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HomeMy WebLinkAboutStormwater Report - 102 PETERS STREET 2/27/2012 Supplement to Stormwater Report 102 Peters Street North Andover, Massachusetts January 25, 2012 Revised February 27, 2012 Prepared for: Dundee Properties, LLC PO Box 3099 Andover, MA 01810 Prepared By: Andover Consultants, Inc. 1 East River Place Methuen, MA 01844 \ � JAIv1ES S. �Cyv G Sc EAIRWEATNER tU Cldll s 34716 4 Scow J1 This document is intended as a supplement to the Stormwater report, dated December 14, 2011, prepared for the 102 Peters Street project, and includes revised HydroCAD calculations and construction period pollution prevention and erosion control revisions made in response to review comments contained in a letter from Lisa Eggleston, P.E. to the North Andover Planning Board and Conservation Commission dated January 23, 2012and in a letter from Lisa Eggleston, P.E. to the North Andover Planning Board and Conservation Commission dated February 24, 2012. DEP Stormwater Management Standards The project is a new, small, commercial construction project and subject to the Massachusetts Stormwater Standards. Standard #I No New Untreated Discharges Runoff from the proposed parking area discharges to a perforated pipe detention system with an overflow drywell outlet that discharges towards Peters Street. The roof of the proposed building discharges to a precast concrete drywell system with an overflow outlet that discharges onsite, thence overland, westerly. Neither system directly discharges to a wetland. Standard #2 Peak Rate Attenuation Runoff rates from the small footprint of the project have been attenuated with the constructed detention/infiltration systems noted above Peak rates of runoff for the 1, 2, 10, and 100-year storm events have been calculated. A comparison is as follows: Northwesterly(to Peters Street 1-year storm 2-year storm 10-year storm 100-year storm Pre = 0.1 cfs pre= 0.1 cfs pre= 0.2 cfs pre= 0.6 cfs Post=0.1 cfs post=0.1 cfs post=0.2 cfs post=0.4 cfs Westerly: 1-year storm 2-year storm 10-year storm 100-year storm Pre = 0.0 cfs pre = 0.1 cfs pre = 0.2 cfs pre= 0.7 cfs Post=0.0 cfs post= 0.0 cfs post=0.2 cfs post=0.4 cfs As can be seen, the peak rates of runoff are small, for both the pre and post developed conditions because of the small scale of the project, and the increases in peak rates are attenuated to be the same rate or less. Standard 43 Recharge The site consists of HSG B soil. The target depth to recharge is 0.35 inches. Infiltration/Recharge Calculations Total, existing impervious area= 1,688 sf Total proposed, new impervious area= 6,674 sf Net new impervious area=4,986 sf New impervious to infiltration=4,624 sf(92.8%> 65%), ok use 1.058 volume multiplier for required recharge) NRCS Soil HSG B soil, target depth=0.35 inches (0.029166 ft) Total recharge volume required=4,986 sf x 0.029166 ft = 146 cf Parking Lot: Volume provided by 6-inch bedding of perforated pipe detention: n=0.40, 1=50.7 ft, w=15 ft, d=0.5 ft Volume= 0.40 x 50.7 x 15 ft x 0.5 ft= 152 cf Volume provided by 3-foot high drywell with 5'-4" inside diameter Volume= x x (5.33 x 5.33)/4 x 3 =22 cf Volume provided by stone trench n=0.40, 1=24 ft, w=5 ft, d=2.5 ft Volume= 0.40x24x5ftx2.5ft = 120 cf Time to drain pipe beddin static method Total volume=vol. = 152 cf Bottom area= A =50.7 ft x 15 ft= 760.5 sf k (HSG B soil =0.52 in/hr(0.0433 ft/hr) t = vol/(k * A), t= 152/(0.0433*760.5) =4.6 hrs <0.72 hrs, ok Time to drain stone trench(static method) Total volume = vol. = 120 cf Bottom area=A =24 ft x 5 ft= 120 sf k (HSG B soil =0.52 in/hr(0.0433 ft/hr) t=vol/(k * A), t= 120/(0.0433*120) =23 hrs < 0.72 hrs, ok Time to drain roof drywell(static method) Total volume = vol. = 633 cf Bottom area=A=32 ft x 10.33 ft= 330 sf k (HSG B soil=0.52 in/hr(0.0433 ft/hr) t=vol/(k * A), t=633/(0.0433*330) =44 hrs < 72 hrs, ok Total volume required = 146 cf x 1.06 = 155 cf Total volume provided = (pipe bedding 152) + (roof drywell 633) + (stone trench 120) = 905 cf 905 cf>155 cf, ok Standard 44 Water Quality Water Quality Calculations Total proposed, new impervious area= 6,674 sf Use 1/2" depth for WQV calculation for project not in critical areas WQV=Aimp x 0.5"/12" per foot WQV= (0.5/12) ft x 6,674 sf=278 cf required. Volume provided = 905 cf and exceeds volume required of 278 c£ Total impervious area tributary to parking lot drainage system = 3,570 sf WQV= (0.5/12) x 3,570 = 148.8 cf Volume provided= 152 cf(pipe bedding) + 120 cf stone trench=272 cf> 149 cf ok INSTRUCTIONS: ueism 1,.automated:Mar.4,2008 1.In BMP Column,dick on Blue Cell to Activate Drop Down Menu 2.Select BMP from Drop Doom Menu 3.After BMP is selected,TSS Removal and other Columns are automatically completed. Location:Ji 02 Peters Street B C D E F TSS Removal Starting TSS Amount Remaining BMP' Rate' Load* Removed C*D Load D-E +r 0 Deep Sump and Hooded 0 Catch Basin 025 1.00 0.25 0.75 t > i Subsurface Infiltration 0 0 Structure 0.80 0.75 0.80 0.15 0 0.00 0.15 0.00 0.15 ~ 0.00 0.15 0.00 0.15 V V 0.00 0.15 0.00 0.15 Separate Form Needs to be Completed for Each Total TSS Removal - 850/6 Outlet or BMP Train Project: 11.12 wro«wow,LLC Prepared By: isf 'Equals remaining load from previous BMP(E) Date: 12t8/20i1 wbich enters the BMP Standard #5 Land Uses With Higher Potential Pollutant Loads (LUHPPLs) The site is not a land use with higher potential pollutant loads. Standard #6 Critical Areas The project will not create any discharges to Critical Areas. Standard #7 Redevelopment Project The project is not a redevelopment project. Standard #8 Construction Period Pollution Prevention and Erosion and Sedimentation Control A Construction Period Pollution Prevention and Erosion and Sedimentation Control plan has been prepared and will be implemented to protect the adjacent properties from sedimentation during construction. The project is not covered by a NPDES Construction General Permit due to the small footprint of the project. Standard #9 Operation and Maintenance Plan An Operation and Maintenance Plan (O&M Plan) has been developed which lists the owner of the property as the responsible party. The O&M Plan details the schedule for routine maintenance and inspection. Standard #10 Prohibition of Illicit Discharges All illicit discharges at the site will be prohibited. An Illicit Discharge Compliance Statement will be submitted prior to the start of any land disturbance activities. Operation and Maintenance Plan 102 Peters Street North Andover, Massachusetts 1. The pipe detention, roof infiltration structure and the drainage structures, including the catch basin sediment sump, and vane grates shall be owned and operated by the lot Owner. The lot Owner will be Dundee Properties, LLC once the project is constructed. In the event that the property is sold to another party, the future owner of the property shall be responsible for the operation and maintenance of the drainage facilities. 