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HomeMy WebLinkAbout2009-03-16 Stormwater Report 2/19/2009 CHRISTIANSEN & SERGI, INC. PROFESSIONAL ENGINEERS AND LAN 160 SUMMER STREET, HAVERHILL, MA 0183D-0318 (978)373-0310 FAX (978)372-3960 RECEIVED FEB 19 2009 NOti I ri tArWOVER PLANNING DEPARTMENT STORMWATER MANAGEMENT REPORT FOR "THE CAPTAIN NATHANIEL BERRY HOMESTEAD" IN NORTH ANDOVER, MASSAC14USETTS PREPARED FOR: 166 SALEM STREET REALTY TRUST DATE: Febi uary 19, 2009 1AMP 7N clivid Stormwater Management Report for "The Captain Nathaniel Berry Homestead",North Andover,Mass, Index I Introduction II Hydrologic Analysis III Soils Analysis Section 1: Introduction V Stormwater Management Report for "The Captain Nathaniel Berry Homestead",North Andover,Mass, 1) Introduction The "The Captain Nathaniel Berry Homestead" Subdivision will consist of the construction of a new residential street(to be constructed as a common driveway) and one new single-family house lot on 2.9 acres of land located at 166 Salem Street in North Andover. The land currently contains a house with outbuildings on a 2.3 acre lot and a second undeveloped 25,000 square foot lot. A proposed 192-foot long roadway (Lydia Lane)will provide street frontage and access for the new lot. The stormwater management system considers the impacts of the new road and all of the proposed construction on the site(i.e. the two new houses and the expansion/modification of the existing house and driveway). The proposed stormwater management system for the project includes the installation of roof runoff drywells which will recharge the roof runoff from the new houses into the groundwater. The grading of the proposed roadway will be such that there will be no increase in impervious area draining toward Salem Street, thus the project will have no negative impact on the existing drainage conditions in Salem Street. Drainage form the northerly portion of the roadway/driveway will flow to a rain garden situated on lot 3. It should be noted that since the project is a housing development comprised of detached single-family dwellings on four or fewer lots, it is exempt from the Massachusetts Department of Environmental Protection's Stonnwater Management Standards. 1 Section H: Hydrologic Analysis I Stormwater Management Report for "The Captain Nathaniel Berry Homestead", North Andover,Mass, 11 Hydrologic Anal sis Y A hydrologic analysis has been performed to determine the impact that the development of the project site will have on off-site peak runoff rates. The"HydroC.A D" Stormwater Modeling System has been used to compare the pre- and past-development runoff rates for the 1, 2, 10, and 100-year storm events. Under existing conditions, stormwater runoff from the project site flows off-site in three distinct flow directions. Figure 1: Plan of Existing Drainage Conditions shows the boundaries and flow directions of the drainage subcatchments, as follows: Subcatchment 1 is the portion of the project site that contributes runoff southward towards Salem Street. Subcatchment 2 is the portion of the project site that contributes runoff towards the abutting properties to the east. Subcatchment 3 is the portion of the project site that contributes runoff towards the abutting property to the north. Figure 2: Plan of Proposed Drainage Conditions shows the project site under the proposed past-development conditions. The drainage areas will be altered under post-development conditions as follows: Subcatchment 1 has been reduced in size from 1.39 acres to 1.16 acres under post-development conditions. This reduction in area will result in post-development peak iunoff rates that are equal to or less than the pre-development peak rates towards Salem Street. Subcatchment 2 has been reduced in size from 0.50 acres to 0.31 acres under post-development conditions. This reduction in area will result in past-development peak runoff rates