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31B-192 91 King Street-Drainage Report FULL 3-18-11
Stormwater Drainage Report ______________________________________________________________________________________ for St. Elizabeth Ann Seton Parish Northampton, MA March 18, 2011 Prepared by: 4 Allen Place, Northampton, Massachusetts 01060 Prepared for: Roman Catholic Bishop of Springfield 65 Elliot Street Springfield, MA 01105 St. Elizabeth Ann Seton Parish March 18, 2011 Northampton, MA Page 1 Table of Contents Introduction 2 Site Terrain and Soils 2 Existing Conditions 2 Proposed Conditions 3 Calculations and Design 4 Stormwater Standard Compliance 4 Summary 6 Figures Figure 1 Pre- Development Drainage Area Map Figure 2 Post Development Drainage Area Map Figure 3 USDA Soils Map Appendices Appendix A Pre- and Post Development Hydrologic Calculations Appendix B Soil Test Pit Information Appendix C TSS Removal Tables & SWTC Sizing Data Appendix D Proposed Stormwater Management System Operation &Maintenance P Plan Appendix E Recharge Calculations St. Elizabeth Ann Seton Parish March 18, 2011 Northampton, MA Page 2 I. Introduction The following report presents an analysis of the stormwater management system for the proposed redevelopment of the St. Elizabeth Ann Seton Parish on King Street in Northampton, MA. The project will include the removal of 3 of the existing buildings and the construction of a new larger building, as well as additional parking, walkway, landscaping, and utility improvements. The redevelopment will generate an additional 32,000sf of impervious area. The purpose of this analysis is to determine 2, 10, and 100-year peak flow rates and quantities for the site in both the pre- and post-development conditions and to determine the potential impact of any increases in stormwater runoff from the site that may occur as a result of the site development. II. Site Terrain and Soils The project site generally slopes south toward the existing stream located at the southerly property line. The subsurface conditions at the site were evaluated based on the available soil survey information and multiple test pits were conducted on site (see Appendix B for Test Pit Logs) and is as follows: The USDA Soil Survey of Hampden County, Massachusetts, report (see Figure 3) classifies the site soils as: • 741A – Amostown-Windsor Silty Urban Land Complex - HSG B III. Existing Conditions The existing project site is located on King Street in Northampton, MA. The existing site contains 5 buildings, grass, and paved areas. The existing site contains 2 subcatchments which are described below: E-1 E-1 is approximately 1.72 acres of land and contains of the majority of roof area and paving areas, as well as grass areas. The runoff sheet flows toward the low point located at the east end of the site which is used as control point 1 (Shown as E-CP1). E-2 E-2 is approximately 1.22 acres of land consisting of the majority of roof area and paved areas, as well as grass areas. The runoff sheet flows toward King Street where it enters the existing drainage infrastructure. The runoff enters catch basin which outlet into the 54” drain line within King Street which is used as control point 2 (Shown as E-CP2). St. Elizabeth Ann Seton Parish March 18, 2011 Northampton, MA Page 3 IV. Proposed Conditions The stormwater management system in proposed conditions has been designed to attenuate, treat and recharge the runoff on site. The stormwater management system has been designed to capture a large portion of the impervious area and discharge it through a series of catch basins or dry wells, which discharge into a large subsurface detention basin, which outlets to a stormwater treatment chamber which ensures that the developed site will not negatively impact the stormwater on site. The proposed site contains 6 subcatchments which are described below: P-1 P-1 contains approximately 1.15 acres of land consisting of the existing roof area (shown as Area P-1a), new paved areas and grass areas. The runoff from the parking area and lawn areas is directed into catch basins which discharge into a subsurface detention basin. The runoff from the roof area (P-1a) is directed to a dry well system prior to overflowing to the detention basin. The detention basin outlets to a stormwater treatment chamber designed to proved the required TSS Removal prior to discharging to the existing drain manhole within King Street which is used as a control point for the site (control point P-CP2). P-2 P-2 contains approximately 0.72 acres of land consisting of the proposed roof area (shown as P-2a), new paved areas and grass areas. The runoff from the parking area and lawn areas is directed into catch basins which discharge into a subsurface detention basin. The runoff from the roof area (P-2a) is directed to a dry well system prior to overflowing to the detention basin. The detention basin outlets to a stormwater treatment chamber designed to proved the required TSS Removal prior to discharging to the existing drain manhole within King Street which is used as a control point for the site (control point P-CP2). P-3 P-3 is approximately 0.31 acres of land and consists largely of grass area and contains a small area of pavement. The runoff sheet flows or is directed through a yard drain toward the low point located at the east end of the site which is used as control point 1 (Shown as P-CP1). P-4 P-4 is approximately 0.76 acres of land consisting of the paved areas, as well as grass areas. The runoff sheet flows toward King Street where it enters the existing drainage infrastructure. The runoff enters existing catch basins which outlet into the 54” drain line within King Street which is used as control point 2 (Shown as P-CP2). St. Elizabeth Ann Seton Parish March 18, 2011 Northampton, MA Page 4 V. Calculations, Design and Standards Water Quantity Drainage calculations were performed on Hydrocad Stormwater Modeling System version 8.0 using Soil Conservation Service (SCS) TR-20 methodology. The SCS method is based on rainfall observations, which were used to develop the Intensity-Duration-Frequency relationship, or IDF curve. The mass curve is a dimensionless distribution of rainfall over time, which indicates the fraction of the rainfall event that occurs at a given time within a 24-hour precipitation event. This synthetic distribution develops peak rates for storms of varying duration and intensities. The SCS distribution provides a cumulative rainfall at any point in time and allows volume dependent routing runoff calculations to occur. Watershed sub-catchment areas, runoff coefficients and watercourse slopes are based on The Berkshire Design Group site plans. The control point used for design was the limit of work for the proposed project and is represented as the dotted perimeter on the attached drainage maps. Calculations were performed for the 2, 10, and 100-year frequency storms under existing and proposed conditions. In all 3 storm events, the peak flow rate and volume of post conditions is less than existing. The results of the calculations are shown in the summary table below: Table 1. Peak Flow and Peak Volume Summary Table Condition & Point of Analysis 2-Year Storm 3.00” 10-Year Storm 4.50” 100-Year Storm 6.50” Peak Flow Rate(cfs) Volume (acre-ft) Peak Flow Rate(cfs) Volume (acre- ft) Peak Flow Rate(cfs) Volume (acre-ft) Existing (E-CP1)* 2.23 0.179 4.51 0.353 7.72 0.607 Proposed (P-CP1)* 0.08 0.010 0.35 0.029 0.81 0.062 Existing (E-CP2)* 1.90 0.176 3.35 0.313 5.30 0.506 Proposed (P-CP2)* 1.84 0.299 3.13 0.541 5.02 0.895 *Names in parentheses refer to HydroCad model and calculations. VI. MADEP Stormwater Standards Compliance The following section details how the project will meet DEP Stormwater Management Policy’s ten stormwater management standards. St. Elizabeth Ann Seton Parish March 18, 2011 Northampton, MA Page 5 Standard 1 - Untreated Stormwater The proposed stormwater system is designed to treat the new direct connection to the King Street drainage infrastructure. The runoff to this connection has been designed to have a minimum of 80% TSS removed prior to discharging ( See Appendix C for TSS removal summary. Standard 2 - Post-Development Peak Discharge Rates The stormwater system is designed so that post-development peak discharge rates are less than pre-development peak discharge rates leaving the site. In order to control the runoff rates in proposed conditions a subsurface detention basin with an outlet control structure is proposed which allows the system to “throttle” the appropriate flow for each storm. Refer to Table 1 Peak Flow and Volume Summary and Appendix A for HydroCAD calculations. Standard 3 - Recharge to Groundwater The proposed site has designed to recharge groundwater as required by MADEP and the Northampton Stormwater Regulations. 