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HomeMy WebLinkAboutStormwater Management Report 4.24.2026Site Developrnent ' Propertv Line ' Subdivision ' Sanitar-v . Land Court . Environmental Permitting STO RMWATER IVIANAG EM E NT RE PO RT UNCLE CHARL 'S PATI-{ S. Yarrnouth, MA APRt L 24, 2026 PREPARED FOR: HABITAT FOR HUMANITY OF CAPE COD, INC 411 MA!N STREET SUITE 6 YARMOUTHPORT, MA 02675 PREPARED BY: J,M. O'REILLY & ASSOCIATES, INC 1573 MAIN STREET P.O. BOX 1773 BREWSTER, MA 02631 508-896-6601 J.M. O'REILLY & ASSOCIATES, !NC. r573 MArN S'rnoer, P.O. Box t773,BxawsrER, MA c2631. PHoNB: (5os) S96-66or . Fax: (5oz) s96-66o2 www.JMoRETLLYAS SOC. COM ROEERT F. REEDY CIVIL o, 560 t J.M. O'RuLLY a. AssocrATES, INC. PRorBssroNer- ENcTNEERTNG, LeNo SunvByrNc ed E,NvTnoNMENTAL SpRr.rce,s Pre-Development 1 Existing Watershed TSR Total Site Runoff Routing Diagram for 9489.PRE-DEV Prepared by J M O'Reilly & Associates Inc, Printed 4/22/2026 HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Subcat Reach Pond Link 9489.PRE-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 2HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Rainfall Events Listing Event# Event Name Storm Type Curve Mode Duration (hours) B/B Depth (inches) AMC 1 2-Year Type III 24-hr Default 24.00 1 3.35 2 2 10-Year Type III 24-hr Default 24.00 1 4.87 2 3 25-Year Type III 24-hr Default 24.00 1 5.82 2 4 50-Year Type III 24-hr Default 24.00 1 6.54 2 5 100-Year Type III 24-hr Default 24.00 1 7.29 2 Type III 24-hr 2-Year Rainfall=3.35"9489.PRE-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 3HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Time span=0.00-30.00 hrs, dt=0.01 hrs, 3001 points x 2 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Dyn-Stor-Ind method - Pond routing by Dyn-Stor-Ind method Runoff Area=43,563 sf 7.47% Impervious Runoff Depth=0.10"Subcatchment 1: Existing Watershed Flow Length=300' Tc=16.9 min CN=47 Runoff=0.01 cfs 0.008 af Inflow=0.01 cfs 0.008 afLink TSR: Total Site Runoff Primary=0.01 cfs 0.008 af Total Runoff Area = 1.000 ac Runoff Volume = 0.008 af Average Runoff Depth = 0.10" 92.53% Pervious = 0.925 ac 7.47% Impervious = 0.075 ac Type III 24-hr 2-Year Rainfall=3.35"9489.PRE-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 4HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment 1: Existing Watershed Runoff = 0.01 cfs @ 14.70 hrs, Volume= 0.008 af, Depth= 0.10" Routed to Link TSR : Total Site Runoff Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 2-Year Rainfall=3.35" Area (sf) CN Description * 3,255 98 Existing Paved Parking, HSG A 40,308 43 Woods/grass comb., Fair, HSG A 43,563 47 Weighted Average 40,308 92.53% Pervious Area 3,255 7.47% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 12.1 50 0.0200 0.07 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.35" 4.8 250 0.0300 0.87 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 16.9 300 Total Subcatchment 1: Existing Watershed Runoff Hydrograph Time (hours) 3029282726252423222120191817161514131211109876543210Flow (cfs)0.014 0.013 0.012 0.011 0.01 0.009 0.008 0.007 0.006 0.005 0.004 0.003 0.002 0.001 0 Type III 24-hr 2-Year Rainfall=3.35" Runoff Area=43,563 sf Runoff Volume=0.008 af Runoff Depth=0.10" Flow Length=300' Tc=16.9 min CN=47 0.01 cfs Type III 24-hr 2-Year Rainfall=3.35"9489.PRE-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 5HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Summary for Link TSR: Total Site Runoff Inflow Area = 1.000 ac, 7.47% Impervious, Inflow Depth = 0.10" for 2-Year event Inflow = 0.01 cfs @ 14.70 hrs, Volume= 0.008 af Primary = 0.01 cfs @ 14.70 hrs, Volume= 0.008 af, Atten= 0%, Lag= 0.0 min Routed to nonexistent node 2R Primary outflow = Inflow, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Link TSR: Total Site Runoff Inflow Primary Hydrograph Time (hours) 3029282726252423222120191817161514131211109876543210Flow (cfs)0.014 0.013 0.012 0.011 0.01 0.009 0.008 0.007 0.006 0.005 0.004 0.003 0.002 0.001 0 Inflow Area=1.000 ac 0.01 cfs 0.01 cfs Type III 24-hr 10-Year Rainfall=4.87"9489.PRE-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 6HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Time span=0.00-30.00 hrs, dt=0.01 hrs, 3001 points x 2 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Dyn-Stor-Ind method - Pond routing by Dyn-Stor-Ind method Runoff Area=43,563 sf 7.47% Impervious Runoff Depth=0.49"Subcatchment 1: Existing Watershed Flow Length=300' Tc=16.9 min CN=47 Runoff=0.22 cfs 0.041 af Inflow=0.22 cfs 0.041 afLink TSR: Total Site Runoff Primary=0.22 cfs 0.041 af Total Runoff Area = 1.000 ac Runoff Volume = 0.041 af Average Runoff Depth = 0.49" 92.53% Pervious = 0.925 ac 7.47% Impervious = 0.075 ac Type III 24-hr 10-Year Rainfall=4.87"9489.PRE-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 7HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment 1: Existing Watershed Runoff = 0.22 cfs @ 12.45 hrs, Volume= 0.041 af, Depth= 0.49" Routed to Link TSR : Total Site Runoff Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 10-Year Rainfall=4.87" Area (sf) CN Description * 3,255 98 Existing Paved Parking, HSG A 40,308 43 Woods/grass comb., Fair, HSG A 43,563 47 Weighted Average 40,308 92.53% Pervious Area 3,255 7.47% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 12.1 50 0.0200 0.07 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.35" 4.8 250 0.0300 0.87 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 16.9 300 Total Subcatchment 1: Existing Watershed Runoff Hydrograph Time (hours) 3029282726252423222120191817161514131211109876543210Flow (cfs)0.24 0.23 0.22 0.21 0.2 0.19 0.18 0.17 0.16 0.15 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 Type III 24-hr 10-Year Rainfall=4.87" Runoff Area=43,563 sf Runoff Volume=0.041 af Runoff Depth=0.49" Flow Length=300' Tc=16.9 min CN=47 0.22 cfs Type III 24-hr 10-Year Rainfall=4.87"9489.PRE-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 8HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Summary for Link TSR: Total Site Runoff Inflow Area = 1.000 ac, 7.47% Impervious, Inflow Depth = 0.49" for 10-Year event Inflow = 0.22 cfs @ 12.45 hrs, Volume= 0.041 af Primary = 0.22 cfs @ 12.45 hrs, Volume= 0.041 af, Atten= 0%, Lag= 0.0 min Routed to nonexistent node 2R Primary outflow = Inflow, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Link TSR: Total Site Runoff Inflow Primary Hydrograph Time (hours) 3029282726252423222120191817161514131211109876543210Flow (cfs)0.24 0.23 0.22 0.21 0.2 0.19 0.18 0.17 0.16 0.15 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 Inflow Area=1.000 ac 0.22 cfs 0.22 cfs Type III 24-hr 25-Year Rainfall=5.82"9489.PRE-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 9HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Time span=0.00-30.00 hrs, dt=0.01 hrs, 3001 points x 2 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Dyn-Stor-Ind method - Pond routing by Dyn-Stor-Ind method Runoff Area=43,563 sf 7.47% Impervious Runoff Depth=0.86"Subcatchment 1: Existing Watershed Flow Length=300' Tc=16.9 min CN=47 Runoff=0.48 cfs 0.071 af Inflow=0.48 cfs 0.071 afLink TSR: Total Site Runoff Primary=0.48 cfs 0.071 af Total Runoff Area = 1.000 ac Runoff Volume = 0.071 af Average Runoff Depth = 0.86" 92.53% Pervious = 0.925 ac 7.47% Impervious = 0.075 ac Type III 24-hr 25-Year Rainfall=5.82"9489.PRE-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 10HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment 1: Existing Watershed Runoff = 0.48 cfs @ 12.33 hrs, Volume= 0.071 af, Depth= 0.86" Routed to Link TSR : Total Site Runoff Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 25-Year Rainfall=5.82" Area (sf) CN Description * 3,255 98 Existing Paved Parking, HSG A 40,308 43 Woods/grass comb., Fair, HSG A 43,563 47 Weighted Average 40,308 92.53% Pervious Area 3,255 7.47% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 12.1 50 0.0200 0.07 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.35" 4.8 250 0.0300 0.87 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 16.9 300 Total Subcatchment 1: Existing Watershed Runoff Hydrograph Time (hours) 3029282726252423222120191817161514131211109876543210Flow (cfs)0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Type III 24-hr 25-Year Rainfall=5.82" Runoff Area=43,563 sf Runoff Volume=0.071 af Runoff Depth=0.86" Flow Length=300' Tc=16.9 min CN=47 0.48 cfs Type III 24-hr 25-Year Rainfall=5.82"9489.PRE-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 11HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Summary for Link TSR: Total Site Runoff Inflow Area = 1.000 ac, 7.47% Impervious, Inflow Depth = 0.86" for 25-Year event Inflow = 0.48 cfs @ 12.33 hrs, Volume= 0.071 af Primary = 0.48 cfs @ 12.33 hrs, Volume= 0.071 af, Atten= 0%, Lag= 0.0 min Routed to nonexistent node 2R Primary outflow = Inflow, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Link TSR: Total Site Runoff Inflow Primary Hydrograph Time (hours) 3029282726252423222120191817161514131211109876543210Flow (cfs)0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Inflow Area=1.000 ac 0.48 cfs 0.48 cfs Type III 24-hr 50-Year Rainfall=6.54"9489.PRE-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 12HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Time span=0.00-30.00 hrs, dt=0.01 hrs, 3001 points x 2 