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Stormwater Design Report900 Route 146 Clifton Park, NY 12065 (P) 518.371.7621 (F) 518.371.9540 edpllp.com STORMWATER DESIGN REPORT NORTHWAY SELF-STORAGE 162 CAREY ROAD QUEENSBURY, NEW YORK FEBRUARY 2022 1. INTRODUCTION Northway Self-Storage, LLC. is proposing site modifications to the existing self-storage property located at 162 Carey Road in the Town of Queensbury, New York. The existing site is approximately 2.77 acre parcel containing 4 self-storage buildings with 160 total units and associated parking and travel surfaces. The proposed project includes construction of two new storage buildings along the western portion of the asphalt pavement and turf area. The proposed project also includes the installation of two new stormwater management devices. The use of pervious pavement is proposed to attenuate and infiltrate the runoff from the majority of the self-storage buildings surfaces and act as travel surfaces. Shallow grass depression are proposed to attenuate and infiltrate any runoff from portions of the proposed building. The total disturbance for the site is on the order of 0.80 acres and therefore the site does not require coverage under a NYSDEC SPDES permit and does not require post construction stormwater designed in accordance with the NYSDEC Stormwater Management Design Manual. The project site is also located outside of the Lake George Park and therefore is not required to meet the stormwater management regulation of Section 147-11 of the Town of Queensbury Code. 2. EXISTING SITE CONDITIONS The existing site currently contains four (4) 6,000 SF self-storage buildings containing 160 individual units total as well as parking & travel surfaces. An stormwater management system consist of four (4) total drywells, six (6) catch basins and one (1) large shallow grass depression that extends on three sides of the paved surfaces. Any overflow from the large grass depression is directed to an existing swale on the north that continuous to an existing depression on the neighboring property. The topography of the site is relatively flat with the majority of slopes ranging from 1% to 10%. The area around the buildings sits slightly higher than paved areas around. Within the buildings, the site generally drains to the middle of each travel way with one large drywell and two catch basins. Outside of the building areas, the site drains off the pavement into a large depression surrounding the area. The USDA Web Soil Survey specifies the one soil type on the project site to the Oakville Loamy Fine Sand which is a very deep, predominantly moderately well drained sand, soil classified as hydrologic soil group “A”. Based on the soils data and information provided a conservative infiltration rate of 12 inches/hour was used in the design of the porous pavement and shallow grass depression. Soil testing will be performed on the site prior to construction. 2 900 Route 146 Clifton Park, NY 12065 (P) 518.371.7621 (F) 518.371.9540 edpllp.com NORTHWAY SELF-STORAGE, LLC Stormwater Design Report 3. STORMWATER DESIGN The proposed project includes the implementation of stormwater management devices in order to attenuate and infiltrate the runoff from portions of the existing and proposed impervious area. The proposed stormwater management devices shall be porous pavement and shallow grass depressions as described below. A. Porous Pavement Porous Pavement is proposed between two proposed as well as in the area between the proposed storage buildings and western most existing building. The porous pavement is designed to collect and infiltrate runoff from the proposed buildings, portion of existing buildings and what falls on the pavement. The contributing area to the pavement is approximately 23,400 SF with 100% impervious. The pavement is designed to treat and infiltrate runoff from the 50-year design storm event with no overflows. In the event that the largest storm even results in runoff rates that exceeds the pavements capacity those flows would be directed to the shallow grass depression. B. Grass Depression A grass depression has been proposed along the western side of the proposed building. The depression will also take surface runoff from a portion of the western