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HomeMy WebLinkAboutStormwater Report - 140 ACADEMY ROAD 6/28/2011 Supplement to Stormwater Report 140 Academy Road at Stevens Street North Andover, Massachusetts June 28, 2011 Prepared for: Tom Patenaude 100 Salem Street North Andover, MA 01845 Prepared By: Andover Consultants, Inc. 1 East River Place Methuen, MA 01844 'tH OF M41Y o= JAMES S. FAMWEATHER 11 G� O ~ pIo.34716 N d 4 SC `cG TE�� �j l� r�� rt � Standard #2 Peak Rate Attenuation Runoff from the site is tributary to two existing drainage structures. Due to the topography at the site, and limited room, an expansion of surface storage at the existing catch basin is proposed to mitigate runoff rate. A surface swale along the frontage of the lots is also proposed to enhance surface storage for runoff that discharges to an existing, shallow culvert. The existing culvert is proposed to be lowered and fitted with a riprap basin to mitigate discharge velocity and erosion potential. These methods provide mitigation to the maximum extent feasible given the site constraints. Peak rates of runoff for the 1, 2, 10, 25 and 100-year storm events have been calculated using the HydroCAD Stormwater Modeling Program and the 24-hour rainfall depths contained in the North Andover Land Disturbance Permit Regulations. A summary of pre vs. post developed rates of runoff are as follows: Existing Catch basin 1-year storm 2-year 10-year 25-year 100-year Pre= 1.2 cfs Pre=2.2 cfs pre= 5.3 cfs pre = 6.1 cfs pre= 14.5 cfs Post= 1.6 cfs post=2.6 cfs post=4.8 cfs post= 5.8 cfs post= 14.9 cfs Existing culvert to be replaced 1 year Storm 2-year 10-year 25-year 100-year Pre= 1.8 cfs pre=3.2 cfs pre=6.8 cfs pre= 12.9 cfs pre=24.2 cfs Post=2.7 cfs post=4.4 cfs post=7.0 cfs post= 12.9 cfs post=26.0 cfs Flood elevations for the 1,2, 10,25 and 100-year storm events have been calculated. A summary of pre vs. post developed elevations are as follows: Existing Catch basin(Flood elevation center line Stevens St= 175.5) 1-year storm 2-year 10-year 25-year 100-year Pre= 172.98 Pre= 173.25 pre= 174.86 pre= 175.51 pre= 175.69 Post= 173.08 Post= 173.39 post= 174.51 post= 175.28 post= 175.70 Existing culvert(Flood elevation center line Stevens St= 171.1) 1-year storm 2-year 10-year 25-year 100-year Pre= 169.31 Pre= 170.09 pre= 171.15 pre= 171.21 pre= 171.29 Post= 167.76 Post= 168.62 post= 170.71 post= 171.18 post= 171.28 Operation and Maintenance Plan Operation and Maintenance Plan 140 Academy Road at Stevens Street Inspection and Maintenance Report Property Owner: Address: Fill out the name and address of the person(s) responsible for operation and maintenance (attach copy of maintenance agreement if contracted to a third party). Responsible person(s): Company(if any): Driveway Condition--------------------------------------------------------------------- Action Taken Grass slopes Condition--------------------------------------------------------------------- Action Taken Retaining walls Condition--------------------------------------------------------------------- Action Taken Gutters and leaders Condition--------------------------------------------------------------------- Action Taken Grass swales Condition--------------------------------------------------------------------- Action Taken Owner's signature Date Inspector's signature (if different than owner) Date Long Term Pollution Prevention Plan Good housekeeping practices The owner of the property shall ensure regular maintenance activities on the lot remain on schedule. Professional Landscape and Building Maintenance services may be utilized to maintain the building and grounds. Provisions for storing materials and waste products inside or under cover No Hazardous materials that are not usual and customary for residential uses shall be stored at this site. Vehicle washing controls Typical passenger car washing activities can take place in the area. Direct dumping of unused detergents into or near the drop inlet structures shall be avoided. Requirements for routine inspections and maintenance of stormwater BMPs The Owner will be responsible for ensuring that the inspection and maintenance activities including regular inspection and maintenance of the paved driveway and storm water management inlet structures (drop inlets) continue indefinitely. Spill prevention and response plans The home owner shall ensure that no oil or other petroleum based product is dumped into the drop inlet structures. Any detected spills shall be reported to the North Andover Board of Health Requirements for storage and use of fertilizers, herbicides, and pesticides Fertilizers, herbicides or pesticides shall be used and stored as recommended by the manufacturer and in accordance with local rules and regulations. Provisions for solid waste management All solid waste produced by the site will be temporarily stored in trash receptacles and emptied weekly via curb side pick up. Snow disposal and plowing plans relative to Wetland Resource Areas No adverse effects to wetland areas due to snow plowing are anticipated for the residential lots. Winter Road Salt and/or Sand Use and Storage restrictions Salt shall be properly stored at the site.Use of salt and sand is allowed slippery conditions warrant. The owner shall try to minimize discharge of sand into the drop inlets, i.e. do not sweep excess sand into them. Driveway sweeping schedules Sweeping of the paved driveways is encouraged to minimize sedimentation of infiltration trenches. Provisions for prevention of illicit discharges to the stormwater management system The storage and use of hazardous materials is prohibited. No illicit discharges of oil or other hazardous materials are permissible at the site. Any detected illicit discharges shall be reported immediately to the North Andover Police and Board of Health. List of Emergency Contacts for implementing Long-Term Pollution Prevention Plan North Andover Police (non emergency) 978-683-3168 North Andover Conservation Department 978-688-9530 North Andover Health Department 978-688-9540 Massachusetts Department of Environmental Protection 978-694-3200 Inspection and Maintenance Schedule 1. Despite being in the Public way,the maintenance of the culvert under your driveway is your responsibility. The lot owner, or his/her designee, shall inspect the structure quarterly. The owner shall ensure that no portion of the structure is damaged, blocked or otherwise in a state that prevents its proper operation. 2. The lot owner, or his/her designee, shall inspect vegetated areas every 60 days when snow is not on the ground to look for eroded areas. Any eroded vegetated areas shall be repaired and stabilized as soon as feasible. 3. The lot owner, or his/her designee, shall inspect retaining walls on a monthly basis to look for unusual erosion or damage to the wall. 4. The lot owner, or his/her designee, shall inspect gutters and downspouts to ensure they are functioning properly. Accumulated debris shall be removed. Inspect these features every 6 months. 5. The driveway shall be cleaned of accumulated sand in April or May of each year. 6. Although in the public Right-of Way, mowing and removal of debris from the swale in front of your lot is encouraged,performing this maintenance work will help ensure that the swale will drain properly. Notes: The property owner shall maintain all inspection and maintenance reports and provide copies to the North Andover Planning Board upon request. Records shall be retained for a period of five years. The Planning Board shall be notified of any changes in ownership and any amendments to the inspection and maintenance schedule shall be subject to their approval upon written notification of proposed amendments. HydroCAD Pre-developed calculations 1S 2S exist to ex cb exist to ex culvert tx 1P 2P ex cb ex culvert Subcat Reach Pon Link Drainage Diagram for Stevens St ex 06-09-11 Prepared by Andover Consultants, Inc. HydroCAD®5.