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Dyn-Stor-Ind method - Pond routing by Dyn-Stor-Ind method Runoff Area=43,563 sf 7.47% Impervious Runoff Depth=1.18"Subcatchment 1: Existing Watershed Flow Length=300' Tc=16.9 min CN=47 Runoff=0.76 cfs 0.098 af Inflow=0.76 cfs 0.098 afLink TSR: Total Site Runoff Primary=0.76 cfs 0.098 af Total Runoff Area = 1.000 ac Runoff Volume = 0.098 af Average Runoff Depth = 1.18" 92.53% Pervious = 0.925 ac 7.47% Impervious = 0.075 ac Type III 24-hr 50-Year Rainfall=6.54"9489.PRE-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 13HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment 1: Existing Watershed Runoff = 0.76 cfs @ 12.30 hrs, Volume= 0.098 af, Depth= 1.18" Routed to Link TSR : Total Site Runoff Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 50-Year Rainfall=6.54" Area (sf) CN Description * 3,255 98 Existing Paved Parking, HSG A 40,308 43 Woods/grass comb., Fair, HSG A 43,563 47 Weighted Average 40,308 92.53% Pervious Area 3,255 7.47% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 12.1 50 0.0200 0.07 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.35" 4.8 250 0.0300 0.87 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 16.9 300 Total Subcatchment 1: Existing Watershed Runoff Hydrograph Time (hours) 3029282726252423222120191817161514131211109876543210Flow (cfs)0.8 0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Type III 24-hr 50-Year Rainfall=6.54" Runoff Area=43,563 sf Runoff Volume=0.098 af Runoff Depth=1.18" Flow Length=300' Tc=16.9 min CN=47 0.76 cfs Type III 24-hr 50-Year Rainfall=6.54"9489.PRE-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 14HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Summary for Link TSR: Total Site Runoff Inflow Area = 1.000 ac, 7.47% Impervious, Inflow Depth = 1.18" for 50-Year event Inflow = 0.76 cfs @ 12.30 hrs, Volume= 0.098 af Primary = 0.76 cfs @ 12.30 hrs, Volume= 0.098 af, Atten= 0%, Lag= 0.0 min Routed to nonexistent node 2R Primary outflow = Inflow, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Link TSR: Total Site Runoff Inflow Primary Hydrograph Time (hours) 3029282726252423222120191817161514131211109876543210Flow (cfs)0.8 0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Inflow Area=1.000 ac 0.76 cfs 0.76 cfs Type III 24-hr 100-Year Rainfall=7.29"9489.PRE-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 15HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Time span=0.00-30.00 hrs, dt=0.01 hrs, 3001 points x 2 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Dyn-Stor-Ind method - Pond routing by Dyn-Stor-Ind method Runoff Area=43,563 sf 7.47% Impervious Runoff Depth=1.55"Subcatchment 1: Existing Watershed Flow Length=300' Tc=16.9 min CN=47 Runoff=1.08 cfs 0.130 af Inflow=1.08 cfs 0.130 afLink TSR: Total Site Runoff Primary=1.08 cfs 0.130 af Total Runoff Area = 1.000 ac Runoff Volume = 0.130 af Average Runoff Depth = 1.55" 92.53% Pervious = 0.925 ac 7.47% Impervious = 0.075 ac Type III 24-hr 100-Year Rainfall=7.29"9489.PRE-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 16HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment 1: Existing Watershed Runoff = 1.08 cfs @ 12.27 hrs, Volume= 0.130 af, Depth= 1.55" Routed to Link TSR : Total Site Runoff Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 100-Year Rainfall=7.29" Area (sf) CN Description * 3,255 98 Existing Paved Parking, HSG A 40,308 43 Woods/grass comb., Fair, HSG A 43,563 47 Weighted Average 40,308 92.53% Pervious Area 3,255 7.47% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 12.1 50 0.0200 0.07 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.35" 4.8 250 0.0300 0.87 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 16.9 300 Total Subcatchment 1: Existing Watershed Runoff Hydrograph Time (hours) 3029282726252423222120191817161514131211109876543210Flow (cfs)1 0 Type III 24-hr 100-Year Rainfall=7.29" Runoff Area=43,563 sf Runoff Volume=0.130 af Runoff Depth=1.55" Flow Length=300' Tc=16.9 min CN=47 1.08 cfs Type III 24-hr 100-Year Rainfall=7.29"9489.PRE-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 17HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Summary for Link TSR: Total Site Runoff Inflow Area = 1.000 ac, 7.47% Impervious, Inflow Depth = 1.55" for 100-Year event Inflow = 1.08 cfs @ 12.27 hrs, Volume= 0.130 af Primary = 1.08 cfs @ 12.27 hrs, Volume= 0.130 af, Atten= 0%, Lag= 0.0 min Routed to nonexistent node 2R Primary outflow = Inflow, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Link TSR: Total Site Runoff Inflow Primary Hydrograph Time (hours) 3029282726252423222120191817161514131211109876543210Flow (cfs)1 0 Inflow Area=1.000 ac 1.08 cfs 1.08 cfs Post-Development 1 Pavement and Surrounding Area 2 (6) Dwellings 3 Non-Recharged Areas 1CB CB (2) Solid Catch Basins 1MH CB (1) Manhole 1P Roadway Leaching Facility 2P Roof Runoff Leaching Facilities TSR Total Site Runoff Routing Diagram for 9489.POST-DEV Prepared by J M O'Reilly & Associates Inc, Printed 4/22/2026 HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Subcat Reach Pond Link 9489.POST-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 2HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Rainfall Events Listing Event# Event Name Storm Type Curve Mode Duration (hours) B/B Depth (inches) AMC 1 2-Year Type III 24-hr Default 24.00 1 3.35 2 2 10-Year Type III 24-hr Default 24.00 1 4.87 2 3 25-Year Type III 24-hr Default 24.00 1 5.82 2 4 50-Year Type III 24-hr Default 24.00 1 6.54 2 5 100-Year Type III 24-hr Default 24.00 1 7.29 2 Type III 24-hr 2-Year Rainfall=3.35"9489.POST-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 3HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Time span=0.00-30.00 hrs, dt=0.01 hrs, 3001 points x 2 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Dyn-Stor-Ind method - Pond routing by Dyn-Stor-Ind method Runoff Area=28,663 sf 32.51% Impervious Runoff Depth=0.40"Subcatchment 1: Pavement and Flow Length=150' Tc=5.9 min CN=58 Runoff=0.16 cfs 0.022 af Runoff Area=4,962 sf 100.00% Impervious Runoff Depth=3.12"Subcatchment 2: (6) Dwellings Tc=6.0 min CN=98 Runoff=0.37 cfs 0.030 af Runoff Area=9,938 sf 0.00% Impervious Runoff Depth=0.00"Subcatchment 3: Non-Recharged Areas Tc=6.0 min CN=39 Runoff=0.00 cfs 0.000 af Peak Elev=14.48' Inflow=0.16 cfs 0.022 afPond 1CB: (2) Solid Catch Basins 12.0" Round Culvert x 2.00 n=0.009 L=9.0' S=0.0111 '/' Outflow=0.16 cfs 0.022 af Peak Elev=14.42' Inflow=0.16 cfs 0.022 afPond 1MH: (1) Manhole 12.0" Round Culvert n=0.009 L=25.0' S=0.0080 '/' Outflow=0.16 cfs 0.022 af Peak Elev=10.02' Storage=10 cf Inflow=0.16 cfs 0.022 afPond 1P: Roadway Leaching Facility Discarded=0.14 cfs 0.022 af Primary=0.00 cfs 0.000 af Outflow=0.14 cfs 0.022 af Peak Elev=101.09' Storage=294 cf Inflow=0.37 cfs 0.030 afPond 2P: Roof Runoff Leaching Facilities Discarded=0.09 cfs 0.030 af Primary=0.00 cfs 0.000 af Outflow=0.09 cfs 0.030 af Inflow=0.00 cfs 0.000 afLink TSR: Total Site Runoff Primary=0.00 cfs 0.000 af Total Runoff Area = 1.000 ac Runoff Volume = 0.051 af Average Runoff Depth = 0.62" 67.22% Pervious = 0.672 ac 32.78% Impervious = 0.328 ac Type III 24-hr 2-Year Rainfall=3.35"9489.POST-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 4HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment 1: Pavement and Surrounding Area Runoff = 0.16 cfs @ 12.13 hrs, Volume= 0.022 af, Depth= 0.40" Routed to Pond 1CB : (2) Solid Catch Basins Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 2-Year Rainfall=3.35" Area (sf) CN Description * 9,319 98 Road & Driveways, HSG A * 19,344 39 Landscaped Areas, Good, HSG A 28,663 58 Weighted Average 19,344 67.49% Pervious Area 9,319 32.51% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.5 50 0.0200 0.15 Sheet Flow, Grass: Short n= 0.150 P2= 3.35" 0.4 100 0.0350 3.80 Shallow Concentrated Flow, Paved Kv= 20.3 fps 5.9 150 Total Subcatchment 1: Pavement and Surrounding Area Runoff Hydrograph Time (hours) 3029282726252423222120191817161514131211109876543210Flow (cfs)0.17 0.16 0.15 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 Type III 24-hr 2-Year Rainfall=3.35" Runoff Area=28,663 sf Runoff Volume=0.022 af Runoff Depth=0.40" Flow Length=150' Tc=5.9 min CN=58 0.16 cfs Type III 24-hr 2-Year Rainfall=3.35"9489.POST-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 5HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment 2: (6) Dwellings Runoff = 0.37 cfs @ 12.08 hrs, Volume= 0.030 af, Depth= 3.12" Routed to Pond 2P : Roof Runoff Leaching Facilities Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 2-Year Rainfall=3.35" Area (sf) CN Description * 4,962 98 Roofs, HSG A 4,962 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, (minimum) Subcatchment 2: (6) Dwellings Runoff Hydrograph Time (hours) 3029282726252423222120191817161514131211109876543210Flow (cfs)0.4 0.38 0.36 0.34 0.32 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Type III 24-hr 2-Year Rainfall=3.35" Runoff Area=4,962 sf Runoff Volume=0.030 af Runoff Depth=3.12" Tc=6.0 min CN=98 0.37 cfs Type III 24-hr 2-Year Rainfall=3.35"9489.POST-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 6HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment 3: Non-Recharged Areas Runoff = 0.00 cfs @ 23.98 hrs, Volume= 0.000 af, Depth= 0.00" Routed to Link TSR : Total Site Runoff Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 