2. The property Owner shall inspect the stormwater management system 4 times per year, including visual inspection of the vane grate, drain manhole, catch basin sediment sumps, roof drywells and terminal drywell. The owner shall ensure that no portion of the stormwater management system is damaged, blocked or otherwise in a state that prevents its proper operation. 3. The property Owner shall ensure that accumulated silt and debris within the drain manholes and catch basins are removed in a timely manner. The catch basins shall be cleaned when the sediment reaches a depth of 2 feet below the outlet (1/2 depth of sump) and cleaned at least annually in the spring following winter sanding. 4. The property Owner shall inspect the vane grate and pipe for blockages and solids accumulation at least monthly and remove debris and sediments as needed. 5. The property Owner shall inspect the parking lot terminal drywell, stone trench,pipe detention and roof infiltration structure after every major storm for the first few months and then every six months there after. 6. Illicit discharges are to be prohibited. The property Owner shall report any illicit discharges once discovered to the North Andover Police and Health Departments. 7. The property Owner should have the parking area swept of sand and debris after the winter sanding season and every other month (60 days) through the summer and fall. The parking lot shall be swept a minimum of 4 times during this interval. 8. The surface of the stone trench shall be inspected every six months. If clogged will silt, the surface filter layer of peastone shall be removed and replaced with clean, double washed peastone when needed. Construction Period Pollution Prevention and Erosion and Sedimentation Control Narrative Erosion control measures will be implemented prior to the start of construction. A staked hay bale and silt fence barrier will be installed as shown on the Site Plan. When paving is complete and all disturbed areas have been stabilized, a certificate of compliance shall be sought from the North Andover Conservation Commission. General Construction Period Operation and Maintenance Plan During construction, the maintenance program shall consist of the following: 1. The erosion control barrier shall be visually inspected daily and shall be repaired or replaced as necessary. 2. Sediment will be removed from the barriers when it has accumulated to a depth of six inches. 3. All seeded or otherwise stabilized areas shall be inspected periodically to insure proper germination and adequate coverage and shall be reseeded/restabilized as necessary. 4. Temporary sediment control structures or devices shall be inspected daily and prior to forecast rainfall of 2 inches or more. 5. In the event that soil stockpiles are required and will be in place for more than a day, the stockpile(s) shall be surrounded by a staked haybale or properly secured (embedded in soil as shown on site details) silt fence. In lieu of perimeter barriers, the stockpile may be mulched or covered with tarps to protect it from eroding. 6. Once the catch basin and vane drain are in place, and prior to connection to the pipe/detention system, a silt sack or suitable equivalent shall be placed in the catch basin. The sediment trapping device shall be capable of catching influent from both the basin grate and the vane drain. The catch basin device shall be inspected daily and cleaned as necessary. In the event of a storm event of 1 inch or more of precipitation, the silt sack or equivalent shall be cleaned, if needed, before the start of the event. 7. The stone trench shall be protected by a staked geotextile to protect the stone from construction period sediments. Once the upstream areas are stabilized with pavement and permanent landscaping, the protective geotextile shall be removed Responsible Party The property Owner shall be responsible for ensuring that the site development contractor hired for the work is continually in compliance with this Plan. Construction Period Pollution Prevention Measures The erosion control barrier shall be constructed prior to the start of construction. All disturbed areas shall be mulched and seeded or otherwise permanently stabilized immediately upon reaching finish grade. Site Development Plan See Site Plans, sheets 1, 2 and 3 of 3, dated December 13, 2011, last revise February 27, 2012 and prepared by Andover Consultants, Inc. for development details. Construction Sequencing Plan Major activities will proceed as follows: 1. Install perimeter erosion control barrier (staked hay bales). 2. Demolish existing structures and remove off site in accordance with all local, state and federal laws and regulations. The paved driveway shall remain as long as feasible to act as the construction entrance/exit. 3. Clear and grub areas within the limit of work (inside erosion barrier). 4. Prepare building site for construction. 5. Construct subsurface utilities connecting to public utilities in Peters St. including water and gas. 6. Install roof drywell system and stone trench and grade swale. 7. Install parking lot drainage system. 8. Prepare sub-grade and install base material for parking areas to grade. 9. Install binder course of pavement for parking lot. 10. Remove existing driveway pavement and grade. 11. Construct sidewalks. 12. Final grade, seed and mulch disturbed non-paved areas. 13. Complete building construction. 14. Install finish course of pavement. 15. Clean project area 16. Once site is stabilized obtain a certificate of compliance from the Conservation Commission and remove perimeter erosion control stakes and properly dispose of in accordance with applicable laws and regulations. Sequencing of Erosion and Sedimentation Controls Erosion and sedimentation controls will be installed prior to any disturbance at the site. An ongoing inspection and maintenance schedule will be followed and additional measures will be added as necessary. Inspection Schedule During construction the inspection schedule shall consist of the following: 1. The erosion barrier shall be visually inspected daily and shall be repaired or replaced as necessary. 2. All seeded areas shall be inspected periodically to insure proper germination and adequate coverage and shall be reseeded as necessary. Any wash outs shall be promptly repaired, reseeded and mulched 3. Maintain existing driveway by sweeping as needed to prevent tracking of soil onto Peters Street, remove any soil tracked onto Street Inspection and Maintenance Log Form See attached. Inspection and Maintenance Report 102 Peters Street North Andover, Massachusetts DEP File No. 242-1539 Vane Drain and grate Condition Action Taken Catch basin Pipe detention Terminal drywell Drain manhole Roof drywell Stone trench Sod berm & swale Signed Date Long Term Pollution Prevention Plan Good housekeeping practices The owner of the property, (Owner), shall ensure regular maintenance activities at the site 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 shall be stored at this site. Vehicle washing controls No vehicle washing activities will take place in the area. 