2 Dry Wells have been designed to capture and infiltrate the runoff from the existing and proposed roof areas. The bottom of the dry well has been designed to maintain the minimum of 2’ separation from the seasonal high groundwater table as shown on the test pit logs. The dry wells have been sized to hold recharge volume for the full site redevelopment and have been designed to drawdown within 72 hours in order to fully comply with Standard 3 requirements (see Appendix E for recharge calculations). Standard 4 – Water Quality The proposed stormwater management system has been designed to remove the average annual Total Suspended Solids (TSS) load equal to or in excess of 80% for the proposed site conditions (see Appendix C for TSS Removal calculations). The stormwater from the developed areas of the site will be directed to deep sump hooded catch basins (25% TSS removal) to a stormwater treatment chamber (76% TSS removal) which outlets into an infiltration basin designed to hold the required recharge volume for the increase in impervious area. Dry wells have been included for roof runoff treatment as well, and have been sized to hold the recharge volume required for the entire size which will provide 80% TSS Removal. (See recharge calculations in Appendix E for dry well sizing). Standard 5 - Higher Potential Pollutant Loads The proposed project is not expected to yield high potential pollutant loads. Standard 6 - Protection of Critical Areas The project site does not discharge to critical areas as defined in MA DEP Stormwater Policy Handbook. St. Elizabeth Ann Seton Parish March 18, 2011 Northampton, MA Page 6 Standard 7 - Redevelopment Projects The redevelopment of previously developed site standard is not applicable for this project. Standard 8 - Erosion/Sediment Control An erosion and sediment control plan will be submitted prior to commencing construction. Standard 9 - Operation/Maintenance Plan An Operation and Maintenance Plan for the proposed project is included in Appendix D. It includes general controls for construction and long term maintenance of the stormwater management system. Standard 10 – Prohibition of Illicit Discharges No Illicit Discharge Compliance Statement is included with this report however one will be submitted prior to the discharge of any stormwater to post- construction BMPs. VII. Summary The impervious area from existing to proposed conditions will increase from the new building construction. The proposed stormwater management system is designed to maintain or reduce the peak flow rates in proposed conditions for the 2-, 10-, and 100-year storm frequencies. Special care has been taken to treat and reduce runoff with a series of best management practices to ensure water quality and annual TSS removal rates equal to or in excess of 80%. These methods include deep sump hooded catch basins, stormwater treatment chamber, dry wells, and a subsurface detention basin. St. Elizabeth Ann Seton Parish Stormwater Drainage Report Northampton, Massachusetts The Berkshire Design Group, Inc. Figures St. Elizabeth Ann Seton Parish Stormwater Drainage Report Northampton, Massachusetts The Berkshire Design Group, Inc. Appendix A Pre- and Post Development Hydrologic Calculations E-1 Existing Site Area to Low Spot E-2 Existing Site Area to King St. P-1 Proposed Site Area to Infiltration Basin P-1a Roof AreaP-2 Proposed Area to King St. P-2a Roof Area P-3 Proposed Area to Low Spot P-4 Proposed Area to King St. E-CP1 Low Spot East of Site E-CP2 King St. P-CP1 Low Spot East of Site P-CP2 King St. P1 Dry Well 1 P2 Dry Well 2 P3 Subsurface Pond 1 Drainage Diagram for St. Elizabeth - Active-b Prepared by The Berkshire Design Group 3/21/2011 HydroCAD® 8.00 s/n 000752 © 2006 HydroCAD Software Solutions LLC Subcat Reach Pond Link St. Elizabeth Ann Seton Parish 3-18-11 St. Elizabeth - Active-b Page 2Prepared by The Berkshire Design Group 3/21/2011HydroCAD® 8.00 s/n 000752 © 2006 HydroCAD Software Solutions LLC Area Listing (selected nodes) Area (acres)CN Description (subcats) 2.202 61 >75% Grass cover, Good, HSG B (E-1,E-2,P-1,P-1,P-2,P-3,P-4) 3.676 98 Paved parking & roofs (E-1,E-2,P-1,P-1,P-1a,P-2,P-2a,P-3,P-4) 5.878 St. Elizabeth Ann Seton Parish 3-18-11 Type III 24-hr 2 YRS Rainfall=3.00"St. Elizabeth - Active-b Page 3Prepared by The Berkshire Design Group 3/21/2011HydroCAD® 8.00 s/n 000752 © 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+Trans method - Pond routing by Stor-Ind method Runoff Area=75,032 sf Runoff Depth>1.25"Subcatchment E-1: Existing Site Area to Low Spot Flow Length=146' Tc=8.4 min CN=80 Runoff=2.23 cfs 0.179 af Runoff Area=52,994 sf Runoff Depth>1.73"Subcatchment E-2: Existing Site Area to King St. Flow Length=265' Tc=14.3 min CN=87 Runoff=1.90 cfs 0.176 af Runoff Area=46,266 sf Runoff Depth>2.35"Subcatchment P-1: Proposed Site Area to Infiltration Basin Tc=6.0 min CN=94 Runoff=2.75 cfs 0.208 af Runoff Area=4,000 sf Runoff Depth>2.77"Subcatchment P-1a: Roof Area Tc=6.0 min CN=98 Runoff=0.26 cfs 0.021 af Runoff Area=12,007 sf Runoff Depth>1.90"Subcatchment P-2: Proposed Area to King St. Flow Length=130' Tc=9.8 min CN=89 Runoff=0.53 cfs 0.044 af Runoff Area=19,479 sf Runoff Depth>2.77"Subcatchment P-2a: Roof Area Tc=6.0 min CN=98 Runoff=1.27 cfs 0.103 af Runoff Area=13,278 sf Runoff Depth>0.40"Subcatchment P-3: Proposed Area to Low Spot Flow Length=100' Slope=0.0550 '/' Tc=6.8 min CN=62 Runoff=0.08 cfs 0.010 af Runoff Area=32,996 sf Runoff Depth>0.86"Subcatchment P-4: Proposed Area to King St. Flow Length=130' Tc=9.8 min CN=73 Runoff=0.61 cfs 0.054 af Inflow=2.23 cfs 0.179 afReach E-CP1: Low Spot East of Site Outflow=2.23 cfs 0.179 af Inflow=1.90 cfs 0.176 afReach E-CP2: King St. Outflow=1.90 cfs 0.176 af Inflow=0.08 cfs 0.010 afReach P-CP1: Low Spot East of Site Outflow=0.08 cfs 0.010 af Inflow=1.84 cfs 0.299 afReach P-CP2: King St. Outflow=1.84 cfs 0.299 af Peak Elev=137.86' Storage=722 cf Inflow=1.27 cfs 0.103 afPond P1: Dry Well 1 Discarded=0.40 cfs 0.103 af Primary=0.00 cfs 0.000 af Outflow=0.40 cfs 0.103 af Peak Elev=135.42' Storage=96 cf Inflow=0.26 cfs 0.021 afPond P2: Dry Well 2 Discarded=0.11 cfs 0.021 af Primary=0.00 cfs 0.000 af Outflow=0.11 cfs 0.021 af Peak Elev=134.13' Storage=2,839 cf Inflow=3.24 cfs 0.251 afPond P3: Subsurface Pond 1 Primary=1.33 cfs 0.245 af Secondary=0.00 cfs 0.000 af Outflow=1.33 cfs 0.245 af St. Elizabeth Ann Seton Parish 3-18-11 Type III 24-hr 2 YRS Rainfall=3.00"St. Elizabeth - Active-b Page 4Prepared by The Berkshire Design Group 3/21/2011HydroCAD® 8.00 s/n 000752 © 2006 HydroCAD Software Solutions LLC Total Runoff Area = 5.878 ac Runoff Volume = 0.795 af Average Runoff Depth = 1.62" 37.47% Pervious Area = 2.202 ac 62.53% Impervious Area = 3.676 ac St. Elizabeth Ann Seton Parish 3-18-11 Type III 24-hr 2 YRS Rainfall=3.00"St. Elizabeth - Active-b Page 5Prepared by The Berkshire Design Group 3/21/2011HydroCAD® 8.00 s/n 000752 © 2006 HydroCAD Software Solutions LLC Subcatchment E-1: Existing Site Area to Low Spot Runoff = 2.23 cfs @ 12.13 hrs, Volume= 0.179 af, Depth> 1.25" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 2 YRS Rainfall=3.00" Area (sf) CN Description 37,198 61 >75% Grass cover, Good, HSG B 37,834 98 Paved parking & roofs 75,032 80 Weighted Average 37,198 Pervious Area 37,834 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 8.1 100 0.0350 0.21 Sheet Flow, Grass: Short n= 0.150 P2= 3.00" 0.3 46 0.0320 2.68 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 8.4 146 Total Subcatchment E-2: Existing Site Area to King St. Runoff = 1.90 cfs @ 12.20 hrs, Volume= 0.176 af, Depth> 1.73" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 2 YRS Rainfall=3.00" Area (sf) CN Description 15,192 61 >75% Grass cover, Good, HSG B 37,802 98 Paved parking & roofs 52,994 87 Weighted Average 15,192 Pervious Area 37,802 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 12.9 100 0.0110 0.13 Sheet Flow, Sheet Flow over Grass Grass: Short n= 0.150 P2= 3.00" 1.4 165 0.0180 2.01 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 14.3 265 Total St. Elizabeth Ann Seton Parish 3-18-11 Type III 24-hr 2 YRS Rainfall=3.00"St. Elizabeth - Active-b Page 6Prepared by The Berkshire Design Group 3/21/2011HydroCAD® 8.00 s/n 000752 © 2006 HydroCAD Software Solutions LLC Subcatchment P-1: Proposed Site Area to Infiltration Basin Runoff = 2.75 cfs @ 12.09 hrs, Volume= 0.208 af, Depth> 2.35" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 2 YRS Rainfall=3.00" Area (sf) CN Description 32,131 98 Paved parking & roofs 4,173 61 >75% Grass cover, Good, HSG B 9,232 98 Paved parking & roofs 730 61 >75% Grass cover, Good, HSG B 46,266 94 Weighted Average 4,903 Pervious Area 41,363 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum ToC Subcatchment P-1a: Roof Area Runoff = 0.26 cfs @ 12.09 hrs, Volume= 0.021 af, Depth> 2.77" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 2 YRS Rainfall=3.00" Area (sf) CN Description 