2-Year Rainfall=3.35" Area (sf) CN Description 500 43 Woods/grass comb., Fair, HSG A * 9,438 39 Landscaped Areas, Good, HSG A 9,938 39 Weighted Average 9,938 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, (minimum) Subcatchment 3: Non-Recharged Areas Runoff Hydrograph Time (hours) 3029282726252423222120191817161514131211109876543210Flow (cfs)0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0 0 0 0 0 0 0 0 0 0 Type III 24-hr 2-Year Rainfall=3.35" Runoff Area=9,938 sf Runoff Volume=0.000 af Runoff Depth=0.00" Tc=6.0 min CN=39 0.00 cfs Type III 24-hr 2-Year Rainfall=3.35"9489.POST-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 7HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Summary for Pond 1CB: (2) Solid Catch Basins Inflow Area = 0.658 ac, 32.51% Impervious, Inflow Depth = 0.40" for 2-Year event Inflow = 0.16 cfs @ 12.13 hrs, Volume= 0.022 af Outflow = 0.16 cfs @ 12.13 hrs, Volume= 0.022 af, Atten= 0%, Lag= 0.0 min Primary = 0.16 cfs @ 12.13 hrs, Volume= 0.022 af Routed to Pond 1MH : (1) Manhole Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs / 2 Peak Elev= 14.48' @ 12.13 hrs Device Routing Invert Outlet Devices #1 Primary 14.30'12.0" Round Culvert X 2.00 L= 9.0' CPP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 14.30' / 14.20' S= 0.0111 '/' Cc= 0.900 n= 0.009 Corrugated PE, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max=0.16 cfs @ 12.13 hrs HW=14.48' TW=14.42' (Dynamic Tailwater) 1=Culvert (Outlet Controls 0.16 cfs @ 1.26 fps) Pond 1CB: (2) Solid Catch Basins Inflow Primary Hydrograph Time (hours) 3029282726252423222120191817161514131211109876543210Flow (cfs)0.17 0.16 0.15 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 Inflow Area=0.658 ac Peak Elev=14.48' 12.0" Round Culvert x 2.00 n=0.009 L=9.0' S=0.0111 '/' 0.16 cfs 0.16 cfs Type III 24-hr 2-Year Rainfall=3.35"9489.POST-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 8HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Summary for Pond 1MH: (1) Manhole Inflow Area = 0.658 ac, 32.51% Impervious, Inflow Depth = 0.40" for 2-Year event Inflow = 0.16 cfs @ 12.13 hrs, Volume= 0.022 af Outflow = 0.16 cfs @ 12.13 hrs, Volume= 0.022 af, Atten= 0%, Lag= 0.0 min Primary = 0.16 cfs @ 12.13 hrs, Volume= 0.022 af Routed to Pond 1P : Roadway Leaching Facility Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs / 2 Peak Elev= 14.42' @ 12.13 hrs Device Routing Invert Outlet Devices #1 Primary 14.20'12.0" Round Culvert L= 25.0' CPP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 14.20' / 14.00' S= 0.0080 '/' Cc= 0.900 n= 0.009 Corrugated PE, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max=0.16 cfs @ 12.13 hrs HW=14.42' TW=10.02' (Dynamic Tailwater) 1=Culvert (Inlet Controls 0.16 cfs @ 1.26 fps) Pond 1MH: (1) Manhole Inflow Primary Hydrograph Time (hours) 3029282726252423222120191817161514131211109876543210Flow (cfs)0.17 0.16 0.15 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 Inflow Area=0.658 ac Peak Elev=14.42' 12.0" Round Culvert n=0.009 L=25.0' S=0.0080 '/' 0.16 cfs 0.16 cfs Type III 24-hr 2-Year Rainfall=3.35"9489.POST-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 9HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Summary for Pond 1P: Roadway Leaching Facility Inflow Area = 0.658 ac, 32.51% Impervious, Inflow Depth = 0.40" for 2-Year event Inflow = 0.16 cfs @ 12.13 hrs, Volume= 0.022 af Outflow = 0.14 cfs @ 12.24 hrs, Volume= 0.022 af, Atten= 14%, Lag= 6.6 min Discarded = 0.14 cfs @ 12.24 hrs, Volume= 0.022 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routed to Link TSR : Total Site Runoff Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs / 2 Peak Elev= 10.02' @ 12.24 hrs Surf.Area= 720 sf Storage= 10 cf Plug-Flow detention time= 0.6 min calculated for 0.022 af (100% of inflow) Center-of-Mass det. time= 0.6 min ( 926.2 - 925.6 ) Volume Invert Avail.Storage Storage Description #1 10.00' 679 cf 6.00'D x 4.00'H Leach Pits x 6 Inside #2 796 cf Overall - 3.0" Wall Thickness = 679 cf #2 10.00' 938 cf 24.00'W x 30.00'L x 4.00'H Stone 2,880 cf Overall - 796 cf Embedded = 2,084 cf x 45.0% Voids 1,616 cf Total Available Storage Device Routing Invert Outlet Devices #1 Discarded 10.00'8.270 in/hr Exfiltration over Wetted area Phase-In= 0.01' #2 Primary 13.90'10.0' long (Profile 6) Broad-Crested Rectangular Weir Head (feet) 0.49 0.98 1.48 Coef. (English) 3.12 3.41 3.59 Discarded OutFlow Max=0.14 cfs @ 12.24 hrs HW=10.02' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.14 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=10.00' TW=0.00' (Dynamic Tailwater) 2=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Type III 24-hr 2-Year Rainfall=3.35"9489.POST-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 10HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Pond 1P: Roadway Leaching Facility Inflow Outflow Discarded Primary Hydrograph Time (hours) 3029282726252423222120191817161514131211109876543210Flow (cfs)0.17 0.16 0.15 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 Inflow Area=0.658 ac Peak Elev=10.02' Storage=10 cf 0.16 cfs 0.14 cfs 0.14 cfs 0.00 cfs Type III 24-hr 2-Year Rainfall=3.35"9489.POST-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 11HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Summary for Pond 2P: Roof Runoff Leaching Facilities Inflow Area = 0.114 ac,100.00% Impervious, Inflow Depth = 3.12" for 2-Year event Inflow = 0.37 cfs @ 12.08 hrs, Volume= 0.030 af Outflow = 0.09 cfs @ 12.46 hrs, Volume= 0.030 af, Atten= 75%, Lag= 22.3 min Discarded = 0.09 cfs @ 12.46 hrs, Volume= 0.030 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routed to Link TSR : Total Site Runoff Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs / 2 Peak Elev= 101.09' @ 12.46 hrs Surf.Area= 294 sf Storage= 294 cf Plug-Flow detention time= 18.6 min calculated for 0.030 af (100% of inflow) Center-of-Mass det. time= 18.6 min ( 774.0 - 755.4 ) Volume Invert Avail.Storage Storage Description #1 100.00' 317 cf 4.00'W x 4.00'L x 3.30'H Prismatoid x 6 Inside #2 401 cf Overall - 3.0" Wall Thickness = 317 cf #2 100.00' 569 cf 7.00'W x 7.00'L x 3.30'H Prismatoid x 6 970 cf Overall - 401 cf Embedded = 569 cf 886 cf Total Available Storage Device Routing Invert Outlet Devices #1 Discarded 100.00'8.270 in/hr Exfiltration over Wetted area Phase-In= 0.01' #2 Primary 103.20'10.0' long (Profile 6) Broad-Crested Rectangular Weir Head (feet) 0.49 0.98 1.48 Coef. (English) 3.12 3.41 3.59 Discarded OutFlow Max=0.09 cfs @ 12.46 hrs HW=101.09' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.09 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=100.00' TW=0.00' (Dynamic Tailwater) 2=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Type III 24-hr 2-Year Rainfall=3.35"9489.POST-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 12HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Pond 2P: Roof Runoff Leaching Facilities Inflow Outflow Discarded Primary Hydrograph Time (hours) 3029282726252423222120191817161514131211109876543210Flow (cfs)0.4 0.38 0.36 0.34 0.32 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Inflow Area=0.114 ac Peak Elev=101.09' Storage=294 cf 0.37 cfs 0.09 cfs 0.09 cfs 0.00 cfs Type III 24-hr 2-Year Rainfall=3.35"9489.POST-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 13HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Summary for Link TSR: Total Site Runoff Inflow Area = 1.000 ac, 32.78% Impervious, Inflow Depth = 0.00" for 2-Year event Inflow = 0.00 cfs @ 23.98 hrs, Volume= 0.000 af Primary = 0.00 cfs @ 23.98 hrs, Volume= 0.000 af, Atten= 0%, Lag= 0.0 min Routed to nonexistent node 2R Primary outflow = Inflow, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Link TSR: Total Site Runoff Inflow Primary Hydrograph Time (hours) 3029282726252423222120191817161514131211109876543210Flow (cfs)0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0 0 0 0 0 0 0 0 0 0 Inflow Area=1.000 ac 0.00 cfs 0.00 cfs Type III 24-hr 10-Year Rainfall=4.87"9489.POST-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 14HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Time span=0.00-30.00 hrs, dt=0.01 hrs, 3001 points x 2 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Dyn-Stor-Ind method - Pond routing by Dyn-Stor-Ind method Runoff Area=28,663 sf 32.51% Impervious Runoff Depth=1.10"Subcatchment 1: Pavement and Flow Length=150' Tc=5.9 min CN=58 Runoff=0.72 cfs 0.060 af Runoff Area=4,962 sf 100.00% Impervious Runoff Depth=4.63"Subcatchment 2: (6) Dwellings Tc=6.0 min CN=98 Runoff=0.54 cfs 0.044 af Runoff Area=9,938 sf 0.00% Impervious Runoff Depth=0.17"Subcatchment 3: Non-Recharged Areas Tc=6.0 min CN=39 Runoff=0.01 cfs 0.003 af Peak Elev=14.76' Inflow=0.72 cfs 0.060 afPond 1CB: (2) Solid Catch Basins 12.0" Round Culvert x 2.00 n=0.009 L=9.0' S=0.0111 '/' Outflow=0.72 cfs 0.060 af Peak Elev=14.69' Inflow=0.72 cfs 0.060 afPond 1MH: (1) Manhole 12.0" Round Culvert n=0.009 L=25.0' S=0.0080 '/' Outflow=0.72 cfs 0.060 af Peak Elev=11.42' Storage=574 cf Inflow=0.72 cfs 0.060 afPond 1P: Roadway Leaching Facility Discarded=0.17 cfs 0.060 af Primary=0.00 cfs 0.000 af Outflow=0.17 cfs 0.060 af Peak Elev=101.86' Storage=500 cf Inflow=0.54 cfs 0.044 afPond 2P: Roof Runoff Leaching Facilities Discarded=0.12 cfs 0.044 af Primary=0.00 cfs 0.000 af Outflow=0.12 cfs 0.044 af Inflow=0.01 cfs 0.003 afLink