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 storm water management structures continue indefinitely. Requirements for storage and use of fertilizers, herbicides, and pesticides No fertilizers, herbicides or pesticides shall be stored outside. These materials shall be stored in compliance with the manufacturer's recommendations and in compliance with all local, state and federal rules and regulations. Provisions for solid waste management Any solid waste produced by the site will be temporarily stored in trash receptacles and emptied weekly. Snow disposal and plowing Snow shall not be plowed directly into the street but stored just off the edge of pavement. Plow damage to grassed areas adjacent to the pavement shall be repaired in the spring once growing season starts. Winter Road Salt and/or Sand Use and Storage restrictions No salt shall be stored outside at the site. Minimal use of salt and sand is encouraged to mitigate slippery conditions. Parking Lot sweeping schedules The paved parking area shall be swept in the spring (April or May) after the winter sanding season and every 60 days through the summer and fall, 4 times minimum per year. 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 shall occur 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 Dundee Properties, LLC 978-682-4042 North Andover Police Department 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 Illicit Discharge Statement 102 Peters Street North Andover, MA 01845 As the owner of the project depicted on design plans for Assessor Parcel ID 210/024.0-0021 in the Town of North Andover, Massachusetts, I hereby certify that no illicit discharges are proposed or exist on the site. Print Name Signature Date HydroCAD Calculations HydroCAD Pre-developed calculations 1 Exist 1 i Exist 2 Subcat Reach Pon Link Drainage Diagram for Existing Prepared by Andover Consultants, Inc. HydroCAD®8.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC 1-Year Storm P=2.6 inches Existing Type /// 24-hr 1-Yr Rainfall=2.60" Prepared by Andover Consultants, Inc. HydroCAD® 8.00_ s/n 002099 ©2006 HydroCAD Software Solutions LLC Subcatchment 1: Exist 1 Runoff = 0.1 cfs @ 12.09 hrs, Volume= 0.005 af, Depth= 0.47" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 1-Yr Rainfall=2.60" Area (sf) CN Description 4,327 61 >75% Grass cover, Good, HSG B 141 55 Woods, Good, HSG B 1,188 98 Paved parking & roofs 5,656 69 Weighted Average 4,468 Pervious Area 1,188 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 3.6 30 0.0230 0.14 Sheet Flow, Grass: Short n= 0.150 P2= 3.10" 0.1 20 0.1300 5.80 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.6 110 0.0250 3.21 Shallow Concentrated Flow, Paved Kv= 20.3 fps 4.3 160 Total Existing Type ///24-hr 1-Yr Rainfall=2.60" Prepared by Andover Consultants, Inc. HydroCAD®8.00 s/n 002099 0 2006 HydroCAD Software Solutions LLC Subcatchment 2: Exist 2 Runoff = 0.0 cfs @ 12.33 hrs, Volume= 1 0.004 af, Depth= 0.20" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 1-Yr Rainfall=2.60" Area (sf) CN Description 4,578 61 >75% Grass cover, Good, HSG B 4,928 55 Woods, Good, HSG B 500 98 Roof 10,006 60 Weighted Average 9,506 Pervious Area 500 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.7 50 0.0200 0.15 Sheet Flow, Grass: Short n= 0.150 P2= 3.10" 0.2 42 0.0350 3.01 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 5.9 92 Total 2-Year Storm P=3.1 inches Existing Type /// 24-hr 2-Yr Rainfall=3.10" Prepared by Andover Consultants, Inc. HydroCAD®8.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Subcatchment 1: Exist 1 Runoff = 0.1 cfs @ 12.08 hrs, Volume= 0.008 af, Depth= 0.72" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 2-Yr Rainfall=3.10" Area (sf) CN Description 4,327 61 >75% Grass cover, Good, HSG B 141 55 Woods, Good, HSG B 1,188 98 Paved parking & roofs 5,656 69 Weighted Average 4,468 Pervious Area 1,188 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 3.6 30 0.0230 0.14 Sheet Flow, Grass: Short n= 0.150 P2= 3.10" 0.1 20 0.1300 5.80 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.6 110 0.0250 3.21 Shallow Concentrated Flow, Paved Kv= 20.3 fps 4.3 160 Total Existing Type 111 24-hr 2-Yr Rainfall=3.10" Prepared by Andover Consultants, Inc. HydroCAD®8.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Subcatchment 2: Exist 2 Runoff = 0.1 cfs @ 12.15 hrs, Volume= 0.007 af, Depth= 0.37" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 2-Yr Rainfall=3.10" Area (sf) CN Description 4,578 61 >75% Grass cover, Good, HSG B 4,928 55 Woods, Good, HSG B 500 98 Roof 10,006 60 Weighted Average 9,506 Pervious Area 500 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.7 50 0.0200 0.15 Sheet Flow, Grass: Short n= 0.150 P2= 3.10" 0.2 42 0.0350 3.01 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 5.9 92 Total 10-Year Storm P=4.5 inches Existing Type ///24-hr 10-Yr Rainfall=4.50" Prepared by Andover Consultants, Inc. HydroCAD® 8.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Subcatchment 1: Exist 1 Runoff = 0.2 cfs @ 12.07 hrs, Volume= 0.017 af, Depth= 1.60" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 10-Yr Rainfall=4.50" Area (sf) CN Description 4,327 61 >75% Grass cover, Good, HSG B 141 55 Woods, Good, HSG B 1,188 98 Paved parking & roofs 5,656 69 Weighted Average 4,468 Pervious Area 1,188 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 3.6 30 0.0230 0.14 Sheet Flow, Grass: Short n= 0.150 P2= 3.10" 0.1 20 0.1300 5.80 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.6 110 0.0250 3.21 Shallow Concentrated Flow, Paved Kv= 20.3 fps 4.3 160 Total Existing Type ///24-hr 10-Yr Rainfall=4.50" Prepared by Andover Consultants, Inc. HydroCAD®8.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Subcatchment 2: Exist 2 Runoff = 0.2 cfs @ 12.11 hrs, Volume= 0.020 af, Depth= 1.02" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 10-Yr Rainfall=4.50" Area (sfl CN Description 4,578 61 >75% Grass cover, Good, HSG B 4,928 55 Woods, Good, HSG B 500 98 Roof 10,006 60 Weighted Average 9,506 Pervious Area 500 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.7 50 0.0200 0.15 Sheet Flow, Grass: Short n= 0.150 P2= 3.10" 0.2 42 0.0350 3.01 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 5.9 92 Total 100-Year Storm P=7.0 inches Existing Type /// 24-hr 100-Yr Rainfall=7.00" Prepared by Andover Consultants, Inc. HydroCAD® 8 00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Subcatchment 1: Exist 1 Runoff = 0.6 cfs @ 12.07 hrs, Volume= 0.038 af, Depth= 3.51" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 100-Yr Rainfall=7.00" Area (sf) CN Description 4,327 61 >75% Grass cover, Good, HSG B 141 55 Woods, Good, HSG B 1,188 98 Paved parking & roofs 5,656 69 Weighted Average 4,468 Pervious Area 1,188 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 3.6 30 0.0230 0.14 Sheet Flow, Grass: Short n= 0.150 P2= 3.10" 0.1 20 0.1300 5.80 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.6 110 0.0250 3.21 Shallow Concentrated Flow, Paved Kv= 20.3 fps 4.3 160 Total Existing Type 111 24-hr 100-Yr Rainfall=7.00" Prepared by Andover Consultants, Inc. HydroCAD®8.