most proposed building as well as the landscaped area along Carey Road. The total area contributing to the grass depression will be 24,000 SF, 2,000 SF of impervious. The total storage of the depression is on the order of 1,520 CF. During large storm events any overflows from the porous pavement will discharge into the shallow grass depressions and has been designed to fully attenuate and infiltrate the contributing runoff. In accordance with section 179-6-080 of the Town of Queensbury code the stormwater management system has been designed to limit the post-development runoff rates and volumes for the 50-year, 24-hour design storm event to less than the predevelopment runoff rates and volumes in order to prevent impacts to the downstream drainage corridors. HydroCAD stormwater modeling software was used to analyze the existing and proposed site conditions with the results summarized in the following table. Table 1: 50-Year Design Storm, Runoff Rates and Volumes Design Point Peak Runoff Rate (cfs) Runoff Volume (ac-ft) Predevelopment Post-Development Predevelopment Post-Development 1 0.00 0.00 0.00 0.00 3 900 Route 146 Clifton Park, NY 12065 (P) 518.371.7621 (F) 518.371.9540 edpllp.com NORTHWAY SELF-STORAGE, LLC Stormwater Design Report 4. SUMMARY The modifications to the proposed site will result in an increase in the amount of impervious area on the project site. While the drainage patterns will be generally the same as the existing conditions porous pavement and a shallow depression will be included to provide infiltration on proposed hard surfaces and alleviate any ponding along the existing western pavement. In conclusion the proposed site modifications will not result in any increases in runoff rates and volumes from the site and will not result in any flooding of downstream properties. Respectively Submitted, Brandon M. Ferguson, P.E. Environmental Design Partnership, LLP STORMWATER ANALYSIS FOR 162 CAREY ROAD TOWN OF QUEENSBURY FEBRUARY 15, 2022 NORTHWAY SELF-STORAGE1"=40'PREDEVLOPMENTWARREN COUNTY, NEW YORK1 TAX MAP. No. 13-2-31.11900 Route 146 Clifton Park, New York 12065 edpllp.com(518) 371-7621 E N V I R O N M E N T A L D E S I G N P A R T N E R S H I P, L L P. S1 S2 S3 S4 S5 P1 EX. DEPRESSION P2 Dry Well P3 Dry Well P4 Dry Well P5 Dry Well OFF Routing Diagram for predevelopment Prepared by {enter your company name here}, Printed 2/14/2022 HydroCAD® 10.00-20 s/n 11387 © 2017 HydroCAD Software Solutions LLC Subcat Reach Pond Link predevelopment Printed 2/14/2022Prepared by {enter your company name here} Page 2HydroCAD® 10.00-20 s/n 11387 © 2017 HydroCAD Software Solutions LLC Area Listing (all nodes) Area (sq-ft) CN Description (subcatchment-numbers) 63,147 39 >75% Grass cover, Good, HSG A (S1, S2) 35,638 98 Paved parking, HSG A (S1, S2, S3, S4, S5) 14,876 98 Unconnected roofs, HSG A (S1, S2, S3, S4, S5) 113,661 65 TOTAL AREA predevelopment Printed 2/14/2022Prepared by {enter your company name here} Page 3HydroCAD® 10.00-20 s/n 11387 © 2017 HydroCAD Software Solutions LLC Soil Listing (all nodes) Area (sq-ft) Soil Group Subcatchment Numbers 113,661 HSG A S1, S2, S3, S4, S5 0 HSG B 0 HSG C 0 HSG D 0 Other 113,661 TOTAL AREA predevelopment Printed 2/14/2022Prepared by {enter your company name here} Page 4HydroCAD® 10.00-20 s/n 11387 © 2017 HydroCAD Software Solutions LLC Ground Covers (all nodes) HSG-A (sq-ft) HSG-B (sq-ft) HSG-C (sq-ft) HSG-D (sq-ft) Other (sq-ft) Total (sq-ft) Ground Cover Subcatchment Numbers 63,147 0 0 0 0 63,147 >75% Grass cover, Good 35,638 0 0 0 0 35,638 Paved parking 14,876 0 0 0 0 14,876 Unconnected roofs 113,661 0 0 0 0 113,661 TOTAL AREA Type II 24-hr 50 year Rainfall=5.23"predevelopment Printed 2/14/2022Prepared by {enter your company name here} Page 5HydroCAD® 10.00-20 s/n 11387 © 2017 HydroCAD Software Solutions LLC Time span=0.00-200.00 hrs, dt=0.05 hrs, 4001 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=40,744 sf 46.56% Impervious Runoff Depth=1.89"Subcatchment S1: Flow Length=159' Slope=0.0150 '/' Tc=6.0 min CN=66 Runoff=3.06 cfs 6,404 cf Runoff Area=49,031 sf 15.62% Impervious Runoff Depth=0.57"Subcatchment S2: Flow Length=189' Tc=22.2 min UI Adjusted CN=46 Runoff=0.36 cfs 2,321 cf Runoff Area=7,962 sf 100.00% Impervious Runoff Depth=4.99"Subcatchment S3: Tc=0.0 min CN=98 Runoff=1.53 cfs 3,313 cf Runoff Area=7,962 sf 100.00% Impervious Runoff Depth=4.99"Subcatchment S4: Tc=0.0 min CN=98 Runoff=1.53 cfs 3,313 cf Runoff Area=7,962 sf 100.00% Impervious Runoff Depth=4.99"Subcatchment S5: Tc=0.0 min CN=98 Runoff=1.53 cfs 3,313 cf Peak Elev=382.80' Storage=1,596 cf Inflow=3.06 cfs 6,404 cfPond P1: EX. DEPRESSION Discarded=0.76 cfs 6,404 cf Primary=0.00 cfs 0 cf Outflow=0.76 cfs 6,404 cf Peak Elev=382.48' Storage=402 cf Inflow=0.36 cfs 2,321 cfPond P2: Dry Well Discarded=0.28 cfs 2,321 cf Primary=0.00 cfs 0 cf Outflow=0.28 cfs 2,321 cf Peak Elev=381.32' Storage=1,303 cf Inflow=1.53 cfs 3,313 cfPond P3: Dry Well Outflow=0.17 cfs 3,313 cf Peak Elev=381.07' Storage=1,303 cf Inflow=1.53 cfs 3,313 cfPond P4: Dry Well Outflow=0.17 cfs 3,313 cf Peak Elev=381.07' Storage=1,303 cf Inflow=1.53 cfs 3,313 cfPond P5: Dry Well Outflow=0.17 cfs 3,313 cf Inflow=0.00 cfs 0 cfLink OFF: Primary=0.00 cfs 0 cf Total Runoff Area = 113,661 sf Runoff Volume = 18,664 cf Average Runoff Depth = 1.97" 55.56% Pervious = 63,147 sf 44.44% Impervious = 50,514 sf Type II 24-hr 50 year Rainfall=5.23"predevelopment Printed 2/14/2022Prepared by {enter your company name here} Page 6HydroCAD® 10.00-20 s/n 11387 © 2017 HydroCAD Software Solutions LLC Summary for Subcatchment S1: Runoff = 3.06 cfs @ 11.98 hrs, Volume= 6,404 cf, Depth= 1.89" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-200.00 hrs, dt= 0.05 hrs Type II 24-hr 50 year Rainfall=5.23" Area (sf) CN Description 16,191 98 Paved parking, HSG A 21,773 39 >75% Grass cover, Good, HSG A 2,780 98 Unconnected roofs, HSG A 40,744 66 Weighted Average 21,773 53.44% Pervious Area 18,971 46.56% Impervious Area 2,780 14.65% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.5 100 0.0150 1.10 Sheet Flow, Smooth surfaces n= 0.011 P2= 2.57" 1.1 59 0.0150 0.86 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 2.6 159 Total, Increased to minimum Tc = 6.0 min Summary for Subcatchment S2: Runoff = 0.36 cfs @ 12.23 hrs, Volume= 2,321 cf, Depth= 0.57" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-200.00 hrs, dt= 0.05 hrs Type II 24-hr 50 year Rainfall=5.23" Area (sf) CN Adj Description 3,000 98 Unconnected roofs, HSG A 4,657 98 Paved parking, HSG A 41,374 39 >75% Grass cover, Good, HSG A 49,031 48 46 Weighted Average, UI Adjusted 41,374 84.38% Pervious Area 7,657 15.62% Impervious Area 3,000 39.18% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 21.0 100 0.0100 0.08 Sheet Flow, Grass: Dense n= 0.240 P2= 2.57" 1.2 89 0.0337 1.29 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 22.2 189 Total Type II 24-hr 50 year Rainfall=5.23"predevelopment Printed 2/14/2022Prepared by {enter your company name here} Page 7HydroCAD® 10.00-20 s/n 11387 © 2017 HydroCAD Software Solutions LLC Summary for Subcatchment S3: Runoff = 1.53 cfs @ 11.89 hrs, Volume= 3,313 cf, Depth= 4.99" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-200.00 hrs, dt= 0.05 hrs Type II 24-hr 50 year Rainfall=5.23" Area (sf) CN Description 3,032 98 Unconnected roofs, HSG A 4,930 98 Paved parking, HSG A 7,962 98 Weighted Average 7,962 100.00% Impervious Area 3,032 38.08% Unconnected Summary for Subcatchment S4: Runoff = 1.53 cfs @ 11.89 hrs, Volume= 3,313 cf, Depth= 4.99" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-200.00 hrs, dt= 0.05 hrs Type II 24-hr 50 year Rainfall=5.23" Area (sf) CN Description 3,032 98 Unconnected roofs, HSG A 4,930 98 Paved parking, HSG A 7,962 98 Weighted Average 7,962 100.00% Impervious Area 3,032 38.08% Unconnected Summary for Subcatchment S5: Runoff = 1.53 cfs @ 11.89 hrs, Volume= 3,313 cf, Depth= 4.99" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-200.00 hrs, dt= 0.05 hrs Type II 24-hr 50 year Rainfall=5.23" Area (sf) CN Description 3,032 98 Unconnected roofs, HSG A 4,930 98 Paved parking, HSG A 7,962 98 Weighted Average 7,962 100.00% Impervious Area 3,032 38.08% Unconnected Summary for Pond P1: EX. DEPRESSION Inflow Area = 89,775 sf, 29.66% Impervious, Inflow Depth = 0.86" for 50 year event Inflow = 3.06 cfs @ 11.98 hrs, Volume= 6,404 cf Outflow = 0.76 cfs @ 12.14 hrs, Volume= 6,404 cf, Atten= 75%, Lag= 9.6 min Discarded = 0.76 cfs @ 12.14 hrs, Volume= 6,404 cf Primary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Type