TSR: Total Site Runoff Primary=0.01 cfs 0.003 af Total Runoff Area = 1.000 ac Runoff Volume = 0.108 af Average Runoff Depth = 1.29" 67.22% Pervious = 0.672 ac 32.78% Impervious = 0.328 ac Type III 24-hr 10-Year Rainfall=4.87"9489.POST-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 15HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment 1: Pavement and Surrounding Area Runoff = 0.72 cfs @ 12.10 hrs, Volume= 0.060 af, Depth= 1.10" Routed to Pond 1CB : (2) Solid Catch Basins Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 10-Year Rainfall=4.87" Area (sf) CN Description * 9,319 98 Road & Driveways, HSG A * 19,344 39 Landscaped Areas, Good, HSG A 28,663 58 Weighted Average 19,344 67.49% Pervious Area 9,319 32.51% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.5 50 0.0200 0.15 Sheet Flow, Grass: Short n= 0.150 P2= 3.35" 0.4 100 0.0350 3.80 Shallow Concentrated Flow, Paved Kv= 20.3 fps 5.9 150 Total Subcatchment 1: Pavement and Surrounding Area Runoff Hydrograph Time (hours) 3029282726252423222120191817161514131211109876543210Flow (cfs)0.8 0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Type III 24-hr 10-Year Rainfall=4.87" Runoff Area=28,663 sf Runoff Volume=0.060 af Runoff Depth=1.10" Flow Length=150' Tc=5.9 min CN=58 0.72 cfs Type III 24-hr 10-Year Rainfall=4.87"9489.POST-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 16HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment 2: (6) Dwellings Runoff = 0.54 cfs @ 12.08 hrs, Volume= 0.044 af, Depth= 4.63" Routed to Pond 2P : Roof Runoff Leaching Facilities Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 10-Year Rainfall=4.87" Area (sf) CN Description * 4,962 98 Roofs, HSG A 4,962 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, (minimum) Subcatchment 2: (6) Dwellings Runoff Hydrograph Time (hours) 3029282726252423222120191817161514131211109876543210Flow (cfs)0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Type III 24-hr 10-Year Rainfall=4.87" Runoff Area=4,962 sf Runoff Volume=0.044 af Runoff Depth=4.63" Tc=6.0 min CN=98 0.54 cfs Type III 24-hr 10-Year Rainfall=4.87"9489.POST-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 17HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment 3: Non-Recharged Areas Runoff = 0.01 cfs @ 12.50 hrs, Volume= 0.003 af, Depth= 0.17" Routed to Link TSR : Total Site Runoff Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 10-Year Rainfall=4.87" Area (sf) CN Description 500 43 Woods/grass comb., Fair, HSG A * 9,438 39 Landscaped Areas, Good, HSG A 9,938 39 Weighted Average 9,938 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, (minimum) Subcatchment 3: Non-Recharged Areas Runoff Hydrograph Time (hours) 3029282726252423222120191817161514131211109876543210Flow (cfs)0.006 0.005 0.005 0.004 0.004 0.003 0.003 0.002 0.002 0.001 0.001 0.000 0 Type III 24-hr 10-Year Rainfall=4.87" Runoff Area=9,938 sf Runoff Volume=0.003 af Runoff Depth=0.17" Tc=6.0 min CN=39 0.01 cfs Type III 24-hr 10-Year Rainfall=4.87"9489.POST-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 18HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Summary for Pond 1CB: (2) Solid Catch Basins Inflow Area = 0.658 ac, 32.51% Impervious, Inflow Depth = 1.10" for 10-Year event Inflow = 0.72 cfs @ 12.10 hrs, Volume= 0.060 af Outflow = 0.72 cfs @ 12.10 hrs, Volume= 0.060 af, Atten= 0%, Lag= 0.0 min Primary = 0.72 cfs @ 12.10 hrs, Volume= 0.060 af Routed to Pond 1MH : (1) Manhole Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs / 2 Peak Elev= 14.76' @ 12.10 hrs Device Routing Invert Outlet Devices #1 Primary 14.30'12.0" Round Culvert X 2.00 L= 9.0' CPP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 14.30' / 14.20' S= 0.0111 '/' Cc= 0.900 n= 0.009 Corrugated PE, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max=0.72 cfs @ 12.10 hrs HW=14.76' TW=14.69' (Dynamic Tailwater) 1=Culvert (Outlet Controls 0.72 cfs @ 1.49 fps) Pond 1CB: (2) Solid Catch Basins Inflow Primary Hydrograph Time (hours) 3029282726252423222120191817161514131211109876543210Flow (cfs)0.8 0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Inflow Area=0.658 ac Peak Elev=14.76' 12.0" Round Culvert x 2.00 n=0.009 L=9.0' S=0.0111 '/' 0.72 cfs 0.72 cfs Type III 24-hr 10-Year Rainfall=4.87"9489.POST-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 19HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Summary for Pond 1MH: (1) Manhole Inflow Area = 0.658 ac, 32.51% Impervious, Inflow Depth = 1.10" for 10-Year event Inflow = 0.72 cfs @ 12.10 hrs, Volume= 0.060 af Outflow = 0.72 cfs @ 12.10 hrs, Volume= 0.060 af, Atten= 0%, Lag= 0.0 min Primary = 0.72 cfs @ 12.10 hrs, Volume= 0.060 af Routed to Pond 1P : Roadway Leaching Facility Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs / 2 Peak Elev= 14.69' @ 12.10 hrs Device Routing Invert Outlet Devices #1 Primary 14.20'12.0" Round Culvert L= 25.0' CPP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 14.20' / 14.00' S= 0.0080 '/' Cc= 0.900 n= 0.009 Corrugated PE, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max=0.72 cfs @ 12.10 hrs HW=14.69' TW=10.44' (Dynamic Tailwater) 1=Culvert (Inlet Controls 0.72 cfs @ 1.88 fps) Pond 1MH: (1) Manhole Inflow Primary Hydrograph Time (hours) 3029282726252423222120191817161514131211109876543210Flow (cfs)0.8 0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Inflow Area=0.658 ac Peak Elev=14.69' 12.0" Round Culvert n=0.009 L=25.0' S=0.0080 '/' 0.72 cfs 0.72 cfs Type III 24-hr 10-Year Rainfall=4.87"9489.POST-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 20HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Summary for Pond 1P: Roadway Leaching Facility Inflow Area = 0.658 ac, 32.51% Impervious, Inflow Depth = 1.10" for 10-Year event Inflow = 0.72 cfs @ 12.10 hrs, Volume= 0.060 af Outflow = 0.17 cfs @ 12.58 hrs, Volume= 0.060 af, Atten= 77%, Lag= 28.8 min Discarded = 0.17 cfs @ 12.58 hrs, Volume= 0.060 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routed to Link TSR : Total Site Runoff Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs / 2 Peak Elev= 11.42' @ 12.58 hrs Surf.Area= 720 sf Storage= 574 cf Plug-Flow detention time= 22.6 min calculated for 0.060 af (100% of inflow) Center-of-Mass det. time= 22.5 min ( 906.5 - 884.0 ) Volume Invert Avail.Storage Storage Description #1 10.00' 679 cf 6.00'D x 4.00'H Leach Pits x 6 Inside #2 796 cf Overall - 3.0" Wall Thickness = 679 cf #2 10.00' 938 cf 24.00'W x 30.00'L x 4.00'H Stone 2,880 cf Overall - 796 cf Embedded = 2,084 cf x 45.0% Voids 1,616 cf Total Available Storage Device Routing Invert Outlet Devices #1 Discarded 10.00'8.270 in/hr Exfiltration over Wetted area Phase-In= 0.01' #2 Primary 13.90'10.0' long (Profile 6) Broad-Crested Rectangular Weir Head (feet) 0.49 0.98 1.48 Coef. (English) 3.12 3.41 3.59 Discarded OutFlow Max=0.17 cfs @ 12.58 hrs HW=11.42' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.17 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=10.00' TW=0.00' (Dynamic Tailwater) 2=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Type III 24-hr 10-Year Rainfall=4.87"9489.POST-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 21HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Pond 1P: Roadway Leaching Facility Inflow Outflow Discarded Primary Hydrograph Time (hours) 3029282726252423222120191817161514131211109876543210Flow (cfs)0.8 0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Inflow Area=0.658 ac Peak Elev=11.42' Storage=574 cf 0.72 cfs 0.17 cfs 0.17 cfs 0.00 cfs Type III 24-hr 10-Year Rainfall=4.87"9489.POST-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 22HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Summary for Pond 2P: Roof Runoff Leaching Facilities Inflow Area = 0.114 ac,100.00% Impervious, Inflow Depth = 4.63" for 10-Year event Inflow = 0.54 cfs @ 12.08 hrs, Volume= 0.044 af Outflow = 0.12 cfs @ 12.49 hrs, Volume= 0.044 af, Atten= 79%, Lag= 24.5 min Discarded = 0.12 cfs @ 12.49 hrs, Volume= 0.044 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routed to Link TSR : Total Site Runoff Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs / 2 Peak Elev= 101.86' @ 12.49 hrs Surf.Area= 294 sf Storage= 500 cf Plug-Flow detention time= 28.2 min calculated for 0.044 af (100% of inflow) Center-of-Mass det. time= 28.1 min ( 776.6 - 748.5 ) Volume Invert Avail.Storage Storage Description #1 100.00' 317 cf 4.00'W x 4.00'L x 3.30'H Prismatoid x 6 Inside #2 401 cf Overall - 3.0" Wall Thickness = 317 cf #2 100.00' 569 cf 7.00'W x 7.00'L x 3.30'H Prismatoid x 6 970 cf Overall - 401 cf Embedded = 569 cf 886 cf Total Available Storage Device Routing Invert Outlet Devices #1 Discarded 100.00'8.270 in/hr Exfiltration over Wetted area Phase-In= 0.01' #2 Primary 103.20'10.0' long (Profile 6) Broad-Crested Rectangular Weir Head (feet) 0.49 0.98 1.48 Coef. (English) 3.12 3.41 3.59 Discarded OutFlow Max=0.12 cfs @ 12.49 hrs HW=101.86' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.12 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=100.00' TW=0.00' (Dynamic Tailwater) 2=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Type III 24-hr 10-Year Rainfall=4.87"9489.POST-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 23HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Pond 2P: Roof Runoff Leaching Facilities Inflow Outflow Discarded Primary Hydrograph Time (hours) 