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Subcatchment 2: Exist 2 Runoff = 0.7 cfs @ 12.10 hrs, Volume= 0.050 af, Depth= 2.60" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 100-Yr Rainfall=7.00" Area (sf) CN Description 4,578 61 >75% Grass cover, Good, HSG B 4,928 55 Woods, Good, HSG B 500 98 Roof 10,006 60 Weighted Average 9,506 Pervious Area 500 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.7 50 0.0200 0.15 Sheet Flow, Grass: Short n= 0.150 P2= 3.10" 0.2 42 0.0350 3.01 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 5.9 92 Total HydroCAD Post-developed calculations 1 sum1 Developed 1 SUM wqv c1 P stone trench to 2 detention PDE Developed 2 pipe detention 3 RDE Developed 3 sum2 Roof Infil sum 4 Developed 4 Subcat Reach Pon ILinkl Drainage Diagram for Revised 2-27-12 No infiltration Prepared by Andover Consultants, Inc. HydroCAD®8.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC 1-Year Storm P=2.6 inches Revised 2®2712 No infiltration Type 111 24-hr 1-Yr Rainfall=2.60" Prepared by Andover Consultants, Inc. H droCAD®8.00 s/n 002099 ©2006 H droCAD Software Solutions LLC Subcatchment 1: Developed 1 Runoff = 0.0 cfs @ 12.06 hrs, Volume= 0.002 af, Depth= 0.37" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 1-Yr Rainfall=2.60" Area (sf) CN Description 359 98 Paved 2,527 61 >75% Grass cover, Good HSG B 2,886 66 Weighted Average 2,527 Pervious Area 359 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.7 20 0.0700 0.20 Sheet Flow, Grass: Short n= 0.150 P2= 3.10" 0.0 14 0.1100 5.34 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.6 110 0.0250 3.21 Shallow Concentrated Flow, Paved Kv= 20.3 fps 2.3 144 Total Revised 2-27-12 No infiltration 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 Subcatchment 2: Developed 2 Runoff = 0.2 cfs @ 12.05 hrs, Volume= 0.014 af, Depth= 1.62" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 1-Yr Rainfall=2.60" Area (sf) CN Description 3,570 98 Paved 1,013 61 >75% Grass cover, Good, HSG B 4,583 90 Weighted Average 1,013 Pervious Area 3,570 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 3.1 20 0.0150 0.11 Sheet Flow, Grass: Short n= 0.150 P2= 3.10" 0.1 16 0.0150 1.97 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.1 40 0.0550 4.76 Shallow Concentrated Flow, Paved Kv= 20.3 fps 3.3 76 Total Revised 2-27-12 No infiltration Type /// 24-hr 1-Yr Rainfall=2.60" Prepared by Andover Consultants, Inc. HydroCAD® 8.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Subcatchment 3: Developed 3 Runoff = 0.2 cfs @ 12.03 hrs, Volume= 0.012 af, Depth= 2.37" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 1-Yr Rainfall=2.60" Area (sn CN Description 2,745 98 Roof 2,745 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 2.0 Direct Entry, Revised 2-27-12 No infiltration Type /// 24-hr 1-Yr Rainfall=2.60" Prepared by Andover Consultants, Inc. HydroCAD® 8.00 s/n 002099 0 2006 HydroCAD Software Solutions LLC Subcatchment 4: Developed 4 Runoff = 0.0 cfs @ 12.26 hrs, Volume= 0.002 af, Depth= 0.23" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 1-Yr Rainfall=2.60" Area (sf) CN Description 5,448 61 >75% Grass cover, Good, HSG B 5,448 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.7 10 0.0170 0.10 Sheet Flow, Grass: Short n= 0.150 P2= 3.10" 0.2 20 0.0170 2.10 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.7 100 0.0200 2.28 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 2.6 130 Total Revised 2-27-12 No infiltration Type 11124-hr 1-Yr Rainfall=2.60" Prepared by Andover Consultants, Inc. HydroCAD®8.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Pond p1: to detention Inflow Area = 0.105 ac, Inflow Depth = 1.62" for 1-Yr event Inflow = 0.2 cfs @ 12.05 hrs, Volume= 0.014 of Outflow = 0.2 cfs @ 12.05 hrs, Volume= 0.014 af, Atten= 0%, Lag= 0.0 min Primary = 0.2 cfs @ 12.05 hrs, Volume= 0.014 of Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs/2 Peak Elev= 189.53' @ 12.08 hrs Flood Elev= 191.50' Device Routing Invert Outlet Devices #1 Primary 189.20' 8.0" x 22.0' long Culvert Ke= 0.500 Outlet Invert= 189.00' S= 0.0091 T Cc= 0.900 n= 0.011 Primary OutFlow Max=0.2 cfs @ 12.05 hrs HW=189.53' TW=189.38' (Dynamic Tailwater) t1=Culvert (Outlet Controls 0.2 cfs @ 1.89 fps) Revised 2-27-12 No infiltration Type /// 24-hr 1-Yr Rainfall=2.60" Prepared by Andover Consultants, Inc. HydroCAD®8.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Pond PDET: pipe detention Inflow Area = 0.105 ac, Inflow Depth = 1.62" for 1-Yr event Inflow = 0.2 cfs @ 12.05 hrs, Volume= 0.014 of Outflow = 0.1 cfs @ 12.26 hrs, Volume= 0.013 af, Atten= 62%, Lag= 12.9 min Primary = 0.1 cfs @ 12.26 hrs, Volume= 0.013 of Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs/2 Peak Elev= 189.49' @ 12.26 hrs Surf.Area= 761 sf Storage= 177 cf Plug-Flow detention time= 101.5 min calculated for 0.013 of(93% of inflow) Center-of-Mass det. time= 63.2 min ( 875.9 - 812.7 ) Volume Invert Avail.Storage Storage Description #1 189.00' 691 cf 15.00'W x 50.701 x 3.50'H Prismatoid 2,662 cf Overall - 933 cf Embedded = 1,729 cf x 40.0% Voids #2 189.00' 648 cf 36.0"D x 44.00'L Horizontal Cylinder x 3 Inside#1 933 cf Overall x 69.4% Voids 1,339 cf Total Available Storage Device Routing Invert Outlet Devices #1 Primary 189.00' 8.0" x 11.0' long Culvert Ke= 0.500 Outlet Invert= 189.00' S= 0.0000 T Cc= 0.900 n= 0.011 #2 Device 1 189.00' 2.5"Vert. Orifice/Grate C= 0.600 Primary OutFlow Max=0.1 cfs @ 12.26 hrs HW=189.49' TW=189.23' (Dynamic Tailwater) t-Culvert (Passes 0.1 cfs of 0.4 cfs potential flow) 2=Orifice/Grate (Orifice Controls 0.1 cfs @ 2.42 fps) Revised 2-27-12 No infiltration Type /// 24-hr 1-Yr Rainfall=2.60" Prepared by Andover Consultants, Inc. HydroCAD®8.00 s/n 002099 0 2006 HydroCAD Software Solutions LLC Pond RDET: Roof Infil Inflow Area = 0.063 ac, Inflow Depth = 2.37" for 1-Yr event Inflow = 0.2 cfs @ 12.03 hrs, Volume= 0.012 of Outflow = 0.0 cfs @ 11.90 hrs, Volume= 0.012 af, Atten= 92%, Lag= 0.0 min Discarded = 0.0 cfs @ 11.90 hrs, Volume= 0.012 of Primary = 0.0 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs/2 Peak Elev= 191.54' @ 12.88 hrs Surf.Area= 602 sf Storage= 214 cf Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 120.6 min ( 877.9 - 757.3 ) Volume Invert Avail.Storage Storage Description #1 190.50' 66 cf 10.33'W x 32.001 x 0.50'H Prismatoid 165 cf Overall x 40.0% Voids #2 191.00' 633 cf 4.58'W x 7.421 x 2.33'H Prismatoid x 8 #3 193.33' 2 cf 1.17'D x 2.00'H Vertical Cone/Cylinder-Impervious 702 cf Total Available Storage Device Routing Invert Outlet Devices #1 Discarded 0.00' 1.020 in/hr Exfiltration over Surface area #2 Primary 194.50' 20.0" Horiz. Orifice/Grate Limited to weir flow C= 0.600 Discarded OutFlow Max=0.0 cfs @ 11.90 hrs HW=191.01' (Free Discharge) t-1=Exfiltration (Exfiltration Controls 0.0 cfs) Primary OutFlow Max=0.0 cfs @ 0.00 hrs HW=190.50' TW=0.00' (Dynamic Tailwater) L2=Orifice/Grate ( Controls 0.0 cfs) Revised 2-27-12 No infiltration 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 wqv: stone trench Inflow Area = 0.105 ac, Inflow Depth = 1.44" for 1-Yr event Inflow = 0.1 cfs @ 12.26 hrs, Volume= 0.013 of Outflow = 0.1 cfs @ 12.27 hrs, Volume= 0.012 af, Atten= 0%, Lag= 0.5 min Primary = 0.1 cfs @ 12.27 hrs, Volume= 0.012 of Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs/2 Starting Elev= 186.50' Surf.Area= 0 sf Storage= 0 cf Peak Elev= 189.23' @ 12.27 hrs Surf.Area= 120 sf Storage= 28 cf Plug-Flow detention time= 34.0 min calculated for 0.012 of (96% of inflow) Center-of-Mass det. time= 10.3 min ( 857.1 - 846.9 ) Volume Invert Avail.Storage Storage Description #1 189.00' 30 cf 5.00'W x 24.001 x 0.25'H Prismatoid Device Routing Invert Outlet Devices #1 Primary 189.20' 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 Primary OutFlow Max=0.1 cfs @ 12.27 hrs HW=189.23' TW=0.00' (Dynamic Tailwater) 't-1=Broad-Crested Rectangular Weir (Weir Controls 0.1 cfs @ 0.50 fps) Link sum1: sum Inflow Area = 0.171 ac, Inflow Depth = 0.99" for 1-Yr event Inflow - 0.1 cfs @ 12.23 hrs, Volume= 0.014 of Primary = 0.1 cfs @ 12.23 hrs, Volume= 0.014 af, Atten= 0%, Lag= 0.0 min Primary outflow= Inflow, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Revised 2-2712 No infiltration Type 111 24-hr 1-Yr Rainfall=2.60" Prepared by Andover Consultants, Inc. HydroGAD®8.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Link sum1: sum Inflow Area = 0.171 ac, Inflow Depth = 0.99" for 1-Yr event Inflow = 0.1 cfs @ 12.23 hrs, Volume= 0.014 of Primary = 0.1 cfs @ 12.23 hrs, Volume= 0.014 af, Men= 0%, Lag= 0.0 min Primary outflow= Inflow, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Revised 2-27-12 No infiltration Type 111 24-hr 1-Yr Rainfall=2.60" Prepared by Andover Consultants, Inc. H droCAD®8.00 s/n 002099 0 2006 H droCAD Software Solutions LLC Link sum2: sum Inflow Area = 0.188 ac, Inflow Depth = 0.15" for 1-Yr event Inflow = 0.0 cfs @ 12.26 hrs, Volume= 0.002 of Primary = 0.0 cfs @ 12.26 hrs, Volume= 0.002 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs 2-Year Storm P=3.1 inches Revised 2-27-12 No infiltration Type /// 24-hr 2-Yr Rainfall=3.10" Prepared by Andover Consultants, Inc. HydroCAD®8 00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Subcatchment 1: Developed 1 Runoff = 0.0 cfs @ 12.05 hrs, Volume= 0.003 af, Depth= 0.59" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 2-Yr Rainfall=3.10" Area (sf) CN Description 359 98 Paved 2,527 61 >75% Grass cover, Good, HSG B 2,886 66 Weighted Average 2,527 Pervious Area 359 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.7 20 0.0700 0.20 Sheet Flow, Grass: Short n= 0.150 P2= 3.10" 0.0 14 0.1100 5.34 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.6 110 0.0250 3.21 Shallow Concentrated Flow, Paved Kv= 20.3 fps 2.3 144 Total Revised 2-27-12 No infiltration Type ///24-hr 2-Yr Rainfall=3.10" Prepared by Andover Consultants, Inc. HydroCAD® 8.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Subcatchment 2: Developed 2 Runoff = 0.3 cfs @ 12.05 hrs, Volume= 0.018 af, Depth= 2.08" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 2-Yr Rainfall=3.10" Area (sf) CN Description 3,570 98 Paved 1,013 61 >75% Grass cover, Good, HSG B 4,583 90 Weighted Average 1,013 Pervious Area 3,570 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 3.1 20 0.0150 0.11 Sheet Flow, Grass: Short n= 0.150 P2= 3.10" 0.1 16 0.0150 1.97 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.1 40 0.0550 4.76 Shallow Concentrated Flow, Paved Kv= 20.3 fps 3.3 76 Total Revised 2-27-12 No infiltration Type 11124-hr 2-Yr Rainfall=3.10" Prepared by Andover Consultants, Inc. HydroCAD®8 00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Subcatchment 3: Developed 3 Runoff = 0.2 cfs @ 12.03 hrs, Volume= 0.015 af, Depth= 2.87" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 2-Yr Rainfall=3.10" Area (sf) CN Description 2,745 98 Roof 2,745 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 2.0 Direct Entry, Revised 2-27-12 No infiltration Type /// 24-hr 2-Yr Rainfall=3. 10" Prepared by Andover Consultants, Inc. HydroCAD®8.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Subcatchment 4: Developed 4 Runoff = 0.0 cfs @ 12.07 hrs, Volume= 0.004 af, Depth= 0.40" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 2-Yr Rainfall=3.10" Area (sD CN Description 5,448 61 >75% Grass cover, Good, HSG B 5,448 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.7 10 0.0170 0.10 Sheet Flow, Grass: Short n= 0.150 P2= 3.10" 0.2 20 0.0170 2.10 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.7 100 0.0200 2.28 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 2.6 130 Total Revised 2-27-12 No infiltration Type 11124-hr 2-Yr Rainfall=3.10" Prepared by Andover Consultants, Inc. HydroCAD®8.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Pond p1: to detention Inflow Area = 0.105 ac, Inflow Depth = 2.08" for 2-Yr event Inflow = 0.3 cfs @ 12.05 hrs, Volume= 0.018 of Outflow = 0.3 cfs @ 12.05 hrs, Volume= 0.018 af, Atten= 0%, Lag= 0.0 min Primary = 0.3 cfs @ 12.05 hrs, Volume= 0.018 of Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs/2 Peak Elev= 189.63' @ 12.25 hrs Flood Elev= 191.50' Device Routing Invert Outlet Devices #1 Primary 189.20' 8.0" x 22.0' long Culvert Ke= 0.500 Outlet Invert= 189.00' S= 0.0091 T Cc= 0.900 n= 0.011 Primary OutFlow Max=0.3 cfs @ 12.05 hrs HW=189.60' TW=189.47' (Dynamic Tailwater) L1=Culvert (Outlet Controls 0.3 cfs @ 1.84 fps) Revised 2-2712 No infiltration Type 111 24-hr 2-Yr Rainfall=3.10" Prepared by Andover Consultants, Inc. HydroCAD®8.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Pond PDET: pipe detention Inflow Area = 0.105 ac, Inflow Depth = 2.08" for 2-Yr event Inflow = 0.3 cfs @ 12.05 hrs, Volume= 0.018 of Outflow = 0.1 cfs @ 12.28 hrs, Volume= 0.017 af, Atten= 64%, Lag= 13.7 min Primary = 0.1 cfs @ 12.28 hrs, Volume= 0.017 of Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs/2 Peak Elev= 189.61' @ 12.28 hrs Surf.Area= 761 sf Storage= 226 cf Plug-Flow detention time= 87.4 min calculated for 0.017 of (94% of inflow) Center-of-Mass det. time= 55.9 min ( 861.5 - 805.6 ) Volume Invert Avail.Storage Storage Description #1 189.00' 691 cf 15.00'W x 50.701 x 3.50'H Prismatoid 2,662 cf Overall - 933 cf Embedded = 1,729 cf x 40.0% Voids #2 189.00' 648 cf 36.0"D x 44.00'L Horizontal Cylinder x 3 Inside#1 933 cf Overall x 69.4% Voids 1,339 cf Total Available Storage Device Routing Invert Outlet Devices #1 Primary 189.00' 8.0" x 11.0' long Culvert Ke= 0.500 Outlet Invert= 189.00' S= 0.0000 '/' Cc= 0.900 n= 0.011 #2 Device 1 189.00' 2.5"Vert. Orifice/Grate C= 0.600 Primary OutFlow Max=0.1 cfs @ 12.28 hrs HW=189.61' TW=189.24' (Dynamic Tailwater) 't-- Culvert (Passes 0.1 cfs of 0.6 cfs potential flow) 2=Orifice/Grate (Orifice Controls 0.1 cfs @ 2.94 fps) Revised 2-27-12 No infiltration Type /// 24-hr 2-Yr Rainfall=3.10" Prepared by Andover Consultants, Inc. HydroCAD®8 00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Pond