4,000 98 Paved parking & roofs 4,000 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum ToC Subcatchment P-2: Proposed Area to King St. Runoff = 0.53 cfs @ 12.14 hrs, Volume= 0.044 af, Depth> 1.90" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 2 YRS Rainfall=3.00" Area (sf) CN Description 8,963 98 Paved parking & roofs 3,044 61 >75% Grass cover, Good, HSG B 12,007 89 Weighted Average 3,044 Pervious Area 8,963 Impervious Area St. Elizabeth Ann Seton Parish 3-18-11 Type III 24-hr 2 YRS Rainfall=3.00"St. Elizabeth - Active-b Page 7Prepared by The Berkshire Design Group 3/21/2011HydroCAD® 8.00 s/n 000752 © 2006 HydroCAD Software Solutions LLC Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 9.7 100 0.0220 0.17 Sheet Flow, Grass: Short n= 0.150 P2= 3.00" 0.1 30 0.0700 3.97 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 9.8 130 Total Subcatchment P-2a: Roof Area Runoff = 1.27 cfs @ 12.09 hrs, Volume= 0.103 af, Depth> 2.77" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 2 YRS Rainfall=3.00" Area (sf) CN Description 19,479 98 Paved parking & roofs 19,479 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment P-3: Proposed Area to Low Spot Runoff = 0.08 cfs @ 12.15 hrs, Volume= 0.010 af, Depth> 0.40" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 2 YRS Rainfall=3.00" Area (sf) CN Description 13,068 61 >75% Grass cover, Good, HSG B 210 98 Paved parking & roofs 13,278 62 Weighted Average 13,068 Pervious Area 210 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.8 100 0.0550 0.25 Sheet Flow, Sheet Flow over Grass Grass: Short n= 0.150 P2= 3.00" Subcatchment P-4: Proposed Area to King St. Runoff = 0.61 cfs @ 12.16 hrs, Volume= 0.054 af, Depth> 0.86" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 2 YRS Rainfall=3.00" St. Elizabeth Ann Seton Parish 3-18-11 Type III 24-hr 2 YRS Rainfall=3.00"St. Elizabeth - Active-b Page 8Prepared by The Berkshire Design Group 3/21/2011HydroCAD® 8.00 s/n 000752 © 2006 HydroCAD Software Solutions LLC Area (sf) CN Description 10,471 98 Paved parking & roofs 22,525 61 >75% Grass cover, Good, HSG B 32,996 73 Weighted Average 22,525 Pervious Area 10,471 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 9.7 100 0.0220 0.17 Sheet Flow, Grass: Short n= 0.150 P2= 3.00" 0.1 30 0.0700 3.97 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 9.8 130 Total Reach E-CP1: Low Spot East of Site [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 1.722 ac, Inflow Depth > 1.25" for 2 YRS event Inflow = 2.23 cfs @ 12.13 hrs, Volume= 0.179 af Outflow = 2.23 cfs @ 12.13 hrs, Volume= 0.179 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Reach E-CP2: King St. [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 1.217 ac, Inflow Depth > 1.73" for 2 YRS event Inflow = 1.90 cfs @ 12.20 hrs, Volume= 0.176 af Outflow = 1.90 cfs @ 12.20 hrs, Volume= 0.176 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Reach P-CP1: Low Spot East of Site [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.305 ac, Inflow Depth > 0.40" for 2 YRS event Inflow = 0.08 cfs @ 12.15 hrs, Volume= 0.010 af Outflow = 0.08 cfs @ 12.15 hrs, Volume= 0.010 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs St. Elizabeth Ann Seton Parish 3-18-11 Type III 24-hr 2 YRS Rainfall=3.00"St. Elizabeth - Active-b Page 9Prepared by The Berkshire Design Group 3/21/2011HydroCAD® 8.00 s/n 000752 © 2006 HydroCAD Software Solutions LLC Reach P-CP2: King St. [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 2.634 ac, Inflow Depth > 1.36" for 2 YRS event Inflow = 1.84 cfs @ 12.19 hrs, Volume= 0.299 af Outflow = 1.84 cfs @ 12.19 hrs, Volume= 0.299 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Pond P1: Dry Well 1 Inflow Area = 0.447 ac, Inflow Depth > 2.77" for 2 YRS event Inflow = 1.27 cfs @ 12.09 hrs, Volume= 0.103 af Outflow = 0.40 cfs @ 11.90 hrs, Volume= 0.103 af, Atten= 68%, Lag= 0.0 min Discarded = 0.40 cfs @ 11.90 hrs, Volume= 0.103 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 137.86' @ 12.39 hrs Surf.Area= 2,100 sf Storage= 722 cf Plug-Flow detention time= 9.3 min calculated for 0.103 af (100% of inflow) Center-of-Mass det. time= 9.0 min ( 766.4 - 757.3 ) Volume Invert Avail.Storage Storage Description #1 137.00' 1,165 cf Custom Stage Data (Prismatic) Listed below (Recalc) 2,912 cf Overall x 40.0% Voids Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 137.00 2,100 0 0 138.35 2,100 2,835 2,835 138.36 10 11 2,846 145.00 10 66 2,912 Device Routing Invert Outlet Devices #1 Discarded 0.00'8.270 in/hr Exfiltration over Surface area #2 Primary 138.35'12.0" Horiz. Orifice/Grate Limited to weir flow C= 0.600 Discarded OutFlow Max=0.40 cfs @ 11.90 hrs HW=137.10' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.40 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=137.00' (Free Discharge) 2=Orifice/Grate ( Controls 0.00 cfs) St. Elizabeth Ann Seton Parish 3-18-11 Type III 24-hr 2 YRS Rainfall=3.00"St. Elizabeth - Active-b Page 10Prepared by The Berkshire Design Group 3/21/2011HydroCAD® 8.00 s/n 000752 © 2006 HydroCAD Software Solutions LLC Pond P2: Dry Well 2 Inflow Area = 0.092 ac, Inflow Depth > 2.77" for 2 YRS event Inflow = 0.26 cfs @ 12.09 hrs, Volume= 0.021 af Outflow = 0.11 cfs @ 11.95 hrs, Volume= 0.021 af, Atten= 58%, Lag= 0.0 min Discarded = 0.11 cfs @ 11.95 hrs, Volume= 0.021 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 135.42' @ 12.29 hrs Surf.Area= 575 sf Storage= 96 cf Plug-Flow detention time= 4.0 min calculated for 0.021 af (100% of inflow) Center-of-Mass det. time= 3.9 min ( 761.2 - 757.3 ) Volume Invert Avail.Storage Storage Description #1 135.00' 690 cf Custom Stage Data (Prismatic) Listed below (Recalc) 1,725 cf Overall x 40.0% Voids Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 135.00 575 0 0 137.35 575 1,351 1,351 138.00 575 374 1,725 Device Routing Invert Outlet Devices #1 Primary 137.35'12.0" Vert. Orifice/Grate C= 0.600 #2 Discarded 0.00'8.270 in/hr Exfiltration over Surface area Discarded OutFlow Max=0.11 cfs @ 11.95 hrs HW=135.04' (Free Discharge) 2=Exfiltration (Exfiltration Controls 0.11 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=135.00' (Free Discharge) 1=Orifice/Grate ( Controls 0.00 cfs) Pond P3: Subsurface Pond 1 Inflow Area = 1.877 ac, Inflow Depth > 1.61" for 2 YRS event Inflow = 3.24 cfs @ 12.09 hrs, Volume= 0.251 af Outflow = 1.33 cfs @ 12.34 hrs, Volume= 0.245 af, Atten= 59%, Lag= 14.5 min Primary = 1.33 cfs @ 12.34 hrs, Volume= 0.245 af Secondary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 134.13' @ 12.34 hrs Surf.Area= 6,000 sf Storage= 2,839 cf Plug-Flow detention time= 50.1 min calculated for 0.245 af (97% of inflow) Center-of-Mass det. time= 36.0 min ( 829.5 - 793.5 ) St. Elizabeth Ann Seton Parish 3-18-11 Type III 24-hr 2 YRS Rainfall=3.00"St. Elizabeth - Active-b Page 11Prepared by The Berkshire Design Group 3/21/2011HydroCAD® 8.00 s/n 000752 © 2006 HydroCAD Software Solutions LLC Volume Invert Avail.Storage Storage Description #1 133.00' 8,946 cf Custom Stage Data (Pyramidal) Listed below (Recalc) 21,300 cf Overall x 42.0% Voids #2 136.50' 258 cf Internal CB and Surface Storage (Prismatic) Listed below (Recalc) 9,204 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 133.00 6,000 0 0 6,000 136.55 6,000 21,300 21,300 7,100 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 136.50 48 0 0 136.55 48 2 2 136.80 2,000 256 258 Device Routing Invert Outlet Devices #1 Primary 133.00'12.0" x 30.0' long Culvert CMP, projecting, no headwall, Ke= 0.900 Outlet Invert= 132.70' S= 0.0100 '/' Cc= 0.900 n= 0.010 PVC, smooth interior #2 Device 1 133.00'7.5" Vert. Orifice/Grate C= 0.600 #3 Device 1 136.55'12.0" Horiz. Orifice/Grate Limited to weir flow C= 0.600 #4 Secondary 136.80'5.0' long x 1.0' breadth Overflow At Dumpster Pad 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 #5 Primary 136.70'1.0' long x 1.0' breadth South East Drive Overflow 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=1.33 cfs @ 12.34 hrs HW=134.13' (Free Discharge) 1=Culvert (Passes 1.33 cfs of 2.36 cfs potential flow) 2=Orifice/Grate (Orifice Controls 1.33 cfs @ 4.34 fps) 3=Orifice/Grate ( Controls 0.00 cfs) 5=South East Drive Overflow ( Controls 0.00 cfs) Secondary OutFlow Max=0.00 cfs @ 0.00 hrs HW=133.00' (Free Discharge) 4=Overflow At Dumpster Pad ( Controls 0.00 cfs) St. Elizabeth Ann Seton Parish 3-18-11 Type III 24-hr 10 YRS Rainfall=4.50"St. Elizabeth - Active-b Page 12Prepared by The Berkshire Design Group 3/21/2011HydroCAD® 8.00 s/n 000752 © 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+Trans method - Pond routing by Stor-Ind method Runoff Area=75,032 sf Runoff Depth>2.46"Subcatchment E-1: Existing Site Area to Low Spot Flow Length=146' Tc=8.4 min CN=80 Runoff=4.51 cfs 0.353 af Runoff Area=52,994 sf Runoff Depth>3.09"Subcatchment E-2: Existing Site Area to King St. Flow Length=265' Tc=14.3 min CN=87 Runoff=3.35 cfs 0.313 af Runoff