3029282726252423222120191817161514131211109876543210Flow (cfs)0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Inflow Area=0.114 ac Peak Elev=101.86' Storage=500 cf 0.54 cfs 0.12 cfs 0.12 cfs 0.00 cfs Type III 24-hr 10-Year Rainfall=4.87"9489.POST-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 24HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Summary for Link TSR: Total Site Runoff Inflow Area = 1.000 ac, 32.78% Impervious, Inflow Depth = 0.04" for 10-Year event Inflow = 0.01 cfs @ 12.50 hrs, Volume= 0.003 af Primary = 0.01 cfs @ 12.50 hrs, Volume= 0.003 af, Atten= 0%, Lag= 0.0 min Routed to nonexistent node 2R Primary outflow = Inflow, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Link TSR: Total Site Runoff Inflow Primary Hydrograph Time (hours) 3029282726252423222120191817161514131211109876543210Flow (cfs)0.006 0.005 0.005 0.004 0.004 0.003 0.003 0.002 0.002 0.001 0.001 0.000 0 Inflow Area=1.000 ac 0.01 cfs 0.01 cfs Type III 24-hr 25-Year Rainfall=5.82"9489.POST-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 25HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Time span=0.00-30.00 hrs, dt=0.01 hrs, 3001 points x 2 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Dyn-Stor-Ind method - Pond routing by Dyn-Stor-Ind method Runoff Area=28,663 sf 32.51% Impervious Runoff Depth=1.65"Subcatchment 1: Pavement and Flow Length=150' Tc=5.9 min CN=58 Runoff=1.17 cfs 0.090 af Runoff Area=4,962 sf 100.00% Impervious Runoff Depth=5.58"Subcatchment 2: (6) Dwellings Tc=6.0 min CN=98 Runoff=0.65 cfs 0.053 af Runoff Area=9,938 sf 0.00% Impervious Runoff Depth=0.40"Subcatchment 3: Non-Recharged Areas Tc=6.0 min CN=39 Runoff=0.03 cfs 0.008 af Peak Elev=14.93' Inflow=1.17 cfs 0.090 afPond 1CB: (2) Solid Catch Basins 12.0" Round Culvert x 2.00 n=0.009 L=9.0' S=0.0111 '/' Outflow=1.17 cfs 0.090 af Peak Elev=14.85' Inflow=1.17 cfs 0.090 afPond 1MH: (1) Manhole 12.0" Round Culvert n=0.009 L=25.0' S=0.0080 '/' Outflow=1.17 cfs 0.090 af Peak Elev=12.77' Storage=1,119 cf Inflow=1.17 cfs 0.090 afPond 1P: Roadway Leaching Facility Discarded=0.20 cfs 0.090 af Primary=0.00 cfs 0.000 af Outflow=0.20 cfs 0.090 af Peak Elev=102.37' Storage=636 cf Inflow=0.65 cfs 0.053 afPond 2P: Roof Runoff Leaching Facilities Discarded=0.13 cfs 0.053 af Primary=0.00 cfs 0.000 af Outflow=0.13 cfs 0.053 af Inflow=0.03 cfs 0.008 afLink TSR: Total Site Runoff Primary=0.03 cfs 0.008 af Total Runoff Area = 1.000 ac Runoff Volume = 0.151 af Average Runoff Depth = 1.81" 67.22% Pervious = 0.672 ac 32.78% Impervious = 0.328 ac Type III 24-hr 25-Year Rainfall=5.82"9489.POST-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 26HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment 1: Pavement and Surrounding Area Runoff = 1.17 cfs @ 12.10 hrs, Volume= 0.090 af, Depth= 1.65" Routed to Pond 1CB : (2) Solid Catch Basins Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 25-Year Rainfall=5.82" Area (sf) CN Description * 9,319 98 Road & Driveways, HSG A * 19,344 39 Landscaped Areas, Good, HSG A 28,663 58 Weighted Average 19,344 67.49% Pervious Area 9,319 32.51% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.5 50 0.0200 0.15 Sheet Flow, Grass: Short n= 0.150 P2= 3.35" 0.4 100 0.0350 3.80 Shallow Concentrated Flow, Paved Kv= 20.3 fps 5.9 150 Total Subcatchment 1: Pavement and Surrounding Area Runoff Hydrograph Time (hours) 3029282726252423222120191817161514131211109876543210Flow (cfs)1 0 Type III 24-hr 25-Year Rainfall=5.82" Runoff Area=28,663 sf Runoff Volume=0.090 af Runoff Depth=1.65" Flow Length=150' Tc=5.9 min CN=58 1.17 cfs Type III 24-hr 25-Year Rainfall=5.82"9489.POST-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 27HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment 2: (6) Dwellings Runoff = 0.65 cfs @ 12.08 hrs, Volume= 0.053 af, Depth= 5.58" Routed to Pond 2P : Roof Runoff Leaching Facilities Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 25-Year Rainfall=5.82" Area (sf) CN Description * 4,962 98 Roofs, HSG A 4,962 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, (minimum) Subcatchment 2: (6) Dwellings Runoff Hydrograph Time (hours) 3029282726252423222120191817161514131211109876543210Flow (cfs)0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Type III 24-hr 25-Year Rainfall=5.82" Runoff Area=4,962 sf Runoff Volume=0.053 af Runoff Depth=5.58" Tc=6.0 min CN=98 0.65 cfs Type III 24-hr 25-Year Rainfall=5.82"9489.POST-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 28HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment 3: Non-Recharged Areas Runoff = 0.03 cfs @ 12.36 hrs, Volume= 0.008 af, Depth= 0.40" Routed to Link TSR : Total Site Runoff Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 25-Year Rainfall=5.82" Area (sf) CN Description 500 43 Woods/grass comb., Fair, HSG A * 9,438 39 Landscaped Areas, Good, HSG A 9,938 39 Weighted Average 9,938 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, (minimum) Subcatchment 3: Non-Recharged Areas Runoff Hydrograph Time (hours) 3029282726252423222120191817161514131211109876543210Flow (cfs)0.036 0.034 0.032 0.03 0.028 0.026 0.024 0.022 0.02 0.018 0.016 0.014 0.012 0.01 0.008 0.006 0.004 0.002 0 Type III 24-hr 25-Year Rainfall=5.82" Runoff Area=9,938 sf Runoff Volume=0.008 af Runoff Depth=0.40" Tc=6.0 min CN=39 0.03 cfs Type III 24-hr 25-Year Rainfall=5.82"9489.POST-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 29HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Summary for Pond 1CB: (2) Solid Catch Basins Inflow Area = 0.658 ac, 32.51% Impervious, Inflow Depth = 1.65" for 25-Year event Inflow = 1.17 cfs @ 12.10 hrs, Volume= 0.090 af Outflow = 1.17 cfs @ 12.10 hrs, Volume= 0.090 af, Atten= 0%, Lag= 0.0 min Primary = 1.17 cfs @ 12.10 hrs, Volume= 0.090 af Routed to Pond 1MH : (1) Manhole Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs / 2 Peak Elev= 14.93' @ 12.10 hrs Device Routing Invert Outlet Devices #1 Primary 14.30'12.0" Round Culvert X 2.00 L= 9.0' CPP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 14.30' / 14.20' S= 0.0111 '/' Cc= 0.900 n= 0.009 Corrugated PE, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max=1.17 cfs @ 12.10 hrs HW=14.93' TW=14.85' (Dynamic Tailwater) 1=Culvert (Inlet Controls 1.17 cfs @ 1.11 fps) Pond 1CB: (2) Solid Catch Basins Inflow Primary Hydrograph Time (hours) 3029282726252423222120191817161514131211109876543210Flow (cfs)1 0 Inflow Area=0.658 ac Peak Elev=14.93' 12.0" Round Culvert x 2.00 n=0.009 L=9.0' S=0.0111 '/' 1.17 cfs 1.17 cfs Type III 24-hr 25-Year Rainfall=5.82"9489.POST-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 30HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Summary for Pond 1MH: (1) Manhole Inflow Area = 0.658 ac, 32.51% Impervious, Inflow Depth = 1.65" for 25-Year event Inflow = 1.17 cfs @ 12.10 hrs, Volume= 0.090 af Outflow = 1.17 cfs @ 12.10 hrs, Volume= 0.090 af, Atten= 0%, Lag= 0.0 min Primary = 1.17 cfs @ 12.10 hrs, Volume= 0.090 af Routed to Pond 1P : Roadway Leaching Facility Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs / 2 Peak Elev= 14.85' @ 12.10 hrs Device Routing Invert Outlet Devices #1 Primary 14.20'12.0" Round Culvert L= 25.0' CPP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 14.20' / 14.00' S= 0.0080 '/' Cc= 0.900 n= 0.009 Corrugated PE, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max=1.17 cfs @ 12.10 hrs HW=14.85' TW=10.96' (Dynamic Tailwater) 1=Culvert (Inlet Controls 1.17 cfs @ 2.17 fps) Pond 1MH: (1) Manhole Inflow Primary Hydrograph Time (hours) 3029282726252423222120191817161514131211109876543210Flow (cfs)1 0 Inflow Area=0.658 ac Peak Elev=14.85' 12.0" Round Culvert n=0.009 L=25.0' S=0.0080 '/' 1.17 cfs 1.17 cfs Type III 24-hr 25-Year Rainfall=5.82"9489.POST-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 31HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Summary for Pond 1P: Roadway Leaching Facility Inflow Area = 0.658 ac, 32.51% Impervious, Inflow Depth = 1.65" for 25-Year event Inflow = 1.17 cfs @ 12.10 hrs, Volume= 0.090 af Outflow = 0.20 cfs @ 12.72 hrs, Volume= 0.090 af, Atten= 83%, Lag= 37.7 min Discarded = 0.20 cfs @ 12.72 hrs, Volume= 0.090 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routed to Link TSR : Total Site Runoff Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs / 2 Peak Elev= 12.77' @ 12.72 hrs Surf.Area= 720 sf Storage= 1,119 cf Plug-Flow detention time= 48.0 min calculated for 0.090 af (100% of inflow) Center-of-Mass det. time= 48.0 min ( 918.3 - 870.3 ) Volume Invert Avail.Storage Storage Description #1 10.00' 679 cf 6.00'D x 4.00'H Leach Pits x 6 Inside #2 796 cf Overall - 3.0" Wall Thickness = 679 cf #2 10.00' 938 cf 24.00'W x 30.00'L x 4.00'H Stone 2,880 cf Overall - 796 cf Embedded = 2,084 cf x 45.0% Voids 1,616 cf Total Available Storage Device Routing Invert Outlet Devices #1 Discarded 10.00'8.270 in/hr Exfiltration over Wetted area Phase-In= 0.01' #2 Primary 13.90'10.0' long (Profile 6) Broad-Crested Rectangular Weir Head (feet) 0.49 0.98 1.48 Coef. (English) 3.12 3.41 3.59 Discarded OutFlow Max=0.20 cfs @ 12.72 hrs HW=12.77' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.20 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=10.00' TW=0.00' (Dynamic Tailwater) 2=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Type III 24-hr 25-Year Rainfall=5.82"9489.POST-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 32HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Pond 1P: Roadway Leaching Facility Inflow Outflow Discarded Primary Hydrograph Time (hours) 3029282726252423222120191817161514131211109876543210Flow (cfs)1 0 Inflow Area=0.658 ac Peak Elev=12.77' Storage=1,119 cf 1.17 cfs 0.20 cfs 0.20 cfs 0.00 cfs Type III 24-hr 25-Year Rainfall=5.82"9489.POST-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 33HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Summary for Pond 2P: Roof Runoff Leaching Facilities Inflow Area = 0.114 ac,100.00% Impervious, Inflow Depth = 5.58" for 25-Year event Inflow = 0.65 cfs @ 12.08 hrs, Volume= 0.053 af Outflow = 0.13 cfs @ 12.50 hrs, Volume= 0.053 af, Atten= 80%, Lag= 25.1 min Discarded = 0.13 cfs @ 12.50 hrs, Volume= 0.053 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routed to Link TSR : Total Site Runoff Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs / 2 Peak Elev= 102.37' @ 12.50 hrs Surf.Area= 294 sf Storage= 636 cf Plug-Flow detention time= 33.4 min calculated for 0.053 af (100% of inflow) Center-of-Mass det. time= 33.4 min ( 779.1 - 745.6 ) Volume Invert Avail.Storage Storage Description #1 100.00' 317 cf 4.00'W x 4.00'L x 3.30'H Prismatoid x 6 Inside #2 401 cf Overall - 3.0" Wall Thickness = 317 cf #2 100.00' 569 cf 7.00'W x 7.00'L x 3.30'H Prismatoid x 6 970 cf Overall - 401 cf Embedded = 569 cf 886 cf Total Available Storage Device Routing Invert Outlet Devices #1 Discarded 100.00'8.270 in/hr Exfiltration over Wetted area Phase-In= 0.01' #2 Primary 103.20'10.0' long (Profile 6) Broad-Crested Rectangular Weir Head (feet) 0.49 0.98 1.48 Coef. (English) 3.12 3.41 3.59 Discarded OutFlow Max=0.13 cfs @ 12.50 hrs HW=102.37' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.13 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=100.00' TW=0.00' (Dynamic Tailwater) 2=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Type III 24-hr 25-Year Rainfall=5.82"9489.POST-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 34HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Pond 2P: Roof Runoff Leaching Facilities Inflow Outflow Discarded Primary Hydrograph Time (hours) 3029282726252423222120191817161514131211109876543210Flow (cfs)0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Inflow Area=0.114 ac Peak Elev=102.37' Storage=636 cf 0.65 cfs 0.13 cfs 0.13 cfs 0.00 cfs Type III 24-hr 25-Year Rainfall=5.82"9489.POST-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 35HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Summary for Link TSR: Total Site Runoff Inflow Area = 1.000 ac, 32.78% Impervious, Inflow Depth = 0.09" for 25-Year event Inflow = 0.03 cfs @ 12.36 hrs, Volume= 0.008 af Primary = 0.03 cfs @ 12.36 hrs, Volume= 0.008 af, Atten= 0%, Lag= 0.0 min Routed to nonexistent node 2R Primary outflow = Inflow, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Link TSR: Total Site Runoff Inflow Primary Hydrograph Time (hours) 3029282726252423222120191817161514131211109876543210Flow (cfs)0.036 0.034 0.032 0.03 0.028 0.026 0.024 0.022 0.02 0.018 0.016 0.014 0.012 0.01 0.008 0.006 0.004 0.002 0 Inflow Area=1.000 ac 0.03 cfs 0.03 cfs Type III 24-hr 50-Year Rainfall=6.54"9489.POST-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 36HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Time span=0.00-30.00 hrs, dt=0.01 hrs, 3001 points x 2 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Dyn-Stor-Ind method - Pond routing by Dyn-Stor-Ind method Runoff Area=28,663 sf 32.51% Impervious Runoff Depth=2.10"Subcatchment 1: Pavement and Flow Length=150' Tc=5.9 min CN=58 Runoff=1.54 cfs 0.115 af Runoff Area=4,962 sf 100.00% Impervious Runoff Depth=6.30"Subcatchment 2: (6) Dwellings Tc=6.0 min CN=98 Runoff=0.73 cfs 0.060 af Runoff Area=9,938 sf 0.00% Impervious Runoff Depth=0.61"Subcatchment 3: Non-Recharged Areas Tc=6.0 min CN=39 Runoff=0.06 cfs 0.012 af Peak Elev=15.07' Inflow=1.54 cfs 0.115 afPond 1CB: (2) Solid Catch Basins 12.0" Round Culvert x 2.00 n=0.009 L=9.0' S=0.0111 '/' Outflow=1.54 cfs 0.115 af Peak Elev=14.97' Inflow=1.54 cfs 0.115 afPond 1MH: (1) Manhole 12.0" Round Culvert n=0.009 L=25.0' S=0.0080 '/' Outflow=1.54 cfs 0.115 af Peak Elev=13.92' Storage=1,582 cf Inflow=1.54 cfs 0.115 afPond 1P: Roadway Leaching Facility Discarded=0.22 cfs 0.115 af Primary=0.06 cfs 0.001 af Outflow=0.28 cfs 0.115 af Peak Elev=102.76' Storage=740 cf Inflow=0.73 cfs 0.060 afPond 2P: Roof Runoff Leaching Facilities Discarded=0.14 cfs 0.060 af Primary=0.00 cfs 0.000 af Outflow=0.14 cfs 0.060 af Inflow=0.09 cfs 0.012 afLink TSR: Total Site Runoff Primary=0.09 cfs 0.012 af Total Runoff Area = 1.000 ac Runoff Volume = 0.187 af Average Runoff Depth = 2.24" 67.22% Pervious = 0.672 ac 32.78% Impervious = 0.328 ac Type III 24-hr 50-Year Rainfall=6.54"9489.POST-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 37HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment 1: Pavement and Surrounding Area Runoff = 1.54 cfs @ 12.09 hrs, Volume= 0.115 af, Depth= 2.10" Routed to Pond 1CB : (2) Solid Catch Basins Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 50-Year Rainfall=6.54" Area (sf) CN Description * 9,319 98 Road & Driveways, HSG A * 19,344 39 Landscaped Areas, Good, HSG A 28,663 58 Weighted Average 19,344 67.49% Pervious Area 9,319 32.51% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.5 50 0.0200 0.15 Sheet Flow, Grass: Short n= 0.150 P2= 3.35" 0.4 100 0.0350 3.80 Shallow Concentrated Flow, Paved Kv= 20.3 fps 5.9 150 Total Subcatchment 1: Pavement and Surrounding Area Runoff Hydrograph Time (hours) 3029282726252423222120191817161514131211109876543210Flow (cfs)1 0 Type III 24-hr 50-Year Rainfall=6.54" Runoff Area=28,663 sf Runoff Volume=0.115 af Runoff Depth=2.10" Flow Length=150' Tc=5.9 min CN=58 1.54 cfs Type III 24-hr 50-Year Rainfall=6.54"9489.POST-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 38HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment 2: (6) Dwellings Runoff = 0.73 cfs @ 12.08 hrs, Volume= 0.060 af, Depth= 6.30" Routed to Pond 2P : Roof Runoff Leaching Facilities Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 50-Year Rainfall=6.54" Area (sf) CN Description * 4,962 98 Roofs, HSG A 4,962 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, (minimum) Subcatchment 2: (6) Dwellings Runoff Hydrograph Time (hours) 3029282726252423222120191817161514131211109876543210Flow (cfs)0.8 0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Type III 24-hr 50-Year Rainfall=6.54" Runoff Area=4,962 sf Runoff Volume=0.060 af Runoff Depth=6.30" Tc=6.0 min CN=98 0.73 cfs Type III 24-hr 50-Year Rainfall=6.54"9489.POST-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 39HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment 3: Non-Recharged Areas Runoff = 0.06 cfs @ 12.29 hrs, Volume= 0.012 af, Depth= 0.61" Routed to Link TSR : Total Site Runoff Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 50-Year Rainfall=6.54" Area (sf) CN Description 500 43 Woods/grass comb., Fair, HSG A * 9,438 39 Landscaped Areas, Good, HSG A 9,938 39 Weighted Average 9,938 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, (minimum) Subcatchment 3: Non-Recharged Areas Runoff Hydrograph Time (hours) 3029282726252423222120191817161514131211109876543210Flow (cfs)0.07 0.065 0.06 0.055 0.05 0.045 0.04 0.035 0.03 0.025 0.02 0.015 0.01 0.005 0 Type III 24-hr 50-Year Rainfall=6.54" Runoff Area=9,938 sf Runoff Volume=0.012 af Runoff Depth=0.61" Tc=6.0 min CN=39 0.06 cfs Type III 24-hr 50-Year Rainfall=6.54"9489.POST-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 40HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Summary for Pond 1CB: (2) Solid Catch Basins Inflow Area = 0.658 ac, 32.51% Impervious, Inflow Depth = 2.10" for 50-Year event Inflow = 1.54 cfs @ 12.09 hrs, Volume= 0.115 af Outflow = 1.54 cfs @ 12.09 hrs, Volume= 0.115 af, Atten= 0%, Lag= 0.0 min Primary = 1.54 cfs @ 12.09 hrs, Volume= 0.115 af Routed to Pond 1MH : (1) Manhole Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs / 2 Peak Elev= 15.07' @ 12.09 hrs Device Routing Invert Outlet Devices #1 Primary 14.30'12.0" Round Culvert X 2.00 L= 9.0' CPP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 14.30' / 14.20' S= 0.0111 '/' Cc= 0.900 n= 0.009 Corrugated PE, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max=1.54 cfs @ 12.09 hrs HW=15.07' TW=14.97' (Dynamic Tailwater) 1=Culvert (Inlet Controls 1.54 cfs @ 1.19 fps) Pond 1CB: (2) Solid Catch Basins Inflow Primary Hydrograph Time (hours) 3029282726252423222120191817161514131211109876543210Flow (cfs)1 0 Inflow Area=0.658 ac Peak Elev=15.07' 12.0" Round Culvert x 2.00 n=0.009 L=9.0' S=0.0111 '/' 1.54 cfs 1.54 cfs Type III 24-hr 50-Year Rainfall=6.54"9489.POST-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 41HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Summary for Pond 1MH: (1) Manhole Inflow Area = 0.658 ac, 32.51% Impervious, Inflow Depth = 2.10" for 50-Year event Inflow = 1.54 cfs @ 12.09 hrs, Volume= 0.115 af Outflow = 1.54 cfs @ 12.09 hrs, Volume= 0.115 af, Atten= 0%, Lag= 0.0 min Primary = 1.54 cfs @ 12.09 hrs, Volume= 0.115 af Routed to Pond 1P : Roadway Leaching Facility Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs / 2 Peak Elev= 14.97' @ 12.09 hrs Device Routing Invert Outlet Devices #1 Primary 14.20'12.0" Round Culvert L= 25.0' CPP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 