RDET: Roof Infil Inflow Area = 0.063 ac, Inflow Depth = 2.87" for 2-Yr event Inflow = 0.2 cfs @ 12.03 hrs, Volume= 0.015 of Outflow = 0.0 cfs @ 11.79 hrs, Volume= 0.015 af, Atten= 93%, Lag= 0.0 min Discarded = 0.0 cfs @ 11.79 hrs, Volume= 0.015 of Primary = 0.0 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs/2 Peak Elev= 191.78' @ 13.05 hrs Surf.Area= 602 sf Storage= 277 cf Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 161.0 min ( 914.4 - 753.4 ) Volume Invert Avail Storage Storage Description #1 190.50' 66 cf 10.33'W x 32.00'L x 0.50'H Prismatoid 165 cf Overall x 40.0% Voids #2 191.00' 633 cf 4.58'W x 7.421 x 2.33'H Prismatoid x 8 #3 193.33' 2 cf 1.17'D x 2.00'H Vertical Cone/Cylinder-Impervious 702 cf Total Available Storage Device Routing Invert Outlet Devices #1 Discarded 0.00' 1.020 in/hr Exfiltration over Surface area #2 Primary 194.50' 20.0" Horiz. Orifice/Grate Limited to weir flow C= 0.600 Qiscarded OutFlow Max=0.0 cfs @ 11.79 hrs HW=191.00' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.0 cfs) Primary OutFlow Max=0.0 cfs @ 0.00 hrs HW=190.50' TW=0.00' (Dynamic Tailwater) L2=Orifice/Grate ( Controls 0.0 cfs) Revised 2-27-12 No infiltration Type /// 24-hr 2-Yr Rainfall=3.10" Prepared by Andover Consultants, Inc. HydroCAD® 8.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Pond wqv: stone trench Inflow Area = 0.105 ac, Inflow Depth = 1.90" for 2-Yr event Inflow = 0.1 cfs @ 12.28 hrs, Volume= 0.017 of Outflow = 0.1 cfs @ 12.28 hrs, Volume= 0.016 af, Atten= 0%, Lag= 0.5 min Primary = 0.1 cfs @ 12.28 hrs, Volume= 0.016 of Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs /2 Starting Elev= 186.50' Surf.Area= 0 sf Storage= 0 cf Peak Elev= 189.24' @ 12.28 hrs Surf.Area= 120 sf Storage= 29 cf Plug-Flow detention time= 27.4 min calculated for 0.016 of(97% of inflow) Center-of-Mass det. time= 8.9 min ( 848.3 - 839.4 ) Volume Invert Avail.Storage_ Storage Description #1 189.00' 30 cf 5.00'W x 24.001 x 0.25'H Prismatoid Device Routing Invert Outlet Devices #1 Primary 189.20' 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 Primary OutFlow Max=0.1 cfs @ 12.28 hrs HW=189.24' TW=0.00' (Dynamic Tailwater) L1=Broad-Crested Rectangular Weir (Weir Controls 0.1 cfs @ 0.53 fps) Link sum1: sum Inflow Area = 0.171 ac, Inflow Depth = 1.35" for 2-Yr event Inflow = 0.1 cfs @ 12.09 hrs, Volume= 0.019 of Primary = 0.1 cfs @ 12.09 hrs, Volume= 0.019 af, Atten= 0%, Lag= 0.0 min Primary outflow= Inflow, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Revised 2-27-12 No infiltration Type 111 24-hr 2-Yr Rainfall=3.10" Prepared by Andover Consultants, Inc. HydroCAD® 8.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Link sum1: sum Inflow Area = 0.171 ac, Inflow Depth = 1.35" for 2-Yr event Inflow = 0.1 cfs @ 12.09 hrs, Volume= 0.019 of Primary = 0.1 cfs @ 12.09 hrs, Volume= 0.019 af, Atten= 0%, Lag= 0.0 min Primary outflow= Inflow, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Revised 2-27-12 No infiltration Type 111 24-hr 2-Yr Rainfall=3.10" Prepared by Andover Consultants, Inc. HydroCAD® 8.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Link sum2: sum Inflow Area = 0.188 ac, Inflow Depth = 0.27" for 2-Yr event Inflow = 0.0 cfs @ 12.07 hrs, Volume= 0.004 of Primary = 0.0 cfs @ 12.07 hrs, Volume= 0.004 af, Atten= 0%, Lag= 0.0 min Primary outflow= Inflow, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs 10-Year Storm P=4.5 inches Revised 2®2712 No infiltration Type 111 24-hr 10-Yr Rainfall=4.50" Prepared by Andover Consultants, Inc. HydroCAD®8.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Subcatchment 1: Developed 1 Runoff = 0.1 cfs @ 12.04 hrs, Volume= 0.008 af, Depth= 1.40" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 10-Yr Rainfall=4.50" Area (sf) CN Description 359 98 Paved 2,527 61 >75% Grass cover, Good, HSG B 2,886 66 Weighted Average 2,527 Pervious Area 359 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.7 20 0.0700 0.20 Sheet Flow, Grass: Short n= 0.150 P2= 3.10" 0.0 14 0.1100 5.34 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.6 110 0.0250 3.21 Shallow Concentrated Flow, Paved Kv= 20.3 fps 2.3 144 Total Revised 2-27-12 No infiltration Type ///24-hr 10-Yr Rainfall=4.50" Prepared by Andover Consultants, Inc. HydroCADO 8 00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Subcatchment 2: Developed 2 Runoff = 0.4 cfs @ 12.05 hrs, Volume= 0.030 af, Depth= 3.40" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 10-Yr Rainfall=4.50" Areas CN Description 3,570 98 Paved 1,013 61 >75% Grass cover, Good HSG B 4,583 90 Weighted Average 1,013 Pervious Area 3,570 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 3.1 20 0.0150 0.11 Sheet Flow, Grass: Short n= 0.150 P2= 3.10" 0.1 16 0.0150 1.97 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.1 40 0.0550 4.76 Shallow Concentrated Flow, Paved Kv= 20.3 fps 3.3 76 Total Revised 2-27-12 No infiltration Type /// 24-hr 10-Yr Rainfall=4.50" Prepared by Andover Consultants, Inc. H droCAD®8.00 s/n 002099 ©2006 H droCAD Software Solutions LLC Subcatchment 3: Developed 3 Runoff = 0.3 cfs @ 12.03 hrs, Volume= 0.022 af, Depth= 4.26" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 10-Yr Rainfall=4.50" Area (sf) CN Description 2,745 98 Roof 2,745 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 2.0 Direct Entry, Revised 2-27-12 No infiltration Type /// 24-hr 10-Yr Rainfall=4.50" Prepared by Andover Consultants, Inc. HydroCAD®8.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Subcatchment 4: Developed 4 Runoff = 0.2 cfs @ 12.05 hrs, Volume= 0.011 af, Depth= 1.08" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 10-Yr Rainfall=4.50" Area (sf) CN Description 5,448 61 >75% Grass cover, Good HSG B 5,448 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.7 10 0.0170 0.10 Sheet Flow, Grass: Short n= 0.150 P2= 3.10" 0.2 20 0.0170 2.10 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.7 100 0.0200 2.28 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 2.6 130 Total Revised 2-27-12 No infiltration Type ///24-hr 10-Yr Rainfall=4.50" Prepared by Andover Consultants, Inc. HydroCAD®8.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Pond p1: to detention Inflow Area = 0.105 ac, Inflow Depth = 3.40" for 10-Yr event Inflow = 0.4 cfs @ 12.05 hrs, Volume= 0.030 of Outflow = 0.4 cfs @ 12.05 hrs, Volume= 0.030 af, Atten= 0%, Lag= 0.0 min Primary = 0.4 cfs @ 12.05 hrs, Volume= 0.030 of Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs/2 Peak Elev= 189.97' @ 12.31 hrs Flood Elev= 191.50' Device Routing Invert Outlet Devices #1 Primary 189.20' 8.0" x 22.0' long Culvert Ke= 0.500 Outlet Invert= 189.00' S= 0.0091 T Cc= 0.900 n= 0.011 Primary OutFlow Max=0.4 cfs @ 12.05 hrs HW=189.81' TW=189.70' (Dynamic Tailwater) t-1=Culvert (Outlet Controls 0.4 cfs @ 1.76 fps) Revised 2-27-12 No infiltration Type /// 24-hr 10-Yr Rainfall=4.50" Prepared by Andover Consultants, Inc. HydroCAD® 8.