Area=46,266 sf Runoff Depth>3.81"Subcatchment P-1: Proposed Site Area to Infiltration Basin Tc=6.0 min CN=94 Runoff=4.35 cfs 0.337 af Runoff Area=4,000 sf Runoff Depth>4.26"Subcatchment P-1a: Roof Area Tc=6.0 min CN=98 Runoff=0.39 cfs 0.033 af Runoff Area=12,007 sf Runoff Depth>3.29"Subcatchment P-2: Proposed Area to King St. Flow Length=130' Tc=9.8 min CN=89 Runoff=0.90 cfs 0.076 af Runoff Area=19,479 sf Runoff Depth>4.26"Subcatchment P-2a: Roof Area Tc=6.0 min CN=98 Runoff=1.92 cfs 0.159 af Runoff Area=13,278 sf Runoff Depth>1.14"Subcatchment P-3: Proposed Area to Low Spot Flow Length=100' Slope=0.0550 '/' Tc=6.8 min CN=62 Runoff=0.35 cfs 0.029 af Runoff Area=32,996 sf Runoff Depth>1.89"Subcatchment P-4: Proposed Area to King St. Flow Length=130' Tc=9.8 min CN=73 Runoff=1.44 cfs 0.119 af Inflow=4.51 cfs 0.353 afReach E-CP1: Low Spot East of Site Outflow=4.51 cfs 0.353 af Inflow=3.35 cfs 0.313 afReach E-CP2: King St. Outflow=3.35 cfs 0.313 af Inflow=0.35 cfs 0.029 afReach P-CP1: Low Spot East of Site Outflow=0.35 cfs 0.029 af Inflow=3.13 cfs 0.541 afReach P-CP2: King St. Outflow=3.13 cfs 0.541 af Peak Elev=138.66' Storage=1,139 cf Inflow=1.92 cfs 0.159 afPond P1: Dry Well 1 Discarded=0.40 cfs 0.143 af Primary=1.77 cfs 0.016 af Outflow=1.77 cfs 0.159 af Peak Elev=136.07' Storage=246 cf Inflow=0.39 cfs 0.033 afPond P2: Dry Well 2 Discarded=0.11 cfs 0.033 af Primary=0.00 cfs 0.000 af Outflow=0.11 cfs 0.033 af Peak Elev=135.11' Storage=5,306 cf Inflow=5.18 cfs 0.429 afPond P3: Subsurface Pond 1 Primary=1.98 cfs 0.421 af Secondary=0.00 cfs 0.000 af Outflow=1.98 cfs 0.421 af St. Elizabeth Ann Seton Parish 3-18-11 Type III 24-hr 10 YRS Rainfall=4.50"St. Elizabeth - Active-b Page 13Prepared by The Berkshire Design Group 3/21/2011HydroCAD® 8.00 s/n 000752 © 2006 HydroCAD Software Solutions LLC Total Runoff Area = 5.878 ac Runoff Volume = 1.419 af Average Runoff Depth = 2.90" 37.47% Pervious Area = 2.202 ac 62.53% Impervious Area = 3.676 ac St. Elizabeth Ann Seton Parish 3-18-11 Type III 24-hr 10 YRS Rainfall=4.50"St. Elizabeth - Active-b Page 14Prepared by The Berkshire Design Group 3/21/2011HydroCAD® 8.00 s/n 000752 © 2006 HydroCAD Software Solutions LLC Subcatchment E-1: Existing Site Area to Low Spot Runoff = 4.51 cfs @ 12.12 hrs, Volume= 0.353 af, Depth> 2.46" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 10 YRS Rainfall=4.50" Area (sf) CN Description 37,198 61 >75% Grass cover, Good, HSG B 37,834 98 Paved parking & roofs 75,032 80 Weighted Average 37,198 Pervious Area 37,834 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 8.1 100 0.0350 0.21 Sheet Flow, Grass: Short n= 0.150 P2= 3.00" 0.3 46 0.0320 2.68 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 8.4 146 Total Subcatchment E-2: Existing Site Area to King St. Runoff = 3.35 cfs @ 12.20 hrs, Volume= 0.313 af, Depth> 3.09" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 10 YRS Rainfall=4.50" Area (sf) CN Description 15,192 61 >75% Grass cover, Good, HSG B 37,802 98 Paved parking & roofs 52,994 87 Weighted Average 15,192 Pervious Area 37,802 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 12.9 100 0.0110 0.13 Sheet Flow, Sheet Flow over Grass Grass: Short n= 0.150 P2= 3.00" 1.4 165 0.0180 2.01 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 14.3 265 Total St. Elizabeth Ann Seton Parish 3-18-11 Type III 24-hr 10 YRS Rainfall=4.50"St. Elizabeth - Active-b Page 15Prepared by The Berkshire Design Group 3/21/2011HydroCAD® 8.00 s/n 000752 © 2006 HydroCAD Software Solutions LLC Subcatchment P-1: Proposed Site Area to Infiltration Basin Runoff = 4.35 cfs @ 12.09 hrs, Volume= 0.337 af, Depth> 3.81" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 10 YRS Rainfall=4.50" Area (sf) CN Description 32,131 98 Paved parking & roofs 4,173 61 >75% Grass cover, Good, HSG B 9,232 98 Paved parking & roofs 730 61 >75% Grass cover, Good, HSG B 46,266 94 Weighted Average 4,903 Pervious Area 41,363 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum ToC Subcatchment P-1a: Roof Area Runoff = 0.39 cfs @ 12.09 hrs, Volume= 0.033 af, Depth> 4.26" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 10 YRS Rainfall=4.50" Area (sf) CN Description 4,000 98 Paved parking & roofs 4,000 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum ToC Subcatchment P-2: Proposed Area to King St. Runoff = 0.90 cfs @ 12.14 hrs, Volume= 0.076 af, Depth> 3.29" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 10 YRS Rainfall=4.50" Area (sf) CN Description 8,963 98 Paved parking & roofs 3,044 61 >75% Grass cover, Good, HSG B 12,007 89 Weighted Average 3,044 Pervious Area 8,963 Impervious Area St. Elizabeth Ann Seton Parish 3-18-11 Type III 24-hr 10 YRS Rainfall=4.50"St. Elizabeth - Active-b Page 16Prepared by The Berkshire Design Group 3/21/2011HydroCAD® 8.00 s/n 000752 © 2006 HydroCAD Software Solutions LLC Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 9.7 100 0.0220 0.17 Sheet Flow, Grass: Short n= 0.150 P2= 3.00" 0.1 30 0.0700 3.97 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 9.8 130 Total Subcatchment P-2a: Roof Area Runoff = 1.92 cfs @ 12.09 hrs, Volume= 0.159 af, Depth> 4.26" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 10 YRS Rainfall=4.50" Area (sf) CN Description 19,479 98 Paved parking & roofs 19,479 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment P-3: Proposed Area to Low Spot Runoff = 0.35 cfs @ 12.11 hrs, Volume= 0.029 af, Depth> 1.14" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 10 YRS Rainfall=4.50" Area (sf) CN Description 13,068 61 >75% Grass cover, Good, HSG B 210 98 Paved parking & roofs 13,278 62 Weighted Average 13,068 Pervious Area 210 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.8 100 0.0550 0.25 Sheet Flow, Sheet Flow over Grass Grass: Short n= 0.150 P2= 3.00" Subcatchment P-4: Proposed Area to King St. Runoff = 1.44 cfs @ 12.15 hrs, Volume= 0.119 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 YRS Rainfall=4.50" St. Elizabeth Ann Seton Parish 3-18-11 Type III 24-hr 10 YRS Rainfall=4.50"St. Elizabeth - Active-b Page 17Prepared by The Berkshire Design Group 3/21/2011HydroCAD® 8.00 s/n 000752 © 2006 HydroCAD Software Solutions LLC Area (sf) CN Description 10,471 98 Paved parking & roofs 22,525 61 >75% Grass cover, Good, HSG B 32,996 73 Weighted Average 22,525 Pervious Area 10,471 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 9.7 100 0.0220 0.17 Sheet Flow, Grass: Short n= 0.150 P2= 3.00" 0.1 30 0.0700 3.97 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 9.8 130 Total Reach E-CP1: Low Spot East of Site [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 1.722 ac, Inflow Depth > 2.46" for 10 YRS event Inflow = 4.51 cfs @ 12.12 hrs, Volume= 0.353 af Outflow = 4.51 cfs @ 12.12 hrs, Volume= 0.353 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Reach E-CP2: King St. [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 1.217 ac, Inflow Depth > 3.09" for 10 YRS event Inflow = 3.35 cfs @ 12.20 hrs, Volume= 0.313 af Outflow = 3.35 cfs @ 12.20 hrs, Volume= 0.313 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Reach P-CP1: Low Spot East of Site [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.305 ac, Inflow Depth > 1.14" for 10 YRS event Inflow = 0.35 cfs @ 12.11 hrs, Volume= 0.029 af Outflow = 0.35 cfs @ 12.11 hrs, Volume= 0.029 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs St. Elizabeth Ann Seton Parish 3-18-11 Type III 24-hr 10 YRS Rainfall=4.50"St. Elizabeth - Active-b Page 18Prepared by The Berkshire Design Group 3/21/2011HydroCAD® 8.00 s/n 000752 © 2006 HydroCAD Software Solutions LLC Reach P-CP2: King St. [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 2.634 ac, Inflow Depth > 2.46" for 10 YRS event Inflow = 3.13 cfs @ 12.17 hrs, Volume= 0.541 af Outflow = 3.13 cfs @ 12.17 hrs, Volume= 0.541 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Pond P1: Dry Well 1 Inflow Area = 0.447 ac, Inflow Depth > 4.26" for 10 YRS event Inflow = 1.92 cfs @ 12.09 hrs, Volume= 0.159 af Outflow = 1.77 cfs @ 12.20 hrs, Volume= 0.159 af, Atten= 8%, Lag= 6.8 min Discarded = 0.40 cfs @ 11.75 hrs, Volume= 0.143 af Primary = 1.77 cfs @ 12.20 hrs, Volume= 0.016 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 138.66' @ 12.20 hrs Surf.Area= 10 sf Storage= 1,139 cf Plug-Flow detention time= 13.6 min calculated for 0.159 af (100% of inflow) Center-of-Mass det. time= 13.3 min ( 762.7 - 749.4 ) Volume Invert Avail.Storage Storage Description #1 137.00' 1,165 cf Custom Stage Data (Prismatic) Listed below (Recalc) 2,912 cf Overall x 40.0% Voids Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 137.00 2,100 0 0 138.35 2,100 2,835 2,835 138.36 10 11 2,846 145.00 10 66 2,912 Device Routing Invert Outlet Devices #1 Discarded 0.00'8.270 in/hr Exfiltration over Surface area #2 Primary 138.35'12.0" Horiz. Orifice/Grate Limited to weir flow C= 0.600 Discarded OutFlow Max=0.40 cfs @ 11.75 hrs