14.20' / 14.00' S= 0.0080 '/' Cc= 0.900 n= 0.009 Corrugated PE, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max=1.54 cfs @ 12.09 hrs HW=14.97' TW=11.47' (Dynamic Tailwater) 1=Culvert (Inlet Controls 1.54 cfs @ 2.36 fps) Pond 1MH: (1) Manhole Inflow Primary Hydrograph Time (hours) 3029282726252423222120191817161514131211109876543210Flow (cfs)1 0 Inflow Area=0.658 ac Peak Elev=14.97' 12.0" Round Culvert n=0.009 L=25.0' S=0.0080 '/' 1.54 cfs 1.54 cfs Type III 24-hr 50-Year Rainfall=6.54"9489.POST-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 42HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Summary for Pond 1P: Roadway Leaching Facility Inflow Area = 0.658 ac, 32.51% Impervious, Inflow Depth = 2.10" for 50-Year event Inflow = 1.54 cfs @ 12.09 hrs, Volume= 0.115 af Outflow = 0.28 cfs @ 12.61 hrs, Volume= 0.115 af, Atten= 82%, Lag= 31.1 min Discarded = 0.22 cfs @ 12.61 hrs, Volume= 0.115 af Primary = 0.06 cfs @ 12.61 hrs, Volume= 0.001 af Routed to Link TSR : Total Site Runoff Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs / 2 Peak Elev= 13.92' @ 12.61 hrs Surf.Area= 720 sf Storage= 1,582 cf Plug-Flow detention time= 66.3 min calculated for 0.115 af (100% of inflow) Center-of-Mass det. time= 66.3 min ( 928.8 - 862.5 ) Volume Invert Avail.Storage Storage Description #1 10.00' 679 cf 6.00'D x 4.00'H Leach Pits x 6 Inside #2 796 cf Overall - 3.0" Wall Thickness = 679 cf #2 10.00' 938 cf 24.00'W x 30.00'L x 4.00'H Stone 2,880 cf Overall - 796 cf Embedded = 2,084 cf x 45.0% Voids 1,616 cf Total Available Storage Device Routing Invert Outlet Devices #1 Discarded 10.00'8.270 in/hr Exfiltration over Wetted area Phase-In= 0.01' #2 Primary 13.90'10.0' long (Profile 6) Broad-Crested Rectangular Weir Head (feet) 0.49 0.98 1.48 Coef. (English) 3.12 3.41 3.59 Discarded OutFlow Max=0.22 cfs @ 12.61 hrs HW=13.92' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.22 cfs) Primary OutFlow Max=0.06 cfs @ 12.61 hrs HW=13.92' TW=0.00' (Dynamic Tailwater) 2=Broad-Crested Rectangular Weir (Weir Controls 0.06 cfs @ 0.39 fps) Type III 24-hr 50-Year Rainfall=6.54"9489.POST-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 43HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Pond 1P: Roadway Leaching Facility Inflow Outflow Discarded Primary Hydrograph Time (hours) 3029282726252423222120191817161514131211109876543210Flow (cfs)1 0 Inflow Area=0.658 ac Peak Elev=13.92' Storage=1,582 cf 1.54 cfs 0.28 cfs 0.22 cfs 0.06 cfs Type III 24-hr 50-Year Rainfall=6.54"9489.POST-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 44HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Summary for Pond 2P: Roof Runoff Leaching Facilities Inflow Area = 0.114 ac,100.00% Impervious, Inflow Depth = 6.30" for 50-Year event Inflow = 0.73 cfs @ 12.08 hrs, Volume= 0.060 af Outflow = 0.14 cfs @ 12.51 hrs, Volume= 0.060 af, Atten= 80%, Lag= 25.5 min Discarded = 0.14 cfs @ 12.51 hrs, Volume= 0.060 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routed to Link TSR : Total Site Runoff Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs / 2 Peak Elev= 102.76' @ 12.51 hrs Surf.Area= 294 sf Storage= 740 cf Plug-Flow detention time= 37.1 min calculated for 0.060 af (100% of inflow) Center-of-Mass det. time= 37.1 min ( 781.0 - 743.9 ) Volume Invert Avail.Storage Storage Description #1 100.00' 317 cf 4.00'W x 4.00'L x 3.30'H Prismatoid x 6 Inside #2 401 cf Overall - 3.0" Wall Thickness = 317 cf #2 100.00' 569 cf 7.00'W x 7.00'L x 3.30'H Prismatoid x 6 970 cf Overall - 401 cf Embedded = 569 cf 886 cf Total Available Storage Device Routing Invert Outlet Devices #1 Discarded 100.00'8.270 in/hr Exfiltration over Wetted area Phase-In= 0.01' #2 Primary 103.20'10.0' long (Profile 6) Broad-Crested Rectangular Weir Head (feet) 0.49 0.98 1.48 Coef. (English) 3.12 3.41 3.59 Discarded OutFlow Max=0.14 cfs @ 12.51 hrs HW=102.76' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.14 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=100.00' TW=0.00' (Dynamic Tailwater) 2=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Type III 24-hr 50-Year Rainfall=6.54"9489.POST-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 45HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Pond 2P: Roof Runoff Leaching Facilities Inflow Outflow Discarded Primary Hydrograph Time (hours) 3029282726252423222120191817161514131211109876543210Flow (cfs)0.8 0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Inflow Area=0.114 ac Peak Elev=102.76' Storage=740 cf 0.73 cfs 0.14 cfs 0.14 cfs 0.00 cfs Type III 24-hr 50-Year Rainfall=6.54"9489.POST-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 46HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Summary for Link TSR: Total Site Runoff Inflow Area = 1.000 ac, 32.78% Impervious, Inflow Depth = 0.15" for 50-Year event Inflow = 0.09 cfs @ 12.61 hrs, Volume= 0.012 af Primary = 0.09 cfs @ 12.61 hrs, Volume= 0.012 af, Atten= 0%, Lag= 0.0 min Routed to nonexistent node 2R Primary outflow = Inflow, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Link TSR: Total Site Runoff Inflow Primary Hydrograph Time (hours) 3029282726252423222120191817161514131211109876543210Flow (cfs)0.1 0.095 0.09 0.085 0.08 0.075 0.07 0.065 0.06 0.055 0.05 0.045 0.04 0.035 0.03 0.025 0.02 0.015 0.01 0.005 0 Inflow Area=1.000 ac 0.09 cfs 0.09 cfs Type III 24-hr 100-Year Rainfall=7.29"9489.POST-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 47HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Time span=0.00-30.00 hrs, dt=0.01 hrs, 3001 points x 2 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Dyn-Stor-Ind method - Pond routing by Dyn-Stor-Ind method Runoff Area=28,663 sf 32.51% Impervious Runoff Depth=2.61"Subcatchment 1: Pavement and Flow Length=150' Tc=5.9 min CN=58 Runoff=1.95 cfs 0.143 af Runoff Area=4,962 sf 100.00% Impervious Runoff Depth=7.05"Subcatchment 2: (6) Dwellings Tc=6.0 min CN=98 Runoff=0.81 cfs 0.067 af Runoff Area=9,938 sf 0.00% Impervious Runoff Depth=0.87"Subcatchment 3: Non-Recharged Areas Tc=6.0 min CN=39 Runoff=0.13 cfs 0.017 af Peak Elev=15.23' Inflow=1.95 cfs 0.143 afPond 1CB: (2) Solid Catch Basins 12.0" Round Culvert x 2.00 n=0.009 L=9.0' S=0.0111 '/' Outflow=1.95 cfs 0.143 af Peak Elev=15.12' Inflow=1.95 cfs 0.143 afPond 1MH: (1) Manhole 12.0" Round Culvert n=0.009 L=25.0' S=0.0080 '/' Outflow=1.95 cfs 0.143 af Peak Elev=13.98' Storage=1,609 cf Inflow=1.95 cfs 0.143 afPond 1P: Roadway Leaching Facility Discarded=0.22 cfs 0.128 af Primary=0.74 cfs 0.015 af Outflow=0.96 cfs 0.143 af Peak Elev=103.17' Storage=851 cf Inflow=0.81 cfs 0.067 afPond 2P: Roof Runoff Leaching Facilities Discarded=0.16 cfs 0.067 af Primary=0.00 cfs 0.000 af Outflow=0.16 cfs 0.067 af Inflow=0.84 cfs 0.032 afLink TSR: Total Site Runoff Primary=0.84 cfs 0.032 af Total Runoff Area = 1.000 ac Runoff Volume = 0.227 af Average Runoff Depth = 2.72" 67.22% Pervious = 0.672 ac 32.78% Impervious = 0.328 ac Type III 24-hr 100-Year Rainfall=7.29"9489.POST-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 48HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment 1: Pavement and Surrounding Area Runoff = 1.95 cfs @ 12.09 hrs, Volume= 0.143 af, Depth= 2.61" Routed to Pond 1CB : (2) Solid Catch Basins Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 100-Year Rainfall=7.29" Area (sf) CN Description * 9,319 98 Road & Driveways, HSG A * 19,344 39 Landscaped Areas, Good, HSG A 28,663 58 Weighted Average 19,344 67.49% Pervious Area 9,319 32.51% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.5 50 0.0200 0.15 Sheet Flow, Grass: Short n= 0.150 P2= 3.35" 0.4 100 0.0350 3.80 Shallow Concentrated Flow, Paved Kv= 20.3 fps 5.9 150 Total Subcatchment 1: Pavement and Surrounding Area Runoff Hydrograph Time (hours) 3029282726252423222120191817161514131211109876543210Flow (cfs)2 1 0 Type III 24-hr 100-Year Rainfall=7.29" Runoff Area=28,663 sf Runoff Volume=0.143 af Runoff Depth=2.61" Flow Length=150' Tc=5.9 min CN=58 1.95 cfs Type III 24-hr 100-Year Rainfall=7.29"9489.POST-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 49HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment 2: (6) Dwellings Runoff = 0.81 cfs @ 12.08 hrs, Volume= 0.067 af, Depth= 7.05" Routed to Pond 2P : Roof Runoff Leaching Facilities Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 100-Year Rainfall=7.29" Area (sf) CN Description * 4,962 98 Roofs, HSG A 4,962 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, (minimum) Subcatchment 2: (6) Dwellings Runoff Hydrograph Time (hours) 3029282726252423222120191817161514131211109876543210Flow (cfs)0.9 0.85 0.8 0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Type III 24-hr 100-Year Rainfall=7.29" Runoff Area=4,962 sf Runoff Volume=0.067 af Runoff Depth=7.05" Tc=6.0 min CN=98 0.81 cfs Type III 24-hr 100-Year Rainfall=7.29"9489.POST-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 50HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment 3: Non-Recharged Areas Runoff = 0.13 cfs @ 12.13 hrs, Volume= 0.017 af, Depth= 0.87" Routed to Link TSR : Total Site Runoff Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 100-Year Rainfall=7.29" Area (sf) CN Description 500 43 Woods/grass comb., Fair, HSG A * 9,438 39 Landscaped Areas, Good, HSG A 9,938 39 Weighted Average 9,938 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, (minimum) Subcatchment 