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Pond PDET: pipe detention Inflow Area = 0.105 ac, Inflow Depth = 3.40" for 10-Yr event Inflow = 0.4 cfs @ 12.05 hrs, Volume= 0.030 of Outflow = 0.1 cfs @ 12.33 hrs, Volume= 0.029 af, Atten= 69%, Lag= 16.6 min Primary = 0.1 cfs @ 12.33 hrs, Volume= 0.029 of Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs/2 Peak Elev= 189.96' @ 12.33 hrs Surf.Area= 761 sf Storage= 368 cf Plug-Flow detention time= 68.5 min calculated for 0.029 of (96% of inflow) Center-of-Mass det. time= 47.8 min ( 839.7 - 791.8) Volume Invert Avail.Storage Storage Description #1 189.00' 691 cf 15.00'W x 50.701 x 3.50'H Prismatoid 2,662 cf Overall - 933 cf Embedded = 1,729 cf x 40.0% Voids #2 189.00' 648 cf 36.0"D x 44.00'L Horizontal Cylinder x 3 Inside#1 933 cf Overall x 69.4% Voids 1,339 cf Total Available Storage Device Routing Invert Outlet Devices #1 Primary 189.00' 8.0" x 11.0' long Culvert Ke= 0.500 Outlet Invert= 189.00' S= 0.0000 '/' Cc= 0.900 n= 0.011 #2 Device 1 189.00' 2.5"Vert. Orifice/Grate C= 0.600 Primary OutFlow Max=0.1 cfs @ 12.33 hrs HW=189.96' TW=189.25' (Dynamic Tailwater) 't- Culvert (Passes 0.1 cfs of 1.1 cfs potential flow) 2=Orifice/Grate (Orifice Controls 0.1 cfs @ 4.07 fps) Revised 2-27-12 No infiltration Type /// 24-hr 10-Yr Rainfall=4.50" Prepared by Andover Consultants, Inc. HydroCAD®8.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Pond RDET: Roof Infil Inflow Area = 0.063 ac, Inflow Depth = 4.26" for 10-Yr event Inflow = 0.3 cfs @ 12.03 hrs, Volume= 0.022 of Outflow = 0.0 cfs @ 11.32 hrs, Volume= 0.022 af, Atten= 96%, Lag= 0.0 min Discarded = 0.0 cfs @ 11.32 hrs, Volume= 0.022 of Primary = 0.0 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs/2 Peak Elev= 192.50' @ 13.99 hrs Surf.Area= 602 sf Storage=475 cf Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 292.2 min ( 1,038.3- 746.1 ) Volume Invert Avail.Storage Storage Description #1 190.50' 66 cf 10.33'W x 32.00'L x 0.50'H Prismatoid 165 cf Overall x 40.0% Voids #2 191.00' 633 cf 4.58'W x 7.421 x 2.33'H Prismatoid x 8 #3 193.33' 2 cf 1.17'D x 2.00'H Vertical Cone/Cylinder-Impervious 702 cf Total Available Storage Device Routing Invert Outlet Devices #1 Discarded 0.00' 1.020 in/hr Exfiltration over Surface area #2 Primary 194.50' 20.0" Horiz. Orifice/Grate Limited to weir flow C= 0.600 I)iscarded OutFlow Max=0.0 cfs @ 11.32 hrs HW=191.00' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.0 cfs) Primary OutFlow Max=0.0 cfs @ 0.00 hrs HW=190.50' TW=0.00' (Dynamic Tailwater) L2=Orifice/Grate ( Controls 0.0 cfs) Revised 2-27-12 No infiltration Type 111 24-hr 10-Yr Rainfall=4.50" Prepared by Andover Consultants, Inc. H droCADO 8.00 s/n 002099 ©2006 H droCAD Software Solutions LLC Pond wqv: stone trench Inflow Area = 0.105 ac, Inflow Depth = 3.22" for 10-Yr event Inflow = 0.1 cfs @ 12.33 hrs, Volume= 0.028 of Outflow - 0.1 cfs @ 12.33 hrs, Volume= 0.028 af, Atten= 0%, Lag= 0.5 min Primary = 0.1 cfs @ 12.33 hrs, Volume= 0.028 of Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs / 2 Starting Elev= 186.50' Surf.Area= 0 sf Storage= 0 cf Peak Elev= 189.25' @ 12.33 hrs Surf.Area= 120 sf Storage= 30 cf Plug-Flow detention time= 18.5 min calculated for 0.028 of(98% of inflow) Center-of-Mass det. time= 7.0 min ( 833.5- 826.5 ) Volume Invert Avail.Stora a Storage Description #1 189.00' 30 cf 5.00'W x 24.001 x 0.25'H Prismatoid Device Routing Invert Outlet Devices #1 Primary 189'20 Head (feet) 0.20 breadth 0.60 0.80 1.00 1.20 angular 1 401 1.60 e11.80 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 Primary OutFlow Max=0.1 cfs @ 12.33 hrs HW=189.25' TW=0.00' (Dynamic Tailwater) t-1=Broad-Crested Rectangular Weir (Weir Controls 0.1 cfs @ 0.59 fps) Link sum1: sum Inflow Area = 0.171 ac, Inflow Depth = 2.47" for 10-Yr event Inflow = 0.2 cfs @ 12.06 hrs, Volume= 0.035 of Primary = 0.2 cfs @ 12.06 hrs, Volume= 0.035 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Revised 2-27-12 No infiltration Type ///24-hr 10-Yr Rainfall=4.50" Prepared by Andover Consultants, Inc. HydroCAD®8 00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Link sum1: sum Inflow Area = 0.171 ac, Inflow Depth = 2.47" for 10-Yr event Inflow = 0.2 cfs @ 12.06 hrs, Volume= 0.035 of Primary = 0.2 cfs @ 12.06 hrs, Volume= 0.035 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Revised 2-27-12 No infiltration Type 11124-hr 10-Yr Rainfall=4.50" Prepared by Andover Consultants, Inc. H droCAD®8.00 s/n 002099 0 2006 H droCAD Software Solutions LLC Link sum2: sum Inflow Area = 0.188 ac, Inflow Depth = 0.72" for 10-Yr event Inflow = 0.2 cfs @ 12.05 hrs, Volume= 0.011 of Primary = 0.2 cfs @ 12.05 hrs, Volume= 0.011 af, Atten= 0%, Lag= 0.0 min Primary outflow= Inflow, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs 100-Year Storm P=7.0 inches Revised 2-27-12 No infiltration Type /// 24-hr 100-Yr Rainfall=7.00" Prepared by Andover Consultants, Inc. HydroCAD®8 00 s/n 002099 0 2006 HydroCAD Software Solutions LLC Subcatchment 1: Developed 1 Runoff = 0.3 cfs @ 12.04 hrs, Volume= 0.018 af, Depth= 3.20" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 100-Yr Rainfall=7.00" Area (sf) CN Description 359 98 Paved 2,527 61 >75% Grass cover, Good, HSG B 2,886 66 Weighted Average 2,527 Pervious Area 359 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.7 20 0.0700 0.20 Sheet Flow, Grass: Short n= 0.150 P2= 3.10" 0.0 14 0.1100 5.34 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.6 110 0.0250 3.21 Shallow Concentrated Flow, Paved Kv= 20.3 fps 2.3 144 Total Revised 2-27-12 No infiltration Type /// 24-hr 100-Yr Rainfall=7.00" Prepared by Andover Consultants, Inc. HydroCAD®8 00 s/n 002099 0 2006 HydroCAD Software Solutions LLC Subcatchment 2: Developed 2 Runoff = 0.7 cfs @ 12.05 hrs, Volume= 0.051 af, Depth= 5.82" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 100-Yr Rainfall=7.00" Area (sf) CN Description 3,570 98 Paved 1,013 61 >75% Grass cover, Good HSG B 4,583 90 Weighted Average 1,013 Pervious Area 3,570 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 3.1 20 0.0150 0.11 Sheet Flow, Grass: Short n= 0.150 P2= 3.10" 0.1 16 0.0150 1.97 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.1 40 0.0550 4.76 Shallow Concentrated Flow, Paved Kv= 20.3 fps 3.3 76 Total Revised 2-27-12 No infiltration Type /// 24-hr 100-Yr Rainfall=7.00" Prepared by Andover Consultants, Inc. HydroCAD® 8.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Subcatchment 3: Developed 3 Runoff = 0.5 cfs @ 12.03 hrs, Volume= 0.036 af, Depth= 6.76" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 100-Yr Rainfall=7.00" Area (sf) CN Description 2,745 98 Roof 2,745 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 2.0 Direct Entry, Revised 2-27-12 No infiltration Type 111 24-hr 100-Yr Rainfall=7.00" Prepared by Andover Consultants, Inc. HydroCADO 8.