HW=137.09' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.40 cfs) Primary OutFlow Max=1.76 cfs @ 12.20 hrs HW=138.66' (Free Discharge) 2=Orifice/Grate (Weir Controls 1.76 cfs @ 1.82 fps) St. Elizabeth Ann Seton Parish 3-18-11 Type III 24-hr 10 YRS Rainfall=4.50"St. Elizabeth - Active-b Page 19Prepared by The Berkshire Design Group 3/21/2011HydroCAD® 8.00 s/n 000752 © 2006 HydroCAD Software Solutions LLC Pond P2: Dry Well 2 Inflow Area = 0.092 ac, Inflow Depth > 4.26" for 10 YRS event Inflow = 0.39 cfs @ 12.09 hrs, Volume= 0.033 af Outflow = 0.11 cfs @ 11.80 hrs, Volume= 0.033 af, Atten= 72%, Lag= 0.0 min Discarded = 0.11 cfs @ 11.80 hrs, Volume= 0.033 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 136.07' @ 12.43 hrs Surf.Area= 575 sf Storage= 246 cf Plug-Flow detention time= 10.2 min calculated for 0.033 af (100% of inflow) Center-of-Mass det. time= 10.1 min ( 759.5 - 749.4 ) Volume Invert Avail.Storage Storage Description #1 135.00' 690 cf Custom Stage Data (Prismatic) Listed below (Recalc) 1,725 cf Overall x 40.0% Voids Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 135.00 575 0 0 137.35 575 1,351 1,351 138.00 575 374 1,725 Device Routing Invert Outlet Devices #1 Primary 137.35'12.0" Vert. Orifice/Grate C= 0.600 #2 Discarded 0.00'8.270 in/hr Exfiltration over Surface area Discarded OutFlow Max=0.11 cfs @ 11.80 hrs HW=135.04' (Free Discharge) 2=Exfiltration (Exfiltration Controls 0.11 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=135.00' (Free Discharge) 1=Orifice/Grate ( Controls 0.00 cfs) Pond P3: Subsurface Pond 1 Inflow Area = 1.877 ac, Inflow Depth > 2.74" for 10 YRS event Inflow = 5.18 cfs @ 12.09 hrs, Volume= 0.429 af Outflow = 1.98 cfs @ 12.43 hrs, Volume= 0.421 af, Atten= 62%, Lag= 20.3 min Primary = 1.98 cfs @ 12.43 hrs, Volume= 0.421 af Secondary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 135.11' @ 12.43 hrs Surf.Area= 6,000 sf Storage= 5,306 cf Plug-Flow detention time= 46.7 min calculated for 0.420 af (98% of inflow) Center-of-Mass det. time= 36.0 min ( 815.0 - 779.0 ) St. Elizabeth Ann Seton Parish 3-18-11 Type III 24-hr 10 YRS Rainfall=4.50"St. Elizabeth - Active-b Page 20Prepared by The Berkshire Design Group 3/21/2011HydroCAD® 8.00 s/n 000752 © 2006 HydroCAD Software Solutions LLC Volume Invert Avail.Storage Storage Description #1 133.00' 8,946 cf Custom Stage Data (Pyramidal) Listed below (Recalc) 21,300 cf Overall x 42.0% Voids #2 136.50' 258 cf Internal CB and Surface Storage (Prismatic) Listed below (Recalc) 9,204 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 133.00 6,000 0 0 6,000 136.55 6,000 21,300 21,300 7,100 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 136.50 48 0 0 136.55 48 2 2 136.80 2,000 256 258 Device Routing Invert Outlet Devices #1 Primary 133.00'12.0" x 30.0' long Culvert CMP, projecting, no headwall, Ke= 0.900 Outlet Invert= 132.70' S= 0.0100 '/' Cc= 0.900 n= 0.010 PVC, smooth interior #2 Device 1 133.00'7.5" Vert. Orifice/Grate C= 0.600 #3 Device 1 136.55'12.0" Horiz. Orifice/Grate Limited to weir flow C= 0.600 #4 Secondary 136.80'5.0' long x 1.0' breadth Overflow At Dumpster Pad 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 #5 Primary 136.70'1.0' long x 1.0' breadth South East Drive Overflow 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=1.97 cfs @ 12.43 hrs HW=135.10' (Free Discharge) 1=Culvert (Passes 1.97 cfs of 3.78 cfs potential flow) 2=Orifice/Grate (Orifice Controls 1.97 cfs @ 6.44 fps) 3=Orifice/Grate ( Controls 0.00 cfs) 5=South East Drive Overflow ( Controls 0.00 cfs) Secondary OutFlow Max=0.00 cfs @ 0.00 hrs HW=133.00' (Free Discharge) 4=Overflow At Dumpster Pad ( Controls 0.00 cfs) St. Elizabeth Ann Seton Parish 3-18-11 Type III 24-hr 100 YRS Rainfall=6.50"St. Elizabeth - Active-b Page 21Prepared by The Berkshire Design Group 3/21/2011HydroCAD® 8.00 s/n 000752 © 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+Trans method - Pond routing by Stor-Ind method Runoff Area=75,032 sf Runoff Depth>4.23"Subcatchment E-1: Existing Site Area to Low Spot Flow Length=146' Tc=8.4 min CN=80 Runoff=7.72 cfs 0.607 af Runoff Area=52,994 sf Runoff Depth>4.99"Subcatchment E-2: Existing Site Area to King St. Flow Length=265' Tc=14.3 min CN=87 Runoff=5.30 cfs 0.506 af Runoff Area=46,266 sf Runoff Depth>5.79"Subcatchment P-1: Proposed Site Area to Infiltration Basin Tc=6.0 min CN=94 Runoff=6.44 cfs 0.512 af Runoff Area=4,000 sf Runoff Depth>6.26"Subcatchment P-1a: Roof Area Tc=6.0 min CN=98 Runoff=0.57 cfs 0.048 af Runoff Area=12,007 sf Runoff Depth>5.21"Subcatchment P-2: Proposed Area to King St. Flow Length=130' Tc=9.8 min CN=89 Runoff=1.40 cfs 0.120 af Runoff Area=19,479 sf Runoff Depth>6.26"Subcatchment P-2a: Roof Area Tc=6.0 min CN=98 Runoff=2.78 cfs 0.233 af Runoff Area=13,278 sf Runoff Depth>2.44"Subcatchment P-3: Proposed Area to Low Spot Flow Length=100' Slope=0.0550 '/' Tc=6.8 min CN=62 Runoff=0.81 cfs 0.062 af Runoff Area=32,996 sf Runoff Depth>3.50"Subcatchment P-4: Proposed Area to King St. Flow Length=130' Tc=9.8 min CN=73 Runoff=2.70 cfs 0.221 af Inflow=7.72 cfs 0.607 afReach E-CP1: Low Spot East of Site Outflow=7.72 cfs 0.607 af Inflow=5.30 cfs 0.506 afReach E-CP2: King St. Outflow=5.30 cfs 0.506 af Inflow=0.81 cfs 0.062 afReach P-CP1: Low Spot East of Site Outflow=0.81 cfs 0.062 af Inflow=5.02 cfs 0.895 afReach P-CP2: King St. Outflow=5.02 cfs 0.895 af Peak Elev=139.89' Storage=1,144 cf Inflow=2.78 cfs 0.233 afPond P1: Dry Well 1 Discarded=0.40 cfs 0.182 af Primary=4.69 cfs 0.051 af Outflow=4.70 cfs 0.233 af Peak Elev=137.13' Storage=489 cf Inflow=0.57 cfs 0.048 afPond P2: Dry Well 2 Discarded=0.11 cfs 0.048 af Primary=0.00 cfs 0.000 af Outflow=0.11 cfs 0.048 af Peak Elev=136.73' Storage=9,078 cf Inflow=12.41 cfs 0.683 afPond P3: Subsurface Pond 1 Primary=3.50 cfs 0.674 af Secondary=0.00 cfs 0.000 af Outflow=3.50 cfs 0.674 af St. Elizabeth Ann Seton Parish 3-18-11 Type III 24-hr 100 YRS Rainfall=6.50"St. Elizabeth - Active-b Page 22Prepared by The Berkshire Design Group 3/21/2011HydroCAD® 8.00 s/n 000752 © 2006 HydroCAD Software Solutions LLC Total Runoff Area = 5.878 ac Runoff Volume = 2.309 af Average Runoff Depth = 4.71" 37.47% Pervious Area = 2.202 ac 62.53% Impervious Area = 3.676 ac St. Elizabeth Ann Seton Parish 3-18-11 Type III 24-hr 100 YRS Rainfall=6.50"St. Elizabeth - Active-b Page 23Prepared by The Berkshire Design Group 3/21/2011HydroCAD® 8.00 s/n 000752 © 2006 HydroCAD Software Solutions LLC Subcatchment E-1: Existing Site Area to Low Spot Runoff = 7.72 cfs @ 12.12 hrs, Volume= 0.607 af, Depth> 4.23" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 100 YRS Rainfall=6.50" Area (sf) CN Description 37,198 61 >75% Grass cover, Good, HSG B 37,834 98 Paved parking & roofs 75,032 80 Weighted Average 37,198 Pervious Area 37,834 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 8.1 100 0.0350 0.21 Sheet Flow, Grass: Short n= 0.150 P2= 3.00" 0.3 46 0.0320 2.68 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 8.4 146 Total Subcatchment E-2: Existing Site Area to King St. Runoff = 5.30 cfs @ 12.19 hrs, Volume= 0.506 af, Depth> 4.99" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 100 YRS Rainfall=6.50" Area (sf) CN Description 15,192 61 >75% Grass cover, Good, HSG B 37,802 98 Paved parking & roofs 52,994 87 Weighted Average 15,192 Pervious Area 37,802 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 12.9 100 0.0110 0.13 Sheet Flow, Sheet Flow over Grass Grass: Short n= 0.150 P2= 3.00" 1.4 165 0.0180 2.01 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 14.3 265 Total St. Elizabeth Ann Seton Parish 3-18-11 Type III 24-hr 100 YRS Rainfall=6.50"St. Elizabeth - Active-b Page 24Prepared by The Berkshire Design Group 3/21/2011HydroCAD® 8.00 s/n 000752 © 2006 HydroCAD Software Solutions LLC Subcatchment P-1: Proposed Site Area to Infiltration Basin Runoff = 6.44 cfs @ 12.09 hrs, Volume= 0.512 af, Depth> 5.79" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 100 YRS Rainfall=6.50" Area (sf) CN Description 32,131 98 Paved parking & roofs 4,173 61 >75% Grass cover, Good, HSG B 9,232 98 Paved parking & roofs 730 61 >75% Grass cover, Good, HSG B 46,266 94 Weighted Average 4,903 Pervious Area 41,363 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum ToC Subcatchment P-1a: Roof Area Runoff = 0.57 cfs @ 12.09 hrs, Volume= 0.048 af, Depth> 6.26" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 100 YRS Rainfall=6.50" Area (sf) CN Description 4,000 98 Paved parking & roofs 4,000 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Minimum ToC Subcatchment P-2: Proposed Area to King St. Runoff = 1.40 cfs @ 12.14 hrs, Volume= 0.120 af, Depth> 5.21" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 100 YRS Rainfall=6.50" Area (sf) CN Description 8,963 98 Paved parking & roofs 3,044 61 >75% Grass cover, Good, HSG B 12,007 89 Weighted Average 3,044 Pervious Area 8,963 Impervious Area St. Elizabeth Ann Seton Parish 3-18-11 Type III 24-hr 100 YRS Rainfall=6.50"St. Elizabeth - Active-b Page 25Prepared by The Berkshire Design Group 3/21/2011HydroCAD® 8.00 s/n 000752 © 2006 HydroCAD Software Solutions LLC Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 9.7 100 0.0220 0.17 Sheet Flow, Grass: Short n= 0.150 P2= 3.00" 0.1 30 0.0700 3.97 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 9.8 130 Total Subcatchment P-2a: Roof Area Runoff = 2.78 cfs @ 12.09 hrs, Volume= 0.233 af, Depth> 6.26" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 100 YRS Rainfall=6.50" Area (sf) CN Description 19,479 98 Paved parking & roofs 19,479 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment P-3: Proposed Area to Low Spot Runoff = 0.81 cfs @ 12.11 hrs, Volume= 0.062 af, Depth> 2.44" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 100 YRS Rainfall=6.50" Area (sf) CN Description 13,068 61 >75% Grass cover, Good, HSG B 210 98 Paved parking & roofs 13,278 62 Weighted Average 13,068 Pervious Area 210 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.8 100 0.0550 0.25 Sheet Flow, Sheet Flow over Grass Grass: Short n= 0.150 P2= 3.00" Subcatchment P-4: Proposed Area to King St. Runoff = 2.70 cfs @ 12.14 hrs, Volume= 0.221 af, Depth> 3.50" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr 100 YRS Rainfall=6.50" St. Elizabeth Ann Seton Parish 3-18-11 Type III 24-hr 100 YRS Rainfall=6.50"St. Elizabeth - Active-b Page 26Prepared by The Berkshire Design Group 3/21/2011HydroCAD® 8.00 s/n 000752 © 2006 HydroCAD Software Solutions LLC Area (sf) CN Description 10,471 98 Paved parking & roofs 22,525 61 >75% Grass cover, Good, HSG B 32,996 73 Weighted Average 22,525 Pervious Area 10,471 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 9.7 100 0.0220 0.17 Sheet Flow, Grass: Short n= 0.150 P2= 3.00" 0.1 30 0.0700 3.97 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 9.8 130 Total Reach E-CP1: Low Spot East of Site [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 1.722 ac, Inflow Depth > 4.23" for 100 YRS event Inflow = 7.72 cfs @ 12.12 hrs, Volume= 0.607 af Outflow = 7.72 cfs @ 12.12 hrs, Volume= 0.607 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Reach E-CP2: King St. [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 1.217 ac, Inflow Depth > 4.99" for 100 YRS event Inflow = 5.30 cfs @ 12.19 hrs, Volume= 0.506 af Outflow = 5.30 cfs @ 12.19 hrs, Volume= 0.506 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Reach P-CP1: Low Spot East of Site [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.305 ac, Inflow Depth > 2.44" for 100 YRS event Inflow = 0.81 cfs @ 12.11 hrs, Volume= 0.062 af Outflow = 0.81 cfs @ 12.11 hrs, Volume= 0.062 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs St. Elizabeth Ann Seton Parish 3-18-11 Type III 24-hr 100 YRS Rainfall=6.50"St. Elizabeth - Active-b Page 27Prepared by The Berkshire Design Group 3/21/2011HydroCAD® 8.00 s/n 000752 © 2006 HydroCAD Software Solutions LLC Reach P-CP2: King St. [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 2.634 ac, Inflow Depth > 4.08" for 100 YRS event Inflow = 5.02 cfs @ 12.16 hrs, Volume= 0.895 af Outflow = 5.02 cfs @ 12.16 hrs, Volume= 0.895 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Pond P1: Dry Well 1 [88] Warning: Qout>Qin may require Finer Routing>1 [85] Warning: Oscillations may require Finer Routing>1 Inflow Area = 0.447 ac, Inflow Depth > 6.26" for 100 YRS event Inflow = 2.78 cfs @ 12.09 hrs, Volume= 0.233 af Outflow = 4.70 cfs @ 12.10 hrs, Volume= 0.233 af, Atten= 0%, Lag= 0.8 min Discarded = 0.40 cfs @ 11.65 hrs, Volume= 0.182 af Primary = 4.69 cfs @ 12.10 hrs, Volume= 0.051 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 139.89' @ 12.10 hrs Surf.Area= 10 sf Storage= 1,144 cf Plug-Flow detention time= 12.2 min calculated for 0.233 af (100% of inflow) Center-of-Mass det. time= 11.9 min ( 755.5 - 743.6 ) Volume Invert Avail.Storage Storage Description #1 137.00' 1,165 cf Custom Stage Data (Prismatic) Listed below (Recalc) 2,912 cf Overall x 40.0% Voids Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 137.00 2,100 0 0 138.35 2,100 2,835 2,835 138.36 10 11 2,846 145.00 10 66 2,912 Device Routing Invert Outlet Devices #1 Discarded 0.00'8.270 in/hr Exfiltration over Surface area #2 Primary 138.35'12.0" Horiz. Orifice/Grate Limited to weir flow C= 0.600 Discarded OutFlow Max=0.40 cfs @ 11.65 hrs HW=137.09' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.40 cfs) Primary OutFlow Max=4.69 cfs @ 12.10 hrs HW=139.89' (Free Discharge) 2=Orifice/Grate (Orifice Controls 4.69 cfs @ 5.98 fps) St. Elizabeth Ann Seton Parish 3-18-11 Type III 24-hr 100 YRS Rainfall=6.50"St. Elizabeth - Active-b Page 28Prepared by The Berkshire Design Group 3/21/2011HydroCAD® 8.00 s/n 000752 © 2006 HydroCAD Software Solutions LLC Pond P2: Dry Well 2 Inflow Area = 0.092 ac, Inflow Depth > 6.26" for 100 YRS event Inflow = 0.57 cfs @ 12.09 hrs, Volume= 0.048 af Outflow = 0.11 cfs @ 11.70 hrs, Volume= 0.048 af, Atten= 81%, Lag= 0.0 min Discarded = 0.11 cfs @ 11.70 hrs, Volume= 0.048 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 137.13' @ 12.52 hrs Surf.Area= 575 sf Storage= 489 cf Plug-Flow detention time= 22.4 min calculated for 0.048 af (100% of inflow) Center-of-Mass det. time= 22.3 min ( 765.9 - 743.6 ) Volume Invert Avail.Storage Storage Description #1 135.00' 690 cf Custom Stage Data (Prismatic) Listed below (Recalc) 1,725 cf Overall x 40.0% Voids Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 135.00 575 0 0 137.35 575 1,351 1,351 138.00 575 374 1,725 Device Routing Invert Outlet Devices #1 Primary 137.35'12.0" Vert. Orifice/Grate C= 0.600 #2 Discarded 0.00'8.270 in/hr Exfiltration over Surface area Discarded OutFlow Max=0.11 cfs @ 11.70 hrs HW=135.04' (Free Discharge) 2=Exfiltration (Exfiltration Controls 0.11 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=135.00' (Free Discharge) 1=Orifice/Grate ( Controls 0.00 cfs) Pond P3: Subsurface Pond 1 Inflow Area = 1.877 ac, Inflow Depth > 4.37" for 100 YRS event Inflow = 12.41 cfs @ 12.10 hrs, Volume= 0.683 af Outflow = 3.50 cfs @ 12.41 hrs, Volume= 0.674 af, Atten= 72%, Lag= 18.5 min Primary = 3.50 cfs @ 12.41 hrs, Volume= 0.674 af Secondary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 136.73' @ 12.41 hrs Surf.Area= 7,421 sf Storage= 9,078 cf Plug-Flow detention time= 46.8 min calculated for 0.674 af (99% of inflow) Center-of-Mass det. time= 38.4 min ( 805.9 - 767.5 ) St. Elizabeth Ann Seton Parish 3-18-11 Type III 24-hr 100 YRS Rainfall=6.50"St. Elizabeth - Active-b Page 29Prepared by The Berkshire Design Group 3/21/2011HydroCAD® 8.00 s/n 000752 © 2006 HydroCAD Software Solutions LLC Volume Invert Avail.Storage Storage Description #1 133.00' 8,946 cf Custom Stage Data (Pyramidal) Listed below (Recalc) 21,300 cf Overall x 42.0% Voids #2 136.50' 258 cf Internal CB and Surface Storage (Prismatic) Listed below (Recalc) 9,204 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (cubic-feet) (cubic-feet) (sq-ft) 133.00 6,000 0 0 6,000 136.55 6,000 21,300 21,300 7,100 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 136.50 48 0 0 136.55 48 2 2 136.80 2,000 256 258 Device Routing Invert Outlet Devices #1 Primary 133.00'12.0" x 30.0' long Culvert CMP, projecting, no headwall, Ke= 0.900 Outlet Invert= 132.70' S= 0.0100 '/' Cc= 0.900 n= 0.010 PVC, smooth interior #2 Device 1 133.00'7.5" Vert. Orifice/Grate C= 0.600 #3 Device 1 136.55'12.0" Horiz. Orifice/Grate Limited to weir flow C= 0.600 #4 Secondary 136.80'5.0' long x 1.0' breadth Overflow At Dumpster Pad 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 #5 Primary 136.70'1.0' long x 1.0' breadth South East Drive Overflow 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=3.46 cfs @ 12.41 hrs HW=136.72' (Free Discharge) 1=Culvert (Passes 3.45 cfs of 5.36 cfs potential flow) 2=Orifice/Grate (Orifice Controls 2.73 cfs @ 8.89 fps) 3=Orifice/Grate (Weir Controls 0.72 cfs @ 1.35 fps) 5=South East Drive Overflow (Weir Controls 0.01 cfs @ 0.39 fps) Secondary OutFlow Max=0.00 cfs @ 0.00 hrs HW=133.00' (Free Discharge) 4=Overflow At Dumpster Pad ( Controls 0.00 cfs) St. Elizabeth Ann Seton Parish Stormwater Drainage Report Northampton, Massachusetts The Berkshire Design Group, Inc. Appendix B Soil Test Pit Information Location Address or Lot No. St Elizabeth Church. - Northampton, MA Test Pits Performed By B. Darnold, The Berkshire Design Group Witnessed By: Deep Hole Number 1 Date: 3/1/11 Time: 11:15 Weather Sunny 40 Location (identify on site plan) See Plan Land Use Church Slope (%) See Plan Surface Stones n/o Vegetation Grassed yard near pine grove Landform Outwash Plain Position on Landscape (sketch on back) Distances from: See Plan Open Water Body >500 Feet Drainage way 100 Feet Possible Wet Area N/O Feet Property Line 10 Feet Drinking Water Well N/A Feet Other DEEP OBSERVATION HOLE LOG * Depth from Surface(Inches) Soil Horizon Soil Texture (USDA) Soil