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC 1-Year Storm P=2.6 inches Stevens St ex 06-09-11 Type /// 24-hr 1-Yr Rainfall=2.60" Prepared by Andover Consultants, Inc. HydroCADO 8.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Time span=0.00-24.00 hrs, dt=0.05 hrs, 481 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind method - Pond routing by Stor-Ind method Subcatchment 1S: exist to ex cb Runoff Area=2.894 ac Runoff Depth>0.50" Flow Length=734' Slope=0.12897' Tc=9.2 min CN=70 Runoff=1.2 cfs 0.121 of Subcatchment 2S: exist to ex culvert Runoff Area=4.584 ac Runoff Depth>0.47" Flow Length=690' Slope=0.1997'/' Tc=7.2 min CN=69 Runoff=1.8 cfs 0.178 of Pond 1 P: ex cb Peak Elev=172.98' Storage=7 cf Inflow=1.2 cfs 0.121 of Primary=1.2 cfs 0.121 of Secondary=0.0 cfs 0.000 of Outflow=1.2 cfs 0.121 of Pond 2P: ex culvert Peak Elev=169.31' Storage=19 cf Inflow=1.8 cfs 0.178 of Primary=1.8 cfs 0.178 of Secondary=0.0 cfs 0.000 of Outflow=1.8 cfs 0.178 of Stevens St ex 06-09-11 Type 11124-hr 1-Yr Rainfall=2.60" Prepared by Andover Consultants, Inc. HydroCAD®8 00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Subcatchment 1S: exist to ex cb Runoff = 1.2 cfs @ 12.16 hrs, Volume= 0.121 af, Depth> 0.50" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 1-Yr Rainfall=2.60" Area (ac) CN Description 0.460 55 Woods, Good, HSG B 1.436 70 Woods, Good, HSG C 0.833 74 >75% Grass cover, Good, HSG C 0.165 98 Paved & roofs 2.894 70 Weighted Average 2.729 Pervious Area 0.165 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 9.2 734 0.1289 1.33 Lag/CN Method, Contour Length= 1,625' Interval= 10' Stevens St ex 06-09-11 Type ///24-hr 1-Yr Rainfall=2.60" Prepared by Andover Consultants, Inc. HydroCADO 8.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Subcatchment 2S: exist to ex culvert Runoff = 1.8 cfs @ 12.13 hrs, Volume= 0.178 af, Depth> 0.47" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 1-Yr Rainfall=2.60" Area (ac) CN Description 0.209 98 Paved parking & roofs 0.083 61 >75% Grass cover, Good, HSG B 0.565 74 >75% Grass cover, Good, HSG C 0.830 55 Woods, Good, HSG B 2.897 70 Woods, Good, HSG C 4.584 69 Weighted Average 4.375 Pervious Area 0.209 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.2 690 0.1997 1.59 Lag/CN Method, Contour Length= 3,988' Interval= 10' Stevens St ex 06-09-11 Type 11l 24-hr 1-Yr Rainfall=2.60" Prepared by Andover Consultants, Inc. HydroCADO 8.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Pond 1P: ex cb Inflow Area = 2.894 ac, Inflow Depth > 0.50" for 1-Yr event Inflow = 1.2 cfs @ 12.16 hrs, Volume= 0.121 of Outflow = 1.2 cfs @ 12.16 hrs, Volume= 0.121 af, Atten= 0%, Lag= 0.1 min Primary = 1.2 cfs @ 12.16 hrs, Volume= 0.121 of Secondary= 0.0 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs/3 Peak Elev= 172.98' @ 12.16 hrs Surf.Area= 13 sf Storage= 7 cf Plug-Flow detention time= 0.2 min calculated for 0.121 of(100% of inflow) Center-of-Mass det. time= 0.1 min ( 895.0- 894.9) Volume Invert Avail.Storage Storage Description #1 172.41' 1,869 cf Custom Stage Data(Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 172.41 13 0 0 173.41 13 13 13 174.70 86 64 77 175.00 560 97 174 175.50 3,210 943 1,116 175.70 4,320 753 1,869 Device Routing Invert Outlet Devices #1 Primary 172.41' 12.0" x 64.0' long Culvert RCP, square edge headwall, Ke= 0.500 Outlet Invert= 169.66' S= 0.0430 ? Cc= 0.900 n= 0.013 #2 Secondary 175.50' 40.0' long x 2.5' 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 Coef. (English) 2.48 2.60 2.60 2.60 2.64 2.65 2.68 2.75 2.74 2.76 2.89 3.05 3.19 3.32 Primary OutFlow Max=1.2 cfs @ 12.16 hrs HW=172.98' (Free Discharge) t1=Culvert (Inlet Controls 1.2 cfs @ 2.56 fps) Secondary OutFlow Max=0.0 cfs @ 0.00 hrs HW=172.41' (Free Discharge) 2=13road-Crested Rectangular Weir ( Controls 0.0 cfs) Stevens St ex 06-09-11 Type 111 24-hr 1-Yr Rainfall=2.60" Prepared by Andover Consultants, Inc. HydroCADO 8.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Pond 2P: ex culvert Inflow Area = 4.584 ac, Inflow Depth > 0.47" for 1-Yr event Inflow = 1.8 cfs @ 12.13 hrs, Volume= 0.178 of Outflow = 1.8 cfs @ 12.14 hrs, Volume= 0.178 af, Atten= 1%, Lag= 0.6 min Primary = 1.8 cfs @ 12.14 hrs, Volume= 0.178 of Secondary= 0.0 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs/3 Peak Elev= 169.31' @ 12.14 hrs Surf.Area= 81 sf Storage= 19 cf Plug-Flow detention time= 0.7 min calculated for 0.178 of(100% of inflow) Center-of-Mass det. time= 0.2 min ( 898.3 - 898.1 ) Volume Invert Avail.Storage Storage Description #1 168.46' 3,185 cf Custom Stage Data(Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 168.46 0 0 0 169.00 15 4 4 170.00 230 123 127 171.00 3,380 1,805 1,932 171.10 3,980 368 2,300 171.30 4,870 885 3,185 Device Routing Invert Outlet Devices #1 Primary 168.46' 12.0" x 34.0' long Culvert CPP, projecting, no headwall, Ke= 0.900 Outlet Invert= 166.65' S= 0.05327' Cc= 0.900 n= 0.013 #2 Secondary 171.10' 95.0' long x 2.0' 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 Coef. (English) 2.54 2.61 2.61 2.60 2.66 2.70 2.77 2.89 2.88 2.85 3.07 3.20 3.32 Primary OutFlow Max=1.7 cfs @ 12.14 hrs HW=169.30' (Free Discharge) L1=Culvert (Inlet Controls 1.7 cfs @ 2.46 fps) Secondary OutFlow Max=0.0 cfs @ 0.00 hrs HW=168.46' (Free Discharge) L' -Crested Rectangular Weir ( Controls 0.0 cfs) 2-Year Storm P=3.2 inches Stevens St ex 06-09-11 Type 111 24-hr 2-Yr Rainfall=3.20" Prepared by Andover Consultants, Inc. HydroCADO 8.00 s/n 002099 0 2006 HydroCAD Software Solutions LLC Time span=0.00-24.00 hrs, dt=0.05 hrs, 481 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind method - Pond routing by Stor-Ind method Subcatchment 1S: exist to ex cb Runoff Area=2.894 ac Runoff Depth>0.83" Flow Length=734' Slope=0.1289 '/' Tc=9.2 min CN=70 Runoff=2.2 cfs 0.199 of Subcatchment 2S: exist to ex culvert Runoff Area=4.584 ac Runoff Depth>0.78" Flow Length=690' Slope=0.19977' Tc=7.2 min CN=69 Runoff=3.5 cfs 0.297 of Pond 1P: ex cb Peak Elev=173.25' Storage=11 cf Inflow=2.2 cfs 0.199 of Primary=2.2 cfs 0.199 of Secondary=0.0 cfs 0.000 of Outflow=2.2 cfs 0.199 of Pond 2P: ex culvert Peak Elev=170.09' Storage=158 cf Inflow=3.5 cfs 0.297 of Primary=3.2 cfs 0.297 of Secondary=0.0 cfs 0.000 of Outflow=3.2 cfs 0.297 of Stevens St ex 06-09-11 Type ///24-hr 2-Yr Rainfall=3.20" Prepared by Andover Consultants, Inc. HydroCAD®8 00 s/n 002099 0 2006 HydroCAD Software Solutions LLC Subcatchment 1S: exist to ex cb Runoff = 2.2 cfs @ 12.15 hrs, Volume= 0.199 af, Depth> 0.83" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 2-Yr Rainfall=3.20" Area (ac) CN Description 0.460 55 Woods, Good, HSG B 1.436 70 Woods, Good, HSG C 0.833 74 >75% Grass cover, Good, HSG C 0.165 98 Paved & roofs 2.894 70 Weighted Average 2.729 Pervious Area 0.165 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 9.2 734 0.1289 1.33 Lag/CN Method, Contour Length= 1,625' Interval= 10' Stevens St ex 06-09-11 Type 111 24-hr 2-Yr Rainfall=3.20" Prepared by Andover Consultants, Inc. HydroCADO 8.00 s/n 002099 0 2006 HydroCAD Software Solutions LLC Subcatchment 2S: exist to ex culvert Runoff = 3.5 cfs @ 12.12 hrs, Volume= 0.297 af, Depth> 0.78" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 2-Yr Rainfall=3.20" Area (ac) CN Description 0.209 98 Paved parking & roofs 0.083 61 >75% Grass cover, Good, HSG B 0.565 74 >75% Grass cover, Good, HSG C 0.830 55 Woods, Good, HSG B 2.897 70 Woods, Good, HSG C 4.584 69 Weighted Average 4.375 Pervious Area 0.209 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.2 690 0.1997 1.59 Lag/CN Method, Contour Length= 3,988' Interval= 10' Stevens St ex 06-09-11 Type 11124-hr 2-Yr Rainfall=3.20" Prepared by Andover Consultants, Inc. HydroCAD®8.