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Subcatchment 4: Developed 4 Runoff = 0.4 cfs @ 12.04 hrs, Volume= 0.028 af, Depth= 2.70" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 100-Yr Rainfall=7.00" Area (sf) CN Description 5,448 61 >75% Grass cover, Good, HSG B 5,448 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.7 10 0.0170 0.10 Sheet Flow, Grass: Short n= 0.150 P2= 3.10" 0.2 20 0.0170 2.10 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.7 100 0.0200 2.28 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 2.6 130 Total Revised 2-27-12 No infiltration Type ///24-hr 100-Yr Rainfall=7.00" Prepared by Andover Consultants, Inc. HydroCAD®8 00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Subcatchment 2: Developed 2 Runoff = 0.7 cfs @ 12.05 hrs, Volume= 0.051 af, Depth= 5.82" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 100-Yr Rainfall=7.00" Area (sf) CN Description 3,570 98 Paved 1,013 61 >75% Grass cover, Good HSG B 4,583 90 Weighted Average 1,013 Pervious Area 3,570 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 3.1 20 0.0150 0.11 Sheet Flow, Grass: Short n= 0.150 P2= 3.10° 0.1 16 0.0150 1.97 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.1 40 0.0550 4.76 Shallow Concentrated Flow, Paved Kv= 20.3 fps 3.3 76 Total Revised 2-27-12 No infiltration Type 11124-hr 100-Yr Rainfall=7.00" Prepared by Andover Consultants, Inc. HydroCADO 8.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Subcatchment 1: Developed 1 Runoff = 0.3 cfs @ 12.04 hrs, Volume= 0.018 af, Depth= 3.20" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 100-Yr Rainfall=7.00" Area (sf) CN Description 359 98 Paved 2,527 61 >75% Grass cover, Good, HSG B 2,886 66 Weighted Average 2,527 Pervious Area 359 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.7 20 0.0700 0.20 Sheet Flow, Grass: Short n= 0.150 P2= 3.10" 0.0 14 0.1100 5.34 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.6 110 0.0250 3.21 Shallow Concentrated Flow, Paved Kv= 20.3 fps 2.3 144 Total Revised 2-27-12 No infiltration Type /// 24-hr 100-Yr Rainfall=7.00" Prepared by Andover Consultants, Inc. HydroCAM 8.00 s/n 002099 0 2006 HydroCAD Software Solutions LLC Pond p1: to detention Inflow Area = 0.105 ac, Inflow Depth = 5.82" for 100-Yr event Inflow = 0.7 cfs @ 12.05 hrs, Volume= 0.051 of Outflow = 0.7 cfs @ 12.05 hrs, Volume= 0.051 af, Atten= 0%, Lag= 0.0 min Primary = 0.7 cfs @ 12.05 hrs, Volume= 0.051 of Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs/2 Peak Elev= 190.65' @ 12.36 hrs Flood Elev= 191.50' Device Routing Invert Outlet Devices #1 Primary 189.20' 8.0" x 22.0' long Culvert Ke= 0.500 Outlet Invert= 189.00' S= 0.0091 T Cc= 0.900 n= 0.011 Primary OutFlow Max=0.7 cfs @ 12.05 hrs HW=190.32' TW=190.13' (Dynamic Tailwater) L1=Culvert (Inlet Controls 0.7 cfs @ 2.13 fps) Revised 2-27-12 No infiltration Type 11124-hr 100-Yr Rainfall=7.00" Prepared by Andover Consultants, Inc. HydroCAD®8.00 s/n 002099 0 2006 HydroCAD Software Solutions LLC Pond PDET: pipe detention Inflow Area = 0.105 ac, Inflow Depth = 5.82" for 100-Yr event Inflow = 0.7 cfs @ 12.05 hrs, Volume= 0.051 of Outflow = 0.2 cfs @ 12.37 hrs, Volume= 0.050 af, Atten= 74%, Lag= 19.4 min Primary = 0.2 cfs @ 12.37 hrs, Volume= 0.050 of Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs/2 Peak Elev= 190.64' @ 12.38 hrs Surf.Area= 761 sf Storage= 653 cf Plug-Flow detention time= 58.8 min calculated for 0.050 of(98% of inflow) Center-of-Mass det. time= 45.8 min ( 823.2 - 777.4 ) Volume Invert Avail.Storage Storage Description #1 189.00' 691 cf 15.00'W x 50.701 x 3.50'H Prismatoid 2,662 cf Overall - 933 cf Embedded = 1,729 cf x 40.0% Voids #2 189.00' 648 cf 36.0"D x 44.00'L Horizontal Cylinder x 3 Inside#1 933 cf Overall x 69.4% Voids 1,339 cf Total Available Storage Device Routing Invert Outlet Devices #1 Primary 189.00' 8.0" x 11.0' long Culvert Ke= 0.500 Outlet Invert= 189.00' S= 0.00007' Cc= 0.900 n= 0.011 #2 Device 1 189.00' 2.5"Vert. Orifice/Grate C= 0.600 Primary OutFlow Max=0.2 cfs @ 12.37 hrs HW=190.64' TW=189.26' (Dynamic Tailwater) t- Culvert (Passes 0.2 cfs of 1.9 cfs potential flow) 2=Orifice/Grate (Orifice Controls 0.2 cfs @ 5.66 fps) Revised 2-27-12 No infiltration Type //124-hr 100-Yr Rainfall=7.00" Prepared by Andover Consultants, Inc. HydroCADO 8.00 s/n 002099 ©2006 H droCAD Software Solutions LLC Pond RDET: Roof Infil Inflow Area = 0.063 ac, Inflow Depth = 6.76" for 100-Yr event Inflow = 0.5 cfs @ 12.03 hrs, Volume= 0.036 of Outflow = 0.2 cfs @ 12.34 hrs, Volume= 0.032 af, Atten= 62%, Lag= 18.7 min Discarded = 0.0 cfs @ 9.99 hrs, Volume= 0.028 of Primary = 0.2 cfs @ 12.34 hrs, Volume= 0.004 of Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs /2 Peak Elev= 194.55' @ 12.34 hrs Surf.Area= 602 sf Storage= 701 cf Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 300.2 min ( 1,039.5 - 739.2 ) Volume Invert Avail.Storage Storage Description #1 190.50' 66 cf 10.33'W x 32.001 x 0.50'H Prismatoid 165 cf Overall x 40.0% Voids #2 191.00' 633 cf 4.58'W x 7.421 x 2.33'H Prismatoid x 8 #3 193.33' 2 cf 1.17'D x 2.00'H Vertical Cone/Cylinder-Impervious 702 cf Total Available Storage Device Routing Invert Outlet Devices #1 Discarded 0.00' 1.020 in/hr Exfiltration over Surface area #2 Primary 194.50' 20.0" Horiz. Orifice/Grate Limited to weir flow C= 0.600 Qscarded OutFlow Max=0.0 cfs @ 9.99 hrs HW=191.00' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.0 cfs) Primary OutFlow Max=0.2 cfs @ 12.34 hrs HW=194.55' TW=0.00' (Dynamic Tailwater) L2=Orifice/Grate (Weir Controls 0.2 cfs @ 0.69 fps) Revised 2-27-12 No infiltration Type 111 24-hr 100-Yr Rainfall=7.00" Prepared by Andover Consultants, Inc. HydroCAD® 8.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Pond wqv: stone trench Inflow Area = 0.105 ac, Inflow Depth = 5.64" for 100-Yr event Inflow = 0.2 cfs @ 12.37 hrs, Volume= 0.049 of Outflow = 0.2 cfs @ 12.38 hrs, Volume= 0.049 af, Atten= 0%, Lag= 0.4 min Primary = 0.2 cfs @ 12.38 hrs, Volume= 0.049 of Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs/2 Starting Elev= 186.50' Surf.Area= 0 sf Storage= 0 cf Peak Elev= 189.26' @ 12.38 hrs Surf.Area= 120 sf Storage= 30 cf Plug-Flow detention time= 12.2 min calculated for 0.049 of(99% of inflow) Center-of-Mass det. time= 5.4 min ( 821.0- 815.7 ) Volume Invert Avail.Storage Storage Description #1 189.00' 30 cf 5.00'W x 24.001 x 0.25'H Prismatoid Device Routing Invert Outlet Devices #1 Primary 189.20' 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 Primary OutFlow Max=0.2 cfs @ 12.38 hrs HW=189.26' TW=0.00' (Dynamic Tailwater) L1=13road-Crested Rectangular Weir (Weir Controls 0.2 cfs @ 0.66 fps) Link sum1: sum Inflow Area = 0.171 ac, Inflow Depth = 4.66" for 100-Yr event Inflow = 0.4 cfs @ 12.05 hrs, Volume= 0.067 of Primary = 0.4 cfs @ 12.05 hrs, Volume= 0.067 af, Atten= 0%, Lag= 0.0 min Primary outflow= Inflow, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Revised 2-27®12 No infiltration Type 111 24-hr 100-Yr Rainfall=7.00" Prepared by Andover Consultants, Inc. HydroCAD®8.00 s/n 002099 ©2006 HydroCAD Software Solutions LLC Link sum1: sum Inflow Area = 0.171 ac, Inflow Depth = 4.66" for 100-Yr event Inflow = 0.4 cfs @ 12.05 hrs, Volume= 0.067 of Primary = 0.4 cfs @ 12.05 hrs, Volume= 0.067 af, Atten= 0%, Lag= 0.0 min Primary outflow= Inflow, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs