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HomeMy Public PortalAbout2015.02.06 Watertown Drainage Report_201502181107109969 DRAINAGE REPORT ELAN UNION MARKET Mixed--use Site Redevelopment Arsenal/Irving Streets Watertown, Massachusetts, 02472 Prepared For: Greystar 804 Greensboro Drive, Suite 950 McLean, VA 22102 Prepared By: Allen & Major Associates, Inc. 100 Commerce Way P.O. Box 2118 Woburn, MA 01 888-01 1 8 t110F STEWM it. CFiMNARD CIVIL ,9 No 349Dd 4 Q o�F FQ 8 T A� s A&M Project 41888-02A Prepared:February 6,2015 DRAINAGE REPORT ELAN UNION MARKET ARSENALARVING STREETS, WATERTOWN,MA INTRODUCTION The purpose of this drainage report is to provide a detailed review of the stormwater runoff, both quality and quantity, as it pertains to the existing and proposed conditions for the proposed redevelopment of the 5.29-acre site located at the northeast corner of the Arsenal Street/Irving Street intersection in Watertown, Massachusetts. The report will show by means of narrative, calculations and exhibits that appropriate best management practices have been used to mitigate the impacts of the proposed redevelopment. The report will demonstrate that there is a significant decrease in peak rate of runoff from the site at the study point for all design storm events. The redevelopment project consists of two (2), multi-family residential buildings containing a total of 282 apartment units, a 352-space parking structure and various amenity spaces. The westernmost residential units are over a partially below-grade parking garage containing 109 parking spaces. In addition to the residential uses, the Project contains approximately 10,000 square feet of retail space, as well as approximately 11,000 square feet of amenity space including a rental office, fitness facility for residents and community space. SITE LOCATION AND DESCRIPTION The 5.29-acre site located at the northeast quadrant of the Arsenal Street/Irving Street intersection currently includes eight (8) separate buildings ranging in size from 615 square feet to 14,700 square feet. Currently, the site is comprised of approximately 85%impervious surfaces. The site topography slopes generally from east to west from a high elevation of 42 at the abutting property to the east to a low elevation of approximately 26 at Irving Street. The site is essentially the lowest point in the general vicinity as Arsenal Street, Irving Street and the neighborhood to the north are all higher in elevation that the center of the site. Record plans of the municipal drain system on and adjacent to the Site were obtained from the Watertown Engineering Department/DPW and have been examined to determine the sizes of the pipes, direction of flow and approximate contributing area that discharge stormwater runoff into the system. The site currently has twelve (12) on-site catch basins and six (6) drain manholes. A recent site inspection revealed that the majority of the catch basins are suffering from a lack of maintenance as many of the structures have standing water in them,indicating that the pipes may be blocked with sand/debris. Four (4) of the on-site drain manholes are part of the municipal drainage system that passes through the site from off-site areas to the east and north. Two (2) of the on-site catch basins also act as manholes on the municipal drain line system. The on-site municipal drain system transports stormwater runoff from the industrial area to the east and the residential area to the north of the Site, through the Site in a series of 24" and 30" pipes. The flows are then discharged into the 30" drain line in Irving Street. From the Irving Street connection, flows continue in a southerly direction across Arsenal Street. Refer to the following Existing Conditions Exhibit(EX-1) 1-1 o\ r APPLICANT/OWNER: \ ' GREYSTAR 374 CONGRESS STREET, SUITE 202 BOSTON, MA 02210 wA,e V'A� �,p PROJECT: ����� �°� �"°�" "'s �-��''`� � �•� i� � �-��- ELAN UNION MARKET -- ----- - �.,�,,... r=�.,. ` •�K!� ;t: _; rr4 __ _ _ IRVING & ARSENAL STEET — ` \ \\ °/° x (•/ ' ouc.aar M.: Y + '~ i / ° w °, ' t °—� ° ° WATERTOWN, MA �\ /� 'gym �`.�.� :t, �• --;.�%•:. _ I 00— \ PROJECT NO. 1888-02A DATE: 02-10-2015 SCALE: VI DWG. NAME: C1888-02A ° �"""."�➢�_ �� �� .. g --27-� - ) _ _ DESIGNED BY: SRC CHECKED BY: BES �.,e,•, ,.. I� — — —'— \— --- — 28 I / PREPVREDBY: 28 �cp _ r— — — -- re'w.r N\a aura I I l'Y7/7 ° �, � ... ,.. � g ° LLEN MAJOR s .Y t�4RSENAI' - -q ST EJ- �� \ i` °ARSENAL r -..».o STREET A S S O C IA T E S, INC. �- \ civil & structural engineering♦ land surveying m \ I environmental consulting ♦landscape architecture w w w . all e n m a j o r . c o m 100 COMMERCE WAY P.O. BOX 2118 WOBURN MA 01888-0118 TEL: (781) 935-6889 FAX: (781) 935-2896 W0131 HV, MA*LAKEVILLE, MA*MANCHESTER, NH THIS DRAWING HAS BEEN PREPARED IN ELECTRONIC FORMAT. CLIENT/CLIENT'S REPRESENTATIVE OR CONSULTANT MAY BE PROVIDED COPIES OF DRAWINGS AND SPECIFICATIONS ON MAGNETIC MEDIA FOR HIS/HER INFORMATION AND USE FOR SPECIFIC APPLICATION TO THIS PROJECT.DUE TO THE POTENTIAL THAT THE MAGNETIC INFORMATION MAY BE MODIFIED UNINTENTIONALLY OR OTHERWISE,ALLEN&MAJOR ASSOCIATES,INC.MAY REMOVE ALL INDICATION OF THE DOCUMENT'S AUTHORSHIP ON THE MAGNETIC MEDIA.PRINTED REPRESENTATIONS OF THE DRAWINGS AND SPECIFICATIONS ISSUED SHALL BE THE ONLY RECORD COPIES OF ALLEN&MAJOR ASSOCIATES,INC.'S WORK PRODUCT. DRAWING TITLE: SHEET No. EXISTING CONDITIONS EX-1 EXHIBIT N:\PR0JECTS\I1888-02A\CIVIL\DRAWINGS\CURRENT\C- 1888-02A - EXISTING WATERSHED.DWG �opyright©2o All RightsReseroedssoclates,Ino. DRAINAGE REPORT ELAN UNION MARKET ARSENALARVING STREETS, WATERTOWN,MA METHODOLOGY The storm water analysis has been performed for two (2) project site situations. The first analysis consists of the existing site conditions and the second consists of the proposed site redevelopment conditions. The peak rate of runoff was determined using techniques and data found in the following: 1. Urban Hvdrolo2v for Small Watersheds — Technical Release 55 by the United States Department of Agriculture Soils Conservation Service, June 1986. Runoff curve numbers and 24-hour precipitation values were obtained from this reference. 2. HvdroCAD° Stormwater Modeling Svstem by HydroCAD Software Solutions LLC, version 8.50, 2007. The HydroCAD°program was used to generate the runoff hydrographs for the watershed areas, to determine discharge/stage/storage characteristics for the detention basins, to perform drainage routing and to combine the results of the runoff hydrographs. 3. Soil Survev of Middlesex Countv Massachusetts, Southern Part by United States Department of Agriculture, Soil Conservation Service. Soil types and boundaries were obtained from this reference. The underlying soils have been mapped by the U.S. Department of Agriculture, formerly Soil Conservation Service, and are consistent across the site. The soil types include: Map Symbol Unit Name Hydrologic Soil Group (HSG) SCS-602 Urban Land HSG—Unclassified A copy of the Soil Survey and the Soils information follows. Urban Land is an unclassified Hydrologic Soil Group that has typically been disturbed by the construction of the various site elements (buildings, paved parking, landscape areas, etc.). To be conservative for drainage analysis purposes, Allen & Major Associates, Inc. (A&M) has assumed that the soils are an HSG— C to maximize the calculated flows being generated on- site under existing and proposed conditions. This assumption is based upon the soils groups that have been mapped to either side of the project (325D — Newport channery fine sandy loam to the south and 627C — Newport-Urban land complex to the north),both of which are HSG"C". Because the site is the lowest point in the general area of the site, the existing site is considered a single drainage area as depicted on the included Existing Watershed Plan(EWS). Stormwater generated on the site flows to the minimal existing drainage system on the site. These flows enter the municipal storm drain system in Irving Street. 1-2 a\ o\ o\ APPLICANT/OWNER: GREYSTAR y °. 374 CONGRESS STREET, SUITE 202 BOSTON, MA 02210 wA, 'A� !p Raw PROJECT: ELAN UNION MARKET 9 IRVING & ARSENAL STEET - --°- - - ° ,° ° °- ° 2✓° ° " WATERTOWN, MA S.F. _ L=498' F �" I ° PROJECT NO. 1888-02A DATE: 02-10-2015 °—N�_ S.F. � ) SCALE: 1"=100' DWG. NAME: C1888-02A D 2C, S=1.8% _ — DESIGNED BY: SRC CHECKED BY: BES —28 1 PREPARED Bl': S.F - 01 \._...... N� S=1.8% _. �u �•-• L L E N & MAJOR LE cwT m cT4RSENp' ( - » , STRE! �� ARSENAL r - »mo STREET ° o ASSOCIA 1 ES, INC. �m civil & structural ineering* land surveying :...,: ""'-'-' � •_" '1'•'°'•=" -`'-^ -• -•`-• •�"• -•-,�-• ->•- • + --•- • • environmental consultgng ♦landscape architecture \> w w w . all e n m a j o r . c o m 100 COMMERCE WAY P.O. BOX 2118 WOBURN MA 01888-0118 TEL: (781) 935-6889 FAX: (781) 935-2896 WOBURN, MA*LAKEVILLE, MA*MANCHESTER, NH THIS DRAWING HAS BEEN PREPARED IN ELECTRONIC FORMAT. CLIENT/CLIENT'S REPRESENTATIVE OR CONSULTANT MAY BE PROVIDED COPIES OF DRAWINGS AND SPECIFICATIONS ON MAGNETIC MEDIA FOR HIS/HER INFORMATION AND USE FOR SPECIFIC APPLICATION TO THIS PROJECT.DUE TO THE POTENTIAL THAT THE MAGNETIC INFORMATION MAY BE MODIFIED UNINTENTIONALLY OR OTHERWISE,ALLEN&MAJOR ASSOCIATES,INC.MAY REMOVE ALL INDICATION OF THE DOCUMENT'S AUTHORSHIP ON THE MAGNETIC MEDIA.PRINTED REPRESENTATIONS OF THE DRAWINGS AND SPECIFICATIONS ISSUED SHALL BE THE ONLY RECORD COPIES OF ALLEN&MAJOR ASSOCIATES,INC.'S WORK PRODUCT. DRAWING TITLE: SHEET No. EXISTING WATERSHED PLAN EWS Copyright©201 S Allen&Major Associates,Inc. N:\PR0JECTS\ 1888-02A\CIVIL\DRAWINGS\CURRENT\C— 7888-02A — EXISTING WTI TERSHED.DWG / \ All xightsReserved Hydrologic Soil Group—Middlesex County,Massachusetts 3 (150 Arsenal Street,Watertown,MA) o o 320400 320500 320600 320700 320800 320900 321000 321100 321200 321300 42°22'T N A - 42°22'5"N 0 m m m i' In +rid -4.:.. M'Y' • die ' _� 0 -- N O - O O S N 42°21'44"N � .. 1�! _ '.' _ � 42°21'44"N 320400 320500 320600 320700 320800 320900 321000 321100 321200 321300 3 3 o Map Scale:1:4,500 if printed on A landscape(11"x 8.5")sheet. Meters N 0 50 100 200 300 Feet 0 200 400 800 1200 Map projection:Web Mercator Comer coordinates:WGS84 Edge tics:UTM Zone 19N WGS84 uSDA Natural Resources Web Soil Survey 6/3/2014 Conservation Service National Cooperative Soil Survey Page 1 of 4 Hydrologic Soil Group—Middlesex County,Massachusetts (150 Arsenal Street,Watertown,MA) MAP LEGEND MAP INFORMATION Area of Interest(A01) p C The soil surveys that comprise your AOI were mapped at 1:25,000. Area of Interest(AOI) 0 C/D Warning:Soil Map may not be valid at this scale. Soils D Soil Rating Polygons Enlargement of maps beyond the scale of mapping can cause A p Not rated or not available misunderstanding of the detail of mapping and accuracy of soil line placement.The maps do not show the small areas of contrasting A/D Water Features soils that could have been shown at a more detailed scale. Streams and Canals B Transportation Please rely on the bar scale on each map sheet for map 0 B/D t++ Rails measurements. 0 C r-„r Interstate Highways Source of Map: Natural Resources Conservation Service Web Soil Survey URL: http://websoilsurvey.nres.usda.gov 0 C/D US Routes Coordinate System: Web Mercator(EPSG:3857) 0 D Major Roads Maps from the Web Soil Survey are based on the Web Mercator 0 Not rated or not available Local Roads projection,which preserves direction and shape but distorts distance and area.A projection that preserves area,such as the Soil Rating Lines Background Albers equal-area conic projection,should be used if more accurate " A Aerial Photography calculations of distance or area are required. " x A/D This product is generated from the USDA-NRCS certified data as of B the version date(s)listed below. B/D Soil Survey Area: Middlesex County,Massachusetts Survey Area Data: Version 13, Dec 17,2013 " r C Soil map units are labeled(as space allows)for map scales 1:50,000 �-r C/D or larger. " x D Date(s)aerial images were photographed: Mar 30,2011—May 1, " r Not rated or not available 2011 Soil Rating Points The orthophoto or other base map on which the soil lines were 0 A compiled and digitized probably differs from the background imagery displayed on these maps.As a result,some minor shifting p A/D of map unit boundaries may be evident. ■ B ■ B/D uSDA Natural Resources Web Soil Survey 6/3/2014 Conservation Service National Cooperative Soil Survey Page 2 of 4 Hydrologic Soil Group—Middlesex County, Massachusetts 150 Arsenal Street,Watertown, MA Hydrologic Soil Group Hydrologic Soil Group—Summary by Map Unit—Middlesex County,Massachusetts(MA017) Map unit symbol Map unit name Rating Acres in AOI Percent of AOI 325D Newport channery fine C 1.2 1.4% sandy loam,8 to 25 percent slopes 602 Urban land 82.7 90.6% 627C Newport-Urban land C 7.3 8.0% complex,3 to 15 percent slopes Totals for Area of Interest 91.3 100.0% Description Hydrologic soil groups are based on estimates of runoff potential. Soils are assigned to one of four groups according to the rate of water infiltration when the soils are not protected by vegetation, are thoroughly wet, and receive precipitation from long-duration storms. The soils in the United States are assigned to four groups (A, B, C, and D) and three dual classes (A/D, B/D, and C/D). The groups are defined as follows: Group A. Soils having a high infiltration rate (low runoff potential)when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission. Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture. These soils have a moderate rate of water transmission. Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture.These soils have a slow rate of water transmission. Group D. Soils having a very slow infiltration rate (high runoff potential)when thoroughly wet. These consist chiefly of clays that have a high shrink-swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission. If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is for drained areas and the second is for undrained areas. Only the soils that in their natural condition are in group D are assigned to dual classes. LJSDA Natural Resources Web Soil Survey 6/3/2014 Conservation Service National Cooperative Soil Survey Page 3 of 4 Hydrologic Soil Group—Middlesex County, Massachusetts 150 Arsenal Street,Watertown, MA Rating Options Aggregation Method: Dominant Condition Component Percent Cutoff: None Specified Tie-break Rule: Higher LJSDA Natural Resources Web Soil Survey 6/3/2014 Conservation Service National Cooperative Soil Survey Page 4 of 4 DRAINAGE REPORT ELAN UNION MARKET ARSENALARVING STREETS, WATERTOWN,MA PROPOSED SITE CONDITIONS The existing on-site municipal drain system lies directly under the location of the proposed Project buildings. The drain line has been redesigned and has been rerouted to the rear of the property and placed in a proposed 30-foot wide easement to facilitate future maintenance of the pipes and structures by the Town. A hydrologic study of the proposed improvements was conducted in order to determine the impact of the proposed redevelopment on the existing stormwater system. The analysis determined the rates of runoff at the study point affected by the proposed redevelopment(the existing municipal drainage system in Irving Street). See the Proposed Watershed Plan(PWS). The Proposed Watershed Plan depicts nineteen (19) subwatershed areas that contribute to the Study Point. These subwatersheds were developed based on the proposed stormwater management system for the Site. In order to remove stormwater runoff from the municipal system to the extent practicable, under the redevelopment conditions, a series of five (5)under-pavement and landscape area infiltration systems are being proposed. The systems are sized and designed to contain all roof-generated stormwater runoff (up to and including the 100-year design storm) on site and slowly let it infiltrate into the groundwater. Details of the proposed under-pavement and landscaped area infiltration systems are included in the Site Plans for the Project. In addition to the stormwater infiltration systems for the roof runoff, the "hard" surfaces (where practical) are proposed to be constructed of permeable pavers to promote infiltration of stormwater runoff. The elevation of the groundwater on the site varies,but is generally at elevation 20 at the western end of the site near Irving Street. The bottoms of stormwater infiltration systems have to be set 2 feet above the seasonal high groundwater to ensure that they will infiltrate properly. The grades along the rear (northern) property line are approximately elevation 26, which does not allow adequate separation from the groundwater; therefor the stormwater generated on the rear perimeter of the site will drain directly into the new municipal drainage system. 1-3 APPLICANT/OWNER: GREYSTAR 374 CONGRESS STREET, SUITE 202 S��� BOSTON, MA 02210 ti -ZZ PROJECT: ELAN UNION MARKET IRVING & ARSENAL STEET WATERTOWN MA PROJECT NO. 1888-02A DATE: 02-10-2015 PAINING QQM, s. ] ¢ ,� SCALE: 1"=100' DWG. NAME: C1888-02A ° �S _33 I p r DESIGNED BY: SRC CHECKED BY: BES g .l - - _>s Piuli,,vu:u Bi': -31 � 2_ —� � RETAILSPACE _3. '. •� �� ALLEN & MAJOR a e'— 4RSENA' m c- »mv STREE! ARSENAL -..•WDO STREET r ,r A S S O C IAT E S, INC. x,. :.... J civil & structural engineering♦ land surveying ,,, (�� _.:. .;:...;,;,,,;•. environmental consulting ♦landscape architecture w w w all e n m a j o r c o m 100 COMMERCE WAY P.O. BOX 2118 WOBURN MA 01888-0118 TEL: (781) 935-6889 FAX: (781) 935-2896 W0131 RN, MA♦LAK1,V11.1,E, MA♦MANCHESTER, NH THIS DRAWING HAS BEEN PREPARED IN ELECTRONIC FORMAT. CLIENT/CLIENT'S REPRESENTATIVE OR CONSULTANT MAY BE PROVIDED COPIES OF DRAWINGS AND SPECIFICATIONS ON MAGNETIC MEDIA FOR HIS/HER INFORMATION AND USE FOR SPECIFIC APPLICATION TO THIS PROJECT.DUE TO THE POTENTIAL THAT THE MAGNETIC INFORMATION MAY BE MODIFIED UNINTENTIONALLY OR OTHERWISE,ALLEN&MAJOR ASSOCIATES,INC.MAY REMOVE ALL INDICATION OF THE DOCUMENT'S AUTHORSHIP ON THE MAGNETIC MEDIA.PRINTED REPRESENTATIONS OF THE DRAWINGS AND SPECIFICATIONS ISSUED SHALL BE THE ONLY RECORD COPIES OF ALLEN&MAJOR ASSOCIATES,INC.'S WORK PRODUCT. DRAWING TITLE: SHEET No. PROPOSED WATERSHED PLAN PWS Copyrjght©2015 Allen&Major Associates,Inc. N:A PROJECTS 7888-02A\CIVIL\DRAWINGS\CURRENT\C- 7888-02A - PROPOSED WATERSHED.DWG / V All Rights Reserved DRAINAGE REPORT ELAN UNION MARKET ARSENALARVING STREETS, WATERTOWN,MA PEAK RATE OF RUNOFF The storm water runoff analysis of the existing and proposed conditions includes an estimation of the peak rate of runoff for various rainfall events. Peak runoff rates were developed using TR-55 Urban Hydrology for Small Watersheds, developed by the U.S. Department of Commerce, Engineering Division and the HydroCAD° 8.50 computer program. Further, the analysis has been prepared in accordance with the Town of Watertown's requirements and standard engineering practices. The peak rate of runoff has been estimated for each watershed for the 2-, 10-, 50-, and 100-year occurrence storm events. The stormwater runoff model shows that the proposed redevelopment significantly reduces the combined rate of runoff during all storm events at the study point of the municipal drainage system located in Irving Street. The following table provides a summary of the estimated peak rate of runoff at the Study Point for each of the design storm events. The HydroCAD worksheets and hydrographs are included in the "HydroCAD Worksheets" Section of this report. Study Point(Flow to Municipal Storm Drain System in Irving Street) 2-Year 10-Year 50-Year 100-Year Existing Runoff(CFS) 24.20 37.43 55.41 67.57 Developed Runoff(CFS) 3.33 5.65 8.84 10.99 Percent Reduction 86% 85% 84% 86% 1-4 Flow to Municipal S)( tem SP. 1 L ----j Municipal System Subcat Reach on Link Routing Diagram for 1888-02A-Existing Prepared by Microsoft, Printed 2/10/2015 HydroCAD®10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC 1888-02A - Existing Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 2 Area Listing (all nodes) Area CN Description (acres) (subcatchment-numbers) 0.794 79 50-75% Grass cover, Fair, HSG C (1) 4.499 98 Paved parking, HSG C (1) 5.292 95 TOTAL AREA 1888-02A - Existing Type 1124-hr 2 Year Storm Rainfall=3.20" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 3 Time span=0.00-30.00 hrs, dt=0.05 hrs, 601 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Dyn-Stor-Ind method - Pond routing by Dyn-Stor-Ind method Subcatchment 1: Flow to Municipal Runoff Area=230,535 sf 85.00% Impervious Runoff Depth=2.64" Flow Length=733' Tc=3.2 min CN=95 Runoff=24.20 cfs 1.166 of Reach SP-1: Municipal System Inflow=24.20 cfs 1.166 of Outflow=24.20 cfs 1.166 of Total Runoff Area = 5.292 ac Runoff Volume = 1.166 of Average Runoff Depth = 2.64" 15.00% Pervious = 0.794 ac 85.00% Impervious = 4.499 ac 1888-02A - Existing Type 1124-hr 2 Year Storm Rainfall=3.20" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 4 Summary for Subcatchment 1: Flow to Municipal System Runoff = 24.20 cfs @ 11.93 hrs, Volume= 1.166 af, Depth= 2.64" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type II 24-hr 2 Year Storm Rainfall=3.20" Area (sf) CN Description 195,955 98 Paved parking, HSG C 34,580 79 50-75% Grass cover, Fair, HSG C 230,535 95 Weighted Average 34,580 15.00% Pervious Area 195,955 85.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.3 50 0.0180 2.72 Shallow Concentrated Flow, A to B Paved Kv= 20.3 fps 1.1 185 0.0180 2.72 Shallow Concentrated Flow, B to C Paved Kv= 20.3 fps 1.8 498 0.0030 4.58 22.47 Pipe Channel, C to D 30.0" Round Area= 4.9 sf Perim= 7.9' r= 0.63' n= 0.013 Concrete pipe, bends & connections 3.2 733 Total Summary for Reach SP-1: Municipal System Inflow Area = 5.292 ac, 85.00% Impervious, Inflow Depth = 2.64" for 2 Year Storm event Inflow = 24.20 cfs @ 11.93 hrs, Volume= 1.166 of Outflow = 24.20 cfs @ 11.93 hrs, Volume= 1.166 af, Atten= 0%, Lag= 0.0 min Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs 1888-02A - Existing Type // 24-hr 10 Year Storm Rainfall=4.80" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 5 Time span=0.00-30.00 hrs, dt=0.05 hrs, 601 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Dyn-Stor-Ind method - Pond routing by Dyn-Stor-Ind method Subcatchment 1: Flow to Municipal Runoff Area=230,535 sf 85.00% Impervious Runoff Depth=4.22" Flow Length=733' Tc=3.2 min CN=95 Runoff=37.43 cfs 1.862 of Reach SP-1: Municipal System Inflow=37.43 cfs 1.862 of Outflow=37.43 cfs 1.862 of Total Runoff Area = 5.292 ac Runoff Volume = 1.862 of Average Runoff Depth = 4.22" 15.00% Pervious = 0.794 ac 85.00% Impervious = 4.499 ac 1888-02A - Existing Type // 24-hr 10 Year Storm Rainfall=4.80" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 6 Summary for Subcatchment 1: Flow to Municipal System Runoff = 37.43 cfs @ 11.93 hrs, Volume= 1.862 af, Depth= 4.22" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type II 24-hr 10 Year Storm Rainfall=4.80" Area (sf) CN Description 195,955 98 Paved parking, HSG C 34,580 79 50-75% Grass cover, Fair, HSG C 230,535 95 Weighted Average 34,580 15.00% Pervious Area 195,955 85.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.3 50 0.0180 2.72 Shallow Concentrated Flow, A to B Paved Kv= 20.3 fps 1.1 185 0.0180 2.72 Shallow Concentrated Flow, B to C Paved Kv= 20.3 fps 1.8 498 0.0030 4.58 22.47 Pipe Channel, C to D 30.0" Round Area= 4.9 sf Perim= 7.9' r= 0.63' n= 0.013 Concrete pipe, bends & connections 3.2 733 Total Summary for Reach SP-1: Municipal System Inflow Area = 5.292 ac, 85.00% Impervious, Inflow Depth = 4.22" for 10 Year Storm event Inflow = 37.43 cfs @ 11.93 hrs, Volume= 1.862 of Outflow = 37.43 cfs @ 11.93 hrs, Volume= 1.862 af, Atten= 0%, Lag= 0.0 min Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs 1888-02A - Existing Type 1124-hr 50 Year Storm Rainfall=7.00" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 7 Time span=0.00-30.00 hrs, dt=0.05 hrs, 601 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Dyn-Stor-Ind method - Pond routing by Dyn-Stor-Ind method Subcatchment 1: Flow to Municipal Runoff Area=230,535 sf 85.00% Impervious Runoff Depth=6.41" Flow Length=733' Tc=3.2 min CN=95 Runoff=55.41 cfs 2.825 of Reach SP-1: Municipal System Inflow=55.41 cfs 2.825 of Outflow=55.41 cfs 2.825 of Total Runoff Area = 5.292 ac Runoff Volume = 2.825 of Average Runoff Depth = 6.41" 15.00% Pervious = 0.794 ac 85.00% Impervious = 4.499 ac 1888-02A - Existing Type 1124-hr 50 Year Storm Rainfall=7.00" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 8 Summary for Subcatchment 1: Flow to Municipal System Runoff = 55.41 cfs @ 11.93 hrs, Volume= 2.825 af, Depth= 6.41" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type II 24-hr 50 Year Storm Rainfall=7.00" Area (sf) CN Description 195,955 98 Paved parking, HSG C 34,580 79 50-75% Grass cover, Fair, HSG C 230,535 95 Weighted Average 34,580 15.00% Pervious Area 195,955 85.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.3 50 0.0180 2.72 Shallow Concentrated Flow, A to B Paved Kv= 20.3 fps 1.1 185 0.0180 2.72 Shallow Concentrated Flow, B to C Paved Kv= 20.3 fps 1.8 498 0.0030 4.58 22.47 Pipe Channel, C to D 30.0" Round Area= 4.9 sf Perim= 7.9' r= 0.63' n= 0.013 Concrete pipe, bends & connections 3.2 733 Total Summary for Reach SP-1: Municipal System Inflow Area = 5.292 ac, 85.00% Impervious, Inflow Depth = 6.41" for 50 Year Storm event Inflow = 55.41 cfs @ 11.93 hrs, Volume= 2.825 of Outflow = 55.41 cfs @ 11.93 hrs, Volume= 2.825 af, Atten= 0%, Lag= 0.0 min Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs 1888-02A - Existing Type 1124-hr 100 Year Storm Rainfall=8.50" Prepared by Microsoft Printed 2/10/2015 HydroCADO 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 9 Time span=0.00-30.00 hrs, dt=0.05 hrs, 601 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Dyn-Stor-Ind method - Pond routing by Dyn-Stor-Ind method Subcatchment 1: Flow to Municipal Runoff Area=230,535 sf 85.00% Impervious Runoff Depth=7.90" Flow Length=733' Tc=3.2 min CN=95 Runoff=67.59 cfs 3.484 of Reach SP-1: Municipal System Inflow=67.59 cfs 3.484 of Outflow=67.59 cfs 3.484 of Total Runoff Area = 5.292 ac Runoff Volume = 3.484 of Average Runoff Depth = 7.90" 15.00% Pervious = 0.794 ac 85.00% Impervious = 4.499 ac 1888-02A - Existing Type 1124-hr 100 Year Storm Rainfall=8.50" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 10 Summary for Subcatchment 1: Flow to Municipal System Runoff = 67.59 cfs @ 11.93 hrs, Volume= 3.484 af, Depth= 7.90" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type II 24-hr 100 Year Storm Rainfall=8.50" Area (sf) CN Description 195,955 98 Paved parking, HSG C 34,580 79 50-75% Grass cover, Fair, HSG C 230,535 95 Weighted Average 34,580 15.00% Pervious Area 195,955 85.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.3 50 0.0180 2.72 Shallow Concentrated Flow, A to B Paved Kv= 20.3 fps 1.1 185 0.0180 2.72 Shallow Concentrated Flow, B to C Paved Kv= 20.3 fps 1.8 498 0.0030 4.58 22.47 Pipe Channel, C to D 30.0" Round Area= 4.9 sf Perim= 7.9' r= 0.63' n= 0.013 Concrete pipe, bends & connections 3.2 733 Total Summary for Reach SP-1: Municipal System Inflow Area = 5.292 ac, 85.00% Impervious, Inflow Depth = 7.90" for 100 Year Storm event Inflow = 67.59 cfs @ 11.93 hrs, Volume= 3.484 of Outflow = 67.59 cfs @ 11.93 hrs, Volume= 3.484 af, Atten= 0%, Lag= 0.0 min Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs P1-1 P7-1 Garage go-of Area Flow to Abutting Project P2-1 CBS P2-2 Roof A to IS2 S-1 P6-1 Flow to AD1 Garage I ifiltration low to CB1 S-2 P6-7 P3-1 Arsenal St Infil ation P6- Flow to C134 Roof Area to IS3 v Flow to CB2 S-3 P6-8 v P3-2 Pergola In T ation Area IS P 11 P6-3 Flow to CB5 Pergola Area P3-3 (new t ac Flow to CB3 P6-9 P4-1 Roof Area to IS3 IS5 P6- Flow to Street Roof Area to IS4 v Irving St In i ration Area Flow to CB3 S-4 P6-6 Entrance Infiltration Flow to AD2 P4-2 Area P5-1 P6-5 Entrance Area Flow to IS5 Flow to AD2 Subcat Reach on Link Routing Diagram for 2015-01-20-1888-02A-Watertown Prepared by Microsoft, Printed 2/10/2015 HydroCAD®10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC 2015-01-20 - 1888-02A - Watertown Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 2 Area Listing (all nodes) Area CN Description (acres) (subcatchment-numbers) 0.956 74 >75% Grass cover, Good, HSG C (P2-2, P4-2, P5-1, P6-1, P6-2, P6-3, P6-4, P6-5, P6-6, P6-7, P6-8, P6-9, P7-1) 0.055 89 Gravel roads, HSG C (P3-2) 1.616 98 Paved parking, HSG C (P2-2, P4-2, P6-1, P6-2, P6-3, P6-4, P6-5, P6-6, P6-7, P6-8, P6-9, P7-1) 2.676 98 Unconnected roofs, HSG C (P1-1, P2-1, P3-1, P3-3, P4-1, P5-1) 5.303 94 TOTAL AREA 2015-01-20 - 1888-02A - Watertown Type 111 24-hr 2 Year Storm (NRCC) Rainfall=3.20" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 3 Time span=0.00-30.00 hrs, dt=0.05 hrs, 601 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method SubcatchmentP1-1: Garage Roof Area Runoff Area=24,366 sf 100.00% Impervious Runoff Depth=2.97" Tc=6.0 min CN=98 Runoff=1.70 cfs 0.138 of Subcatchment P2-1: Roof Area to IS2 Runoff