, Inflow Depth = 0.63" for WQ event Inflow = 0.02 cis @ 7.98 hrs, Volume= 0.005 of Outflow = 0.02 ds @ 7.98 hrs, Volume= 0.005 af, Atten= 0%, Lag= 0.0 min Primary = 0.02 cis @ 7.98 hrs, Volume= 0.005 of Routing by Stor-Ind method, Time Span= 0.00-50.00 hrs, dt= 0.05 hrs Peak Elev= 497.08' @ 7.98 hrs Flood EIev=499.00' Device Routing Invert Outlet Devices #1 Primary 497.00' 4.0" Vert. Orifice/Grate C= 0.600 Primary OutFlow Max=0.02 ds @ 7.98 hrs HW=497.08' (Free Discharge) L1=Orifice/Grate (Orifice Controls 0.02 cfs @ 0.97 fps) Pond 16P: Dual Chamber CB Hydrograph 0.01 0.012 0 0.01 0 0.008 LL 0.02 cis — Inflow Inflow Area=0.104 ac — Primary PeakEIev=497.08' 0 5 10 15 20 25 30 35 40 45 50 Time (hours)