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Pond 1 P: ex cb Inflow Area = 2.894 ac, Inflow Depth > 0.83" for 2-Yr event Inflow = 2.2 cfs @ 12.15 hrs, Volume= 0.199 of Outflow = 2.2 cfs @ 12.15 hrs, Volume= 0.199 af, Atten= 0%, Lag= 0.1 min Primary = 2.2 cfs @ 12.15 hrs, Volume= 0.199 of Secondary = 0.0 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs/3 Peak Elev= 173.25' @ 12.15 hrs Surf.Area= 13 sf Storage= 11 cf Plug-Flow detention time= 0.2 min calculated for 0.199 of(100% of inflow) Center-of-Mass det. time= 0.1 min ( 877.5- 877.4) Volume Invert Avail.Storage Storage Description #1 172.41' 1,869 cf Custom Stage Data(Prismatic) Listed below(Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 172.41 13 0 0 173.41 13 13 13 174.70 86 64 77 175.00 560 97 174 175.50 3,210 943 1,116 175.70 4,320 753 1,869 Device Routing Invert Outlet Devices #1 Primary 172.41' 12.0" x 64.0' long Culvert RCP, square edge headwall, Ke= 0.500 Outlet Invert= 169.66' S= 0.0430T Cc= 0.900 n= 0.013 #2 Secondary 175.50' 40.0' long x 2.5' 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 Coef. (English) 2.48 2.60 2.60 2.60 2.64 2.65 .2.68 2.75 2.74 2.76 2.89 3.05 3.19 3.32 Primary OutFlow Max=2.2 cfs @ 12.15 hrs HW=173.25' (Free Discharge) t-1=Culvert (Inlet Controls 2.2 cfs @ 3.13 fps) Secondary OutFlow Max=0.0 cfs @ 0.00 hrs HW=172.41' (Free Discharge) 2=Broad-Crested Rectangular Weir ( Controls 0.0 cfs) Stevens St ex 06-09-11 Type 111 24-hr 2-Yr Rainfall=3.20" Prepared by Andover Consultants, Inc. HydroCADO 8.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Pond 2P: ex culvert Inflow Area = 4.584 ac, Inflow Depth > 0.78" for 2-Yr event Inflow = 3.5 cfs @ 12.12 hrs, Volume= 0.297 of Outflow = 3.2 cfs @ 12.16 hrs, Volume= 0.297 af, Atten= 9%, Lag= 2.5 min Primary = 3.2 cfs @ 12.16 hrs, Volume= 0.297 of Secondary = 0.0 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs/3 Peak Elev= 170.09' @ 12.16 hrs Surf.Area=498 sf Storage= 158 cf Plug-Flow detention time= 0.8 min calculated for 0.296 of(100% of inflow) Center-of-Mass det. time= 0.3 min ( 879.8- 879.5) Volume Invert Avail.Storage Storage Description #1 168.46' 3,185 cf Custom Stage Data(Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 168.46 0 0 0 169.00 15 4 4 170.00 230 123 127 171.00 3,380 1,805 1,932 171.10 3,980 368 2,300 171.30 4,870 885 3,185 Device Routing Invert Outlet Devices #1 Primary 168.46' 12.0" x 34.0' long Culvert CPP, projecting, no headwall, Ke= 0.900 Outlet Invert= 166.65' S= 0.0532 '/' Cc= 0.900 n= 0.013 #2 Secondary 171.10' 95.0' long x 2.0' 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 Coef. (English) 2.54 2.61 2.61 2.60 2.66 2.70 2.77 2.89 2.88 2.85 3.07 3.20 3.32 Primary OutFlow Max=3.1 cfs @ 12.16 hrs HW=170.06' (Free Discharge) t1=Culvert (Inlet Controls 3.1 cfs @ 3.99 fps) Secondary OutFlow Max=0.0 cfs @ 0.00 hrs HW=168.46' (Free Discharge) 2=13road-Crested Rectangular Weir (Controls 0.0 cfs) 10-Year Storm P=4.8 inches Stevens St ex 06-09-11 Type /// 24-hr 10-Yr Rainfall=4.80" Prepared by Andover Consultants, Inc. HydroCAD® 8.00 s/n 002099 0 2006 HydroCAD Software Solutions LLC Time span=0.00-24.00 hrs, dt=0.05 hrs, 481 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind method - Pond routing by Stor-Ind method Subcatchment 1S: exist to ex cb Runoff Area=2.894 ac Runoff Depth>1.89" Flow Length=734' Slope=0.1289 '/' Tc=9.2 min CN=70 Runoff=5.5 cfs 0.455 of Subcatchment 2S: exist to ex culvert Runoff Area=4.584 ac Runoff Depth>1.81" Flow Length=690' Slope=0.1997'/' Tc=7.2 min CN=69 Runoff=9.0 cfs 0.692 of Pond 1 P: ex cb Peak Elev=174.86' Storage=110 cf Inflow=5.5 cfs 0.455 of Primary=5.3 cfs 0.454 of Secondary=0.0 cfs 0.000 of Outflow=5.3 cfs 0.454 of Pond 2P: ex culvert Peak Elev=171.15' Storage=2,505 cf Inflow=9.0 cfs 0.692 of Primary=4.4 cfs 0.673 of Secondary=2.3 cfs 0.019 of Outflow=6.8 cfs 0.692 of Stevens St ex 06-09-11 Type 11124-hr 10-Yr Rainfall=4.80" Prepared by Andover Consultants, Inc. HydroCAD®8 00 s/n 002099 0 2006 HydroCAD Software Solutions LLC Subcatchment 1S: exist to ex cb Runoff = 5.5 cfs @ 12.14 hrs, Volume= 0.455 af, Depth> 1.89" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 10-Yr Rainfall=4.80" Area (ac) CN Description 0.460 55 Woods, Good, HSG B 1.436 70 Woods, Good, HSG C 0.833 74 >75% Grass cover, Good, HSG C 0.165 98 Paved & roofs 2.894 70 Weighted Average 2.729 Pervious Area 0.165 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 9.2 734 0.1289 1.33 Lag/CN Method, Contour Length= 1,625' Interval= 10' Stevens St ex 06-09-11 Type ///24-hr 10-Yr Rainfall=4.80" Prepared by Andover Consultants, Inc. HydroCAD®8.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Subcatchment 2S: exist to ex culvert Runoff = 9.0 cfs @ 12.11 hrs, Volume= 0.692 af, Depth> 1.81" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 10-Yr Rainfall=4.80" Area (ac) CN Description 0.209 98 Paved parking & roofs 0.083 61 >75% Grass cover, Good, HSG B 0.565 74 >75% Grass cover, Good, HSG C 0.830 55 Woods, Good, HSG B 2.897 70 Woods Good, HSG C 4.584 69 Weighted Average 4.375 Pervious Area 0.209 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.2 690 0.1997 1.59 Lag/CN Method, Contour Length= 3,988' Interval= 10' Stevens St ex 06-09-11 Type 111 24-hr 10-Yr Rainfall=4.80" Prepared by Andover Consultants, Inc. HydroCAD®8.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Pond 1 P: ex cb Inflow Area = 2.894 ac, Inflow Depth > 1.89" for 10-Yr event Inflow = 5.5 cfs @ 12.14 hrs, Volume= 0.455 of Outflow = 5.3 cfs @ 12.16 hrs, Volume= 0.454 af, Atten=4%, Lag= 1.5 min Primary = 5.3 cfs @ 12.16 hrs, Volume= 0.454 of Secondary = 0.0 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs/3 Peak Elev= 174.86' @ 12.16 hrs Surf.Area= 337 sf Storage= 110 cf Plug-Flow detention time= 0.8 min calculated for 0.454 of(100% of inflow) Center-of-Mass det. time= 0.2 min ( 852.0- 851.7) Volume Invert Avail.Storage Storage Description #1 172.41' 1,869 cf Custom Stage Data(Prismatic) Listed below(Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 172.41 13 0 0 173.41 13 13 13 174.70 86 64 77 175.00 560 97 174 175.50 3,210 943 1,116 175.70 4,320 753 1,869 Device Routing Invert Outlet Devices #1 Primary 172.41' 12.0" x 64.0' long Culvert RCP, square edge headwall, Ke= 0.500 Outlet Invert= 169.66' S= 0.0430 'P Cc= 0.900 n= 0.013 #2 Secondary 175.50' 40.0' long x 2.5' 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 Coef. (English) 2.48 2.60 2.60 2.60 2.64 2.65 2.68 2.75 2.74 2.76 2.89 3.05 3.19 3.32 Primary OutFlow Max=5.2 cfs @ 12.16 hrs HW=174.82' (Free Discharge) t-1=Culvert (Inlet Controls 5.2 cfs @ 6.66 fps) Secondary OutFlow Max=0.0 cfs @ 0.00 hrs HW=172.41' (Free Discharge) 2=Broad-Crested Rectangular Weir ( Controls 0.0 cfs) Stevens St ex 06-09-11 Type 111 24-hr 10-Yr Rainfall=480" Prepared by Andover Consultants, Inc. HydroCADO 8.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Pond 2P: ex culvert Inflow Area = 4.584 ac, Inflow Depth > 1.81" for 10-Yr event Inflow = 9.0 cfs @ 12.11 hrs, Volume= 0.692 of Outflow = 6.8 cfs @ 12.21 hrs, Volume= 0.692 af, Atten= 25%, Lag= 6.0 min Primary = 4.4 cfs @ 12.22 hrs, Volume= 0.673 of Secondary= 2.3 cfs @ 12.21 hrs, Volume= 0.019 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs/3 Peak Elev= 171.15' @ 12.22 hrs Surf.Area=4,203 sf Storage= 2,505 cf Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 2.4 min ( 855.2- 852.8 ) Volume Invert Avail.Storage Storage Description #1 168.46' 3,185 cf Custom Stage Data(Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 168.46 0 0 0 169.00 15 4 4 170.00 230 123 127 171.00 3,380 1,805 1,932 171.10 3,980 368 2,300 171.30 4,870 885 3,185 Device Routing Invert Outlet Devices #1 Primary 168.46' 12.0" x 34.0' long Culvert CPP, projecting, no headwall, Ke= 0.900 Outlet Invert= 166.65' S= 0.0532 '/' Cc= 0.900 n= 0.013 #2 Secondary 171.10' 95.0' long x 2.0' 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 Coef. (English) 2.54 2.61 2.61 2.60 2.66 2.70 2.77 2.89 2.88 2.85 3.07 3.20 3.32 Primary OutFlow Max=4.4 cfs @ 12.22 hrs HW=171.14' (Free Discharge) t1=Culvert (Inlet Controls 4.4 cfs @ 5.61 fps) Secondary OutFlow Max=2.0 cfs @ 12.21 hrs HW=171.14' (Free Discharge) t2=13road-Crested Rectangular Weir (Weir Controls 2.0 cfs @ 0.51 fps) 25-Year Storm P=6.0 inches Stevens St ex 06-09-11 Type 111 24-hr 25-Yr Rainfall=6.00" Prepared by Andover Consultants, Inc. HydroCADO 8.