Area=39,818 sf 100.00% Impervious Runoff Depth=2.97" Tc=6.0 min CN=98 Runoff=2.77 cfs 0.226 of Subcatchment P2-2: Flow to AM Runoff Area=6,975 sf 28.20% Impervious Runoff Depth=1.47" Tc=6.0 min CN=81 Runoff=0.27 cfs 0.020 of Subcatchment P3-1: Roof Area to IS3 Runoff Area=3,087 sf 100.00% Impervious Runoff Depth=2.97" Tc=6.0 min CN=98 Runoff=0.21 cfs 0.018 of Subcatchment P3-2: Pergola Area Runoff Area=2,395 sf 0.00% Impervious Runoff Depth=2.08" Tc=6.0 min CN=89 Runoff=0.13 cfs 0.010 of Subcatchment P3-3: Roof Area to IS3 Runoff Area=3,168 sf 100.00% Impervious Runoff Depth=2.97" Tc=6.0 min CN=98 Runoff=0.22 cfs 0.018 of SubcatchmentP4-1: Roof Area to IS4 Runoff Area=41,669 sf 100.00% Impervious Runoff Depth=2.97" Tc=6.0 min CN=98 Runoff=2.90 cfs 0.237 of Subcatchment P4-2: Entrance Area Runoff Area=10,793 sf 48.33% Impervious Runoff Depth=1.84" Tc=6.0 min CN=86 Runoff=0.52 cfs 0.038 of Subcatchment P5-1: Flow to IS5 Runoff Area=6,209 sf 71.94% Impervious Runoff Depth=2.26" Tc=6.0 min CN=91 Runoff=0.36 cfs 0.027 of Subcatchment P6-1: Flow to CB1 Runoff Area=7,262 sf 75.85% Impervious Runoff Depth=2.35" Tc=6.0 min CN=92 Runoff=0.44 cfs 0.033 of Subcatchment P6-2: Flow to CB2 Runoff Area=6,958 sf 59.83% Impervious Runoff Depth=2.00" Tc=6.0 min CN=88 Runoff=0.36 cfs 0.027 of Subcatchment P6-3: Flow to CB3 Runoff Area=3,660 sf 42.68% Impervious Runoff Depth=1.68" Tc=6.0 min CN=84 Runoff=0.16 cfs 0.012 of Subcatchment P6-4: Flow to CB3 Runoff Area=5,881 sf 52.90% Impervious Runoff Depth=1.91" Tc=6.0 min CN=87 Runoff=0.30 cfs 0.022 of Subcatchment P6-5: Flow to AD2 Runoff Area=3,757 sf 41.76% Impervious Runoff Depth=1.68" Tc=6.0 min CN=84 Runoff=0.17 cfs 0.012 of Subcatchment P6-6: Flow to AD2 Runoff Area=2,676 sf 43.68% Impervious Runoff Depth=1.68" Tc=6.0 min CN=84 Runoff=0.12 cfs 0.009 of Subcatchment P6-7: Flow to CB4 Runoff Area=8,662 sf 50.38% Impervious Runoff Depth=1.84" Tc=6.0 min CN=86 Runoff=0.42 cfs 0.030 of 2015-01-20 - 1888-02A - Watertown Type 111 24-hr 2 Year Storm (NRCC) Rainfall=3.20" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 4 Subcatchment P6-8: Flow to CB5 Runoff Area=7,481 sf 53.90% Impervious Runoff Depth=1.91" Tc=6.0 min CN=87 Runoff=0.38 cfs 0.027 of Subcatchment P6-9: Flow to Street Runoff Area=16,336 sf 74.87% Impervious Runoff Depth=2.35" Tc=6.0 min CN=92 Runoff=0.99 cfs 0.073 of Subcatchment P7-1: Flow to Abutting Runoff Area=29,867 sf 85.42% Impervious Runoff Depth=2.64" Tc=6.0 min CN=95 Runoff=1.96 cfs 0.151 of Reach SP1: (new Reach) Inflow=3.33 cfs 0.245 of Outflow=3.33 cfs 0.245 of Pond IS-1: Garage Infiltration Peak Elev=23.82' Storage=3,668 cf Inflow=1.70 cfs 0.138 of Discarded=0.05 cfs 0.090 of Primary=0.00 cfs 0.000 of Outflow=0.05 cfs 0.090 of Pond IS-2: Arsenal St Infiltration Peak Elev=25.98' Storage=7,719 cf Inflow=3.04 cfs 0.246 of Discarded=0.05 cfs 0.095 of Primary=0.00 cfs 0.000 of Outflow=0.05 cfs 0.095 of Pond IS-3: Pergola Infiltration Area Peak EIev=24.01' Storage=1,070 cf Inflow=0.57 cfs 0.045 of Discarded=0.02 cfs 0.039 of Primary=0.00 cfs 0.000 of Outflow=0.02 cfs 0.039 of Pond IS-4: Entrance Infiltration Area Peak EIev=25.58' Storage=7,862 cf Inflow=3.42 cfs 0.274 of Discarded=0.07 cfs 0.145 of Primary=0.00 cfs 0.000 of Outflow=0.07 cfs 0.145 of Pond IS5: Irving St Infiltration Area Peak EIev=24.11' Storage=633 cf Inflow=0.36 cfs 0.027 of Discarded=0.02 cfs 0.026 of Primary=0.00 cfs 0.000 of Outflow=0.02 cfs 0.026 of Total Runoff Area = 5.303 ac Runoff Volume = 1.126 of Average Runoff Depth = 2.55" 19.06% Pervious = 1.011 ac 80.94% Impervious = 4.292 ac 2015-01-20 - 1888-02A - Watertown Type 111 24-hr 2 Year Storm (NRCC) Rainfall=3.20" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 5 Summary for Subcatchment 131-1: Garage Roof Area Runoff = 1.70 cfs @ 12.09 hrs, Volume= 0.138 af, Depth= 2.97" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 2 Year Storm (NRCC) Rainfall=3.20" Area (sf) CN Description 24,366 98 Unconnected roofs, HSG C 24,366 100.00% Impervious Area 24,366 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment P2-1: Roof Area to IS2 Runoff = 2.77 cfs @ 12.09 hrs, Volume= 0.226 af, Depth= 2.97" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 2 Year Storm (NRCC) Rainfall=3.20" Area (sf) CN Description 39,818 98 Unconnected roofs, HSG C 39,818 100.00% Impervious Area 39,818 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment P2-2: Flow to AD1 Runoff = 0.27 cfs @ 12.10 hrs, Volume= 0.020 af, Depth= 1.47" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 2 Year Storm (NRCC) Rainfall=3.20" Area (sf) CN Description 5,008 74 >75% Grass cover, Good, HSG C 1,967 98 Paved parkinq, HSG C 6,975 81 Weighted Average 5,008 71.80% Pervious Area 1,967 28.20% Impervious Area 2015-01-20 - 1888-02A - Watertown Type 111 24-hr 2 Year Storm (NRCC) Rainfall=3.20" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 6 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment P3-1: Roof Area to IS3 Runoff = 0.21 cfs @ 12.09 hrs, Volume= 0.018 af, Depth= 2.97" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 2 Year Storm (NRCC) Rainfall=3.20" Area (sf) CN Description 3,087 98 Unconnected roofs, HSG C 3,087 100.00% Impervious Area 3,087 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment P3-2: Pergola Area Runoff = 0.13 cfs @ 12.09 hrs, Volume= 0.010 af, Depth= 2.08" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 2 Year Storm (NRCC) Rainfall=3.20" Area (sf) CN Description 2,395 89 Gravel roads, HSG C 2,395 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment P3-3: Roof Area to IS3 Runoff = 0.22 cfs @ 12.09 hrs, Volume= 0.018 af, Depth= 2.97" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 2 Year Storm (NRCC) Rainfall=3.20" Area (sf) CN Description 3,168 98 Unconnected roofs, HSG C 3,168 100.00% Impervious Area 3,168 100.00% Unconnected 2015-01-20 - 1888-02A - Watertown Type 111 24-hr 2 Year Storm (NRCC) Rainfall=3.20" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 7 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment P4-1: Roof Area to IS4 Runoff = 2.90 cfs @ 12.09 hrs, Volume= 0.237 af, Depth= 2.97" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 2 Year Storm (NRCC) Rainfall=3.20" Area (sf) CN Description 41,669 98 Unconnected roofs, HSG C 41,669 100.00% Impervious Area 41,669 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment P4-2: Entrance Area Runoff = 0.52 cfs @ 12.09 hrs, Volume= 0.038 af, Depth= 1.84" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 2 Year Storm (NRCC) Rainfall=3.20" Area (sf) CN Description 5,577 74 >75% Grass cover, Good, HSG C 5,216 98 Paved parkinq, HSG C 10,793 86 Weighted Average 5,577 51.67% Pervious Area 5,216 48.33% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment P5-1: Flow to IS5 Runoff = 0.36 cfs @ 12.09 hrs, Volume= 0.027 af, Depth= 2.26" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 2 Year Storm (NRCC) Rainfall=3.20" 2015-01-20 - 1888-02A - Watertown Type 111 24-hr 2 Year Storm (NRCC) Rainfall=3.20" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 8 Area (sf) CN Description 1,742 74 >75% Grass cover, Good, HSG C 4,467 98 Unconnected roofs, HSG C 6,209 91 Weighted Average 1,742 28.06% Pervious Area 4,467 71.94% Impervious Area 4,467 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment P6-1: Flow to CB1 Runoff = 0.44 cfs @ 12.09 hrs, Volume= 0.033 af, Depth= 2.35" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 2 Year Storm (NRCC) Rainfall=3.20" Area (sf) CN Description 1,754 74 >75% Grass cover, Good, HSG C 5,508 98 Paved parkinq, HSG C 7,262 92 Weighted Average 1,754 24.15% Pervious Area 5,508 75.85% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment P6-2: Flow to CB2 Runoff = 0.36 cfs @ 12.09 hrs, Volume= 0.027 af, Depth= 2.00" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 2 Year Storm (NRCC) Rainfall=3.20" Area (sf) CN Description 2,795 74 >75% Grass cover, Good, HSG C 4,163 98 Paved parkinq, HSG C 6,958 88 Weighted Average 2,795 40.17% Pervious Area 4,163 59.83% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, 2015-01-20 - 1888-02A - Watertown Type 111 24-hr 2 Year Storm (NRCC) Rainfall=3.20" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 9 Summary for Subcatchment P6-3: Flow to CB3 Runoff = 0.16 cfs @ 12.09 hrs, Volume= 0.012 af, Depth= 1.68" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 2 Year Storm (NRCC) Rainfall=3.20" Area (sf) CN Description 2,098 74 >75% Grass cover, Good, HSG C 1,562 98 Paved parking, HSG C 3,660 84 Weighted Average 2,098 57.32% Pervious Area 1,562 42.68% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 136-4: Flow to CB3 Runoff = 0.30 cfs @ 12.09 hrs, Volume= 0.022 af, Depth= 1.91" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 2 Year Storm (NRCC) Rainfall=3.20" Area (sf) CN Description 2,770 74 >75% Grass cover, Good, HSG C 3,111 98 Paved parking, HSG C 5,881 87 Weighted Average 2,770 47.10% Pervious Area 3,111 52.90% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 136-5: Flow to AD2 Runoff = 0.17 cfs @ 12.09 hrs, Volume= 0.012 af, Depth= 1.68" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 2 Year Storm (NRCC) Rainfall=3.20" Area (sf) CN Description 2,188 74 >75% Grass cover, Good, HSG C 1,569 98 Paved parkinq, HSG C 3,757 84 Weighted Average 2,188 58.24% Pervious Area 1,569 41.76% Impervious Area 2015-01-20 - 1888-02A - Watertown Type 111 24-hr 2 Year Storm (NRCC) Rainfall=3.20" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 10 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment P6-6: Flow to AD2 Runoff = 0.12 cfs @ 12.09 hrs, Volume= 0.009 af, Depth= 1.68" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 2 Year Storm (NRCC) Rainfall=3.20" Area (sf) CN Description 1,507 74 >75% Grass cover, Good, HSG C 1,169 98 Paved parkinq, HSG C 2,676 84 Weighted Average 1,507 56.32% Pervious Area 1,169 43.68% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment P6-7: Flow to CB4 Runoff = 0.42 cfs @ 12.09 hrs, Volume= 0.030 af, Depth= 1.84" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 2 Year Storm (NRCC) Rainfall=3.20" Area (sf) CN Description 4,298 74 >75% Grass cover, Good, HSG C 4,364 98 Paved parkinq, HSG C 8,662 86 Weighted Average 4,298 49.62% Pervious Area 4,364 50.38% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment P6-8: Flow to CB5 Runoff = 0.38 cfs @ 12.09 hrs, Volume= 0.027 af, Depth= 1.91" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 2 Year Storm (NRCC) Rainfall=3.20" 2015-01-20 - 1888-02A - Watertown Type 111 24-hr 2 Year Storm (NRCC) Rainfall=3.20" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 11 Area (sf) CN Description 3,449 74 >75% Grass cover, Good, HSG C 4,032 98 Paved parkinq, HSG C 7,481 87 Weighted Average 3,449 46.10% Pervious Area 4,032 53.90% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment P6-9: Flow to Street Runoff = 0.99 cfs @ 12.09 hrs, Volume= 0.073 af, Depth= 2.35" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 2 Year Storm (NRCC) Rainfall=3.20" Area (sf) CN Description 4,105 74 >75% Grass cover, Good, HSG C 12,231 98 Paved parking, HSG C 16,336 92 Weighted Average 4,105 25.13% Pervious Area 12,231 74.87% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment P7-1: Flow to Abutting Project CBs Runoff = 1.96 cfs @ 12.09 hrs, Volume= 0.151 af, Depth= 2.64" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 2 Year Storm (NRCC) Rainfall=3.20" Area (sf) CN Description 4,355 74 >75% Grass cover, Good, HSG C 25,512 98 Paved parkinq, HSG C 29,867 95 Weighted Average 4,355 14.58% Pervious Area 25,512 85.42% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, 2015-01-20 - 1888-02A - Watertown Type 111 24-hr 2 Year Storm (NRCC) Rainfall=3.20" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 12 Summary for Reach SP1: (new Reach) Inflow Area = 4.618 ac, 80.27% Impervious, Inflow Depth = 0.64" for 2 Year Storm (NRCC) event Inflow = 3.33 cfs @ 12.09 hrs, Volume= 0.245 of Outflow = 3.33 cfs @ 12.09 hrs, Volume= 0.245 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Summary for Pond IS-1: Garage Infiltration Inflow Area = 0.559 ac,100.00% Impervious, Inflow Depth = 2.97" for 2 Year Storm (NRCC) event Inflow = 1.70 cfs @ 12.09 hrs, Volume= 0.138 of Outflow = 0.05 cfs @ 9.05 hrs, Volume= 0.090 af, Atten= 97%, Lag= 0.0 min Discarded = 0.05 cfs @ 9.05 hrs, Volume= 0.090 of Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Peak Elev= 23.82' @ 16.16 hrs Surf.Area= 3,832 sf Storage= 3,668 cf Plug-Flow detention time= 428.1 min calculated for 0.090 of(65% of inflow) Center-of-Mass det. time= 328.6 min ( 1,085.0 - 756.4 ) Volume Invert Avail.Storage Storage Description #1 22.00' 6,483 cf Custom Stage Data (Prismatic)Listed below (Recalc) 22,992 cf Overall - 6,784 cf Embedded = 16,208 cf x 40.0% Voids #2 23.25' 6,784 cf ADS_StormTech MC-3500 c +Cap x 60 Inside#1 Effective Size= 70.4"W x 45.0"H => 15.33 sf x 7.17'L = 110.0 cf Overall Size= 77.0"W x 45.0"H x 7.50'L with 0.33' Overlap Cap Storage= +15.6 cf x 2 x 6 rows = 187.2 cf 13,267 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 22.00 3,832 0 0 28.00 3,832 22,992 22,992 Device Routing Invert Outlet Devices #1 Discarded 22.00' 0.520 in/hr Exfiltration over Surface area #2 Primary 23.00' 12.0" Round Culvert L= 53.0' CMP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 23.00' / 22.47' S= 0.0100 '/' Cc= 0.900 n= 0.013 Concrete pipe, bends & connections, Flow Area= 0.79 sf #3 Device 2 28.00' 4.0' long x 2.00' rise Sharp-Crested Rectangular Weir 2 End Contraction(s) 4.0' Crest Height Discarded OutFlow Max=0.05 cfs @ 9.05 hrs HW=22.08' (Free Discharge) L1=Exfiltration (Exfiltration Controls 0.05 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=22.00' (Free Discharge) L2=Culvert ( Controls 0.00 cfs) t-3=Sharp-Crested Rectangular Weir( Controls 0.00 cfs) 2015-01-20 - 1888-02A - Watertown Type /// 24-hr 2 Year Storm (NRCC) Rainfall=3.20" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 13 Summary for Pond IS-2: Arsenal St Infiltration Inflow Area = 1.074 ac, 89.30% Impervious, Inflow Depth = 2.74" for 2 Year Storm (NRCC) event Inflow = 3.04 cfs @ 12.09 hrs, Volume= 0.246 of Outflow = 0.05 cfs @ 7.95 hrs, Volume= 0.095 af, Atten= 98%, Lag= 0.0 min Discarded = 0.05 cfs @ 7.95 hrs, Volume= 0.095 of Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Peak Elev= 25.98' @ 19.44 hrs Surf.Area= 3,876 sf Storage= 7,719 cf Plug-Flow detention time= 445.2 min calculated for 0.095 of(39% of inflow) Center-of-Mass det. time= 295.8 min ( 1,058.8 - 763.0 ) Volume Invert Avail.Storage Storage Description #1 