3: Non-Recharged Areas Runoff Hydrograph Time (hours) 3029282726252423222120191817161514131211109876543210Flow (cfs)0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 Type III 24-hr 100-Year Rainfall=7.29" Runoff Area=9,938 sf Runoff Volume=0.017 af Runoff Depth=0.87" Tc=6.0 min CN=39 0.13 cfs Type III 24-hr 100-Year Rainfall=7.29"9489.POST-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 51HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Summary for Pond 1CB: (2) Solid Catch Basins Inflow Area = 0.658 ac, 32.51% Impervious, Inflow Depth = 2.61" for 100-Year event Inflow = 1.95 cfs @ 12.09 hrs, Volume= 0.143 af Outflow = 1.95 cfs @ 12.09 hrs, Volume= 0.143 af, Atten= 0%, Lag= 0.0 min Primary = 1.95 cfs @ 12.09 hrs, Volume= 0.143 af Routed to Pond 1MH : (1) Manhole Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs / 2 Peak Elev= 15.23' @ 12.09 hrs Device Routing Invert Outlet Devices #1 Primary 14.30'12.0" Round Culvert X 2.00 L= 9.0' CPP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 14.30' / 14.20' S= 0.0111 '/' Cc= 0.900 n= 0.009 Corrugated PE, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max=1.95 cfs @ 12.09 hrs HW=15.23' TW=15.12' (Dynamic Tailwater) 1=Culvert (Inlet Controls 1.95 cfs @ 1.28 fps) Pond 1CB: (2) Solid Catch Basins Inflow Primary Hydrograph Time (hours) 3029282726252423222120191817161514131211109876543210Flow (cfs)2 1 0 Inflow Area=0.658 ac Peak Elev=15.23' 12.0" Round Culvert x 2.00 n=0.009 L=9.0' S=0.0111 '/' 1.95 cfs 1.95 cfs Type III 24-hr 100-Year Rainfall=7.29"9489.POST-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 52HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Summary for Pond 1MH: (1) Manhole Inflow Area = 0.658 ac, 32.51% Impervious, Inflow Depth = 2.61" for 100-Year event Inflow = 1.95 cfs @ 12.09 hrs, Volume= 0.143 af Outflow = 1.95 cfs @ 12.09 hrs, Volume= 0.143 af, Atten= 0%, Lag= 0.0 min Primary = 1.95 cfs @ 12.09 hrs, Volume= 0.143 af Routed to Pond 1P : Roadway Leaching Facility Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs / 2 Peak Elev= 15.12' @ 12.09 hrs Device Routing Invert Outlet Devices #1 Primary 14.20'12.0" Round Culvert L= 25.0' CPP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 14.20' / 14.00' S= 0.0080 '/' Cc= 0.900 n= 0.009 Corrugated PE, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max=1.95 cfs @ 12.09 hrs HW=15.12' TW=12.08' (Dynamic Tailwater) 1=Culvert (Inlet Controls 1.95 cfs @ 2.58 fps) Pond 1MH: (1) Manhole Inflow Primary Hydrograph Time (hours) 3029282726252423222120191817161514131211109876543210Flow (cfs)2 1 0 Inflow Area=0.658 ac Peak Elev=15.12' 12.0" Round Culvert n=0.009 L=25.0' S=0.0080 '/' 1.95 cfs 1.95 cfs Type III 24-hr 100-Year Rainfall=7.29"9489.POST-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 53HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Summary for Pond 1P: Roadway Leaching Facility Inflow Area = 0.658 ac, 32.51% Impervious, Inflow Depth = 2.61" for 100-Year event Inflow = 1.95 cfs @ 12.09 hrs, Volume= 0.143 af Outflow = 0.96 cfs @ 12.29 hrs, Volume= 0.143 af, Atten= 51%, Lag= 12.1 min Discarded = 0.22 cfs @ 12.29 hrs, Volume= 0.128 af Primary = 0.74 cfs @ 12.29 hrs, Volume= 0.015 af Routed to Link TSR : Total Site Runoff Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs / 2 Peak Elev= 13.98' @ 12.29 hrs Surf.Area= 720 sf Storage= 1,609 cf Plug-Flow detention time= 62.8 min calculated for 0.143 af (100% of inflow) Center-of-Mass det. time= 62.7 min ( 918.6 - 855.9 ) Volume Invert Avail.Storage Storage Description #1 10.00' 679 cf 6.00'D x 4.00'H Leach Pits x 6 Inside #2 796 cf Overall - 3.0" Wall Thickness = 679 cf #2 10.00' 938 cf 24.00'W x 30.00'L x 4.00'H Stone 2,880 cf Overall - 796 cf Embedded = 2,084 cf x 45.0% Voids 1,616 cf Total Available Storage Device Routing Invert Outlet Devices #1 Discarded 10.00'8.270 in/hr Exfiltration over Wetted area Phase-In= 0.01' #2 Primary 13.90'10.0' long (Profile 6) Broad-Crested Rectangular Weir Head (feet) 0.49 0.98 1.48 Coef. (English) 3.12 3.41 3.59 Discarded OutFlow Max=0.22 cfs @ 12.29 hrs HW=13.98' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.22 cfs) Primary OutFlow Max=0.74 cfs @ 12.29 hrs HW=13.98' TW=0.00' (Dynamic Tailwater) 2=Broad-Crested Rectangular Weir (Weir Controls 0.74 cfs @ 0.89 fps) Type III 24-hr 100-Year Rainfall=7.29"9489.POST-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 54HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Pond 1P: Roadway Leaching Facility Inflow Outflow Discarded Primary Hydrograph Time (hours) 3029282726252423222120191817161514131211109876543210Flow (cfs)2 1 0 Inflow Area=0.658 ac Peak Elev=13.98' Storage=1,609 cf 1.95 cfs 0.96 cfs 0.22 cfs 0.74 cfs Type III 24-hr 100-Year Rainfall=7.29"9489.POST-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 55HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Summary for Pond 2P: Roof Runoff Leaching Facilities Inflow Area = 0.114 ac,100.00% Impervious, Inflow Depth = 7.05" for 100-Year event Inflow = 0.81 cfs @ 12.08 hrs, Volume= 0.067 af Outflow = 0.16 cfs @ 12.51 hrs, Volume= 0.067 af, Atten= 81%, Lag= 25.8 min Discarded = 0.16 cfs @ 12.51 hrs, Volume= 0.067 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routed to Link TSR : Total Site Runoff Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs / 2 Peak Elev= 103.17' @ 12.51 hrs Surf.Area= 294 sf Storage= 851 cf Plug-Flow detention time= 40.6 min calculated for 0.067 af (100% of inflow) Center-of-Mass det. time= 40.6 min ( 783.0 - 742.4 ) Volume Invert Avail.Storage Storage Description #1 100.00' 317 cf 4.00'W x 4.00'L x 3.30'H Prismatoid x 6 Inside #2 401 cf Overall - 3.0" Wall Thickness = 317 cf #2 100.00' 569 cf 7.00'W x 7.00'L x 3.30'H Prismatoid x 6 970 cf Overall - 401 cf Embedded = 569 cf 886 cf Total Available Storage Device Routing Invert Outlet Devices #1 Discarded 100.00'8.270 in/hr Exfiltration over Wetted area Phase-In= 0.01' #2 Primary 103.20'10.0' long (Profile 6) Broad-Crested Rectangular Weir Head (feet) 0.49 0.98 1.48 Coef. (English) 3.12 3.41 3.59 Discarded OutFlow Max=0.16 cfs @ 12.51 hrs HW=103.17' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.16 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=100.00' TW=0.00' (Dynamic Tailwater) 2=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Type III 24-hr 100-Year Rainfall=7.29"9489.POST-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 56HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Pond 2P: Roof Runoff Leaching Facilities Inflow Outflow Discarded Primary Hydrograph Time (hours) 3029282726252423222120191817161514131211109876543210Flow (cfs)0.9 0.85 0.8 0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Inflow Area=0.114 ac Peak Elev=103.17' Storage=851 cf 0.81 cfs 0.16 cfs 0.16 cfs 0.00 cfs Type III 24-hr 100-Year Rainfall=7.29"9489.POST-DEV Printed 4/22/2026Prepared by J M O'Reilly & Associates Inc Page 57HydroCAD® 10.20-2h s/n 08678 © 2024 HydroCAD Software Solutions LLC Summary for Link TSR: Total Site Runoff Inflow Area = 1.000 ac, 32.78% Impervious, Inflow Depth = 0.38" for 100-Year event Inflow = 0.84 cfs @ 12.29 hrs, Volume= 0.032 af Primary = 0.84 cfs @ 12.29 hrs, Volume= 0.032 af, Atten= 0%, Lag= 0.0 min Routed to nonexistent node 2R Primary outflow = Inflow, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Link TSR: Total Site Runoff Inflow Primary Hydrograph Time (hours) 3029282726252423222120191817161514131211109876543210Flow (cfs)0.9 0.85 0.8 0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Inflow Area=1.000 ac 0.84 cfs 0.84 cfs VINSTRUCTIONS:Version 1, Automated: Mar. 4, 20081. In BMP Column, click on Blue Cell to Activate Drop Down Menu2. Select BMP from Drop Down Menu3. After BMP is selected, TSS Removal and other Columns are automatically completed.Location: B C DEFTSS Removal Starting TSS Amount RemainingBMP1Rate1Load* Removed (C*D) Load (D-E)Deep Sump and Hooded Catch Basin0.251.000.250.75Deep Sump and Hooded Catch Basin0.250.750.190.56Subsurface Infiltration Structure0.800.560.450.110.000.110.000.110.000.110.000.11Total TSS Removal =89%Separate Form Needs to be Completed for Each Outlet or BMP TrainProject:Habitat9489Prepared By:RFR*Equals remaining load from previous BMP (E)Date:4/24/2026which enters the BMP1121B Route 28, S. YarmouthTSS Removal Calculation WorksheetNon-automated TSS Calculation Sheetmust be used if Proprietary BMP Proposed1. From MassDEP Stormwater Handbook Vol. 1Mass. Dept. of Environmental ProtectionDeep Sump Manhole VINSTRUCTIONS:Version 1, Automated: Mar. 4, 20081. In BMP Column, click on Blue Cell to Activate Drop Down Menu2. Select BMP from Drop Down Menu3. After BMP is selected, TSS Removal and other Columns are automatically completed.Location: B C D E FTSS Removal Starting TSS Amount RemainingBMP1Rate1Load* Removed (C*D) Load (D-E)Subsurface Infiltration Structure 0.801.00 0.80 0.200.000.20 0.00 0.200.000.20 0.00 0.200.000.20 0.00 0.200.000.20 0.00 0.20Total TSS Removal =80%Separate Form Needs to be Completed for Each Outlet or BMP TrainProject:Habitat9489Prepared By:RFR*Equals remaining load from previous BMP (E)Date:4/24/2026which enters the BMP1121B Route 28, S. YarmouthTSS Removal Calculation WorksheetNon-automated TSS Calculation Sheetmust be used if Proprietary BMP Proposed1. From MassDEP Stormwater Handbook Vol. 1Mass. Dept. of Environmental Protection