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Time span=0.00-24.00 hrs, dt=0.05 hrs, 481 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind method - Pond routing by Stor-Ind method Subcatchment 1S: exist to ex cb Runoff Area=2.894 ac Runoff Depth>2.80" Flow Length=734' Slope=0.1289 '/' Tc=9.2 min CN=70 Runoff=8.3 cfs 0.675 of Subcatchment 2S: exist to ex culvert Runoff Area=4.584 ac Runoff Depth>2.71" Flow Length=690' Slope=0.1997 '/' Tc=7.2 min CN=69 Runoff=13.7 cfs 1.035 of Pond 1P: excb Peak Elev=175.51' Storage=1,133 cf Inflow=8.3 cfs 0.675 of Primary=6.1 cfs 0.677 of Secondary=0.1 cfs 0.000 of Outflow=6.1 cfs 0.677 of Pond 2P: ex culvert Peak Elev=171.21' Storage=2,749 cf Inflow=13.7 cfs 1.035 of Primary=4.5 cfs 0.902 of Secondary=8.4 cfs 0.137 of Outflow=12.9 cfs 1.038 of Stevens St ex 06-09-11 Type III 24-hr 25-Yr Rainfall=6.00" Prepared by Andover Consultants, Inc. HydroCADO 8.00 s/n 002099 0 2006 HydroCAD Software Solutions LLC Subcatchment 1S: exist to ex cb Runoff = 8.3 cfs @ 12.14 hrs, Volume= 0.675 af, Depth> 2.80" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 25-Yr Rainfall=6.00" Area (ac) CN Description 0.460 55 Woods, Good, HSG B 1.436 70 Woods, Good, HSG C 0.833 74 >75% Grass cover, Good, HSG C 0.165 98 Paved & roofs 2.894 70 Weighted Average 2.729 Pervious Area 0.165 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 9.2 734 0.1289 1.33 Lag/CN Method, Contour Length= 1,625' Interval= 10' Stevens St ex 06-09-11 Type 1//24-hr 25-Yr Rainfall=6.00" Prepared by Andover Consultants, Inc. HydroCADO 8.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Subcatchment 2S: exist to ex culvert Runoff = 13.7 cfs @ 12.11 hrs, Volume= 1.035 af, Depth> 2.71" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 25-Yr Rainfall=6.00" Area (ac) CN Description 0.209 98 Paved parking & roofs 0.083 61 >75% Grass cover, Good, HSG B 0.565 74 >75% Grass cover, Good, HSG C 0.830 55 Woods, Good, HSG B 2.897 70 Woods, Good, HSG C 4.584 69 Weighted Average 4.375 Pervious Area 0.209 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (fUsec) (cfs) 7.2 690 0.1997 1.59 Lag/CN Method, Contour Length= 3,988' Interval= 10' Stevens St ex 06-09-11 Type 111 24-hr 25-Yr Rainfall=6.00" Prepared by Andover Consultants, Inc. HydroCAD®8.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Pond 1 P: ex cb Inflow Area = 2.894 ac, Inflow Depth > 2.80" for 25-Yr event Inflow = 8.3 cfs @ 12.14 hrs, Volume= 0.675 of Outflow = 6.1 cfs @ 12.25 hrs, Volume= 0.677 af, Atten= 26%, Lag= 6.6 min Primary = 6.1 cfs @ 12.24 hrs, Volume= 0.677 of Secondary = 0.1 cfs @ 12.25 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs/3 Peak Elev= 175.51' @ 12.24 hrs Surf.Area= 3,239 sf Storage= 1,133 cf Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 0.4 min ( 840.6 - 840.2) Volume Invert Avail.Storage Storage Description #1 172.41' 1,869 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 172.41 13 0 0 173.41 13 13 13 174.70 86 64 77 175.00 560 97 174 175.50 3,210 943 1,116 175.70 4,320 753 1,869 Device Routing Invert Outlet Devices #1 Primary 172.41' 12.0" x 64.0' long Culvert RCP, square edge headwall, Ke= 0.500 Outlet Invert= 169.66' S= 0.0430 'P Cc= 0.900 n= 0.013 #2 Secondary 175.50' 40.0' long x 2.5' 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 Coef. (English) 2.48 2.60 2.60 2.60 2.64 2.65 2.68 2.75 2.74 2.76 2.89 3.05 3.19 3.32 Primary OutFlow Max=6.1 cfs @ 12.24 hrs HW=175.50' (Free Discharge) 't-1=Culvert (Inlet Controls 6.1 cfs @ 7.75 fps) Secondary OutFlow Max=0.0 cfs @ 12.25 hrs HW=175.50' (Free Discharge) T­2=13road-Crested Rectangular Weir (Weir Controls 0.0 cfs @ 0.17 fps) Stevens St ex 06-09-11 Type 111 24-hr 25-Yr Rainfall=6.00" Prepared by Andover Consultants, Inc. HydroCAD® 8.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Pond 2P: ex culvert Inflow Area = 4.584 ac, Inflow Depth > 2.71" for 25-Yr event Inflow = 13.7 cfs @ 12.11 hrs, Volume= 1.035 of Outflow = 12.9 cfs @ 12.13 hrs, Volume= 1.038 af, Atten=6%, Lag= 1.2 min Primary = 4.5 cfs @ 12.13 hrs, Volume= 0.902 of Secondary = 8.4 cfs @ 12.13 hrs, Volume= 0.137 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs/3 Peak Elev= 171.21' @ 12.13 hrs Surf.Area=4,454 sf Storage= 2,749 cf Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 2.0 min ( 842.9 - 840.9 ) Volume Invert Avail.Storage Storage Description #1 168.46' 3,185 cf Custom Stage Data(Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 168.46 0 0 0 169.00 15 4 4 170.00 230 123 127 171.00 3,380 1,805 1,932 171.10 3,980 368 2,300 171.30 4,870 885 3,185 Device Routing Invert Outlet Devices #1 Primary 168.46' 12.0" x 34.0' long Culvert CPP, projecting, no headwall, Ke= 0.900 Outlet Invert= 166.65' S= 0.05327' Cc= 0.900 n= 0.013 #2 Secondary 171.10' 95.0' long x 2.0' 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 Coef. (English) 2.54 2.61 2.61 2.60 2.66 2.70 2.77 2.89 2.88 2.85 3.07 3.20 3.32 Primary OutFlow Max=4.5 cfs @ 12.13 hrs HW=171.20' (Free Discharge) L1=Culvert (Inlet Controls 4.5 cfs @ 5.69 fps) Secondary OutFlow Max=8.1 cfs @ 12.13 hrs HW=171.20' (Free Discharge) 2=Broad-Crested Rectangular Weir (Weir Controls 8.1 cfs @ 0.82 fps) 100-Year Storm P=8.6 inches Stevens St ex 06-09-11 Type ///24-hr 100-Yr Rainfall=8.60" Prepared by Andover Consultants, Inc. HydroCADO 8.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Time span=0.00-24.00 hrs, dt=0.05 hrs, 481 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind method - Pond routing by Stor-Ind method Subcatchment 1S: exist to ex cb Runoff Area=2.894 ac Runoff Depth>4.98" Flow Length=734' Slope=0.12897 Tc=9.2 min CN=70 Runoff=14.9 cfs 1.200 of Subcatchment 2S: exist to ex culvert Runoff Area=4.584 ac Runoff Depth>4.86" Flow Length=690' Slope=0.1997 '/' Tc=7.2 min CN=69 Runoff=24.8 cfs 1.856 of Pond 1P: ex cb Peak Elev=175.69' Storage=1,825 cf Inflow=14.9 cfs 1.200 of Primary=6.3 cfs 1.065 of Secondary=8.2 cfs 0.132 of Outflow=14.5 cfs 1.197 of Pond 2P: ex culvert Peak Elev=171.29' Storage=3,126 cf Inflow=24.8 cfs 1.856 of Primary=4.6 cfs 1.381 of Secondary=19.7 cfs 0.478 of Outflow=24.2 cfs 1.858 of Stevens St ex 06-09-11 Type 111 24-hr 100-Yr Rainfall=8.60" Prepared by Andover Consultants, Inc. HydroCADO 8.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Subcatchment 1S: exist to ex cb Runoff = 14.9 cfs @ 12.13 hrs, Volume= 1.200 af, Depth> 4.98" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 100-Yr Rainfall=8.60" Area (ac) CN Description 0.460 55 Woods, Good, HSG B 1.436 70 Woods, Good, HSG C 0.833 74 >75% Grass cover, Good, HSG C 0.165 98 Paved & roofs 2.894 70 Weighted Average 2.729 Pervious Area 0.165 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 9.2 734 0.1289 1.33 Lag/CN Method, Contour Length= 1,625' Interval= 10' Stevens St ex 06-09-11 Type ///24-hr 100-Yr Rainfall=8.60" Prepared by Andover Consultants, Inc. HydroCAD®8.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Subcatchment 2S: exist to ex culvert Runoff = 24.8 cfs @ 12.11 hrs, Volume= 1.856 af, Depth> 4.86" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 100-Yr Rainfall=8.60" Area (ac) CN Description 0.209 98 Paved parking & roofs 0.083 61 >75% Grass cover, Good, HSG B 0.565 74 >75% Grass cover, Good, HSG C 0.830 55 Woods, Good, HSG B 2.897 70 Woods Good, HSG C 4.584 69 Weighted Average 4.375 Pervious Area 0.209 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.2 690 0.1997 1.59 Lag/CN Method, Contour Length= 3,988' Interval= 10' Stevens St ex 06-09-11 Type ///24-hr 100-Yr Rainfall=8.60" Prepared by Andover Consultants, Inc. HydroCADO 8.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Pond 1 P: ex cb Inflow Area = 2.894 ac, Inflow Depth > 4.98" for 100-Yr event Inflow = 14.9 cfs @ 12.13 hrs, Volume= 1.200 of Outflow = 14.5 cfs @ 12.16 hrs, Volume= 1.197 af, Aften= 2%, Lag= 1.5 min Primary = 6.3 cfs @ 12.16 hrs, Volume= 1.065 of Secondary= 8.2 cfs @ 12.16 hrs, Volume= 0.132 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs/3 Peak Elev= 175.69' @ 12.16 hrs Surf.Area=4,263 sf Storage= 1,825 cf Plug-Flow detention time= 2.7 min calculated for 1.197 of(100% of inflow) Center-of-Mass det. time= 1.1 min ( 824.8- 823.7 ) Volume Invert Avail.Stora e Storage Description #1 172.41' 1,869 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 172.41 13 0 0 173.41 13 13 13 174.70 86 64 77 175.00 560 97 174 175.50 3,210 943 1,116 175.70 4,320 753 1,869 Device Routing Invert Outlet Devices #1 Primary 172.41' 12.0" x 64.0' long Culvert RCP, square edge headwall, Ke= 0.500 Outlet Invert= 169.66' S= 0.04307' Cc= 0.900 n= 0.013 #2 Secondary 175.50' 40.0' long x 2.5' 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 Coef. (English) 2.48 2.60 2.60 2.60 2.64 2.65 '2.68 2.75 2.74 2.76 2.89 3.05 3.19 3.32 Primary OutFlow Max=6.3 cfs @ 12.16 hrs HW=175.69' (Free Discharge) t-1=Culvert (Inlet Controls 6.3 cfs @ 8.02 fps) Secondary OutFlow Max=8.0 cfs @ 12.16 hrs HW=175.69' (Free Discharge) 2=Broad-Crested Rectangular Weir (Weir Controls 8.0 cfs @ 1.07 fps) Stevens St ex 06-09-11 Type ///24-hr 100-Yr Rainfall=8.60" Prepared by Andover Consultants, Inc. HydroCAD®8 00 s/n 002099 0 2006 HydroCAD Software Solutions LLC Pond 2P: ex culvert Inflow Area = 4.584 ac, Inflow Depth > 4.86" for 100-Yr event Inflow = 24.8 cfs @ 12.11 hrs, Volume= 1.856 of Outflow = 24.2 cfs @ 12.11 hrs, Volume= 1.858 af, Atten= 2%, Lag= 0.4 min Primary = 4.6 cfs @ 12.11 hrs, Volume= 1.381 of Secondary= 19.7 cfs @ 12.11 hrs, Volume= 0.478 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs/3 Peak Elev= 171.29' @ 12.11 hrs Surf.Area=4,816 sf Storage= 3,126 cf Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 2.0 min ( 826.2 - 824.1 ) Volume Invert Avail.Storage Storage Description #1 168.46' 3,185 cf Custom Stage Data(Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 168.46 0 0 0 169.00 15 4 4 170.00 230 123 127 171.00 3,380 1,805 1,932 171.10 3,980 368 2,300 171.30 4,870 885 3,185 Device Routing Invert Outlet Devices #1 Primary 168.46' 12.0" x 34.0' long Culvert CPP, projecting, no headwall, Ke= 0.900 Outlet Invert= 166.65' S= 0.0532 'P Cc= 0.900 n= 0.013 #2 Secondary 171.10' 95.0' long x 2.0' 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 Coef. (English) 2.54 2.61 2.61 2.60 2.66 2.70 2.77 2.89 2.88 2.85 3.07 3.20 3.32 Primary OutFlow Max=4.6 cfs @ 12.11 hrs HW=171.28' (Free Discharge) t1=Culvert (Inlet Controls 4.6 cfs @ 5.79 fps) Secondary OutFlow Max=19.0 cfs @ 12.11 hrs HW=171.28' (Free Discharge) 2=Broad-Crested Rectangular Weir (Weir Controls 19.0 cfs @ 1.09 fps) HydroCAD Post-developed calculations 2S 1S to culvert to ex cb 2P ex cb 5P renovated culvert SubCat Reach Pon Link Drainage Diagram for Stevens St dev 06-09-11 Prepared by Andover Consultants, Inc. HydroCAD®8.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC 1-Year Storm P=2.6 inches Stevens St dev 06-09-11 Type 111 24-hr 1-Yr Rainfall=2.60" Prepared by Andover Consultants, Inc. HydroCAD®8.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Time span=0.00-24.00 hrs, dt=0.05 hrs, 481 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind method - Pond routing by Stor-Ind method Subcatchment 1S: to ex cb Runoff Area=2.761 ac Runoff Depth>0.62" Flow Length=734' Slope=0.1175'/' Tc=8.9 min CN=73 Runoff=1.6 cfs 0.143 of Subcatchment 2S: to culvert Runoff Area=4.716 ac Runoff Depth>0.62" Flow Length=655' Tc=8.4 min CN=73 Runoff=2.7 cfs 0.244 of Pond 2P: ex cb Peak Elev=173.08' Storage=9 cf Inflow=1.6 cfs 0.143 of Primary=1.6 cfs 0.143 of Secondary=0.0 cfs 0.000 of Outflow=1.6 cfs 0.143 of Pond 5P: renovated culvert Peak Elev=167.76' Storage=13 cf Inflow=2.7 cfs 0.244 of Primary=2.7 cfs 0.244 of Secondary=0.0 cfs 0.000 of Outflow=2.7 cfs 0.244 of Stevens St dev 06-09-11 Type ///24-hr 1-Yr Rainfall=2.60" Prepared by Andover Consultants, Inc. HydroCADO 8.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Subcatchment 1S: to ex cb Runoff = 1.6 cfs @ 12.15 hrs, Volume= 0.143 af, Depth> 0.62" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 1-Yr Rainfall=2.60" Area (ac) CN Description 1.273 70 Woods, Good, HSG C 0.910 74 >75% Grass cover, Good, HSG C 0.247 98 Paved parking & roofs 0.073 55 Woods, Good, HSG B 0.258 61 >75% Grass cover, Good, HSG B 2.761 73 Weighted Average 2.514 Pervious Area 0.247 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 8.9 734 0.1175 1.38 Lag/CN Method, Stevens St dev 06-09-11 Type 111 24-hr 1-Yr Rainfall=2.60° Prepared by Andover Consultants, Inc. HydroCADO 8.00 s/n 002099 ©2006 Hydro ',AD Software Solutions LLC Subcatchment 2S: to culvert Runoff = 2.7 cfs @ 12.14 hrs, Volume= 0.244 af, Depth> 0.62" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 1-Yr Rainfall=2.60" Area (ac) CN Description 0.517 98 Paved parking & roofs 2.067 70 Woods, Good, HSG C 1.421 74 >75% Grass cover, Good, HSG C 0.693 61 >75% Grass cover, Good, HSG B 0.018 55 Woods, Good, HSG B 4.716 73 Weighted Average 4.199 Pervious Area 0.517 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.6 50 0.1500 0.15 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.10" 1.0 440 0.2000 7.20 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 1.8 165 0.0100 1.50 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 8.4 655 Total Stevens St dev 06-09-11 Type ///24-hr 1-Yr Rainfall=2.60" Prepared by Andover Consultants, Inc. HydroCADO 8.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Pond 2P: ex cb Inflow Area = 2.761 ac, Inflow Depth > 0.62" for 1-Yr event Inflow = 1.6 cfs @ 12.15 hrs, Volume= 0.143 of Outflow = 1.6 cfs @ 12.15 hrs, Volume= 0.143 af, Atten= 0%, Lag= 0.1 min Primary = 1.6 cfs @ 12.15 hrs, Volume= 0.143 of Secondary = 0.0 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs/ 3 Peak Elev= 173.08' @ 12.15 hrs Surf.Area= 13 sf Storage= 9 cf Plug-Flow detention time= 0.2 min calculated for 0.143 of(100% of inflow) Center-of-Mass det. time= 0.1 min (882.0- 881.8) Volume Invert Avail.Storage Storage Description #1 172.41' 3,641 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 172.41 13 0 0 173.41 13 13 13 174.70 1,550 1,008 1,021 175.00 1,690 486 1,507 175.50 3,590 1,320 2,827 175.70 4,550 814 3,641 Device Routing Invert Outlet Devices #1 Primary 172.41' 12.0" x 64.0' long Culvert RCP, square edge headwall, Ke= 0.500 Outlet Invert= 169.66' S= 0.0430 ? Cc= 0.900 n= 0.013 #2 Secondary 175.50' 40.0' long x 2.5' 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 Coef. (English) 2.48 2.60 2.60 2.60 2.64 2.65 2.68 2.75 2.74 2.76 2.89 3.05 3.19 3.32 Primary OutFlow Max=1.6 cfs @ 12.15 hrs HW=173.08' (Free Discharge) L1=Culvert (Inlet Controls 1.6 cfs @ 2.79 fps) Secondary OutFlow Max=0.0 cfs @ 0.00 hrs HW=172.41' (Free Discharge) 2=13road-Crested Rectangular Weir ( Controls 0.0 cfs) Stevens St dev 06-09-11 Type ///24-hr 1-Yr Rainfall=2.60" Prepared by Andover Consultants, Inc. HydroCADO 8.00 s/n 002099 0 2006 HydroCAD Software Solutions LLC Pond 5P: renovated culvert Inflow Area = 4.716 ac, Inflow Depth > 0.62" for 1-Yr event Inflow = 2.7 cfs @ 12.14 hrs, Volume= 0.244 of Outflow = 2.7 cfs @ 12.14 hrs, Volume= 0.244 af, Atten= 0%, Lag= 0.1 min Primary = 2.7 cfs @ 12.14 hrs, Volume= 0.244 of Secondary = 0.0 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs/3 Peak Elev= 167.76' @ 12.14 hrs Surf.Area= 13 sf Storage= 13 cf Plug-Flow detention time= 0.2 min calculated for 0.244 of(100% of inflow) Center-of-Mass det. time= 0.1 min ( 881.6- 881.5) Volume Invert Avail.Storage Storage Description #1 166.75' 4,433 cf Custom Stage Data(Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 166.75 13 0 0 167.00 13 3 3 168.00 13 13 16 169.00 250 132 148 170.00 870 560 708 171.00 3,815 2,343 3,050 171.10 4,410 411 3,461 171.30 5,300 971 4,433 Device Routing Invert Outlet Devices #1 Primary 166.75' 12.0" x 36.0' long Culvert RCP, square edge headwall, Ke= 0.500 Outlet Invert= 166.03' S= 0.0200 '/' Cc= 0.900 n= 0.011 #2 Secondary 171.10' 95.0' long x 2.0' 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 Coef. (English) 2.54 2.61 2.61 2.60 2.66 2.70 2.77 2.89 2.88 2.85 3.07 3.20 3.32 Primary OutFlow Max=2.7 cfs @ 12.14 hrs HW=167.75' (Free Discharge) L1=Culvert (Inlet Controls 2.7 cfs @ 3.40 fps) §econdary OutFlow Max=0.0 cfs @ 0.00 hrs HW=166.75' (Free Discharge) 2=B road-C rested Rectangular Weir ( Controls 0.0 cfs) 2-Year Storm P=3.2 inches Stevens St dev 06-09-11 Type 111 24-hr 2-Yr Rainfall=3.20" Prepared by Andover Consultants, Inc. HydroCAD®8.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Time span=0.00-24.00 hrs, dt=0.05 hrs, 481 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind method - Pond routing by Stor-Ind method Subcatchment 1S: to ex cb Runoff Area=2.761 ac Runoff Depth>0.98" Flow Length=734' Slope=0.1175'/' Tc=8.9 min CN=73 Runoff=2.6 cfs 0.226 of Subcatchment 2S: to culvert Runoff Area=4.716 ac Runoff Depth>0.98" Flow Length=655' Tc=8.4 min CN=73 Runoff=4.6 cfs 0.386 of Pond 2P: ex cb Peak Elev=173.39' Storage=13 cf Inflow=2.6 cfs 0.226 of Primary=2.6 cfs 0.226 of Secondary=0.0 cfs 0.000 of Outflow=2.6 cfs 0.226 of Pond 5P: renovated culvert Peak Elev=168.62' Storage=70 cf Inflow=4.6 cfs 0.386 of Primary=4.4 cfs 0.385 of Secondary=0.0 cfs 0.000 of Outflow=4.4 cfs 0.385 of Stevens St dev 06-09-11 Type ///24-hr 2-Yr Rainfall=3.20" Prepared by Andover Consultants, Inc. HydroCADO 8.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Subcatchment 1S: to ex cb Runoff = 2.6 cfs @ 12.14 hrs, Volume= 0.226 af, Depth> 0.98" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 2-Yr Rainfall=3.20" Area (ac) CN Description 1.273 70 Woods, Good, HSG C 0.910 74 >75% Grass cover, Good, HSG C 0.247 98 Paved parking & roofs 0.073 55 Woods, Good, HSG B 0.258 61 >75% Grass cover, Good, HSG B 2.761 73 Weighted Average 2.514 Pervious Area 0.247 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 8.9 734 0.1175 1.38 Lag/CN Method, Stevens St dev 06-09-11 Type 111 24-hr 2-Yr Rainfall=3.20" Prepared by Andover Consultants, Inc. HydroCAD®8 00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Subcatchment 2S: to culvert Runoff = 4.6 cfs @ 12.13 hrs, Volume= 0.386 af, Depth> 0.98" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 2-Yr Rainfall=3.20" Area (ac) CN Description 0.517 98 Paved parking & roofs 2.067 70 Woods, Good, HSG C 1.421 74 >75% Grass cover, Good, HSG C 0.693 61 >75% Grass cover, Good, HSG B 0.018 55 Woods, Good, HSG B 4.716 73 Weighted Average 4.199 Pervious Area 0.517 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.6 50 0.1500 0.15 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.10" 1.0 440 0.2000 7.20 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 1.8 165 0.0100 1.50 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 8.4 655 Total Stevens St dev 06-09-11 Type 111 24-hr 2-Yr Rainfall=3.20" Prepared by Andover Consultants, Inc. HydroCADO 8.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Pond 2P: ex cb Inflow Area = 2.761 ac, Inflow Depth > 0.98" for 2-Yr event Inflow = 2.6 cfs @ 12.14 hrs, Volume= 0.226 of Outflow = 2.6 cfs @ 12.14 hrs, Volume= 0.226 af, Atten= 0%, Lag= 0.1 min Primary = 2.6 cfs @ 12.14 hrs, Volume= 0.226 of Secondary= 0.0 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs/3 Peak Elev= 173.39' @ 12.14 hrs Surf.Area= 13 sf Storage= 13 cf Plug-Flow detention time= 0.2 min calculated for 0.226 of(100% of inflow) Center-of-Mass det. time= 0.1 min ( 867.0- 866.9 ) Volume Invert Avail.Storage Storage Description #1 172.41' 3,641 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 172.41 13 0 0 173.41 13 13 13 174.70 1,550 1,008 1,021 175.00 1,690 486 1,507 175.50 3,590 1,320 2,827 175.70 4,550 814 3,641 Device Routing Invert Outlet Devices #1 Primary 172.41' 12.0" x 64.0' long Culvert RCP, square edge headwall, Ke= 0.500 Outlet Invert= 169.66' S= 0.0430 'P Cc= 0.900 n= 0.013 #2 Secondary 175.50' 40.0' long x 2.5' 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 Coef. (English) 2.48 2.60 2.60 2.60 2.64 2.65 2.68 2.75 2.74 2.76 2.89 3.05 3.19 3.32 Primary OutFlow Max=2.6 cfs @ 12.14 hrs HW=173.38' (Free Discharge) L1=Culvert (Inlet Controls 2.6 cfs @ 3.36 fps) §econdary OutFlow Max=0.0 cfs @ 0.00 hrs HW=172.41' (Free Discharge) 2=Broad-Crested Rectangular Weir ( Controls 0.0 cfs) Stevens St dev 06-09-11 Type 11124-hr 2-Yr Rainfall=3.20" Prepared by Andover Consultants, Inc. HydroCADO 8.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Pond 5P: renovated culvert Inflow Area = 4.716 ac, Inflow Depth > 0.98" for 2-Yr event Inflow = 4.6 cfs @ 12.13 hrs, Volume= 0.386 of Outflow = 4.4 cfs @ 12.15 hrs, Volume= 0.385 af, Atten= 3%, Lag= 1.1 min Primary = 4.4 cfs @ 12.15 hrs, Volume= 0.385 of Secondary = 0.0 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs/3 Peak Elev= 168.62' @ 12.15 hrs Surf.Area= 161 sf Storage= 70 cf Plug-Flow detention time= 1.2 min calculated for 0.384 of(100% of inflow) Center-of-Mass det. time= 0.3 min ( 866.8- 866.5) Volume Invert Avail.Storage Storage Description #1 166.75' 4,433 cf Custom Stage Data(Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 166.75 13 0 0 167.00 13 3 3 168.00 13 13 16 169.00 250 132 148 170.00 870 560 708 171.00 3,815 2,343 3,050 171.10 4,410 411 3,461 171.30 5,300 971 4,433 Device Routing Invert Outlet Devices #1 Primary 166.75' 12.0" x 36.0' long Culvert RCP, square edge headwall, Ke= 0.500 Outlet Invert= 166.03' S= 0.0200 '/' Cc= 0.900 n= 0.011 #2 Secondary 171.10' 95.0' long x 2.0' 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 Coef. (English) 2.54 2.61 2.61 2.60 2.66 2.70 2.77 2.89 2.88 2.85 3.07 3.20 3.32 Primary OutFlow Max=4.4 cfs @ 12.15 hrs HW=168.62' (Free Discharge) L1=Culvert (Inlet Controls 4.4 cfs @ 5.63 fps) Secondary OutFlow Max=0.0 cfs @ 0.00 hrs HW=166.75' (Free Discharge) 2=Broad-Crested Rectangular Weir ( Controls 0.0 cfs) 10-Year Storm P=4.8 inches Stevens St dev 06-09-11 Type ///24-hr 10-Yr Rainfall=4.80" Prepared by Andover Consultants, Inc. H droCADO 8.00 s/n 002099 0 2006 H droCAD Software Solutions LLC Time span=0.00-24.00 hrs, dt=0.05 hrs, 481 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind method - Pond routing by Stor-Ind method Subcatchment 1S: to ex cb Runoff Area=2.761 ac Runoff Depth>2.12" Flow Length=734' Slope=0.1175 '/' Tc=8.9 min CN=73 Runoff=6.0 cfs 0.488 of Subcatchment 2S: to culvert Runoff Area=4.716 ac Runoff Depth>2.12" Flow Length=655' Tc=8.4 min CN=73 Runoff=10.5 cfs 0.834 of Pond 2P: ex cb Peak Elev=174.51' Storage=749 cf Inflow=6.0 cfs 0.488 of Primary=4.8 cfs 0.488 of Secondary=0.0 cfs 0.000 of Outflow=4.8 cfs 0.488 of Pond 5P: renovated culvert Peak Elev=170.71' Storage=2,070 cf Inflow=10.5 cfs 0.834 of Primary=7.0 cfs 0.836 of Secondary=0.0 cfs 0.000 of Outflow=7.0 cfs 0.836 of Stevens St dev 06-09-11 Type 111 24-hr 10-Yr Rainfall=4.80" Prepared by Andover Consultants, Inc. H droCADO 8.00 s/n 002099 ©2006 H droCAD Software Solutions LLC Subcatchment 1S: to ex cb Runoff = 6.0 cfs @ 12.13 hrs, Volume= 0.488 af, Depth> 2.12" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 10-Yr Rainfall=4.80" Area (ac) CN Description 1.273 70 Woods, Good, HSG C 0.910 74 >75% Grass cover, Good, HSG C 0.247 98 Paved parking & roofs 0.073 55 Woods, Good, HSG B 0.258 61 >75% Grass cover, Good, HSG B 2.761 73 Weighted Average 2.514 Pervious Area 0.247 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 8.9 734 0.1175 1.38 Lag/CN Method, Stevens St dev 06-09-11 Type ///24-hr 10-Yr Rainfall=4.80" Prepared by Andover Consultants, Inc. HydroCAD®8 00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Subcatchment 2S: to culvert Runoff = 10.5 cfs @ 12.12 hrs, Volume= 0.834 af, Depth> 2.12" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 10-Yr Rainfall=4.80" Area (ac) CN Description 0.517 98 Paved parking & roofs 2.067 70 Woods, Good, HSG C 1.421 74 >75% Grass cover, Good, HSG C 0.693 61 >75% Grass cover, Good, HSG B 0.018 55 Woods, Good, HSG B 4.716 73 Weighted Average 4.199 Pervious Area 0.517 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.6 50 0.1500 0.15 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.10" 1.0 440 0.2000 7.20 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 1.8 165 0.0100 1.50 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 8.4 655 Total Stevens St dev 06-09-11 Type 11124-hr 10-Yr Rainfall=4.80" Prepared by Andover Consultants, Inc. H droCADO 8.00 s/n 002099 ©2006 H droCAD Software Solutions LLC Pond 2P: ex cb Inflow Area = 2.761 ac, Inflow Depth > 2.12" for 10-Yr event Inflow = 6.0 cfs @ 12.13 hrs, Volume= 0.488 of Outflow = 4.8 cfs @ 12.22 hrs, Volume= 0.488 af, Atten= 21%, Lag= 5.1 min Primary = 4.8 cfs @ 12.22 hrs, Volume= 0.488 of Secondary= 0.0 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs/3 Peak Elev= 174.51' @ 12.22 hrs Surf.Area= 1,325 sf Storage= 749 cf Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 0.6 min ( 844.3- 843.7) Volume Invert Avail.Storage Storage Description #1 172.41' 3,641 cf Custom Stage Data(Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 172.41 13 0 0 173.41 13 13 13 174.70 1,550 1,008 1,021 175.00 1,690 486 1,507 175.50 3,590 1,320 2,827 175.70 4,550 814 3,641 Device Routing Invert Outlet Devices #1 Primary 172.41' 12.0" x 64.0' long Culvert RCP, square edge headwall, Ke=0.500 Outlet Invert= 169.66' S= 0.0430 ? Cc= 0.900 n= 0.013 #2 Secondary 175.50' 40.0' long x 2.5' 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 Coef. (English) 2.48 2.60 2.60 2.60 2.64 2.65 2.68 2.75 2.74 2.76 2.89 3.05 3.19 3.32 Primary OutFlow Max=4.8 cfs @ 12.22 hrs HW=174.49' (Free Discharge) L1=Culvert (Inlet Controls 4.8 cfs @ 6.06 fps) §econdary OutFlow Max=0.0 cfs @ 0.00 hrs HW=172.41' (Free Discharge) 2=13road-Crested Rectangular Weir (Controls 0.0 cfs) Stevens St dev 06-09-11 Type ///24-hr 10-Yr Rainfall=4.80" Prepared by Andover Consultants, Inc. H droCADO 8.00 s/n 002099 ©2006 H droCAD Software Solutions LLC Pond 5P: renovated culvert Inflow Area = 4.716 ac, Inflow Depth > 2.12" for 10-Yr event Inflow = 10.5 cfs @ 12.12 hrs, Volume= 0.834 of Outflow = 7.0 cfs @ 12.25 hrs, Volume= 0.836 af, Atten= 33%, Lag= 7.7 min Primary = 7.0 cfs @ 12.25 hrs, Volume= 0.836 of Secondary= 0.0 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs/3 Peak Elev= 170.71' @ 12.25 hrs Surf.Area= 2,963 sf Storage= 2,070 cf Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 1.0 min ( 844.3- 843.3) Volume Invert Avail Storage Storage Description #1 166.75' 4,433 cf Custom Stage Data(Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 166.75 13 0 0 167.00 13 3 3 168.00 13 13 16 169.00 250 132 148 170.00 870 560 708 171.00 3,815 2,343 3,050 171.10 4,410 411 3,461 171.30 5,300 971 4,433 Device Routing Invert Outlet Devices #1 Primary 166.75' 12.0" x 36.0' long Culvert RCP, square edge headwall, Ke= 0.500 Outlet Invert= 166.03' S= 0.0200 '/' Cc= 0.900 n= 0.011 #2 Secondary 171.10' 95.0' long x 2.0' 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 Coef. (English) 2.54 2.61 2.61 2.60 2.66 2.70 2.77 2.89 2.88 2.85 3.07 3.20 3.32 Primary OutFlow Max=7.0 cfs @ 12.25 hrs HW=170.71' (Free Discharge) L1=Culvert (Inlet Controls 7.0 cfs @ 8.95 fps) Secondary OutFlow Max=0.0 cfs @ 0.00 hrs HW=166.75' (Free Discharge) 2=Broad-Crested Rectangular Weir ( Controls 0.0 cfs) 25-Year Storm P=6.0 inches Stevens St dev 06-09-11 Type 111 24-hr 25-Yr Rainfall=6.00" Prepared by Andover Consultants, Inc. HydroCAD®8.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Time span=0.00-24.00 hrs, dt=0.05 hrs, 481 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind method - Pond routing by Stor-Ind method Subcatchment 1S: to ex cb Runoff Area=2.761 ac Runoff Depth>3.08" Flow Length=734' Slope=0.1175 '/' Tc=8.9 min CN=73 Runoff=8.9 cfs 0.710 of Subcatchment 2S: to culvert Runoff Area=4.716 ac Runoff Depth>3.08" Flow Length=655' Tc=8.4 min CN=73 Runoff=15.5 cfs 1.212 of Pond 2P: ex cb Peak Elev=175.28' Storage=2,136 cf Inflow=8.9 cfs 0.710 of Primary=5.8 cfs 0.707 of Secondary=0.0 cfs 0.000 of Outflow=5.8 cfs 0.707 of Pond 5P: renovated culvert Peak Elev=171.18' Storage=3,822 cf Inflow=15.5 cfs 1.212 of Primary=7.5 cfs 1.155 of Secondary=5.4 cfs 0.050 of Outflow=12.9 cfs 1.205 of Stevens St dev 06-09-11 Type l//24-hr 25-Yr Rainfall=6.00" Prepared by Andover Consultants, Inc. HydroCADO 8.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Subcatchment 1S: to ex cb Runoff = 8.9 cfs @ 12.13 hrs, Volume= 0.710 af, Depth> 3.08" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 25-Yr Rainfall=6.00" Area (ac) CN Description 1.273 70 Woods, Good, HSG C 0.910 74 >75% Grass cover, Good, HSG C 0.247 98 Paved parking & roofs 0.073 55 Woods, Good, HSG B 0.258 61 >75% Grass cover, Good, HSG B 2.761 73 Weighted Average 2.514 Pervious Area 0.247 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 8.9 734 0.1175 1.38 Lag/CN Method, Stevens St dev 06-09-11 Type 111 24-hr 25-Yr Rainfall=6.00" Prepared by Andover Consultants, Inc. HydroCADO 8.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Subcatchment 2S: to culvert Runoff = 15.5 cfs @ 12.12 hrs, Volume= 1.212 af, Depth> 3.08" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 25-Yr Rainfall=6.00" Area (ac) CN Description 0.517 98 Paved parking & roofs 2.067 70 Woods, Good, HSG C 1.421 74 >75% Grass cover, Good, HSG C 0.693 61 >75% Grass cover, Good, HSG B 0.018 55 Woods Good, HSG B 4.716 73 Weighted Average 4.199 Pervious Area 0.517 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.6 50 0.1500 0.15 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.10" 1.0 440 0.2000 7.20 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 1.8 165 0.0100 1.50 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 8.4 655 Total Stevens St dev 06-09-11 Type 111 24-hr 25-Yr Rainfall=6.00" Prepared by Andover Consultants, Inc. HydroCAD®8.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Pond 2P: ex cb Inflow Area = 2.761 ac, Inflow Depth > 3.08" for 25-Yr event Inflow = 8.9 cfs @ 12.13 hrs, Volume= 0.710 of Outflow = 5.8 cfs @ 12.26 hrs, Volume= 0.707 af, Atten= 34%, Lag= 8.1 min Primary = 5.8 cfs @ 12.26 hrs, Volume= 0.707 of Secondary= 0.0 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs/3 Peak Elev= 175.28' @ 12.26 hrs Surf.Area= 2,764 sf Storage= 2,136 cf Plug-Flow detention time=4.4 min calculated for 0.707 of(100% of inflow) Center-of-Mass det. time= 1.9 min ( 834.8- 832.9 ) Volume Invert Avail.Storage Storage Description #1 172.41' 3,641 cf Custom Stage Data(Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 172.41 13 0 0 173.41 13 13 13 174.70 1,550 1,008 1,021 175.00 1,690 486 1,507 175.50 3,590 1,320 2,827 175.70 4,550 814 3,641 Device Routing Invert Outlet Devices #1 Primary 172.41' 12.0" x 64.0' long Culvert RCP, square edge headwall, Ke= 0.500 Outlet Invert= 169.66' S= 0.0430 'f Cc= 0.900 n= 0.013 #2 Secondary 175.50' 40.0' long x 2.5' 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 Coef. (English) 2.48 2.60 2.60 2.60 2.64 2.65 '2.68 2.75 2.74 2.76 2.89 3.05 3.19 3.32 Primary OutFlow Max=5.8 cfs @ 12.26 hrs HW=175.27' (Free Discharge) 't-1=Culvert (Inlet Controls 5.8 cfs @ 7.40 fps) Secondary OutFlow Max=0.0 cfs @ 0.00 hrs HW=172.41' (Free Discharge) 2=Broad-Crested Rectangular Weir ( Controls 0.0 cfs) Stevens St dev 06-09-11 Type Ill 24-hr 25-Yr Rainfall=6.00" Prepared by Andover Consultants, Inc. HydroCAD®8.00 s/n 002099 0 2006 HydroCAD Software Solutions LLC Pond 5P: renovated culvert Inflow Area = 4.716 ac, Inflow Depth > 3.08" for 25-Yr event Inflow = 15.5 cfs @ 12.12 hrs, Volume= 1.212 of Outflow = 12.9 cfs @ 12.21 hrs, Volume= 1.205 af, Atten= 17%, Lag= 5.1 min Primary = 7.5 cfs @ 12.21 hrs, Volume= 1.155 of Secondary = 5.4 cfs @ 12.21 hrs, Volume= 0.050 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs /3 Peak Elev= 171.18' @ 12.21 hrs Surf.Area=4,759 sf Storage= 3,822 cf Plug-Flow detention time= 6.1 min calculated for 1.205 of(99% of inflow) Center-of-Mass det. time= 2.7 min ( 835.2- 832.5) Volume Invert Avail.Storage Storage Description #1 166.75' 4,433 cf Custom Stage Data(Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 166.75 13 0 0 167.00 13 3 3 168.00 13 13 16 169.00 250 132 148 170.00 870 560 708 171.00 3,815 2,343 3,050 171.10 4,410 411 3,461 171.30 5,300 971 4,433 Device Routing Invert Outlet Devices #1 Primary 166.75' 12.0" x 36.0' long Culvert RCP, square edge headwall, Ke= 0.500 Outlet Invert= 166.03' S= 0.02007 Cc= 0.900 n= 0.011 #2 Secondary 171.10' 95.0' long x 2.0' 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 Coef. (English) 2.54 2.61 2.61 2.60 2.66 2.70 2.77 2.89 2.88 2.85 3.07 3.20 3.32 Primary OutFlow Max=7.5 cfs @ 12.21 hrs HW=171.17' (Free Discharge) t-1=Culvert (Inlet Controls 7.5 cfs @ 9.54 fps) Secondary OutFlow Max=4.9 cfs @ 12.21 hrs HW=171.17' (Free Discharge) 2=Broad-Crested Rectangular Weir (Weir Controls 4.9 cfs @ 0.69 fps) 100-Year Storm P=8.6 inches Stevens St dev 06-09-11 Type ///24-hr 100-Yr Rainfall=8.60" Prepared by Andover Consultants, Inc. HydroCADO 8.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Time span=0.00-24.00 hrs, dt=0.05 hrs, 481 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind method - Pond routing by Stor-Ind method Subcatchment 1S: to ex cb Runoff Area=2.761 ac Runoff Depth>5.34" Flow Length=734' Slope=0.1175'/' Tc=8.9 min CN=73 Runoff=15.3 cfs 1.228 of Subcatchment 2S: to culvert Runoff Area=4.716 ac Runoff Depth>5.34" Flow Length=655' Tc=8.4 min CN=73 Runoff=26.8 cfs 2.098 of Pond 2P: ex cb Peak EIev=175.70' Storage=3,635 cf Inflow=15.3 cfs 1.228 of Primary=6.3 cfs 1.109 of Secondary=8.6 cfs 0.114 of Outflow=14.9 cfs 1.224 of Pond 5P: renovated culvert Peak EIev=171.28' Storage=4,325 cf Inflow=26.8 cfs 2.098 of Primary=7.6 cfs 1.736 of Secondary=18.5 cfs 0.368 of Outflow=26.0 cfs 2.104 of Stevens St dev 06-09-11 Type 111 24-hr 100-Yr Rainfall=8.60" Prepared by Andover Consultants, Inc. HydroCAD®8.00 s/n 002099 0 2006 HydroCAD Software Solutions LLC Subcatchment 1S: to ex cb Runoff = 15.3 cfs @ 12.13 hrs, Volume= 1.228 af, Depth> 5.34" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 100-Yr Rainfall=8.60" Area (ac) CN Description 1.273 70 Woods, Good, HSG C 0.910 74 >75% Grass cover, Good, HSG C 0.247 98 Paved parking & roofs 0.073 55 Woods, Good, HSG B 0.258 61 >75% Grass cover, Good HSG B 2.761 73 Weighted Average 2.514 Pervious Area 0.247 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 8.9 734 0.1175 1.38 Lag/CN Method, Stevens St dev 06-09-11 Type ///24-hr 100-Yr Rainfall=8.60" Prepared by Andover Consultants, Inc. HydroCAD®8.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Subcatchment 2S: to culvert Runoff = 26.8 cfs @ 12.12 hrs, Volume= 2.098 af, Depth> 5.34" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 100-Yr Rainfall=8.60" Area (ac) CN Description 0.517 98 Paved parking & roofs 2.067 70 Woods, Good, HSG C 1.421 74 >75% Grass cover, Good, HSG C 0.693 61 >75% Grass cover, Good, HSG B 0.018 55 Woods Good, HSG B 4.716 73 Weighted Average 4.199 Pervious Area 0.517 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.6 50 0.1500 0.15 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.10" 1.0 440 0.2000 7.20 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 1.8 165 0.0100 1.50 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 8.4 655 Total Stevens St dev 06-09-11 Type 11124-hr 100-Yr Rainfall=8.60" Prepared by Andover Consultants, Inc. HydroCAD®8.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Pond 2P: ex cb Inflow Area = 2.761 ac, Inflow Depth > 5.34" for 100-Yr event Inflow = 15.3 cfs @ 12.13 hrs, Volume= 1.228 of Outflow = 14.9 cfs @ 12.17 hrs, Volume= 1.224 af, Atten= 2%, Lag= 2.5 min Primary = 6.3 cfs @ 12.17 hrs, Volume= 1.109 of Secondary = 8.6 cfs @ 12.17 hrs, Volume= 0.114 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs/3 Peak Elev= 175.70' @ 12.17 hrs Surf.Area=4,544 sf Storage= 3,635 cf Plug-Flow detention time=4.8 min calculated for 1.221 of(99% of inflow) Center-of-Mass det. time= 2.5 min ( 819.8- 817.2 ) Volume Invert Avail.Storage Storage Description #1 172.41' 3,641 cf Custom Stage Data(Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 172.41 13 0 0 173.41 13 13 13 174.70 1,550 1,008 1,021 175.00 1,690 486 1,507 175.50 3,590 1,320 2,827 175.70 4,550 814 3,641 Device Routing Invert Outlet Devices #1 Primary 172.41' 12.0" x 64.0' long Culvert RCP, square edge headwall, Ke= 0.500 Outlet Invert= 169.66' S= 0.0430 '/' Cc= 0.900 n= 0.013 #2 Secondary 175.50' 40.0' long x 2.5' 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 Coef. (English) 2.48 2.60 2.60 2.60 2.64 2.65 2.68 2.75 2.74 2.76 2.89 3.05 3.19 3.32 Primary OutFlow Max=6.3 cfs @ 12.17 hrs HW=175.68' (Free Discharge) L1=Culvert (Inlet Controls 6.3 cfs @ 8.02 fps) Secondary OutFlow Max=7.7 cfs @ 12.17 hrs HW=175.68' (Free Discharge) 2=Broad-Crested Rectangular Weir (Weir Controls 7.7 cfs @ 1.06 fps) Stevens St dev 06-09-11 Type 111 24-hr 100-Yr Rainfall=8.60" Prepared by Andover Consultants, Inc. HydroCADO 8.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Pond 5P: renovated culvert Inflow Area = 4.716 ac, Inflow Depth > 5.34" for 100-Yr event Inflow = 26.8 cfs @ 12.12 hrs, Volume= 2.098 of Outflow = 26.0 cfs @ 12.13 hrs, Volume= 2.104 af, Atten= 3%, Lag= 0.7 min Primary = 7.6 cfs @ 12.13 hrs, Volume= 1.736 of Secondary = 18.5 cfs @ 12.13 hrs, Volume= 0.368 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs/3 Peak Elev= 171.28' @ 12.13 hrs Surf.Area= 5,209 sf Storage= 4,325 cf Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 1.7 min ( 818.6- 816.8 ) Volume Invert Avail Storage Storage Description #1 166.75' 4,433 cf Custom Stage Data(Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 166.75 13 0 0 167.00 13 3 3 168.00 13 13 16 169.00 250 132 148 170.00 870 560 708 171.00 3,815 2,343 3,050 171.10 4,410 411 3,461 171.30 5,300 971 4,433 Device Routing Invert Outlet Devices #1 Primary 166.75' 12.0" x 36.0' long Culvert RCP, square edge headwall, Ke= 0.500 Outlet Invert= 166.03' S= 0.0200 '/' Cc= 0.900 n= 0.011 #2 Secondary 171.10' 95.0' long x 2.0' 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 Coef. (English) 2.54 2.61 2.61 2.60 2.66 2.70 2.77 2.89 2.88 2.85 3.07 3.20 3.32 Primary OutFlow Max=7.6 cfs @ 12.13 hrs HW=171.28' (Free Discharge) L1=Culvert (Inlet Controls 7.6 cfs @ 9.66 fps) §econdary OutFlow Max=17.8 cfs @ 12.13 hrs HW=171.28' (Free Discharge) 2=Broad-Crested Rectangular Weir (Weir Controls 17.8 cfs @ 1.07 fps)