II 24-hr 50 year Rainfall=5.23"predevelopment Printed 2/14/2022Prepared by {enter your company name here} Page 8HydroCAD® 10.00-20 s/n 11387 © 2017 HydroCAD Software Solutions LLC Routing by Stor-Ind method, Time Span= 0.00-200.00 hrs, dt= 0.05 hrs Peak Elev= 382.80' @ 12.14 hrs Surf.Area= 6,555 sf Storage= 1,596 cf Plug-Flow detention time= 13.3 min calculated for 6,404 cf (100% of inflow) Center-of-Mass det. time= 13.3 min ( 865.4 - 852.1 ) Volume Invert Avail.Storage Storage Description #1 382.50' 11,865 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 382.50 4,000 0 0 383.00 8,225 3,056 3,056 383.75 15,264 8,808 11,865 Device Routing Invert Outlet Devices #1 Discarded 382.50'5.000 in/hr Exfiltration over Surface area #2 Primary 383.70'5.0' long x 1.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 Coef. (English) 2.69 2.72 2.75 2.85 2.98 3.08 3.20 3.28 3.31 3.30 3.31 3.32 Discarded OutFlow Max=0.76 cfs @ 12.14 hrs HW=382.80' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.76 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=382.50' (Free Discharge) 2=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Summary for Pond P2: Dry Well Inflow Area = 49,031 sf, 15.62% Impervious, Inflow Depth = 0.57" for 50 year event Inflow = 0.36 cfs @ 12.23 hrs, Volume= 2,321 cf Outflow = 0.28 cfs @ 12.50 hrs, Volume= 2,321 cf, Atten= 23%, Lag= 16.0 min Discarded = 0.28 cfs @ 12.50 hrs, Volume= 2,321 cf Primary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Stor-Ind method, Time Span= 0.00-200.00 hrs, dt= 0.05 hrs Peak Elev= 382.48' @ 12.50 hrs Surf.Area= 50 sf Storage= 402 cf Plug-Flow detention time= 168.3 min calculated for 2,321 cf (100% of inflow) Center-of-Mass det. time= 168.4 min ( 1,114.4 - 946.1 ) Volume Invert Avail.Storage Storage Description #1 382.50' 1,028 cf Custom Stage Data (Prismatic) Listed below (Recalc) #2 372.40' 402 cf 8.00'D x 8.00'H Vertical Cone/Cylinder 472 cf Overall - 4.0" Wall Thickness = 402 cf 1,430 cf Total Available Storage Type II 24-hr 50 year Rainfall=5.23"predevelopment Printed 2/14/2022Prepared by {enter your company name here} Page 9HydroCAD® 10.00-20 s/n 11387 © 2017 HydroCAD Software Solutions LLC Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 382.50 2,056 0 0 383.00 2,056 1,028 1,028 Device Routing Invert Outlet Devices #1 Discarded 372.40'12.000 in/hr Exfiltration over Surface area #2 Primary 383.70'150.0' long x 5.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.34 2.50 2.70 2.68 2.68 2.66 2.65 2.65 2.65 2.65 2.67 2.66 2.68 2.70 2.74 2.79 2.88 Discarded OutFlow Max=0.01 cfs @ 12.50 hrs HW=382.48' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.01 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=372.40' (Free Discharge) 2=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Summary for Pond P3: Dry Well Inflow Area = 7,962 sf,100.00% Impervious, Inflow Depth = 4.99" for 50 year event Inflow = 1.53 cfs @ 11.89 hrs, Volume= 3,313 cf Outflow = 0.17 cfs @ 12.10 hrs, Volume= 3,313 cf, Atten= 89%, Lag= 12.7 min Discarded = 0.17 cfs @ 12.10 hrs, Volume= 3,313 cf Routing by Stor-Ind method, Time Span= 0.00-200.00 hrs, dt= 0.05 hrs Peak Elev= 381.32' @ 12.10 hrs Surf.Area= 618 sf Storage= 1,303 cf Plug-Flow detention time= 72.6 min calculated for 3,312 cf (100% of inflow) Center-of-Mass det. time= 72.6 min ( 810.2 - 737.6 ) Volume Invert Avail.Storage Storage Description #1 373.80' 402 cf 8.00'D x 8.00'H Vertical Cone/Cylinder Inside #2 472 cf Overall - 4.0" Wall Thickness = 402 cf #2 372.30' 1,036 cf 10.00'D x 9.50'H Vertical Cone/Cylinder Z=1.0 3,062 cf Overall - 472 cf Embedded = 2,590 cf x 40.0% Voids 1,438 cf Total Available Storage Device Routing Invert Outlet Devices #1 Discarded 372.30'12.000 in/hr Exfiltration over Surface area Discarded OutFlow Max=0.17 cfs @ 12.10 hrs HW=381.32' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.17 cfs) Type II 24-hr 50 year Rainfall=5.23"predevelopment Printed 2/14/2022Prepared by {enter your company name here} Page 10HydroCAD® 10.00-20 s/n 11387 © 2017 HydroCAD Software Solutions LLC Summary for Pond P4: Dry Well Inflow Area = 7,962 sf,100.00% Impervious, Inflow Depth = 4.99" for 50 year event Inflow = 1.53 cfs @ 11.89 hrs, Volume= 3,313 cf Outflow = 0.17 cfs @ 12.10 hrs, Volume= 