23.00' 5,784 cf Stone (Prismatic)Listed below (Recalc) 42,636 cf Overall - 28,175 cf Embedded = 14,461 cf x 40.0% Voids #2 24.17' 22,685 cf CONSPAN 16x 8 x 24 Inside #1 Inside= 192.0"W x 96.0"H => 118.15 sf x 8.00'L = 945.2 cf Outside= 212.0"W x 106.0"H => 146.74 sf x 8.00'L = 1,174.0 cf 28,469 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 23.00 3,876 0 0 34.00 3,876 42,636 42,636 Device Routinq Invert Outlet Devices #1 Discarded 23.00' 0.520 in/hr Exfiltration over Surface area #2 Primary 30.06' 12.0" Round Culvert L= 13.0' CMP, square edge headwall, Ke= 0.500 Inlet/Outlet Invert= 30.06' /29.80' S= 0.0200 T Cc= 0.900 n= 0.013 Concrete pipe, bends & connections, Flow Area= 0.79 sf #3 Device 2 33.75' 4.0' long x 2.00' rise Sharp-Crested Rectangular Weir 2 End Contraction(s) 4.0' Crest Height Discarded OutFlow Max=0.05 cfs @ 7.95 hrs HW=23.13' (Free Discharge) L1=Exfiltration (Exfiltration Controls 0.05 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=23.00' (Free Discharge) L2=Culvert ( Controls 0.00 cfs) L3=Sharp-Crested Rectangular Weir( Controls 0.00 cfs) Summary for Pond IS-3: Pergola Infiltration Area Inflow Area = 0.199 ac, 72.31% Impervious, Inflow Depth = 2.72" for 2 Year Storm (NRCC) event Inflow = 0.57 cfs @ 12.09 hrs, Volume= 0.045 of Outflow = 0.02 cfs @ 10.20 hrs, Volume= 0.039 af, Atten= 96%, Lag= 0.0 min Discarded = 0.02 cfs @ 10.20 hrs, Volume= 0.039 of Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 of 2015-01-20 - 1888-02A - Watertown Type 111 24-hr 2 Year Storm (NRCC) Rainfall=3.20" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 14 Routing by Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Peak Elev= 24.01' @ 15.39 hrs Surf.Area= 1,753 sf Storage= 1,070 cf Plug-Flow detention time= 414.3 min calculated for 0.039 of(87% of inflow) Center-of-Mass det. time= 354.4 min ( 1,122.4 - 768.0 ) Volume Invert Avail.Storage Storage Description #1 22.50' 2,727 cf Stone Area (Prismatic)Listed below (Recalc) 8,765 cf Overall - 1,946 cf Embedded = 6,819 cf x 40.0% Voids #2 24.00' 1,946 cf ADS_StormTech SC-740 x 42 Inside#1 Effective Size= 44.6"W x 30.0"H => 6.45 sf x 7.121 = 45.9 cf Overall Size= 51.0"W x 30.0"H x 7.56'L with 0.44' Overlap Row Length Adjustment= +0.44' x 6.45 sf x 6 rows 4,674 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 22.50 1,753 0 0 27.50 1,753 8,765 8,765 Device Routing Invert Outlet Devices #1 Discarded 22.50' 0.520 in/hr Exfiltration over Surface area #2 Primary 23.50' 12.0" Round Culvert L= 30.0' RCP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 23.50' / 22.90' S= 0.0200 T Cc= 0.900 n= 0.013 Concrete pipe, bends & connections, Flow Area= 0.79 sf #3 Device 2 27.00' 4.0' long x 2.00' rise Sharp-Crested Rectangular Weir 2 End Contraction(s) 4.0' Crest Height Discarded OutFlow Max=0.02 cfs @ 10.20 hrs HW=22.57' (Free Discharge) L1=Exfiltration (Exfiltration Controls 0.02 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=22.50' (Free Discharge) L2=Culvert ( Controls 0.00 cfs) t-3=Sharp-Crested Rectangular Weir( Controls 0.00 cfs) Summary for Pond IS-4: Entrance Infiltration Area Inflow Area = 1.204 ac, 89.37% Impervious, Inflow Depth = 2.73" for 2 Year Storm (NRCC) event Inflow = 3.42 cfs @ 12.09 hrs, Volume= 0.274 of Outflow = 0.07 cfs @ 8.95 hrs, Volume= 0.145 af, Atten= 98%, Lag= 0.0 min Discarded = 0.07 cfs @ 8.95 hrs, Volume= 0.145 of Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Peak Elev= 25.58' @ 17.36 hrs Surf.Area= 6,129 sf Storage= 7,862 cf Plug-Flow detention time= 436.5 min calculated for 0.144 of(53% of inflow) Center-of-Mass det. time= 318.4 min ( 1,083.9 - 765.5 ) 2015-01-20 - 1888-02A - Watertown Type 111 24-hr 2 Year Storm (NRCC) Rainfall=3.20" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 15 Volume Invert Avail.Storage Storage Description #1 23.00' 13,271 cf Custom Stage Data (Prismatic)Listed below (Recalc) 49,032 cf Overall - 15,853 cf Embedded = 33,179 cf x 40.0% Voids #2 25.00' 15,853 cf ADS_StormTech MC-4500 +Cap @ 4.03' Lx 144 Inside #1 Effective Size= 90.4"W x 60.0"H => 26.46 sf x 4.031 = 106.6 cf Overall Size= 100.0"W x 60.0"H x 4.331 with 0.31' Overlap Cap Storage= +35.7 cf x 2 x 7 rows = 499.8 cf 29,125 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 23.00 6,129 0 0 31.00 6,129 49,032 49,032 Device Routing Invert Outlet Devices #1 Discarded 23.00' 0.520 in/hr Exfiltration over Surface area #2 Primary 25.00' 12.0" Round Culvert L= 123.0' RCP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 25.00' / 21.31' S= 0.0300 T Cc= 0.900 n= 0.013 Concrete pipe, bends & connections, Flow Area= 0.79 sf #3 Device 2 31.00' 4.0' long x 2.00' rise Sharp-Crested Rectangular Weir 2 End Contraction(s) 4.0' Crest Height Discarded OutFlow Max=0.07 cfs @ 8.95 hrs HW=23.10' (Free Discharge) L1=Exfiltration (Exfiltration Controls 0.07 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=23.00' (Free Discharge) L2=Culvert ( Controls 0.00 cfs) L3=Sharp-Crested Rectangular Weir( Controls 0.00 cfs) Summary for Pond ISS: Irving St Infiltration Area Inflow Area = 0.143 ac, 71.94% Impervious, Inflow Depth = 2.26" for 2 Year Storm (NRCC) event Inflow = 0.36 cfs @ 12.09 hrs, Volume= 0.027 of Outflow = 0.02 cfs @ 11.10 hrs, Volume= 0.026 af, Atten= 96%, Lag= 0.0 min Discarded = 0.02 cfs @ 11.10 hrs, Volume= 0.026 of Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Peak Elev= 24.11' @ 15.16 hrs Surf.Area= 1,295 sf Storage= 633 cf Plug-Flow detention time= 392.4 min calculated for 0.026 of(98% of inflow) Center-of-Mass det. time= 381.3 min ( 1,183.7 - 802.5 ) Volume Invert Avail.Storage Storage Description #1 23.00' 1,479 cf Custom Stage Data (Prismatic)Listed below (Recalc) 5,180 cf Overall - 1,481 cf Embedded = 3,699 cf x 40.0% Voids #2 24.00' 1,481 cf ADS_StormTech SC-740 x 32 Inside#1 Effective Size= 44.6"W x 30.0"H => 6.45 sf x 7.121 = 45.9 cf Overall Size= 51.0"W x 30.0"H x 7.56'L with 0.44' Overlap Row Length Adjustment= +0.44' x 6.45 sf x 4 rows 2015-01-20 - 1888-02A - Watertown Type /// 24-hr 2 Year Storm (NRCC) Rainfall=3.20" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 16 2,961 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 23.00 1,295 0 0 27.00 1,295 5,180 5,180 Device Routinq Invert Outlet Devices #1 Discarded 23.00' 0.520 in/hr Exfiltration over Surface area #2 Primary 21.38' 12.0" Round Culvert L= 19.0' RCP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 21.38' / 21.00' S= 0.0200 T Cc= 0.900 n= 0.013 Concrete pipe, bends & connections, Flow Area= 0.79 sf #3 Device 2 27.00' 4.0' long x 2.00' rise Sharp-Crested Rectangular Weir 2 End Contraction(s) 4.0' Crest Height Discarded OutFlow Max=0.02 cfs @ 11.10 hrs HW=23.06' (Free Discharge) L1=Exfiltration (Exfiltration Controls 0.02 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=23.00' (Free Discharge) L2=Culvert (Passes 0.00 cfs of 4.00 cfs potential flow) L3=Sharp-Crested Rectangular Weir( Controls 0.00 cfs) 2015-01-20 - 1888-02A - Watertown Type 111 24-hr 10 Year Storm (NRCC) Rainfall=4.80" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 17 Time span=0.00-30.00 hrs, dt=0.05 hrs, 601 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method SubcatchmentP1-1: Garage Roof Area Runoff Area=24,366 sf 100.00% Impervious Runoff Depth=4.56" Tc=6.0 min CN=98 Runoff=2.56 cfs 0.213 of Subcatchment P2-1: Roof Area to IS2 Runoff Area=39,818 sf 100.00% Impervious Runoff Depth=4.56" Tc=6.0 min CN=98 Runoff=4.19 cfs 0.348 of Subcatchment P2-2: Flow to AM Runoff Area=6,975 sf 28.20% Impervious Runoff Depth=2.81" Tc=6.0 min CN=81 Runoff=0.52 cfs 0.037 of Subcatchment P3-1: Roof Area to IS3 Runoff Area=3,087 sf 100.00% Impervious Runoff Depth=4.56" Tc=6.0 min CN=98 Runoff=0.32 cfs 0.027 of Subcatchment P3-2: Pergola Area Runoff Area=2,395 sf 0.00% Impervious Runoff Depth=3.58" Tc=6.0 min CN=89 Runoff=0.22 cfs 0.016 of Subcatchment P3-3: Roof Area to IS3 Runoff Area=3,168 sf 100.00% Impervious Runoff Depth=4.56" Tc=6.0 min CN=98 Runoff=0.33 cfs 0.028 of SubcatchmentP4-1: Roof Area to IS4 Runoff Area=41,669 sf 100.00% Impervious Runoff Depth=4.56" Tc=6.0 min CN=98 Runoff=4.38 cfs 0.364 of Subcatchment P4-2: Entrance Area Runoff Area=10,793 sf 48.33% Impervious Runoff Depth=3.28" Tc=6.0 min CN=86 Runoff=0.92 cfs 0.068 of Subcatchment P5-1: Flow to IS5 Runoff Area=6,209 sf 71.94% Impervious Runoff Depth=3.79" Tc=6.0 min CN=91 Runoff=0.59 cfs 0.045 of Subcatchment P6-1: Flow to CB1 Runoff Area=7,262 sf 75.85% Impervious Runoff Depth=3.89" Tc=6.0 min CN=92 Runoff=0.71 cfs 0.054 of Subcatchment P6-2: Flow to CB2 Runoff Area=6,958 sf 59.83% Impervious Runoff Depth=3.48" Tc=6.0 min CN=88 Runoff=0.62 cfs 0.046 of Subcatchment P6-3: Flow to CB3 Runoff Area=3,660 sf 42.68% Impervious Runoff Depth=3.09" Tc=6.0 min CN=84 Runoff=0.30 cfs 0.022 of Subcatchment P6-4: Flow to CB3 Runoff Area=5,881 sf 52.90% Impervious Runoff Depth=3.38" Tc=6.0 min CN=87 Runoff=0.51 cfs 0.038 of Subcatchment P6-5: Flow to AD2 Runoff Area=3,757 sf 41.76% Impervious Runoff Depth=3.09" Tc=6.0 min CN=84 Runoff=0.30 cfs 0.022 of Subcatchment P6-6: Flow to AD2 Runoff Area=2,676 sf 43.68% Impervious Runoff Depth=3.09" Tc=6.0 min CN=84 Runoff=0.22 cfs 0.016 of Subcatchment P6-7: Flow to CB4 Runoff Area=8,662 sf 50.38% Impervious Runoff Depth=3.28" Tc=6.0 min CN=86 Runoff=0.74 cfs 0.054 of 2015-01-20 - 1888-02A - Watertown Type 111 24-hr 10 Year Storm (NRCC) Rainfall=4.80" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 18 Subcatchment P6-8: Flow to CB5 Runoff Area=7,481 sf 53.90% Impervious Runoff Depth=3.38" Tc=6.0 min CN=87 Runoff=0.65 cfs 0.048 of Subcatchment P6-9: Flow to Street Runoff Area=16,336 sf 74.87% Impervious Runoff Depth=3.89" Tc=6.0 min CN=92 Runoff=1.59 cfs 0.122 of Subcatchment P7-1: Flow to Abutting Runoff Area=29,867 sf 85.42% Impervious Runoff Depth=4.22" Tc=6.0 min CN=95 Runoff=3.05 cfs 0.241 of Reach SP1: (new Reach) Inflow=5.65 cfs 0.422 of Outflow=5.65 cfs 0.422 of Pond IS-1: Garage Infiltration Peak Elev=24.72' Storage=6,327 cf Inflow=2.56 cfs 0.213 of Discarded=0.05 cfs 0.097 of Primary=0.00 cfs 0.000 of Outflow=0.05 cfs 0.097 of Pond IS-2: Arsenal St Infiltration Peak EIev=27.70' Storage=13,353 cf Inflow=4.71 cfs 0.385 of Discarded=0.05 cfs 0.102 of Primary=0.00 cfs 0.000 of Outflow=0.05 cfs 0.102 of Pond IS-3: Pergola Infiltration Area Peak EIev=24.66' Storage=1,944 cf Inflow=0.88 cfs 0.071 of Discarded=0.02 cfs 0.042 of Primary=0.00 cfs 0.000 of Outflow=0.02 cfs 0.042 of Pond IS-4: Entrance Infiltration Area Peak EIev=26.77' Storage=13,783 cf Inflow=5.31 cfs 0.432 of Discarded=0.07 cfs 0.155 of Primary=0.00 cfs 0.000 of Outflow=0.07 cfs 0.155 of Pond IS5: Irving St Infiltration Area Peak EIev=24.71' Storage=1,236 cf Inflow=0.59 cfs 0.045 of Discarded=0.02 cfs 0.028 of Primary=0.00 cfs 0.000 of Outflow=0.02 cfs 0.028 of Total Runoff Area = 5.303 ac Runoff Volume = 1.809 of Average Runoff Depth = 4.09" 19.06% Pervious = 1.011 ac 80.94% Impervious = 4.292 ac 2015-01-20 - 1888-02A - Watertown Type 111 24-hr 10 Year Storm (NRCC) Rainfall=4.80" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 19 Summary for Subcatchment 131-1: Garage Roof Area Runoff = 2.56 cfs @ 12.09 hrs, Volume= 0.213 af, Depth= 4.56" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 10 Year Storm (NRCC) Rainfall=4.80" Area (sf) CN Description 24,366 98 Unconnected roofs, HSG C 24,366 100.00% Impervious Area 24,366 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment P2-1: Roof Area to IS2 Runoff = 4.19 cfs @ 12.09 hrs, Volume= 0.348 af, Depth= 4.56" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 10 Year Storm (NRCC) Rainfall=4.80" Area (sf) CN Description 39,818 98 Unconnected roofs, HSG C 39,818 100.00% Impervious Area 39,818 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment P2-2: Flow to AD1 Runoff = 0.52 cfs @ 12.09 hrs, Volume= 0.037 af, Depth= 2.81" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 10 Year Storm (NRCC) Rainfall=4.80" Area (sf) CN Description 5,008 74 >75% Grass cover, Good, HSG C 1,967 98 Paved parkinq, HSG C 6,975 81 Weighted Average 5,008 71.80% Pervious Area 1,967 28.20% Impervious Area 2015-01-20 - 1888-02A - Watertown Type 111 24-hr 10 Year Storm (NRCC) Rainfall=4.80" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 20 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment P3-1: Roof Area to IS3 Runoff = 0.32 cfs @ 12.09 hrs, Volume= 0.027 af, Depth= 4.56" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 10 Year Storm (NRCC) Rainfall=4.80" Area (sf) CN Description 3,087 98 Unconnected roofs, HSG C 3,087 100.00% Impervious Area 3,087 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment P3-2: Pergola Area Runoff = 0.22 cfs @ 12.09 hrs, Volume= 0.016 af, Depth= 3.58" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 10 Year Storm (NRCC) Rainfall=4.80" Area (sf) CN Description 2,395 89 Gravel roads, HSG C 2,395 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment P3-3: Roof Area to IS3 Runoff = 0.33 cfs @ 12.09 hrs, Volume= 0.028 af, Depth= 4.56" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 10 Year Storm (NRCC) Rainfall=4.80" Area (sf) CN Description 3,168 98 Unconnected roofs, HSG C 3,168 100.00% Impervious Area 3,168 100.00% Unconnected 2015-01-20 - 1888-02A - Watertown Type 111 24-hr 10 Year Storm (NRCC) Rainfall=4.80" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 21 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment P4-1: Roof Area to IS4 Runoff = 4.38 cfs @ 12.09 hrs, Volume= 0.364 af, Depth= 4.56" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 10 Year Storm (NRCC) Rainfall=4.80" Area (sf) CN Description 41,669 98 Unconnected roofs, HSG C 41,669 100.00% Impervious Area 41,669 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment P4-2: Entrance Area Runoff = 0.92 cfs @ 12.09 hrs, Volume= 0.068 af, Depth= 3.28" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 10 Year Storm (NRCC) Rainfall=4.80" Area (sf) CN Description 5,577 74 >75% Grass cover, Good, HSG C 5,216 98 Paved parkinq, HSG C 10,793 86 Weighted Average 5,577 51.67% Pervious Area 5,216 48.33% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment P5-1: Flow to IS5 Runoff = 0.59 cfs @ 12.09 hrs, Volume= 0.045 af, Depth= 3.79" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 10 Year Storm (NRCC) Rainfall=4.80" 2015-01-20 - 1888-02A - Watertown Type 111 24-hr 10 Year Storm (NRCC) Rainfall=4.80" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 22 Area (sf) CN Description 1,742 74 >75% Grass cover, Good, HSG C 4,467 98 Unconnected roofs, HSG C 6,209 91 Weighted Average 1,742 28.06% Pervious Area 4,467 