Color (Munsell) Soil Mottling Other (Structure, Stones, Boulders, Consistency, % Gravel) -2” – 0” O Organic 0” – 8” A Sandy Loam 10YR 3/2 SABK, FRIABLE 8” - 30” B Loamy Sand 2.5Y 5/4 SABK, FRIABLE 30” – 47” C1 Sand 2.5Y 6/4 @32” 3-5% SPOTTED NEAR ROOTS FINE SAND, FRIABLE, STRUCTURELESS 47” – 96” C2 Sand 2.5Y 7/4 FINE SAND, FRIABLE, STRUCTURELESS * MINIMUM OF 2 HOLES REQUIRED AT EVERY PROPOSED DISPOSAL AREA Parent Material (geologic) OUTWASH Depth to Bedrock: N/O Depth to Groundwater: Standing Water in the Hole: N/O @ 8’ Weeping from Pit Face: N/A Estimated Seasonal High Ground Water: NOT OBSERVED Percolation Test: Not Performed Depth to Perc: Start Pre-Soak 12”: End Pre-Soak 12”: Time at 12”: Time at 9”: Time at 6”: Time (9”-6”): Rate: Note: This test pit was performed for investigation of general soil conditions and should not be used for purposes related to Title 5 and/or soil suitability assessments for on-site sewage disposal. Location Address or Lot No. St Elizabeth Church. - Northampton, MA Test Pits Performed By B. Darnold, The Berkshire Design Group Witnessed By: Deep Hole Number 2 Date: 3/1/11 Time: 12:05 Weather Sunny 40 Location (identify on site plan) See Plan Land Use Church Slope (%) See Plan Surface Stones n/o Vegetation Grassed yard Landform Outwash Plain Position on Landscape (sketch on back) Distances from: See Plan Open Water Body >500 Feet Drainage way 95 Feet Possible Wet Area N/O Feet Property Line 75 Feet Drinking Water Well N/A Feet Other DEEP OBSERVATION HOLE LOG * Depth from Surface(Inches) Soil Horizon Soil Texture (USDA) Soil Color (Munsell) Soil Mottling Other (Structure, Stones, Boulders, Consistency, % Gravel) -2” – 0” O Organic 0” – 8” A Sandy Loam 10YR 3/2 SABK, FRIABLE, NO STONES 8” - 29” B Loamy Sand 2.5Y 5/4 SABK, FRIABLE, NO STONES 29” – 68” C1 Sand 2.5Y 6/3 FINE SAND, FRIABLE, STRUCTURELESS 68” – 108” C2 Sand 2.5Y 7/3 @74” 10YR 6/8 FINE SAND, FRIABLE OR FIRM, STRUCTURELESS * MINIMUM OF 2 HOLES REQUIRED AT EVERY PROPOSED DISPOSAL AREA Parent Material (geologic) OUTWASH Depth to Bedrock: N/O Depth to Groundwater: Standing Water in the Hole: N/O @ 9’ Weeping from Pit Face: N/A Estimated Seasonal High Ground Water: 74” Percolation Test: Not Performed Depth to Perc: Start Pre-Soak 12”: End Pre-Soak 12”: Time at 12”: Time at 9”: Time at 6”: Time (9”-6”): Rate: 10” Clay Pipe encountered at 5’, dry and broken. Note: This test pit was performed for investigation of general soil conditions and should not be used for purposes related to Title 5 and/or soil suitability assessments for on-site sewage disposal. Location Address or Lot No. St Elizabeth Church. - Northampton, MA Test Pits Performed By B. Darnold, The Berkshire Design Group Witnessed By: Deep Hole Number 3 Date: 3/1/11 Time: 1:05 Weather Sunny 40 Location (identify on site plan) See Plan Land Use Church Slope (%) See Plan Surface Stones n/o Vegetation Grassed yard Landform Outwash Plain Position on Landscape (sketch on back) Distances from: See Plan Open Water Body >500 Feet Drainage way 150 Feet Possible Wet Area N/O Feet Property Line 170 Feet Drinking Water Well N/A Feet Other DEEP OBSERVATION HOLE LOG * Depth from Surface(Inches) Soil Horizon Soil Texture (USDA) Soil Color (Munsell) Soil Mottling Other (Structure, Stones, Boulders, Consistency, % Gravel) 0” – 14” A Sandy Loam 2.5Y 4/4 SABK, FRIABLE, NO STONES 14” - 36” B Loamy Sand 2.5Y 5/6 SABK, FRIABLE, NO STONES 36” – 96” C1 Sand 2.5Y 6/3 FINE SAND, FRIABLE, STRUCTURELESS 96” – 108” C2 Sand 2.5Y 6/4 @96” 10YR 6/8 COARSE PINK SAND, V. FRIABLE, STRUCTURELESS * MINIMUM OF 2 HOLES REQUIRED AT EVERY PROPOSED DISPOSAL AREA Parent Material (geologic) OUTWASH Depth to Bedrock: N/O Depth to Groundwater: Standing Water in the Hole: @108”’ Weeping from Pit Face: N/A Estimated Seasonal High Ground Water: @96 Percolation Test: Not Performed Depth to Perc: Start Pre-Soak 12”: End Pre-Soak 12”: Time at 12”: Time at 9”: Time at 6”: Time (9”-6”): Rate: Note: This test pit was performed for investigation of general soil conditions and should not be used for purposes related to Title 5 and/or soil suitability assessments for on-site sewage disposal. Location Address or Lot No. St Elizabeth Church. - Northampton, MA Test Pits Performed By B. Darnold, The Berkshire Design Group Witnessed By: Deep Hole Number 4 Date: 3/1/11 Time: 1:54 Weather Sunny 40 Location (identify on site plan) See Plan Land Use Church Slope (%) See Plan Surface Stones n/o Vegetation Grassed yard Landform Outwash Plain Position on Landscape (sketch on back) Distances from: See Plan Open Water Body >500 Feet Drainage way 175 Feet Possible Wet Area N/O Feet Property Line 195 Feet Drinking Water Well N/A Feet Other DEEP OBSERVATION HOLE LOG * Depth from Surface(Inches) Soil Horizon Soil Texture (USDA) Soil Color (Munsell) Soil Mottling Other (Structure, Stones, Boulders, Consistency, % Gravel) 0” – 15” A Sandy Loam 10YR 3/2 SABK, FRIABLE, SOME BRICKS & STONES 15” - 38” B Loamy Sand 10YR 4/6 SABK, FRIABLE, NO STONES 38” – 60” C1 Sand 2.5Y 6/4 @60” 5YR 5/8 FINE SAND, FRIABLE, STRUCTURELESS 60” – 96” C2 Sand 2.5Y 6/6 COARSE PINK SAND, V. FRIABLE, STRUCTURELESS * MINIMUM OF 2 HOLES REQUIRED AT EVERY PROPOSED DISPOSAL AREA Parent Material (geologic) OUTWASH Depth to Bedrock: N/O Depth to Groundwater: Standing Water in the Hole: @90”’ Weeping from Pit Face: N/A Estimated Seasonal High Ground Water: @60” Percolation Test: Not Performed Depth to Perc: Start Pre-Soak 12”: End Pre-Soak 12”: Time at 12”: Time at 9”: Time at 6”: Time (9”-6”): Rate: Note: This test pit was performed for investigation of general soil conditions and should not be used for purposes related to Title 5 and/or soil suitability assessments for on-site sewage disposal. Location Address or Lot No. St Elizabeth Church. - Northampton, MA Test Pits Performed By B. Darnold, The Berkshire Design Group Witnessed By: Deep Hole Number 5 Date: 3/1/11 Time: 2:35 Weather Sunny 40 Location (identify on site plan) See Plan Land Use Church Slope (%) See Plan Surface Stones n/o Vegetation Grassed yard Landform Outwash Plain Position on Landscape (sketch on back) Distances from: See Plan Open Water Body >500 Feet Drainage way 200 Feet Possible Wet Area N/O Feet Property Line 35 Feet Drinking Water Well N/A Feet Other DEEP OBSERVATION HOLE LOG * Depth from Surface(Inches) Soil Horizon Soil Texture (USDA) Soil Color (Munsell) Soil Mottling Other (Structure, Stones, Boulders, Consistency, % Gravel) 0” – 12” A1 Sandy Loam 10YR 2/2 SABK, FRIABLE, SOME BRICKS & STONES, FILL 12” - 24” B1 Sandy Loam 10YR 4/4 SABK, FRIABLE, SOME BRICKS AND STONES - FILL 24” – 46” A2 Sandy Loam 10YR 3/2 SABK, FRIABLE, NO STONES 46” -66” B2 Loamy Sand 2.5Y 5/6 SABK, FRIABLE, NO STONES 66” – 80” C1 Sand 2.5Y 6/3 @72” 10YR 5/8 FINE SAND, FRIABLE, STRUCTURELESS 80” – 96” C2 Sand 10YR 6/4 COARSE PINK SAND, V. FRIABLE, STRUCTURELESS * MINIMUM OF 2 HOLES REQUIRED AT EVERY PROPOSED DISPOSAL AREA Parent Material (geologic) OUTWASH Depth to Bedrock: N/O Depth to Groundwater: Standing Water in the Hole: @96”’ Weeping from Pit Face: N/A Estimated Seasonal High Ground Water: @72” Percolation Test: Not Performed Depth to Perc: Start Pre-Soak 12”: End Pre-Soak 12”: Time at 12”: Time at 9”: Time at 6”: Time (9”-6”): Rate: Note: This test pit was performed for investigation of general soil conditions and should not be used for purposes related to Title 5 and/or soil suitability assessments for on-site sewage disposal. St. Elizabeth Ann Seton Parish Stormwater Drainage Report Northampton, Massachusetts The Berkshire Design Group, Inc. Appendix C TSS Removal & SWTC Sizing Calculations V INSTRUCTIONS:Version 1, Automated: Mar. 4, 2008 1. In BMP Column, click on Blue Cell to Activate Drop Down Menu 2. Select BMP from Drop Down Menu 3. After BMP is selected, TSS Removal and other Columns are automatically completed. Location: B C D E F TSS Removal Starting TSS Amount Remaining BMP1 Rate1 Load*Removed (C*D)Load (D-E) Deep Sump and Hooded Catch Basin 0.25 1.00 0.25 0.75 Proprietary Treatment Practice 0.76 0.75 0.57 0.18 0.00 0.18 0.00 0.18 0.00 0.18 0.00 0.18 0.00 0.18 0.00 0.18 Total TSS Removal =82% Separate Form Needs to be Completed for Each Outlet or BMP Train Project:St Elizabeth, Northampton MA Prepared By:Brian Darnold *Equals remaining load from previous BMP (E) Date:3/11/2011 which enters the BMPTSS Removal Calculation WorksheetCB>STC900 *THE TSS % SHOWN FOR THE STC450 WAS THE LOWEST OF THE 3 Non-automated TSS Calculation Sheet must be used if Proprietary BMP Proposed 1. From MassDEP Stormwater Handbook Vol. 1 Mass. Dept. of Environmental Protection V INSTRUCTIONS:Version 1, Automated: Mar. 4, 2008 1. In BMP Column, click on Blue Cell to Activate Drop Down Menu 2. Select BMP from Drop Down Menu 3. After BMP is selected, TSS Removal and other Columns are automatically completed. Location: B C D E F TSS Removal Starting TSS Amount Remaining BMP1 Rate1 Load*Removed (C*D)Load (D-E) Dry Well 0.80 1.00 0.80 0.20 0.00 0.20 0.00 0.20 0.00 0.20 0.00 0.20 0.00 0.20 0.00 0.20 0.00 0.20 0.00 0.20 Total TSS Removal =80% Separate Form Needs to be Completed for Each Outlet or BMP Train Project:St Elizabeth, Northampton MA Prepared By:Brian Darnold *Equals remaining load from previous BMP (E) Date:3/11/2011 which enters the BMPTSS Removal Calculation WorksheetDry Well 1 & 2 Non-automated TSS Calculation Sheet must be used if Proprietary BMP Proposed 1. From MassDEP Stormwater Handbook Vol. 1 Mass. Dept. of Environmental Protection Stormceptor Sizing Table Version 3.0.0 Selected Rainfall Station State MASSACHUSETTS Name KNIGHTVILLE DAM ID # 3985 Elev. (ft) 630 Latitude N 42 deg 17 min Longitude W 72 deg 52 min Particle Size Distribution Diameter (um) Percent (%) Velocity (ft/s) 20 20.0 0.0013 60 20.0 0.0052 150 20.0 0.0351 400 20.0 0.2116 2000 20.0 0.9416 Note : Sizing Results vary with particle size distribution. BMP comparisons must use the same particle size distribution. Please call (800) 909-7763 for sizing with other distributions Site Parameters Total Area (ac) 2.94 Imperviousness (%) 66 Impervious Area (ac) 1.94 Stormceptor Sizing Table Stormceptor Model % Runoff Treated % TSS Removal STC 450i 77.8 66.0 STC 900 92.1 76.1 STC 1200 92.1 76.2 STC 1800 92.1 76.4 STC 2400 95.9 80.7 STC 3600 95.9 81.5 STC 4800 98.0 84.7 STC 6000 98.0 85.2 STC 7200 98.9 87.5 STC 11000 99.5 90.6 STC 13000 99.5 90.9 STC 16000 99.9 92.4 Comments : St. Elizabeth Church Site Total Area Analyzed: 2.94 Acres Percent Impervious: 66% St. Elizabeth Ann Seton Parish Stormwater Drainage Report Northampton, Massachusetts The Berkshire Design Group, Inc. Appendix D Proposed Stormwater Management System Operation & Maintenance Plan St. Elizabeth Ann Seton Parish March 18, 2011 Northampton, MA Operation & Maintenance Plan 1 Proposed Stormwater Management System Operation & Maintenance Plan During Construction The Contractor shall be responsible for inspection and maintenance during construction. At all times, siltation fabric fencing, stakes and hay bales sufficient to construct a sedimentation control barrier a minimum of 50 feet long will be stockpiled on the site in order to repair established barriers which may have been damaged or breached. An inspection of all erosion control and stormwater management systems shall be conducted by the Contractor at least once a week and during all rain storms until the completion of construction. In case of any noted breach or failure, the Contractor shall immediately make appropriate repairs to any erosion control system and notify the engineer of any problems involving stormwater management systems. A rain storm shall be defined as all or one of the following: • Any storm in which rain is predicted to last for twelve consecutive hours or more. • Any storm for which a flash flood watch or warning is issued. • Any single storm predicted to have a cumulative rainfall of greater than one- half inch. • Any storm not meeting the previous three thresholds but which would mark a third consecutive day of measurable rainfall. The Contractor shall also inspect the erosion control and stormwater management systems at times of significant increase in surface water runoff due to rapid thawing when the risk of failure of erosion control measures is significant. In such instances as remedial action is necessary, the Contractor shall repair any and all significant deficiencies in erosion control systems within two days. The Department of Public Works shall be notified of any significant failure of stormwater management systems and erosion and sediment control measures and shall be notified of any release of pollutants to a water body (stream, brook, pond, etc.) or into a conveyance system to a water body. St. Elizabeth Ann Seton Parish March 18, 2011 Northampton, MA Operation & Maintenance Plan 2 The Contractor shall remove the sediment from behind the fence of the sedimentation control barrier when the accumulated sediment has reached one- half of the original installed height of the barrier. Post-Construction Stormwater Management System Owner: The Owner, Roman Catholic Bishop of Springfield 65 Elliot Street Springfield, MA 01105 shall own the stormwater management system. Party Responsible for Operation & Maintenance: The Owner (subject to change prior to O&M Agreement), Roman Catholic Bishop of Springfield 65 Elliot Street Springfield, MA 01105 shall operate and maintain the stormwater management system. Inspection & Maintenance Schedule: 1) Street Sweeping Street and parking area sweeping shall take place twice annually. 2) Hooded Catch Basin and/or Drain Manhole with Sump Oil and water separators should be inspected at least four times per year and cleaned annually or more often if required. Oil and sediments should be removed and disposed of in accordance with local, state and federal guidelines and regulations. In the case of an oil or bulk pollutant release, the system must be cleaned immediately following the spill and the proper authorities notified. 3) Stormwater Treatment Chamber The Stormwater Treatment Chamber, of which there is 1 StormCeptor Model # STC900 water quality structure or equal, shall be inspected and maintained according the manufacturer’s specifications. Rinker, the manufacturer of St. Elizabeth Ann Seton Parish March 18, 2011 Northampton, MA Operation & Maintenance Plan 3 Stormceptor recommends that maintenance be completed on the structures at least once per year, but advises that the units be checked once every three months during the first year to determine the rate of sediment and oil accumulation and to establish an appropriate maintenance schedule. The rate at which the system collects pollutants will depend on site activities. Maintenance or cleaning shall be performed when the stored volume reaches 15% (6 inch sediment depth) of the Stormceptor capacity, when oil (hydrocarbon) has accumulated to 1 inch or greater depth, or immediately in the event of a fuel or oil spill according the manufacturer’s specifications. All material removed from the Stormceptor shall be disposed in accordance with applicable local, state, and federal guidelines and regulations. For more detail of how the StormCeptor should be maintained see the StormCeptor's Owner Manual. 4) Dry Wells Dry well basins have been incorporated into the stormwater system for the site to specifically receive roof runoff and, therefore, are not expected to receive large amounts of bulk sediments. Proper maintenance of roof gutters that drain to the system will help to protect the integrity of the infiltration basins. Sediments and debris should be removed and disposed of in accordance with local, state and federal guidelines and regulations. 5) Subsurface Detention Basin The subsurface infiltration basin should be visually inspected at least twice per year for sediment and debris accumulation in the perforated pipe network through the cleanout and access risers shown on the plans. Sediments and debris should be removed and disposed of in accordance with local, state and federal guidelines and regulations. INSPECTION AND MAINTANENCE REPORT FORM The Berkshire Design Group, Inc. Page 1/3 III NNN SSS PPP EEE CCCTTTIIIOOONNN AAA NNNDDD MMM AAA IIINNNTTTEEENNNAAANNNCCC EEE RRREEEPPPOOORRRTTT FFF OOORRRMMM For Stormwater Infrastructure St. Elizabeth Ann Seton Parish - Northampton, MA Inspection Schedule: FORM TO BE COMPLETED PER SCHEDULE PRESENTED IN OPERATION & MAINTENANCE PLAN Inspector: Date: Time: Inspector’s Qualifications: Days Since Last Rainfall: Amount of Last Rainfall (inches): Catch Basins CB # or Location Is Surface Runoff Being Directed to Catch Basins Properly Are Sediment Traps Installed at Catch Basin Inlets Are Catch Basin Outlet Hoods Installed and Working Properly Depth of Sediment in Basin Sump Are Any Correction Measures Required INSPECTION AND MAINTANENCE REPORT FORM The Berkshire Design Group, Inc. Page 2/3 Maintenance Required: To Be Performed By: On or Before: Stormwater Treatment Chamber SWTC # Is Stormwater Being Retained and Discharged Properly Depth of Sediment in Sump Are Any Correction Measures Required 1 Maintenance Required: To Be Performed By: On or Before: Dry Wells Structure Is Structure Working Properly Are Any Correction Measures Required Is the Trench Drawn Down 72 Hours After Storms Dry Well 1 Dry Well 2 Maintenance Required: To Be Performed By: On or Before: INSPECTION AND MAINTANENCE REPORT FORM The Berkshire Design Group, Inc. Page 3/3 OO TTHHEE RR CCOONNTTRROOLL SS List Other Miscellaneous Controls and Observations Item Describe Failure/Inadequate Control Describe Recommended Remedy Maintenance Required: To Be Performed By: On or Before: St. Elizabeth Ann Seton Parish Stormwater Drainage Report Northampton, Massachusetts The Berkshire Design Group, Inc. Appendix E Recharge Calculations