3,313 cf, Atten= 89%, Lag= 12.7 min Discarded = 0.17 cfs @ 12.10 hrs, Volume= 3,313 cf Routing by Stor-Ind method, Time Span= 0.00-200.00 hrs, dt= 0.05 hrs Peak Elev= 381.07' @ 12.10 hrs Surf.Area= 618 sf Storage= 1,303 cf Plug-Flow detention time= 72.6 min calculated for 3,312 cf (100% of inflow) Center-of-Mass det. time= 72.6 min ( 810.2 - 737.6 ) Volume Invert Avail.Storage Storage Description #1 373.55' 402 cf 8.00'D x 8.00'H Vertical Cone/Cylinder Inside #2 472 cf Overall - 4.0" Wall Thickness = 402 cf #2 372.05' 1,036 cf 10.00'D x 9.50'H Vertical Cone/Cylinder Z=1.0 3,062 cf Overall - 472 cf Embedded = 2,590 cf x 40.0% Voids 1,438 cf Total Available Storage Device Routing Invert Outlet Devices #1 Discarded 372.05'12.000 in/hr Exfiltration over Surface area Discarded OutFlow Max=0.17 cfs @ 12.10 hrs HW=381.07' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.17 cfs) Summary for Pond P5: Dry Well Inflow Area = 7,962 sf,100.00% Impervious, Inflow Depth = 4.99" for 50 year event Inflow = 1.53 cfs @ 11.89 hrs, Volume= 3,313 cf Outflow = 0.17 cfs @ 12.10 hrs, Volume= 3,313 cf, Atten= 89%, Lag= 12.7 min Discarded = 0.17 cfs @ 12.10 hrs, Volume= 3,313 cf Routing by Stor-Ind method, Time Span= 0.00-200.00 hrs, dt= 0.05 hrs Peak Elev= 381.07' @ 12.10 hrs Surf.Area= 618 sf Storage= 1,303 cf Plug-Flow detention time= 72.6 min calculated for 3,312 cf (100% of inflow) Center-of-Mass det. time= 72.6 min ( 810.2 - 737.6 ) Volume Invert Avail.Storage Storage Description #1 373.55' 402 cf 8.00'D x 8.00'H Vertical Cone/Cylinder Inside #2 472 cf Overall - 4.0" Wall Thickness = 402 cf #2 372.05' 1,036 cf 10.00'D x 9.50'H Vertical Cone/Cylinder Z=1.0 3,062 cf Overall - 472 cf Embedded = 2,590 cf x 40.0% Voids 1,438 cf Total Available Storage Device Routing Invert Outlet Devices #1 Discarded 372.05'12.000 in/hr Exfiltration over Surface area Discarded OutFlow Max=0.17 cfs @ 12.10 hrs HW=381.07' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.17 cfs) Type II 24-hr 50 year Rainfall=5.23"predevelopment Printed 2/14/2022Prepared by {enter your company name here} Page 11HydroCAD® 10.00-20 s/n 11387 © 2017 HydroCAD Software Solutions LLC Summary for Link OFF: Inflow Area = 89,775 sf, 29.66% Impervious, Inflow Depth = 0.00" for 50 year event Inflow = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Primary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-200.00 hrs, dt= 0.05 hrs STORMWATER ANALYSIS FOR 162 CAREY ROAD TOWN OF QUEENSBURY FEBRUARY 15, 2022 NORTHWAY SELF-STORAGE1"=40'POSTDEVLOPMENTWARREN COUNTY, NEW YORK2 TAX MAP. No. 13-2-31.11900 Route 146 Clifton Park, New York 12065 edpllp.com(518) 371-7621 E N V I R O N M E N T A L D E S I G N P A R T N E R S H I P, L L P. S1 S2 S3 S4 S5S6 P1 EX. DEPRESSION P2 Depression P3 Dry Well P4 Dry Well P5 Dry Well PP6 Porous Pavement OFF Routing Diagram for postdevelopment Prepared by {enter your company name here}, Printed 2/14/2022 HydroCAD® 10.00-20 s/n 11387 © 2017 HydroCAD Software Solutions LLC Subcat Reach Pond Link postdevelopment Printed 2/14/2022Prepared by {enter your company name here} Page 2HydroCAD® 10.00-20 s/n 11387 © 2017 HydroCAD Software Solutions LLC Area Listing (all nodes) Area (sq-ft) CN Description (subcatchment-numbers) 43,698 39 >75% Grass cover, Good, HSG A (S1, S2) 43,372 98 Paved parking, HSG A (S1, S3, S4, S5, S6) 24,876 98 Unconnected roofs, HSG A (S1, S2, S3, S4, S5, S6) 111,946 75 TOTAL AREA postdevelopment Printed 2/14/2022Prepared by {enter your company name here} Page 3HydroCAD® 10.00-20 s/n 11387 © 2017 HydroCAD Software Solutions LLC Soil Listing (all nodes) Area (sq-ft) Soil Group Subcatchment Numbers 111,946 HSG A S1, S2, S3, S4, S5, S6 0 HSG B 0 HSG C 0 HSG D 0 Other 111,946 TOTAL AREA postdevelopment Printed 2/14/2022Prepared by {enter your company name here} Page 4HydroCAD® 10.00-20 s/n 11387 © 2017 HydroCAD Software Solutions LLC Ground Covers (all nodes) HSG-A (sq-ft) HSG-B (sq-ft) HSG-C (sq-ft) HSG-D (sq-ft) Other (sq-ft) Total (sq-ft) Ground Cover Subcatchment Numbers 43,698 0 0 0 0 43,698 >75% Grass cover, Good 43,372 0 0 0 0 43,372 Paved parking 24,876 0 0 0 0 24,876 Unconnected roofs 111,946 0 0 0 0 111,946 TOTAL AREA Type II 24-hr 50 year Rainfall=5.23"postdevelopment Printed 2/14/2022Prepared by {enter your company name here} Page 5HydroCAD® 10.00-20 s/n 11387 © 2017 HydroCAD Software Solutions LLC Time span=0.00-200.00 hrs, dt=0.05 hrs, 4001 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=40,744 sf 46.56% Impervious Runoff Depth=1.89"Subcatchment S1: Flow Length=159' Slope=0.0150 '/' Tc=6.0 min CN=66 Runoff=3.06 cfs 6,404 cf Runoff Area=23,925 sf 8.36% Impervious Runoff Depth=0.33"Subcatchment S2: Flow Length=79' Tc=10.6 min UI Adjusted CN=41 Runoff=0.08 cfs 659 cf Runoff Area=7,962 sf 100.00% Impervious Runoff Depth=4.99"Subcatchment S3: Tc=0.0 min CN=98 Runoff=1.53 cfs 3,313 cf Runoff Area=7,962 sf 100.00% Impervious Runoff Depth=4.99"Subcatchment S4: Tc=0.0 min CN=98 Runoff=1.53 cfs 3,313 cf Runoff Area=7,962 sf 100.00% Impervious Runoff Depth=4.99"Subcatchment S5: Tc=0.0 min CN=98 Runoff=1.53 cfs 3,313 cf Runoff Area=23,391 sf 100.00% Impervious Runoff Depth=4.99"Subcatchment S6: Tc=0.0 min CN=98 Runoff=4.49 cfs 9,732 cf Peak Elev=382.68' Storage=831 cf Inflow=3.06 cfs 6,404 cfPond P1: EX. DEPRESSION Discarded=1.52 cfs 6,404 cf Primary=0.00 cfs 0 cf Outflow=1.52 cfs 6,404 cf Peak Elev=382.50' Storage=3 cf Inflow=0.08 cfs 659 cfPond P2: Depression Discarded=0.08 cfs 659 cf Primary=0.00 cfs 0 cf Outflow=0.08 cfs 659 cf Peak Elev=381.32' Storage=1,303 cf Inflow=1.53 cfs 3,313 cfPond P3: Dry Well Outflow=0.17 cfs 3,313 cf Peak Elev=381.07' Storage=1,303 cf Inflow=1.53 cfs 3,313 cfPond P4: Dry Well Outflow=0.17 cfs 3,313 cf Peak Elev=381.07' Storage=1,303 cf Inflow=1.53 cfs 3,313 cfPond P5: Dry Well Outflow=0.17 cfs 3,313 cf Peak Elev=382.50' Storage=731 cf Inflow=4.49 cfs 9,732 cfPond PP6: Porous Pavement Outflow=2.48 cfs 9,751 cf Inflow=0.00 cfs 0 cfLink OFF: Primary=0.00 cfs 0 cf Total Runoff Area = 111,946 sf Runoff Volume = 26,733 cf Average Runoff Depth = 2.87" 39.03% Pervious = 43,698 sf 60.97% Impervious = 68,248 sf Type II 24-hr 50 year Rainfall=5.23"postdevelopment Printed 2/14/2022Prepared by {enter your company name here} Page 6HydroCAD® 10.00-20 s/n 11387 © 2017 HydroCAD Software Solutions LLC Summary for Subcatchment S1: Runoff = 3.06 cfs @ 11.98 hrs, Volume= 6,404 cf, Depth= 1.89" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-200.00 hrs, dt= 0.05 hrs Type II 24-hr 50 year Rainfall=5.23" Area (sf) CN Description 16,191 98 Paved parking, HSG A 21,773 39 >75% Grass cover, Good, HSG A 2,780 98 Unconnected roofs, HSG A 40,744 66 Weighted Average 21,773 53.44% Pervious Area 18,971 46.56% Impervious Area 2,780 14.65% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.5 100 0.0150 1.10 Sheet Flow, Smooth surfaces n= 0.011 P2= 2.57" 1.1 59 0.0150 0.86 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 2.6 159 Total, Increased to minimum Tc = 6.0 min Summary for Subcatchment S2: Runoff = 0.08 cfs @ 12.10 hrs, Volume= 659 cf, Depth= 0.33" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-200.00 hrs, dt= 0.05 hrs Type II 24-hr 50 year Rainfall=5.23" Area (sf) CN Adj Description 2,000 98 Unconnected roofs, HSG A 21,925 39 >75% Grass cover, Good, HSG A 23,925 44 41 Weighted Average, UI Adjusted 21,925 91.64% Pervious Area 2,000 8.36% Impervious Area 2,000 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 8.9 55 0.0100 0.10 Sheet Flow, Grass: Short n= 0.150 P2= 2.57" 1.7 24 0.3333 0.24 Sheet Flow, Grass: Dense n= 0.240 P2= 2.57" 10.6 79 Total Type II 24-hr 50 year Rainfall=5.23"postdevelopment Printed 2/14/2022Prepared by {enter your company name here} Page 7HydroCAD® 10.00-20 s/n 11387 © 2017 HydroCAD Software Solutions LLC Summary for Subcatchment S3: Runoff = 1.53 cfs @ 11.89 hrs, Volume= 3,313 cf, Depth= 4.99" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-200.00 hrs, dt= 0.05 hrs Type II 24-hr 50 year Rainfall=5.23" Area (sf) CN Description 3,032 98 Unconnected roofs, HSG A 4,930 98 Paved parking, HSG A 7,962 98 Weighted Average 7,962 100.00% Impervious Area 3,032 38.08% Unconnected Summary for Subcatchment S4: Runoff = 1.53 cfs @ 11.89 hrs, Volume= 3,313 cf, Depth= 4.99" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-200.00 hrs, dt= 0.05 hrs Type II 24-hr 50 year Rainfall=5.23" Area (sf) CN Description 3,032 98 Unconnected roofs, HSG A 4,930 98 Paved parking, HSG A 7,962 98 Weighted Average 7,962 100.00% Impervious Area 3,032 38.08% Unconnected Summary for Subcatchment S5: Runoff = 1.53 cfs @ 11.89 hrs, Volume= 3,313 cf, Depth= 4.99" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-200.00 hrs, dt= 0.05 hrs Type II 24-hr 50 year Rainfall=5.23" Area (sf) CN Description 3,032 98 Unconnected roofs, HSG A 4,930 98 Paved parking, HSG A 7,962 98 Weighted Average 7,962 100.00% Impervious Area 3,032 38.08% Unconnected Summary for Subcatchment S6: Runoff = 4.49 cfs @ 11.89 hrs, Volume= 9,732 cf, Depth= 4.99" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-200.00 hrs, dt= 0.05 hrs Type II 24-hr 50 year Rainfall=5.23" Type II 24-hr 50 year Rainfall=5.23"postdevelopment Printed 2/14/2022Prepared by {enter your company name here} Page 8HydroCAD® 10.00-20 s/n 11387 © 2017 HydroCAD Software Solutions LLC Area (sf) CN Description 11,000 98 Unconnected roofs, HSG A 12,391 98 Paved parking, HSG A 23,391 98 Weighted Average 23,391 100.00% Impervious Area 11,000 47.03% Unconnected Summary for Pond P1: EX. DEPRESSION Inflow Area = 64,669 sf, 32.43% Impervious, Inflow Depth = 1.19" for 50 year event Inflow = 3.06 cfs @ 11.98 hrs, Volume= 6,404 cf Outflow = 1.52 cfs @ 12.07 hrs, Volume= 6,404 cf, Atten= 50%, Lag= 5.7 min Discarded = 1.52 cfs @ 12.07 hrs, Volume= 6,404 cf Primary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Routing by Stor-Ind method, Time Span= 0.00-200.00 hrs, dt= 0.05 hrs Peak Elev= 382.68' @ 12.07 hrs Surf.Area= 5,482 sf Storage= 831 cf Plug-Flow detention time= 2.6 min calculated for 6,402 cf (100% of inflow) Center-of-Mass det. time= 2.6 min ( 854.7 - 852.1 ) Volume Invert Avail.Storage Storage Description #1 382.50' 3,056 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 382.50 4,000 0 0 383.00 8,225 3,056 3,056 Device Routing Invert Outlet Devices #1 Discarded 382.50'12.000 in/hr Exfiltration over Surface area #2 Primary 383.70'500.0' long x 1.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 Coef. (English) 2.69 2.72 2.75 2.85 2.98 3.08 3.20 3.28 3.31 3.30 3.31 3.32 Discarded OutFlow Max=1.51 cfs @ 12.07 hrs HW=382.67' (Free Discharge) 1=Exfiltration (Exfiltration Controls 1.51 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=382.50' (Free Discharge) 2=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Summary for Pond P2: Depression Inflow Area = 23,925 sf, 8.36% Impervious, Inflow Depth = 0.33" for 50 year event Inflow = 0.08 cfs @ 12.10 hrs, Volume= 659 cf Outflow = 0.08 cfs @ 12.11 hrs, Volume= 659 cf, Atten= 0%, Lag= 0.7 min Discarded = 0.08 cfs @ 12.11 hrs, Volume= 659 cf Primary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Type II 24-hr 50 year Rainfall=5.23"postdevelopment Printed 2/14/2022Prepared by {enter your company name here} Page 9HydroCAD® 10.00-20 s/n 11387 © 2017 HydroCAD Software Solutions LLC Routing by Stor-Ind method, Time Span= 0.00-200.00 hrs, dt= 0.05 hrs Peak Elev= 382.50' @ 12.11 hrs Surf.Area= 2,333 sf Storage= 3 cf Plug-Flow detention time= 0.7 min calculated for 659 cf (100% of inflow) Center-of-Mass det. time= 0.7 min ( 979.6 - 978.9 ) Volume Invert Avail.Storage Storage Description #1 382.50' 1,342 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 382.50 2,331 0 0 383.00 3,036 1,342 1,342 Device Routing Invert Outlet Devices #1 Discarded 382.50'12.000 in/hr Exfiltration over Surface area #2 Primary 383.70'500.0' long x 5.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.34 2.50 2.70 2.68 2.68 2.66 2.65 2.65 2.65 2.65 2.67 2.66 2.68 2.70 2.74 2.79 2.88 Discarded OutFlow Max=0.65 cfs @ 12.11 hrs HW=382.50' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.65 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=382.50' (Free Discharge) 2=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Summary for Pond P3: Dry Well Inflow Area = 7,962 sf,100.00% Impervious, Inflow Depth = 4.99" for 50 year event Inflow = 1.53 cfs @ 11.89 hrs, Volume= 3,313 cf Outflow = 0.17 cfs @ 12.10 hrs, Volume= 3,313 cf, Atten= 89%, Lag= 12.7 min Discarded = 0.17 cfs @ 12.10 hrs, Volume= 3,313 cf Routing by Stor-Ind method, Time Span= 0.00-200.00 hrs, dt= 0.05 hrs Peak Elev= 381.32' @ 12.10 hrs Surf.Area= 618 sf Storage= 1,303 cf Plug-Flow detention time= 72.6 min calculated for 3,312 cf (100% of inflow) Center-of-Mass det. time= 72.6 min ( 810.2 - 737.6 ) Volume Invert Avail.Storage Storage Description #1 373.80' 402 cf 8.00'D x 8.00'H Vertical Cone/Cylinder Inside #2 472 cf Overall - 4.0" Wall Thickness = 402 cf #2 372.30' 1,036 cf 10.00'D x 9.50'H Vertical Cone/Cylinder Z=1.0 3,062 cf Overall - 472 cf Embedded = 2,590 cf x 40.0% Voids 1,438 cf Total Available Storage Device Routing Invert Outlet Devices #1 Discarded 372.30'12.000 in/hr Exfiltration over Surface area Type II 24-hr 50 year Rainfall=5.23"postdevelopment Printed 2/14/2022Prepared by {enter your company name here} Page 10HydroCAD® 10.00-20 s/n 11387 © 2017 HydroCAD Software Solutions LLC Discarded OutFlow Max=0.17 cfs @ 12.10 hrs HW=381.32' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.17 cfs) Summary for Pond P4: Dry Well Inflow Area = 7,962 sf,100.00% Impervious, Inflow Depth = 4.99" for 50 year event Inflow = 1.53 cfs @ 11.89 hrs, Volume= 3,313 cf Outflow = 0.17 cfs @ 12.10 hrs, Volume= 3,313 cf, Atten= 89%, Lag= 12.7 min Discarded = 0.17 cfs @ 12.10 hrs, Volume= 3,313 cf Routing by Stor-Ind method, Time Span= 0.00-200.00 hrs, dt= 0.05 hrs Peak Elev= 381.07' @ 12.10 hrs Surf.Area= 618 sf Storage= 1,303 cf Plug-Flow detention time= 72.6 min calculated for 3,312 cf (100% of inflow) Center-of-Mass det. time= 72.6 min ( 810.2 - 737.6 ) Volume Invert Avail.Storage Storage Description #1 373.55' 402 cf 8.00'D x 8.00'H Vertical Cone/Cylinder Inside #2 472 cf Overall - 4.0" Wall Thickness = 402 cf #2 372.05' 1,036 cf 10.00'D x 9.50'H Vertical Cone/Cylinder Z=1.0 3,062 cf Overall - 472 cf Embedded = 2,590 cf x 40.0% Voids 1,438 cf Total Available Storage Device Routing Invert Outlet Devices #1 Discarded 372.05'12.000 in/hr Exfiltration over Surface area Discarded OutFlow Max=0.17 cfs @ 12.10 hrs HW=381.07' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.17 cfs) Summary for Pond P5: Dry Well Inflow Area = 7,962 sf,100.00% Impervious, Inflow Depth = 4.99" for 50 year event Inflow = 1.53 cfs @ 11.89 hrs, Volume= 3,313 cf Outflow = 0.17 cfs @ 12.10 hrs, Volume= 3,313 cf, Atten= 89%, Lag= 12.7 min Discarded = 0.17 cfs @ 12.10 hrs, Volume= 3,313 cf Routing by Stor-Ind method, Time Span= 0.00-200.00 hrs, dt= 0.05 hrs Peak Elev= 381.07' @ 12.10 hrs Surf.Area= 618 sf Storage= 1,303 cf Plug-Flow detention time= 72.6 min calculated for 3,312 cf (100% of inflow) Center-of-Mass det. time= 72.6 min ( 810.2 - 737.6 ) Volume Invert Avail.Storage Storage Description #1 373.55' 402 cf 8.00'D x 8.00'H Vertical Cone/Cylinder Inside #2 472 cf Overall - 4.0" Wall Thickness = 402 cf #2 372.05' 1,036 cf 10.00'D x 9.50'H Vertical Cone/Cylinder Z=1.0 3,062 cf Overall - 472 cf Embedded = 2,590 cf x 40.0% Voids 1,438 cf Total Available Storage Type II 24-hr 50 year Rainfall=5.23"postdevelopment Printed 2/14/2022Prepared by {enter your company name here} Page 11HydroCAD® 10.00-20 s/n 11387 © 2017 HydroCAD Software Solutions LLC Device Routing Invert Outlet Devices #1 Discarded 372.05'12.000 in/hr Exfiltration over Surface area Discarded OutFlow Max=0.17 cfs @ 12.10 hrs HW=381.07' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.17 cfs) Summary for Pond PP6: Porous Pavement Inflow Area = 23,391 sf,100.00% Impervious, Inflow Depth = 4.99" for 50 year event Inflow = 4.49 cfs @ 11.89 hrs, Volume= 9,732 cf Outflow = 2.48 cfs @ 11.80 hrs, Volume= 9,751 cf, Atten= 45%, Lag= 0.0 min Discarded = 2.48 cfs @ 11.80 hrs, Volume= 9,751 cf Routing by Stor-Ind method, Time Span= 0.00-200.00 hrs, dt= 0.05 hrs Peak Elev= 382.50' @ 11.95 hrs Surf.Area= 8,923 sf Storage= 731 cf Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 0.9 min ( 738.5 - 737.6 ) Volume Invert Avail.Storage Storage Description #1 382.30' 3,569 cf Custom Stage Data (Irregular) Listed below (Recalc) 8,923 cf Overall x 40.0% Voids Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 382.30 8,923 560.0 0 0 8,923 383.30 8,923 560.0 8,923 8,923 9,483 Device Routing Invert Outlet Devices #1 Discarded 382.30'12.000 in/hr Exfiltration over Surface area Phase-In= 0.01' Discarded OutFlow Max=2.48 cfs @ 11.80 hrs HW=382.32' (Free Discharge) 1=Exfiltration (Exfiltration Controls 2.48 cfs) Summary for Link OFF: Inflow Area = 64,669 sf, 32.43% Impervious, Inflow Depth = 0.00" for 50 year event Inflow = 0.00 cfs @ 0.00 hrs, Volume= 0 cf Primary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-200.00 hrs, dt= 0.05 hrs