71.94% Impervious Area 4,467 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment P6-1: Flow to CB1 Runoff = 0.71 cfs @ 12.09 hrs, Volume= 0.054 af, Depth= 3.89" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 10 Year Storm (NRCC) Rainfall=4.80" Area (sf) CN Description 1,754 74 >75% Grass cover, Good, HSG C 5,508 98 Paved parkinq, HSG C 7,262 92 Weighted Average 1,754 24.15% Pervious Area 5,508 75.85% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment P6-2: Flow to CB2 Runoff = 0.62 cfs @ 12.09 hrs, Volume= 0.046 af, Depth= 3.48" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 10 Year Storm (NRCC) Rainfall=4.80" Area (sf) CN Description 2,795 74 >75% Grass cover, Good, HSG C 4,163 98 Paved parkinq, HSG C 6,958 88 Weighted Average 2,795 40.17% Pervious Area 4,163 59.83% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, 2015-01-20 - 1888-02A - Watertown Type 111 24-hr 10 Year Storm (NRCC) Rainfall=4.80" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 23 Summary for Subcatchment P6-3: Flow to CB3 Runoff = 0.30 cfs @ 12.09 hrs, Volume= 0.022 af, Depth= 3.09" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 10 Year Storm (NRCC) Rainfall=4.80" Area (sf) CN Description 2,098 74 >75% Grass cover, Good, HSG C 1,562 98 Paved parking, HSG C 3,660 84 Weighted Average 2,098 57.32% Pervious Area 1,562 42.68% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 136-4: Flow to CB3 Runoff = 0.51 cfs @ 12.09 hrs, Volume= 0.038 af, Depth= 3.38" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 10 Year Storm (NRCC) Rainfall=4.80" Area (sf) CN Description 2,770 74 >75% Grass cover, Good, HSG C 3,111 98 Paved parking, HSG C 5,881 87 Weighted Average 2,770 47.10% Pervious Area 3,111 52.90% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 136-5: Flow to AD2 Runoff = 0.30 cfs @ 12.09 hrs, Volume= 0.022 af, Depth= 3.09" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 10 Year Storm (NRCC) Rainfall=4.80" Area (sf) CN Description 2,188 74 >75% Grass cover, Good, HSG C 1,569 98 Paved parkinq, HSG C 3,757 84 Weighted Average 2,188 58.24% Pervious Area 1,569 41.76% Impervious Area 2015-01-20 - 1888-02A - Watertown Type 111 24-hr 10 Year Storm (NRCC) Rainfall=4.80" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 24 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment P6-6: Flow to AD2 Runoff = 0.22 cfs @ 12.09 hrs, Volume= 0.016 af, Depth= 3.09" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 10 Year Storm (NRCC) Rainfall=4.80" Area (sf) CN Description 1,507 74 >75% Grass cover, Good, HSG C 1,169 98 Paved parkinq, HSG C 2,676 84 Weighted Average 1,507 56.32% Pervious Area 1,169 43.68% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment P6-7: Flow to CB4 Runoff = 0.74 cfs @ 12.09 hrs, Volume= 0.054 af, Depth= 3.28" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 10 Year Storm (NRCC) Rainfall=4.80" Area (sf) CN Description 4,298 74 >75% Grass cover, Good, HSG C 4,364 98 Paved parkinq, HSG C 8,662 86 Weighted Average 4,298 49.62% Pervious Area 4,364 50.38% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment P6-8: Flow to CB5 Runoff = 0.65 cfs @ 12.09 hrs, Volume= 0.048 af, Depth= 3.38" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 10 Year Storm (NRCC) Rainfall=4.80" 2015-01-20 - 1888-02A - Watertown Type 111 24-hr 10 Year Storm (NRCC) Rainfall=4.80" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 25 Area (sf) CN Description 3,449 74 >75% Grass cover, Good, HSG C 4,032 98 Paved parkinq, HSG C 7,481 87 Weighted Average 3,449 46.10% Pervious Area 4,032 53.90% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment P6-9: Flow to Street Runoff = 1.59 cfs @ 12.09 hrs, Volume= 0.122 af, Depth= 3.89" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 10 Year Storm (NRCC) Rainfall=4.80" Area (sf) CN Description 4,105 74 >75% Grass cover, Good, HSG C 12,231 98 Paved parking, HSG C 16,336 92 Weighted Average 4,105 25.13% Pervious Area 12,231 74.87% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment P7-1: Flow to Abutting Project CBs Runoff = 3.05 cfs @ 12.09 hrs, Volume= 0.241 af, Depth= 4.22" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 10 Year Storm (NRCC) Rainfall=4.80" Area (sf) CN Description 4,355 74 >75% Grass cover, Good, HSG C 25,512 98 Paved parkinq, HSG C 29,867 95 Weighted Average 4,355 14.58% Pervious Area 25,512 85.42% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, 2015-01-20 - 1888-02A - Watertown Type /// 24-hr 10 Year Storm (NRCC) Rainfall=4.80" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 26 Summary for Reach SP1: (new Reach) Inflow Area = 4.618 ac, 80.27% Impervious, Inflow Depth = 1.10" for 10 Year Storm (NRCC) event Inflow = 5.65 cfs @ 12.09 hrs, Volume= 0.422 of Outflow = 5.65 cfs @ 12.09 hrs, Volume= 0.422 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Summary for Pond IS-1: Garage Infiltration Inflow Area = 0.559 ac,100.00% Impervious, Inflow Depth = 4.56" for 10 Year Storm (NRCC) event Inflow = 2.56 cfs @ 12.09 hrs, Volume= 0.213 of Outflow = 0.05 cfs @ 7.50 hrs, Volume= 0.097 af, Atten= 98%, Lag= 0.0 min Discarded = 0.05 cfs @ 7.50 hrs, Volume= 0.097 of Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Peak Elev= 24.72' @ 17.88 hrs Surf.Area= 3,832 sf Storage= 6,327 cf Plug-Flow detention time= 425.6 min calculated for 0.097 of(46% of inflow) Center-of-Mass det. time= 286.0 min ( 1,034.7 - 748.7 ) Volume Invert Avail.Storage Storage Description #1 22.00' 6,483 cf Custom Stage Data (Prismatic)Listed below (Recalc) 22,992 cf Overall - 6,784 cf Embedded = 16,208 cf x 40.0% Voids #2 23.25' 6,784 cf ADS_StormTech MC-3500 c +Cap x 60 Inside#1 Effective Size= 70.4"W x 45.0"H => 15.33 sf x 7.17'L = 110.0 cf Overall Size= 77.0"W x 45.0"H x 7.50'L with 0.33' Overlap Cap Storage= +15.6 cf x 2 x 6 rows = 187.2 cf 13,267 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 22.00 3,832 0 0 28.00 3,832 22,992 22,992 Device Routing Invert Outlet Devices #1 Discarded 22.00' 0.520 in/hr Exfiltration over Surface area #2 Primary 23.00' 12.0" Round Culvert L= 53.0' CMP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 23.00' / 22.47' S= 0.0100 '/' Cc= 0.900 n= 0.013 Concrete pipe, bends & connections, Flow Area= 0.79 sf #3 Device 2 28.00' 4.0' long x 2.00' rise Sharp-Crested Rectangular Weir 2 End Contraction(s) 4.0' Crest Height Discarded OutFlow Max=0.05 cfs @ 7.50 hrs HW=22.08' (Free Discharge) L1=Exfiltration (Exfiltration Controls 0.05 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=22.00' (Free Discharge) L2=Culvert ( Controls 0.00 cfs) t-3=Sharp-Crested Rectangular Weir( Controls 0.00 cfs) 2015-01-20 - 1888-02A - Watertown Type /// 24-hr 10 Year Storm (NRCC) Rainfall=4.80" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 27 Summary for Pond IS-2: Arsenal St Infiltration Inflow Area = 1.074 ac, 89.30% Impervious, Inflow Depth = 4.30" for 10 Year Storm (NRCC) event Inflow = 4.71 cfs @ 12.09 hrs, Volume= 0.385 of Outflow = 0.05 cfs @ 6.00 hrs, Volume= 0.102 af, Atten= 99%, Lag= 0.0 min Discarded = 0.05 cfs @ 6.00 hrs, Volume= 0.102 of Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Peak Elev= 27.70' @ 23.51 hrs Surf.Area= 3,876 sf Storage= 13,353 cf Plug-Flow detention time= 463.0 min calculated for 0.102 of(26% of inflow) Center-of-Mass det. time= 254.0 min ( 1,009.7 - 755.7 ) Volume Invert Avail.Storage Storage Description #1 23.00' 5,784 cf Stone (Prismatic)Listed below (Recalc) 42,636 cf Overall - 28,175 cf Embedded = 14,461 cf x 40.0% Voids #2 24.17' 22,685 cf CONSPAN 16x 8 x 24 Inside #1 Inside= 192.0"W x 96.0"H => 118.15 sf x 8.00'L = 945.2 cf Outside= 212.0"W x 106.0"H => 146.74 sf x 8.00'L = 1,174.0 cf 28,469 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 23.00 3,876 0 0 34.00 3,876 42,636 42,636 Device Routinq Invert Outlet Devices #1 Discarded 23.00' 0.520 in/hr Exfiltration over Surface area #2 Primary 30.06' 12.0" Round Culvert L= 13.0' CMP, square edge headwall, Ke= 0.500 Inlet/Outlet Invert= 30.06' /29.80' S= 0.0200 T Cc= 0.900 n= 0.013 Concrete pipe, bends & connections, Flow Area= 0.79 sf #3 Device 2 33.75' 4.0' long x 2.00' rise Sharp-Crested Rectangular Weir 2 End Contraction(s) 4.0' Crest Height Discarded OutFlow Max=0.05 cfs @ 6.00 hrs HW=23.13' (Free Discharge) L1=Exfiltration (Exfiltration Controls 0.05 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=23.00' (Free Discharge) L2=Culvert ( Controls 0.00 cfs) L3=Sharp-Crested Rectangular Weir( Controls 0.00 cfs) Summary for Pond IS-3: Pergola Infiltration Area Inflow Area = 0.199 ac, 72.31% Impervious, Inflow Depth = 4.29" for 10 Year Storm (NRCC) event Inflow = 0.88 cfs @ 12.09 hrs, Volume= 0.071 of Outflow = 0.02 cfs @ 8.85 hrs, Volume= 0.042 af, Atten= 98%, Lag= 0.0 min Discarded = 0.02 cfs @ 8.85 hrs, Volume= 0.042 of Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 of 2015-01-20 - 1888-02A - Watertown Type /// 24-hr 10 Year Storm (NRCC) Rainfall=4.80" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 28 Routing by Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Peak Elev= 24.66' @ 16.83 hrs Surf.Area= 1,753 sf Storage= 1,944 cf Plug-Flow detention time= 424.6 min calculated for 0.042 of(59% of inflow) Center-of-Mass det. time= 315.0 min ( 1,074.6 - 759.6 ) Volume Invert Avail.Storage Storage Description #1 22.50' 2,727 cf Stone Area (Prismatic)Listed below (Recalc) 8,765 cf Overall - 1,946 cf Embedded = 6,819 cf x 40.0% Voids #2 24.00' 1,946 cf ADS_StormTech SC-740 x 42 Inside#1 Effective Size= 44.6"W x 30.0"H => 6.45 sf x 7.121 = 45.9 cf Overall Size= 51.0"W x 30.0"H x 7.56'L with 0.44' Overlap Row Length Adjustment= +0.44' x 6.45 sf x 6 rows 4,674 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 22.50 1,753 0 0 27.50 1,753 8,765 8,765 Device Routing Invert Outlet Devices #1 Discarded 22.50' 0.520 in/hr Exfiltration over Surface area #2 Primary 23.50' 12.0" Round Culvert L= 30.0' RCP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 23.50' / 22.90' S= 0.0200 T Cc= 0.900 n= 0.013 Concrete pipe, bends & connections, Flow Area= 0.79 sf #3 Device 2 27.00' 4.0' long x 2.00' rise Sharp-Crested Rectangular Weir 2 End Contraction(s) 4.0' Crest Height Discarded OutFlow Max=0.02 cfs @ 8.85 hrs HW=22.57' (Free Discharge) L1=Exfiltration (Exfiltration Controls 0.02 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=22.50' (Free Discharge) L2=Culvert ( Controls 0.00 cfs) t-3=Sharp-Crested Rectangular Weir( Controls 0.00 cfs) Summary for Pond IS-4: Entrance Infiltration Area Inflow Area = 1.204 ac, 89.37% Impervious, Inflow Depth = 4.30" for 10 Year Storm (NRCC) event Inflow = 5.31 cfs @ 12.09 hrs, Volume= 0.432 of Outflow = 0.07 cfs @ 7.30 hrs, Volume= 0.155 af, Atten= 99%, Lag= 0.0 min Discarded = 0.07 cfs @ 7.30 hrs, Volume= 0.155 of Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Peak Elev= 26.77' @ 20.20 hrs Surf.Area= 6,129 sf Storage= 13,783 cf Plug-Flow detention time= 437.6 min calculated for 0.155 of(36% of inflow) Center-of-Mass det. time= 275.8 min ( 1,033.5 - 757.7 ) 2015-01-20 - 1888-02A - Watertown Type /// 24-hr 10 Year Storm (NRCC) Rainfall=4.80" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 29 Volume Invert Avail.Storage Storage Description #1 23.00' 13,271 cf Custom Stage Data (Prismatic)Listed below (Recalc) 49,032 cf Overall - 15,853 cf Embedded = 33,179 cf x 40.0% Voids #2 25.00' 15,853 cf ADS_StormTech MC-4500 +Cap @ 4.03' Lx 144 Inside #1 Effective Size= 90.4"W x 60.0"H => 26.46 sf x 4.031 = 106.6 cf Overall Size= 100.0"W x 60.0"H x 4.331 with 0.31' Overlap Cap Storage= +35.7 cf x 2 x 7 rows = 499.8 cf 29,125 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 23.00 6,129 0 0 31.00 6,129 49,032 49,032 Device Routing Invert Outlet Devices #1 Discarded 23.00' 0.520 in/hr Exfiltration over Surface area #2 Primary 25.00' 12.0" Round Culvert L= 123.0' RCP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 25.00' / 21.31' S= 0.0300 T Cc= 0.900 n= 0.013 Concrete pipe, bends & connections, Flow Area= 0.79 sf #3 Device 2 31.00' 4.0' long x 2.00' rise Sharp-Crested Rectangular Weir 2 End Contraction(s) 4.0' Crest Height Discarded OutFlow Max=0.07 cfs @ 7.30 hrs HW=23.10' (Free Discharge) L1=Exfiltration (Exfiltration Controls 0.07 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=23.00' (Free Discharge) L2=Culvert ( Controls 0.00 cfs) L3=Sharp-Crested Rectangular Weir( Controls 0.00 cfs) Summary for Pond ISS: Irving St Infiltration Area Inflow Area = 0.143 ac, 71.94% Impervious, Inflow Depth = 3.79" for 10 Year Storm (NRCC) event Inflow = 0.59 cfs @ 12.09 hrs, Volume= 0.045 of Outflow = 0.02 cfs @ 9.80 hrs, Volume= 0.028 af, Atten= 97%, Lag= 0.0 min Discarded = 0.02 cfs @ 9.80 hrs, Volume= 0.028 of Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Peak Elev= 24.71' @ 16.60 hrs Surf.Area= 1,295 sf Storage= 1,236 cf Plug-Flow detention time= 450.8 min calculated for 0.028 of(63% of inflow) Center-of-Mass det. time= 350.7 min ( 1,138.9 - 788.2 ) Volume Invert Avail.Storage Storage Description #1 23.00' 1,479 cf Custom Stage Data (Prismatic)Listed below (Recalc) 5,180 cf Overall - 1,481 cf Embedded = 3,699 cf x 40.0% Voids #2 24.00' 1,481 cf ADS_StormTech SC-740 x 32 Inside#1 Effective Size= 44.6"W x 30.0"H => 6.45 sf x 7.121 = 45.9 cf Overall Size= 51.0"W x 30.0"H x 7.56'L with 0.44' Overlap Row Length Adjustment= +0.44' x 6.45 sf x 4 rows 2015-01-20 - 1888-02A - Watertown Type /// 24-hr 10 Year Storm (NRCC) Rainfall=4.80" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 30 2,961 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 23.00 1,295 0 0 27.00 1,295 5,180 5,180 Device Routinq Invert Outlet Devices #1 Discarded 23.00' 0.520 in/hr Exfiltration over Surface area #2 Primary 21.38' 12.0" Round Culvert L= 19.0' RCP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 21.38' / 21.00' S= 0.0200 T Cc= 0.900 n= 0.013 Concrete pipe, bends & connections, Flow Area= 0.79 sf #3 Device 2 27.00' 4.0' long x 2.00' rise Sharp-Crested Rectangular Weir 2 End Contraction(s) 4.0' Crest Height Discarded OutFlow Max=0.02 cfs @ 9.80 hrs HW=23.06' (Free Discharge) L1=Exfiltration (Exfiltration Controls 0.02 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=23.00' (Free Discharge) L2=Culvert (Passes 0.00 cfs of 4.00 cfs potential flow) L3=Sharp-Crested Rectangular Weir( Controls 0.00 cfs) 2015-01-20 - 1888-02A - Watertown Type 111 24-hr 50 Year Storm (NRCC) Rainfall=7.00" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 31 Time span=0.00-30.00 hrs, dt=0.05 hrs, 601 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method SubcatchmentP1-1: Garage Roof Area Runoff Area=24,366 sf 100.00% Impervious Runoff Depth=6.76" Tc=6.0 min CN=98 Runoff=3.75 cfs 0.315 of Subcatchment P2-1: Roof Area to IS2 Runoff Area=39,818 sf 100.00% Impervious Runoff Depth=6.76" Tc=6.0 min CN=98 Runoff=6.13 cfs 0.515 of Subcatchment P2-2: Flow to AM Runoff Area=6,975 sf 28.20% Impervious Runoff Depth=4.81" Tc=6.0 min CN=81 Runoff=0.87 cfs 0.064 of Subcatchment P3-1: Roof Area to IS3 Runoff Area=3,087 sf 100.00% Impervious Runoff Depth=6.76" Tc=6.0 min CN=98 Runoff=0.48 cfs 0.040 of Subcatchment P3-2: Pergola Area Runoff Area=2,395 sf 0.00% Impervious Runoff Depth=5.71" Tc=6.0 min CN=89 Runoff=0.34 cfs 0.026 of Subcatchment P3-3: Roof Area to IS3 Runoff Area=3,168 sf 100.00% Impervious Runoff Depth=6.76" Tc=6.0 min CN=98 Runoff=0.49 cfs 0.041 of SubcatchmentP4-1: Roof Area to IS4 Runoff Area=41,669 sf 100.00% Impervious Runoff Depth=6.76" Tc=6.0 min CN=98 Runoff=6.41 cfs 0.539 of Subcatchment P4-2: Entrance Area Runoff Area=10,793 sf 48.33% Impervious Runoff Depth=5.37" Tc=6.0 min CN=86 Runoff=1.47 cfs 0.111 of Subcatchment P5-1: Flow to IS5 Runoff Area=6,209 sf 71.94% Impervious Runoff Depth=5.94" Tc=6.0 min CN=91 Runoff=0.91 cfs 0.071 of Subcatchment P6-1: Flow to CB1 Runoff Area=7,262 sf 75.85% Impervious Runoff Depth=6.05" Tc=6.0 min CN=92 Runoff=1.07 cfs 0.084 of Subcatchment P6-2: Flow to CB2 Runoff Area=6,958 sf 59.83% Impervious Runoff Depth=5.59" Tc=6.0 min CN=88 Runoff=0.98 cfs 0.074 of Subcatchment P6-3: Flow to CB3 Runoff Area=3,660 sf 42.68% Impervious Runoff Depth=5.14" Tc=6.0 min CN=84 Runoff=0.48 cfs 0.036 of Subcatchment P6-4: Flow to CB3 Runoff Area=5,881 sf 52.90% Impervious Runoff Depth=5.48" Tc=6.0 min CN=87 Runoff=0.82 cfs 0.062 of Subcatchment P6-5: Flow to AD2 Runoff Area=3,757 sf 41.76% Impervious Runoff Depth=5.14" Tc=6.0 min CN=84 Runoff=0.50 cfs 0.037 of Subcatchment P6-6: Flow to AD2 Runoff Area=2,676 sf 43.68% Impervious Runoff Depth=5.14" Tc=6.0 min CN=84 Runoff=0.35 cfs 0.026 of Subcatchment P6-7: Flow to CB4 Runoff Area=8,662 sf 50.38% Impervious Runoff Depth=5.37" Tc=6.0 min CN=86 Runoff=1.18 cfs 0.089 of 2015-01-20 - 1888-02A - Watertown Type 111 24-hr 50 Year Storm (NRCC) Rainfall=7.00" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 32 Subcatchment P6-8: Flow to CB5 Runoff Area=7,481 sf 53.90% Impervious Runoff Depth=5.48" Tc=6.0 min CN=87 Runoff=1.04 cfs 0.078 of Subcatchment P6-9: Flow to Street Runoff Area=16,336 sf 74.87% Impervious Runoff Depth=6.05" Tc=6.0 min CN=92 Runoff=2.41 cfs 0.189 of Subcatchment P7-1: Flow to Abutting Runoff Area=29,867 sf 85.42% Impervious Runoff Depth=6.41" Tc=6.0 min CN=95 Runoff=4.53 cfs 0.366 of Reach SP1: (new Reach) Inflow=8.84 cfs 0.676 of Outflow=8.84 cfs 0.676 of Pond IS-1: Garage Infiltration Peak Elev=26.23' Storage=10,294 cf Inflow=3.75 cfs 0.315 of Discarded=0.05 cfs 0.103 of Primary=0.00 cfs 0.000 of Outflow=0.05 cfs 0.103 of Pond IS-2: Arsenal St Infiltration Peak EIev=30.26' Storage=21,590 cf Inflow=7.00 cfs 0.579 of Discarded=0.05 cfs 0.106 of Primary=0.00 cfs 0.000 of Outflow=0.05 cfs 0.106 of Pond IS-3: Pergola Infiltration Area Peak EIev=25.73' Storage=3,263 cf Inflow=1.30 cfs 0.107 of Discarded=0.02 cfs 0.045 of Primary=0.00 cfs 0.000 of Outflow=0.02 cfs 0.045 of Pond IS-4: Entrance Infiltration Area Peak EIev=28.77' Storage=22,707 cf Inflow=7.89 cfs 0.650 of Discarded=0.07 cfs 0.165 of Primary=0.00 cfs 0.000 of Outflow=0.07 cfs 0.165 of Pond IS5: Irving St Infiltration Area Peak EIev=25.72' Storage=2,166 cf Inflow=0.91 cfs 0.071 of Discarded=0.02 cfs 0.030 of Primary=0.00 cfs 0.000 of Outflow=0.02 cfs 0.030 of Total Runoff Area = 5.303 ac Runoff Volume = 2.764 of Average Runoff Depth = 6.25" 19.06% Pervious = 1.011 ac 80.94% Impervious = 4.292 ac 2015-01-20 - 1888-02A - Watertown Type 111 24-hr 50 Year Storm (NRCC) Rainfall=7.00" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 33 Summary for Subcatchment 131-1: Garage Roof Area Runoff = 3.75 cfs @ 12.09 hrs, Volume= 0.315 af, Depth= 6.76" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 50 Year Storm (NRCC) Rainfall=7.00" Area (sf) CN Description 24,366 98 Unconnected roofs, HSG C 24,366 100.00% Impervious Area 24,366 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment P2-1: Roof Area to IS2 Runoff = 6.13 cfs @ 12.09 hrs, Volume= 0.515 af, Depth= 6.76" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 50 Year Storm (NRCC) Rainfall=7.00" Area (sf) CN Description 39,818 98 Unconnected roofs, HSG C 39,818 100.00% Impervious Area 39,818 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment P2-2: Flow to AD1 Runoff = 0.87 cfs @ 12.09 hrs, Volume= 0.064 af, Depth= 4.81" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 50 Year Storm (NRCC) Rainfall=7.00" Area (sf) CN Description 5,008 74 >75% Grass cover, Good, HSG C 1,967 98 Paved parkinq, HSG C 6,975 81 Weighted Average 5,008 71.80% Pervious Area 1,967 28.20% Impervious Area 2015-01-20 - 1888-02A - Watertown Type 111 24-hr 50 Year Storm (NRCC) Rainfall=7.00" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 34 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment P3-1: Roof Area to IS3 Runoff = 0.48 cfs @ 12.09 hrs, Volume= 0.040 af, Depth= 6.76" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 50 Year Storm (NRCC) Rainfall=7.00" Area (sf) CN Description 3,087 98 Unconnected roofs, HSG C 3,087 100.00% Impervious Area 3,087 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment P3-2: Pergola Area Runoff = 0.34 cfs @ 12.09 hrs, Volume= 0.026 af, Depth= 5.71" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 50 Year Storm (NRCC) Rainfall=7.00" Area (sf) CN Description 2,395 89 Gravel roads, HSG C 2,395 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment P3-3: Roof Area to IS3 Runoff = 0.49 cfs @ 12.09 hrs, Volume= 0.041 af, Depth= 6.76" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 50 Year Storm (NRCC) Rainfall=7.00" Area (sf) CN Description 3,168 98 Unconnected roofs, HSG C 3,168 100.00% Impervious Area 3,168 100.00% Unconnected 2015-01-20 - 1888-02A - Watertown Type 111 24-hr 50 Year Storm (NRCC) Rainfall=7.00" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 35 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment P4-1: Roof Area to IS4 Runoff = 6.41 cfs @ 12.09 hrs, Volume= 0.539 af, Depth= 6.76" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 50 Year Storm (NRCC) Rainfall=7.00" Area (sf) CN Description 41,669 98 Unconnected roofs, HSG C 41,669 100.00% Impervious Area 41,669 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment P4-2: Entrance Area Runoff = 1.47 cfs @ 12.09 hrs, Volume= 0.111 af, Depth= 5.37" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 50 Year Storm (NRCC) Rainfall=7.00" Area (sf) CN Description 5,577 74 >75% Grass cover, Good, HSG C 5,216 98 Paved parkinq, HSG C 10,793 86 Weighted Average 5,577 51.67% Pervious Area 5,216 48.33% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment P5-1: Flow to IS5 Runoff = 0.91 cfs @ 12.09 hrs, Volume= 0.071 af, Depth= 5.94" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 50 Year Storm (NRCC) Rainfall=7.00" 2015-01-20 - 1888-02A - Watertown Type 111 24-hr 50 Year Storm (NRCC) Rainfall=7.00" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 36 Area (sf) CN Description 1,742 74 >75% Grass cover, Good, HSG C 4,467 98 Unconnected roofs, HSG C 6,209 91 Weighted Average 1,742 28.06% Pervious Area 4,467 71.94% Impervious Area 4,467 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment P6-1: Flow to CB1 Runoff = 1.07 cfs @ 12.09 hrs, Volume= 0.084 af, Depth= 6.05" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 50 Year Storm (NRCC) Rainfall=7.00" Area (sf) CN Description 1,754 74 >75% Grass cover, Good, HSG C 5,508 98 Paved parkinq, HSG C 7,262 92 Weighted Average 1,754 24.15% Pervious Area 5,508 75.85% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment P6-2: Flow to CB2 Runoff = 0.98 cfs @ 12.09 hrs, Volume= 0.074 af, Depth= 5.59" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 50 Year Storm (NRCC) Rainfall=7.00" Area (sf) CN Description 2,795 74 >75% Grass cover, Good, HSG C 4,163 98 Paved parkinq, HSG C 6,958 88 Weighted Average 2,795 40.17% Pervious Area 4,163 59.83% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, 2015-01-20 - 1888-02A - Watertown Type 111 24-hr 50 Year Storm (NRCC) Rainfall=7.00" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 37 Summary for Subcatchment P6-3: Flow to CB3 Runoff = 0.48 cfs @ 12.09 hrs, Volume= 0.036 af, Depth= 5.14" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 50 Year Storm (NRCC) Rainfall=7.00" Area (sf) CN Description 2,098 74 >75% Grass cover, Good, HSG C 1,562 98 Paved parking, HSG C 3,660 84 Weighted Average 2,098 57.32% Pervious Area 1,562 42.68% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 136-4: Flow to CB3 Runoff = 0.82 cfs @ 12.09 hrs, Volume= 0.062 af, Depth= 5.48" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 50 Year Storm (NRCC) Rainfall=7.00" Area (sf) CN Description 2,770 74 >75% Grass cover, Good, HSG C 3,111 98 Paved parking, HSG C 5,881 87 Weighted Average 2,770 47.10% Pervious Area 3,111 52.90% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 136-5: Flow to AD2 Runoff = 0.50 cfs @ 12.09 hrs, Volume= 0.037 af, Depth= 5.14" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 50 Year Storm (NRCC) Rainfall=7.00" Area (sf) CN Description 2,188 74 >75% Grass cover, Good, HSG C 1,569 98 Paved parkinq, HSG C 3,757 84 Weighted Average 2,188 58.24% Pervious Area 1,569 41.76% Impervious Area 2015-01-20 - 1888-02A - Watertown Type 111 24-hr 50 Year Storm (NRCC) Rainfall=7.00" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 38 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment P6-6: Flow to AD2 Runoff = 0.35 cfs @ 12.09 hrs, Volume= 0.026 af, Depth= 5.14" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 50 Year Storm (NRCC) Rainfall=7.00" Area (sf) CN Description 1,507 74 >75% Grass cover, Good, HSG C 1,169 98 Paved parkinq, HSG C 2,676 84 Weighted Average 1,507 56.32% Pervious Area 1,169 43.68% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment P6-7: Flow to CB4 Runoff = 1.18 cfs @ 12.09 hrs, Volume= 0.089 af, Depth= 5.37" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 50 Year Storm (NRCC) Rainfall=7.00" Area (sf) CN Description 4,298 74 >75% Grass cover, Good, HSG C 4,364 98 Paved parkinq, HSG C 8,662 86 Weighted Average 4,298 49.62% Pervious Area 4,364 50.38% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment P6-8: Flow to CB5 Runoff = 1.04 cfs @ 12.09 hrs, Volume= 0.078 af, Depth= 5.48" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 50 Year Storm (NRCC) Rainfall=7.00" 2015-01-20 - 1888-02A - Watertown Type 111 24-hr 50 Year Storm (NRCC) Rainfall=7.00" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 39 Area (sf) CN Description 3,449 74 >75% Grass cover, Good, HSG C 4,032 98 Paved parkinq, HSG C 7,481 87 Weighted Average 3,449 46.10% Pervious Area 4,032 53.90% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment P6-9: Flow to Street Runoff = 2.41 cfs @ 12.09 hrs, Volume= 0.189 af, Depth= 6.05" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 50 Year Storm (NRCC) Rainfall=7.00" Area (sf) CN Description 4,105 74 >75% Grass cover, Good, HSG C 12,231 98 Paved parking, HSG C 16,336 92 Weighted Average 4,105 25.13% Pervious Area 12,231 74.87% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment P7-1: Flow to Abutting Project CBs Runoff = 4.53 cfs @ 12.09 hrs, Volume= 0.366 af, Depth= 6.41" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 50 Year Storm (NRCC) Rainfall=7.00" Area (sf) CN Description 4,355 74 >75% Grass cover, Good, HSG C 25,512 98 Paved parkinq, HSG C 29,867 95 Weighted Average 4,355 14.58% Pervious Area 25,512 85.42% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, 2015-01-20 - 1888-02A - Watertown Type /// 24-hr 50 Year Storm (NRCC) Rainfall=7.00" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 40 Summary for Reach SP1: (new Reach) Inflow Area = 4.618 ac, 80.27% Impervious, Inflow Depth = 1.76" for 50 Year Storm (NRCC) event Inflow = 8.84 cfs @ 12.09 hrs, Volume= 0.676 of Outflow = 8.84 cfs @ 12.09 hrs, Volume= 0.676 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Summary for Pond IS-1: Garage Infiltration Inflow Area = 0.559 ac,100.00% Impervious, Inflow Depth = 6.76" for 50 Year Storm (NRCC) event Inflow = 3.75 cfs @ 12.09 hrs, Volume= 0.315 of Outflow = 0.05 cfs @ 5.45 hrs, Volume= 0.103 af, Atten= 99%, Lag= 0.0 min Discarded = 0.05 cfs @ 5.45 hrs, Volume= 0.103 of Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Peak Elev= 26.23' @ 21.25 hrs Surf.Area= 3,832 sf Storage= 10,294 cf Plug-Flow detention time= 436.5 min calculated for 0.103 of(33% of inflow) Center-of-Mass det. time= 246.7 min ( 989.7 - 743.0 ) Volume Invert Avail.Storage Storage Description #1 22.00' 6,483 cf Custom Stage Data (Prismatic)Listed below (Recalc) 22,992 cf Overall - 6,784 cf Embedded = 16,208 cf x 40.0% Voids #2 23.25' 6,784 cf ADS_StormTech MC-3500 c +Cap x 60 Inside#1 Effective Size= 70.4"W x 45.0"H => 15.33 sf x 7.17'L = 110.0 cf Overall Size= 77.0"W x 45.0"H x 7.50'L with 0.33' Overlap Cap Storage= +15.6 cf x 2 x 6 rows = 187.2 cf 13,267 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 22.00 3,832 0 0 28.00 3,832 22,992 22,992 Device Routing Invert Outlet Devices #1 Discarded 22.00' 0.520 in/hr Exfiltration over Surface area #2 Primary 23.00' 12.0" Round Culvert L= 53.0' CMP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 23.00' / 22.47' S= 0.0100 '/' Cc= 0.900 n= 0.013 Concrete pipe, bends & connections, Flow Area= 0.79 sf #3 Device 2 28.00' 4.0' long x 2.00' rise Sharp-Crested Rectangular Weir 2 End Contraction(s) 4.0' Crest Height Discarded OutFlow Max=0.05 cfs @ 5.45 hrs HW=22.08' (Free Discharge) L1=Exfiltration (Exfiltration Controls 0.05 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=22.00' (Free Discharge) L2=Culvert ( Controls 0.00 cfs) t-3=Sharp-Crested Rectangular Weir( Controls 0.00 cfs) 2015-01-20 - 1888-02A - Watertown Type /// 24-hr 50 Year Storm (NRCC) Rainfall=7.00" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 41 Summary for Pond IS-2: Arsenal St Infiltration Inflow Area = 1.074 ac, 89.30% Impervious, Inflow Depth = 6.47" for 50 Year Storm (NRCC) event Inflow = 7.00 cfs @ 12.09 hrs, Volume= 0.579 of Outflow = 0.05 cfs @ 3.95 hrs, Volume= 0.106 af, Atten= 99%, Lag= 0.0 min Discarded = 0.05 cfs @ 3.95 hrs, Volume= 0.106 of Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Peak Elev= 30.26' @ 24.06 hrs Surf.Area= 3,876 sf Storage= 21,590 cf Plug-Flow detention time= 502.7 min calculated for 0.106 of(18% of inflow) Center-of-Mass det. time= 223.9 min ( 973.8 - 749.9 ) Volume Invert Avail.Storage Storage Description #1 23.00' 5,784 cf Stone (Prismatic)Listed below (Recalc) 42,636 cf Overall - 28,175 cf Embedded = 14,461 cf x 40.0% Voids #2 24.17' 22,685 cf CONSPAN 16x 8 x 24 Inside #1 Inside= 192.0"W x 96.0"H => 118.15 sf x 8.00'L = 945.2 cf Outside= 212.0"W x 106.0"H => 146.74 sf x 8.00'L = 1,174.0 cf 28,469 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 23.00 3,876 0 0 34.00 3,876 42,636 42,636 Device Routinq Invert Outlet Devices #1 Discarded 23.00' 0.520 in/hr Exfiltration over Surface area #2 Primary 30.06' 12.0" Round Culvert L= 13.0' CMP, square edge headwall, Ke= 0.500 Inlet/Outlet Invert= 30.06' /29.80' S= 0.0200 T Cc= 0.900 n= 0.013 Concrete pipe, bends & connections, Flow Area= 0.79 sf #3 Device 2 33.75' 4.0' long x 2.00' rise Sharp-Crested Rectangular Weir 2 End Contraction(s) 4.0' Crest Height Discarded OutFlow Max=0.05 cfs @ 3.95 hrs HW=23.13' (Free Discharge) L1=Exfiltration (Exfiltration Controls 0.05 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=23.00' (Free Discharge) L2=Culvert ( Controls 0.00 cfs) L3=Sharp-Crested Rectangular Weir( Controls 0.00 cfs) Summary for Pond IS-3: Pergola Infiltration Area Inflow Area = 0.199 ac, 72.31% Impervious, Inflow Depth = 6.47" for 50 Year Storm (NRCC) event Inflow = 1.30 cfs @ 12.09 hrs, Volume= 0.107 of Outflow = 0.02 cfs @ 7.35 hrs, Volume= 0.045 af, Atten= 98%, Lag= 0.0 min Discarded = 0.02 cfs @ 7.35 hrs, Volume= 0.045 of Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 of 2015-01-20 - 1888-02A - Watertown Type /// 24-hr 50 Year Storm (NRCC) Rainfall=7.00" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 42 Routing by Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Peak Elev= 25.73' @ 18.64 hrs Surf.Area= 1,753 sf Storage= 3,263 cf Plug-Flow detention time= 422.3 min calculated for 0.045 of(42% of inflow) Center-of-Mass det. time= 275.1 min ( 1,027.9 - 752.8 ) Volume Invert Avail.Storage Storage Description #1 22.50' 2,727 cf Stone Area (Prismatic)Listed below (Recalc) 8,765 cf Overall - 1,946 cf Embedded = 6,819 cf x 40.0% Voids #2 24.00' 1,946 cf ADS_StormTech SC-740 x 42 Inside#1 Effective Size= 44.6"W x 30.0"H => 6.45 sf x 7.121 = 45.9 cf Overall Size= 51.0"W x 30.0"H x 7.56'L with 0.44' Overlap Row Length Adjustment= +0.44' x 6.45 sf x 6 rows 4,674 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 22.50 1,753 0 0 27.50 1,753 8,765 8,765 Device Routing Invert Outlet Devices #1 Discarded 22.50' 0.520 in/hr Exfiltration over Surface area #2 Primary 23.50' 12.0" Round Culvert L= 30.0' RCP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 23.50' / 22.90' S= 0.0200 T Cc= 0.900 n= 0.013 Concrete pipe, bends & connections, Flow Area= 0.79 sf #3 Device 2 27.00' 4.0' long x 2.00' rise Sharp-Crested Rectangular Weir 2 End Contraction(s) 4.0' Crest Height Discarded OutFlow Max=0.02 cfs @ 7.35 hrs HW=22.57' (Free Discharge) L1=Exfiltration (Exfiltration Controls 0.02 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=22.50' (Free Discharge) L2=Culvert ( Controls 0.00 cfs) t-3=Sharp-Crested Rectangular Weir( Controls 0.00 cfs) Summary for Pond IS-4: Entrance Infiltration Area Inflow Area = 1.204 ac, 89.37% Impervious, Inflow Depth = 6.47" for 50 Year Storm (NRCC) event Inflow = 7.89 cfs @ 12.09 hrs, Volume= 0.650 of Outflow = 0.07 cfs @ 5.25 hrs, Volume= 0.165 af, Atten= 99%, Lag= 0.0 min Discarded = 0.07 cfs @ 5.25 hrs, Volume= 0.165 of Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Peak Elev= 28.77' @ 23.87 hrs Surf.Area= 6,129 sf Storage= 22,707 cf Plug-Flow detention time= 458.7 min calculated for 0.164 of(25% of inflow) Center-of-Mass det. time= 238.3 min ( 989.7 - 751.4 ) 2015-01-20 - 1888-02A - Watertown Type /// 24-hr 50 Year Storm (NRCC) Rainfall=7.00" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 43 Volume Invert Avail.Storage Storage Description #1 23.00' 13,271 cf Custom Stage Data (Prismatic)Listed below (Recalc) 49,032 cf Overall - 15,853 cf Embedded = 33,179 cf x 40.0% Voids #2 25.00' 15,853 cf ADS_StormTech MC-4500 +Cap @ 4.03' Lx 144 Inside #1 Effective Size= 90.4"W x 60.0"H => 26.46 sf x 4.031 = 106.6 cf Overall Size= 100.0"W x 60.0"H x 4.331 with 0.31' Overlap Cap Storage= +35.7 cf x 2 x 7 rows = 499.8 cf 29,125 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 23.00 6,129 0 0 31.00 6,129 49,032 49,032 Device Routing Invert Outlet Devices #1 Discarded 23.00' 0.520 in/hr Exfiltration over Surface area #2 Primary 25.00' 12.0" Round Culvert L= 123.0' RCP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 25.00' / 21.31' S= 0.0300 T Cc= 0.900 n= 0.013 Concrete pipe, bends & connections, Flow Area= 0.79 sf #3 Device 2 31.00' 4.0' long x 2.00' rise Sharp-Crested Rectangular Weir 2 End Contraction(s) 4.0' Crest Height Discarded OutFlow Max=0.07 cfs @ 5.25 hrs HW=23.10' (Free Discharge) L1=Exfiltration (Exfiltration Controls 0.07 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=23.00' (Free Discharge) L2=Culvert ( Controls 0.00 cfs) L3=Sharp-Crested Rectangular Weir( Controls 0.00 cfs) Summary for Pond ISS: Irving St Infiltration Area Inflow Area = 0.143 ac, 71.94% Impervious, Inflow Depth = 5.94" for 50 Year Storm (NRCC) event Inflow = 0.91 cfs @ 12.09 hrs, Volume= 0.071 of Outflow = 0.02 cfs @ 8.50 hrs, Volume= 0.030 af, Atten= 98%, Lag= 0.0 min Discarded = 0.02 cfs @ 8.50 hrs, Volume= 0.030 of Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Peak Elev= 25.72' @ 18.24 hrs Surf.Area= 1,295 sf Storage= 2,166 cf Plug-Flow detention time= 444.4 min calculated for 0.030 of(43% of inflow) Center-of-Mass det. time= 316.6 min ( 1,093.0 - 776.4 ) Volume Invert Avail.Storage Storage Description #1 23.00' 1,479 cf Custom Stage Data (Prismatic)Listed below (Recalc) 5,180 cf Overall - 1,481 cf Embedded = 3,699 cf x 40.0% Voids #2 24.00' 1,481 cf ADS_StormTech SC-740 x 32 Inside#1 Effective Size= 44.6"W x 30.0"H => 6.45 sf x 7.121 = 45.9 cf Overall Size= 51.0"W x 30.0"H x 7.56'L with 0.44' Overlap Row Length Adjustment= +0.44' x 6.45 sf x 4 rows 2015-01-20 - 1888-02A - Watertown Type /// 24-hr 50 Year Storm (NRCC) Rainfall=7.00" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 44 2,961 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 23.00 1,295 0 0 27.00 1,295 5,180 5,180 Device Routinq Invert Outlet Devices #1 Discarded 23.00' 0.520 in/hr Exfiltration over Surface area #2 Primary 21.38' 12.0" Round Culvert L= 19.0' RCP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 21.38' / 21.00' S= 0.0200 T Cc= 0.900 n= 0.013 Concrete pipe, bends & connections, Flow Area= 0.79 sf #3 Device 2 27.00' 4.0' long x 2.00' rise Sharp-Crested Rectangular Weir 2 End Contraction(s) 4.0' Crest Height Discarded OutFlow Max=0.02 cfs @ 8.50 hrs HW=23.06' (Free Discharge) L1=Exfiltration (Exfiltration Controls 0.02 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=23.00' (Free Discharge) L2=Culvert (Passes 0.00 cfs of 4.00 cfs potential flow) L3=Sharp-Crested Rectangular Weir( Controls 0.00 cfs) 2015-01-20 - 1888-02A - Watertown Type /// 24-hr 100 Year Storm (NRCC) Rainfall=8.50" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 45 Time span=0.00-30.00 hrs, dt=0.05 hrs, 601 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method SubcatchmentP1-1: Garage Roof Area Runoff Area=24,366 sf 100.00% Impervious Runoff Depth=8.26" Tc=6.0 min CN=98 Runoff=4.56 cfs 0.385 of Subcatchment P2-1: Roof Area to IS2 Runoff Area=39,818 sf 100.00% Impervious Runoff Depth=8.26" Tc=6.0 min CN=98 Runoff=7.45 cfs 0.629 of Subcatchment P2-2: Flow to AM Runoff Area=6,975 sf 28.20% Impervious Runoff Depth=6.22" Tc=6.0 min CN=81 Runoff=1.12 cfs 0.083 of Subcatchment P3-1: Roof Area to IS3 Runoff Area=3,087 sf 100.00% Impervious Runoff Depth=8.26" Tc=6.0 min CN=98 Runoff=0.58 cfs 0.049 of Subcatchment P3-2: Pergola Area Runoff Area=2,395 sf 0.00% Impervious Runoff Depth=7.18" Tc=6.0 min CN=89 Runoff=0.42 cfs 0.033 of Subcatchment P3-3: Roof Area to IS3 Runoff Area=3,168 sf 100.00% Impervious Runoff Depth=8.26" Tc=6.0 min CN=98 Runoff=0.59 cfs 0.050 of SubcatchmentP4-1: Roof Area to IS4 Runoff Area=41,669 sf 100.00% Impervious Runoff Depth=8.26" Tc=6.0 min CN=98 Runoff=7.80 cfs 0.658 of Subcatchment P4-2: Entrance Area Runoff Area=10,793 sf 48.33% Impervious Runoff Depth=6.82" Tc=6.0 min CN=86 Runoff=1.85 cfs 0.141 of Subcatchment P5-1: Flow to IS5 Runoff Area=6,209 sf 71.94% Impervious Runoff Depth=7.42" Tc=6.0 min CN=91 Runoff=1.12 cfs 0.088 of Subcatchment P6-1: Flow to CB1 Runoff Area=7,262 sf 75.85% Impervious Runoff Depth=7.54" Tc=6.0 min CN=92 Runoff=1.32 cfs 0.105 of Subcatchment P6-2: Flow to CB2 Runoff Area=6,958 sf 59.83% Impervious Runoff Depth=7.06" Tc=6.0 min CN=88 Runoff=1.22 cfs 0.094 of Subcatchment P6-3: Flow to CB3 Runoff Area=3,660 sf 42.68% Impervious Runoff Depth=6.58" Tc=6.0 min CN=84 Runoff=0.61 cfs 0.046 of Subcatchment P6-4: Flow to CB3 Runoff Area=5,881 sf 52.90% Impervious Runoff Depth=6.94" Tc=6.0 min CN=87 Runoff=1.02 cfs 0.078 of Subcatchment P6-5: Flow to AD2 Runoff Area=3,757 sf 41.76% Impervious Runoff Depth=6.58" Tc=6.0 min CN=84 Runoff=0.63 cfs 0.047 of Subcatchment P6-6: Flow to AD2 Runoff Area=2,676 sf 43.68% Impervious Runoff Depth=6.58" Tc=6.0 min CN=84 Runoff=0.45 cfs 0.034 of Subcatchment P6-7: Flow to CB4 Runoff Area=8,662 sf 50.38% Impervious Runoff Depth=6.82" Tc=6.0 min CN=86 Runoff=1.48 cfs 0.113 of 2015-01-20 - 1888-02A - Watertown Type /// 24-hr 100 Year Storm (NRCC) Rainfall=8.50" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 46 Subcatchment P6-8: Flow to CB5 Runoff Area=7,481 sf 53.90% Impervious Runoff Depth=6.94" Tc=6.0 min CN=87 Runoff=1.30 cfs 0.099 of Subcatchment P6-9: Flow to Street Runoff Area=16,336 sf 74.87% Impervious Runoff Depth=7.54" Tc=6.0 min CN=92 Runoff=2.97 cfs 0.236 of Subcatchment P7-1: Flow to Abutting Runoff Area=29,867 sf 85.42% Impervious Runoff Depth=7.90" Tc=6.0 min CN=95 Runoff=5.53 cfs 0.451 of Reach SP1: (new Reach) Inflow=10.99 cfs 0.852 of Outflow=10.99 cfs 0.852 of Pond IS-1: Garage Infiltration Peak Elev=27.94' Storage=13,175 cf Inflow=4.56 cfs 0.385 of Discarded=0.05 cfs 0.105 of Primary=0.00 cfs 0.000 of Outflow=0.05 cfs 0.105 of Pond IS-2: Arsenal St Infiltration Peak Elev=33.25' Storage=27,302 cf Inflow=8.57 cfs 0.712 of Discarded=0.05 cfs 0.108 of Primary=0.00 cfs 0.000 of Outflow=0.05 cfs 0.108 of Pond IS-3: Pergola Infiltration Area Peak Elev=26.85' Storage=4,220 cf Inflow=1.59 cfs 0.132 of Discarded=0.02 cfs 0.046 of Primary=0.00 cfs 0.000 of Outflow=0.02 cfs 0.046 of Pond IS-4: Entrance Infiltration Area Peak EIev=30.97' Storage=29,048 cf Inflow=9.65 cfs 0.799 of Discarded=0.07 cfs 0.168 of Primary=0.00 cfs 0.000 of Outflow=0.07 cfs 0.168 of Pond IS5: Irving St Infiltration Area Peak EIev=26.77' Storage=2,842 cf Inflow=1.12 cfs 0.088 of Discarded=0.02 cfs 0.031 of Primary=0.00 cfs 0.000 of Outflow=0.02 cfs 0.031 of Total Runoff Area = 5.303 ac Runoff Volume = 3.419 of Average Runoff Depth = 7.74" 19.06% Pervious = 1.011 ac 80.94% Impervious = 4.292 ac 2015-01-20 - 1888-02A - Watertown Type /// 24-hr 100 Year Storm (NRCC) Rainfall=8.50" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 47 Summary for Subcatchment 131-1: Garage Roof Area Runoff = 4.56 cfs @ 12.09 hrs, Volume= 0.385 af, Depth= 8.26" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 100 Year Storm (NRCC) Rainfall=8.50" Area (sf) CN Description 24,366 98 Unconnected roofs, HSG C 24,366 100.00% Impervious Area 24,366 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment P2-1: Roof Area to IS2 Runoff = 7.45 cfs @ 12.09 hrs, Volume= 0.629 af, Depth= 8.26" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 100 Year Storm (NRCC) Rainfall=8.50" Area (sf) CN Description 39,818 98 Unconnected roofs, HSG C 39,818 100.00% Impervious Area 39,818 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment P2-2: Flow to AD1 Runoff = 1.12 cfs @ 12.09 hrs, Volume= 0.083 af, Depth= 6.22" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 100 Year Storm (NRCC) Rainfall=8.50" Area (sf) CN Description 5,008 74 >75% Grass cover, Good, HSG C 1,967 98 Paved parkinq, HSG C 6,975 81 Weighted Average 5,008 71.80% Pervious Area 1,967 28.20% Impervious Area 2015-01-20 - 1888-02A - Watertown Type /// 24-hr 100 Year Storm (NRCC) Rainfall=8.50" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 48 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment P3-1: Roof Area to IS3 Runoff = 0.58 cfs @ 12.09 hrs, Volume= 0.049 af, Depth= 8.26" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 100 Year Storm (NRCC) Rainfall=8.50" Area (sf) CN Description 3,087 98 Unconnected roofs, HSG C 3,087 100.00% Impervious Area 3,087 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment P3-2: Pergola Area Runoff = 0.42 cfs @ 12.09 hrs, Volume= 0.033 af, Depth= 7.18" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 100 Year Storm (NRCC) Rainfall=8.50" Area (sf) CN Description 2,395 89 Gravel roads, HSG C 2,395 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment P3-3: Roof Area to IS3 Runoff = 0.59 cfs @ 12.09 hrs, Volume= 0.050 af, Depth= 8.26" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 100 Year Storm (NRCC) Rainfall=8.50" Area (sf) CN Description 3,168 98 Unconnected roofs, HSG C 3,168 100.00% Impervious Area 3,168 100.00% Unconnected 2015-01-20 - 1888-02A - Watertown Type /// 24-hr 100 Year Storm (NRCC) Rainfall=8.50" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 49 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment P4-1: Roof Area to IS4 Runoff = 7.80 cfs @ 12.09 hrs, Volume= 0.658 af, Depth= 8.26" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 100 Year Storm (NRCC) Rainfall=8.50" Area (sf) CN Description 41,669 98 Unconnected roofs, HSG C 41,669 100.00% Impervious Area 41,669 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment P4-2: Entrance Area Runoff = 1.85 cfs @ 12.09 hrs, Volume= 0.141 af, Depth= 6.82" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 100 Year Storm (NRCC) Rainfall=8.50" Area (sf) CN Description 5,577 74 >75% Grass cover, Good, HSG C 5,216 98 Paved parkinq, HSG C 10,793 86 Weighted Average 5,577 51.67% Pervious Area 5,216 48.33% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment P5-1: Flow to IS5 Runoff = 1.12 cfs @ 12.09 hrs, Volume= 0.088 af, Depth= 7.42" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 100 Year Storm (NRCC) Rainfall=8.50" 2015-01-20 - 1888-02A - Watertown Type /// 24-hr 100 Year Storm (NRCC) Rainfall=8.50" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 50 Area (sf) CN Description 1,742 74 >75% Grass cover, Good, HSG C 4,467 98 Unconnected roofs, HSG C 6,209 91 Weighted Average 1,742 28.06% Pervious Area 4,467 71.94% Impervious Area 4,467 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment P6-1: Flow to CB1 Runoff = 1.32 cfs @ 12.09 hrs, Volume= 0.105 af, Depth= 7.54" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 100 Year Storm (NRCC) Rainfall=8.50" Area (sf) CN Description 1,754 74 >75% Grass cover, Good, HSG C 5,508 98 Paved parkinq, HSG C 7,262 92 Weighted Average 1,754 24.15% Pervious Area 5,508 75.85% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment P6-2: Flow to CB2 Runoff = 1.22 cfs @ 12.09 hrs, Volume= 0.094 af, Depth= 7.06" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 100 Year Storm (NRCC) Rainfall=8.50" Area (sf) CN Description 2,795 74 >75% Grass cover, Good, HSG C 4,163 98 Paved parkinq, HSG C 6,958 88 Weighted Average 2,795 40.17% Pervious Area 4,163 59.83% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, 2015-01-20 - 1888-02A - Watertown Type /// 24-hr 100 Year Storm (NRCC) Rainfall=8.50" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 51 Summary for Subcatchment P6-3: Flow to CB3 Runoff = 0.61 cfs @ 12.09 hrs, Volume= 0.046 af, Depth= 6.58" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 100 Year Storm (NRCC) Rainfall=8.50" Area (sf) CN Description 2,098 74 >75% Grass cover, Good, HSG C 1,562 98 Paved parking, HSG C 3,660 84 Weighted Average 2,098 57.32% Pervious Area 1,562 42.68% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 136-4: Flow to CB3 Runoff = 1.02 cfs @ 12.09 hrs, Volume= 0.078 af, Depth= 6.94" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 100 Year Storm (NRCC) Rainfall=8.50" Area (sf) CN Description 2,770 74 >75% Grass cover, Good, HSG C 3,111 98 Paved parking, HSG C 5,881 87 Weighted Average 2,770 47.10% Pervious Area 3,111 52.90% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 136-5: Flow to AD2 Runoff = 0.63 cfs @ 12.09 hrs, Volume= 0.047 af, Depth= 6.58" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 100 Year Storm (NRCC) Rainfall=8.50" Area (sf) CN Description 2,188 74 >75% Grass cover, Good, HSG C 1,569 98 Paved parkinq, HSG C 3,757 84 Weighted Average 2,188 58.24% Pervious Area 1,569 41.76% Impervious Area 2015-01-20 - 1888-02A - Watertown Type /// 24-hr 100 Year Storm (NRCC) Rainfall=8.50" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 52 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment P6-6: Flow to AD2 Runoff = 0.45 cfs @ 12.09 hrs, Volume= 0.034 af, Depth= 6.58" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 100 Year Storm (NRCC) Rainfall=8.50" Area (sf) CN Description 1,507 74 >75% Grass cover, Good, HSG C 1,169 98 Paved parkinq, HSG C 2,676 84 Weighted Average 1,507 56.32% Pervious Area 1,169 43.68% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment P6-7: Flow to CB4 Runoff = 1.48 cfs @ 12.09 hrs, Volume= 0.113 af, Depth= 6.82" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 100 Year Storm (NRCC) Rainfall=8.50" Area (sf) CN Description 4,298 74 >75% Grass cover, Good, HSG C 4,364 98 Paved parkinq, HSG C 8,662 86 Weighted Average 4,298 49.62% Pervious Area 4,364 50.38% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment P6-8: Flow to CB5 Runoff = 1.30 cfs @ 12.09 hrs, Volume= 0.099 af, Depth= 6.94" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 100 Year Storm (NRCC) Rainfall=8.50" 2015-01-20 - 1888-02A - Watertown Type /// 24-hr 100 Year Storm (NRCC) Rainfall=8.50" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 53 Area (sf) CN Description 3,449 74 >75% Grass cover, Good, HSG C 4,032 98 Paved parkinq, HSG C 7,481 87 Weighted Average 3,449 46.10% Pervious Area 4,032 53.90% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment P6-9: Flow to Street Runoff = 2.97 cfs @ 12.09 hrs, Volume= 0.236 af, Depth= 7.54" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 100 Year Storm (NRCC) Rainfall=8.50" Area (sf) CN Description 4,105 74 >75% Grass cover, Good, HSG C 12,231 98 Paved parking, HSG C 16,336 92 Weighted Average 4,105 25.13% Pervious Area 12,231 74.87% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment P7-1: Flow to Abutting Project CBs Runoff = 5.53 cfs @ 12.09 hrs, Volume= 0.451 af, Depth= 7.90" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type III 24-hr 100 Year Storm (NRCC) Rainfall=8.50" Area (sf) CN Description 4,355 74 >75% Grass cover, Good, HSG C 25,512 98 Paved parkinq, HSG C 29,867 95 Weighted Average 4,355 14.58% Pervious Area 25,512 85.42% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, 2015-01-20 - 1888-02A - Watertown Type/1/ 24-hr 100 Year Storm (NRCC) Rainfall=8.50" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 54 Summary for Reach SP1: (new Reach) Inflow Area = 4.618 ac, 80.27% Impervious, Inflow Depth = 2.21" for 100 Year Storm (NRCC) event Inflow = 10.99 cfs @ 12.09 hrs, Volume= 0.852 of Outflow = 10.99 cfs @ 12.09 hrs, Volume= 0.852 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Summary for Pond IS-1: Garage Infiltration Inflow Area = 0.559 ac,100.00% Impervious, Inflow Depth = 8.26" for 100 Year Storm (NRCC) event Inflow = 4.56 cfs @ 12.09 hrs, Volume= 0.385 of Outflow = 0.05 cfs @ 4.25 hrs, Volume= 0.105 af, Atten= 99%, Lag= 0.0 min Discarded = 0.05 cfs @ 4.25 hrs, Volume= 0.105 of Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Peak Elev= 27.94' @ 23.09 hrs Surf.Area= 3,832 sf Storage= 13,175 cf Plug-Flow detention time= 455.1 min calculated for 0.105 of(27% of inflow) Center-of-Mass det. time= 230.5 min ( 970.9 - 740.5 ) Volume Invert Avail.Storage Storage Description #1 22.00' 6,483 cf Custom Stage Data (Prismatic)Listed below (Recalc) 22,992 cf Overall - 6,784 cf Embedded = 16,208 cf x 40.0% Voids #2 23.25' 6,784 cf ADS_StormTech MC-3500 c +Cap x 60 Inside#1 Effective Size= 70.4"W x 45.0"H => 15.33 sf x 7.17'L = 110.0 cf Overall Size= 77.0"W x 45.0"H x 7.50'L with 0.33' Overlap Cap Storage= +15.6 cf x 2 x 6 rows = 187.2 cf 13,267 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 22.00 3,832 0 0 28.00 3,832 22,992 22,992 Device Routing Invert Outlet Devices #1 Discarded 22.00' 0.520 in/hr Exfiltration over Surface area #2 Primary 23.00' 12.0" Round Culvert L= 53.0' CMP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 23.00' / 22.47' S= 0.0100 '/' Cc= 0.900 n= 0.013 Concrete pipe, bends & connections, Flow Area= 0.79 sf #3 Device 2 28.00' 4.0' long x 2.00' rise Sharp-Crested Rectangular Weir 2 End Contraction(s) 4.0' Crest Height Discarded OutFlow Max=0.05 cfs @ 4.25 hrs HW=22.08' (Free Discharge) L1=Exfiltration (Exfiltration Controls 0.05 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=22.00' (Free Discharge) L2=Culvert ( Controls 0.00 cfs) t-3=Sharp-Crested Rectangular Weir( Controls 0.00 cfs) 2015-01-20 - 1888-02A - Watertown Type/1/ 24-hr 100 Year Storm (NRCC) Rainfall=8.50" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 55 Summary for Pond IS-2: Arsenal St Infiltration Inflow Area = 1.074 ac, 89.30% Impervious, Inflow Depth = 7.96" for 100 Year Storm (NRCC) event Inflow = 8.57 cfs @ 12.09 hrs, Volume= 0.712 of Outflow = 0.05 cfs @ 3.15 hrs, Volume= 0.108 af, Atten= 99%, Lag= 0.0 min Discarded = 0.05 cfs @ 3.15 hrs, Volume= 0.108 of Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Peak Elev= 33.25' @ 24.08 hrs Surf.Area= 3,876 sf Storage= 27,302 cf Plug-Flow detention time= 530.2 min calculated for 0.108 of(15% of inflow) Center-of-Mass det. time= 212.5 min ( 959.7 - 747.2 ) Volume Invert Avail.Storage Storage Description #1 23.00' 5,784 cf Stone (Prismatic)Listed below (Recalc) 42,636 cf Overall - 28,175 cf Embedded = 14,461 cf x 40.0% Voids #2 24.17' 22,685 cf CONSPAN 16x 8 x 24 Inside #1 Inside= 192.0"W x 96.0"H => 118.15 sf x 8.00'L = 945.2 cf Outside= 212.0"W x 106.0"H => 146.74 sf x 8.00'L = 1,174.0 cf 28,469 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 23.00 3,876 0 0 34.00 3,876 42,636 42,636 Device Routinq Invert Outlet Devices #1 Discarded 23.00' 0.520 in/hr Exfiltration over Surface area #2 Primary 30.06' 12.0" Round Culvert L= 13.0' CMP, square edge headwall, Ke= 0.500 Inlet/Outlet Invert= 30.06' /29.80' S= 0.0200 T Cc= 0.900 n= 0.013 Concrete pipe, bends & connections, Flow Area= 0.79 sf #3 Device 2 33.75' 4.0' long x 2.00' rise Sharp-Crested Rectangular Weir 2 End Contraction(s) 4.0' Crest Height Discarded OutFlow Max=0.05 cfs @ 3.15 hrs HW=23.13' (Free Discharge) L1=Exfiltration (Exfiltration Controls 0.05 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=23.00' (Free Discharge) L2=Culvert ( Controls 0.00 cfs) L3=Sharp-Crested Rectangular Weir( Controls 0.00 cfs) Summary for Pond IS-3: Pergola Infiltration Area Inflow Area = 0.199 ac, 72.31% Impervious, Inflow Depth = 7.96" for 100 Year Storm (NRCC) event Inflow = 1.59 cfs @ 12.09 hrs, Volume= 0.132 of Outflow = 0.02 cfs @ 6.50 hrs, Volume= 0.046 af, Atten= 99%, Lag= 0.0 min Discarded = 0.02 cfs @ 6.50 hrs, Volume= 0.046 of Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 of 2015-01-20 - 1888-02A - Watertown Type/1/ 24-hr 100 Year Storm (NRCC) Rainfall=8.50" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 56 Routing by Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Peak Elev= 26.85' @ 20.57 hrs Surf.Area= 1,753 sf Storage= 4,220 cf Plug-Flow detention time= 427.0 min calculated for 0.046 of(35% of inflow) Center-of-Mass det. time= 254.4 min ( 1,004.1 - 749.7 ) Volume Invert Avail.Storage Storage Description #1 22.50' 2,727 cf Stone Area (Prismatic)Listed below (Recalc) 8,765 cf Overall - 1,946 cf Embedded = 6,819 cf x 40.0% Voids #2 24.00' 1,946 cf ADS_StormTech SC-740 x 42 Inside#1 Effective Size= 44.6"W x 30.0"H => 6.45 sf x 7.121 = 45.9 cf Overall Size= 51.0"W x 30.0"H x 7.56'L with 0.44' Overlap Row Length Adjustment= +0.44' x 6.45 sf x 6 rows 4,674 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 22.50 1,753 0 0 27.50 1,753 8,765 8,765 Device Routing Invert Outlet Devices #1 Discarded 22.50' 0.520 in/hr Exfiltration over Surface area #2 Primary 23.50' 12.0" Round Culvert L= 30.0' RCP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 23.50' / 22.90' S= 0.0200 T Cc= 0.900 n= 0.013 Concrete pipe, bends & connections, Flow Area= 0.79 sf #3 Device 2 27.00' 4.0' long x 2.00' rise Sharp-Crested Rectangular Weir 2 End Contraction(s) 4.0' Crest Height Discarded OutFlow Max=0.02 cfs @ 6.50 hrs HW=22.57' (Free Discharge) L1=Exfiltration (Exfiltration Controls 0.02 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=22.50' (Free Discharge) L2=Culvert ( Controls 0.00 cfs) t-3=Sharp-Crested Rectangular Weir( Controls 0.00 cfs) Summary for Pond IS-4: Entrance Infiltration Area Inflow Area = 1.204 ac, 89.37% Impervious, Inflow Depth = 7.96" for 100 Year Storm (NRCC) event Inflow = 9.65 cfs @ 12.09 hrs, Volume= 0.799 of Outflow = 0.07 cfs @ 4.15 hrs, Volume= 0.168 af, Atten= 99%, Lag= 0.0 min Discarded = 0.07 cfs @ 4.15 hrs, Volume= 0.168 of Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Peak Elev= 30.97' @ 24.04 hrs Surf.Area= 6,129 sf Storage= 29,048 cf Plug-Flow detention time= 481.1 min calculated for 0.168 of(21% of inflow) Center-of-Mass det. time= 223.3 min ( 971.7 - 748.5 ) 2015-01-20 - 1888-02A - Watertown Type/1/ 24-hr 100 Year Storm (NRCC) Rainfall=8.50" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 57 Volume Invert Avail.Storage Storage Description #1 23.00' 13,271 cf Custom Stage Data (Prismatic)Listed below (Recalc) 49,032 cf Overall - 15,853 cf Embedded = 33,179 cf x 40.0% Voids #2 25.00' 15,853 cf ADS_StormTech MC-4500 +Cap @ 4.03' Lx 144 Inside #1 Effective Size= 90.4"W x 60.0"H => 26.46 sf x 4.031 = 106.6 cf Overall Size= 100.0"W x 60.0"H x 4.331 with 0.31' Overlap Cap Storage= +35.7 cf x 2 x 7 rows = 499.8 cf 29,125 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 23.00 6,129 0 0 31.00 6,129 49,032 49,032 Device Routing Invert Outlet Devices #1 Discarded 23.00' 0.520 in/hr Exfiltration over Surface area #2 Primary 25.00' 12.0" Round Culvert L= 123.0' RCP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 25.00' / 21.31' S= 0.0300 T Cc= 0.900 n= 0.013 Concrete pipe, bends & connections, Flow Area= 0.79 sf #3 Device 2 31.00' 4.0' long x 2.00' rise Sharp-Crested Rectangular Weir 2 End Contraction(s) 4.0' Crest Height Discarded OutFlow Max=0.07 cfs @ 4.15 hrs HW=23.10' (Free Discharge) L1=Exfiltration (Exfiltration Controls 0.07 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=23.00' (Free Discharge) L2=Culvert ( Controls 0.00 cfs) L3=Sharp-Crested Rectangular Weir( Controls 0.00 cfs) Summary for Pond ISS: Irving St Infiltration Area Inflow Area = 0.143 ac, 71.94% Impervious, Inflow Depth = 7.42" for 100 Year Storm (NRCC) event Inflow = 1.12 cfs @ 12.09 hrs, Volume= 0.088 of Outflow = 0.02 cfs @ 7.70 hrs, Volume= 0.031 af, Atten= 99%, Lag= 0.0 min Discarded = 0.02 cfs @ 7.70 hrs, Volume= 0.031 of Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Peak Elev= 26.77' @ 20.17 hrs Surf.Area= 1,295 sf Storage= 2,842 cf Plug-Flow detention time= 444.9 min calculated for 0.031 of(36% of inflow) Center-of-Mass det. time= 297.2 min ( 1,068.1 - 770.9 ) Volume Invert Avail.Storage Storage Description #1 23.00' 1,479 cf Custom Stage Data (Prismatic)Listed below (Recalc) 5,180 cf Overall - 1,481 cf Embedded = 3,699 cf x 40.0% Voids #2 24.00' 1,481 cf ADS_StormTech SC-740 x 32 Inside#1 Effective Size= 44.6"W x 30.0"H => 6.45 sf x 7.121 = 45.9 cf Overall Size= 51.0"W x 30.0"H x 7.56'L with 0.44' Overlap Row Length Adjustment= +0.44' x 6.45 sf x 4 rows 2015-01-20 - 1888-02A - Watertown Type/1/ 24-hr 100 Year Storm (NRCC) Rainfall=8.50" Prepared by Microsoft Printed 2/10/2015 HydroCAD® 10.00 s/n 02881 ©2013 HydroCAD Software Solutions LLC Page 58 2,961 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 23.00 1,295 0 0 27.00 1,295 5,180 5,180 Device Routinq Invert Outlet Devices #1 Discarded 23.00' 0.520 in/hr Exfiltration over Surface area #2 Primary 21.38' 12.0" Round Culvert L= 19.0' RCP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 21.38' / 21.00' S= 0.0200 T Cc= 0.900 n= 0.013 Concrete pipe, bends & connections, Flow Area= 0.79 sf #3 Device 2 27.00' 4.0' long x 2.00' rise Sharp-Crested Rectangular Weir 2 End Contraction(s) 4.0' Crest Height Discarded OutFlow Max=0.02 cfs @ 7.70 hrs HW=23.06' (Free Discharge) L1=Exfiltration (Exfiltration Controls 0.02 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=23.00' (Free Discharge) L2=Culvert (Passes 0.00 cfs of 4.00 cfs potential flow) L3=Sharp-Crested Rectangular Weir( Controls 0.00 cfs)