that are equal to or less than the pre-development peak rates towards the properties to the east. Subcatchment 3 has been increased in size fiom 1.13 acres to 1.47 acres under post-development conditions. This increase in area will result in slightly higher peak rates of runoff towards the north. The proposed roof areas have been separated out from the drainage areas in which they lie in order to model the roof runoff infiltration areas on each of the lots. Subcatchments R-1 through R-3 are the proposed new roof areas on Lots 1 through 3. The runoff from these areas will be collected by gutters and downspouts and discharged d into the proposed roof runoff drywells in the yards. Any overflow from the drywells during extreme events is added to the runoff totals of the underlying subcatehments. The overall peak runoff rates and total runoff volumes to the south , east and north will be unchanged or decreased under post-development conditions As a result of the recharge into the groundwater by the roof iunoff infiltration areas, and the rain garden the total volume of runoff produced on the site under proposed conditions will be slightly lower than the total volume of runoff produced under existing conditions. The results of the hydrologic analysis are summarized in the following tables. TABLE 1: SUMMARY OF PEAK RUNOF RATES South (Subcatchment 1) East (Subcatchment 2) North (Subcatchment 3) Peak Rate Peak Rate Peak Rate CFS (CFS CFS 1-Year Existing 0.43 0.04 0.04 Storm Proposed 0.42 0.03 0.03 2-Year Existing 0.92 0.14 0.16 Storm Proposed 0.86 0.09 0.16 10-Year Existing 2.37 0.56 0.88 Storm Proposed 2.31 0.35 0.81 100 Year Existing 4.85 1.35 2.37 Storm Proposed 1 4.54 0.85 2.26 TABLE 2: SUMMARY OF RUNOFF VOLUMES South East North Total for Site Total Volume Total Volume Total Volume Total Volume Acre-Feet Acre-Feet Acre-Feet Acre-Feet 1-Year Existing 0.045 0.008 0.013 0.066 Propose Storm d 0.040 0.005 0.010 0.055 2-Year Existing 0.079 0.017 0.029 0.125 Propose Storm d 0.070 0.011 0.024 0.105 10-Year Existing 0.178 0.045 0.085 0.308 Propose Storm d 0.158 0.029 0.076 0.263 100-Year Existing 0.349 0.098 0.195 0.642 Propose Storm d 0.309 0.063 0.180 0.552 The exfiltration rate used in the calculations for the roof runoff infiltration areas is 7.5 inches per hour over the bottom area of the drywells. The 7.5 inches per hour rate is based on one-half of the slowest measured infiltrations rate recorded during soil testing on the site. Infiltration rates were measured using a double ring infiltrometer. Five tests were performed at various depths and the rates ranged from 15 to 21 inches per hour. I The HydroCAD drainage diagrams and calculation/data sheets for the analysis of the 1,2, 10, and 100-year storms for existing and post-development conditions are included to support the results of the analysis. The order of presentation of the calculation/data sheets is as follows: Page 1 Existing Conditions: Drainage Diagram Pages 2 - 4 Existing Conditions: 1-Year Storm Pages 5 - 7 Existing Conditions: 2-Year Storm Pages 8 - 10 Existing Conditions: 10-Year Storm Pages 11 - 13 Existing Conditions: 100-Year Storm Page 14 Proposed Conditions: Drainage Diagram Page 15 Composite CN Worksheet for Subcatchment 3 Pages 16 -22 Proposed Conditions: 1-Year Storm Pages 23 ---30 Proposed Conditions: 2-Year Storm Pages 31 - 38 Proposed Conditions: 10-Year Storm Pages 39—46 Proposed Conditions: 100-Year Storm \ ` \ FIGURE 1: EXISTING DRAINAGE \ \\ CONDITIONS DATE: 12116/08 NORTH �01�GEST\FLAW SUB ATCNMENT \\ t \ � \ \BOUN \Y (TYP.) \\ r 14 \\ �* \ (2II EAST 220 � �r ago -218- \ --216 N -- N i FIGURE 2: PROPOSED DRAINAGE CONDITIONS SCALE. 1" = 60' DATE: 12118108 NORTH LbN6W PLC V `\PkT,V\(TY�,) `SUBCATCHMENT'` ?, \U DARY (TYP.) a 1 \ 3B Of N 1 Yea 1 � � \— 273� \ 2 B• � � � 1 1 / m L� 22` '�`® EAST A \\ c'�d1 1 2 4 40 l bQT \ 226—\ \ N 2243 N 220 \ 10 ,- 2tB- N — - 20 3 '1 South East North ,9 u Obc a t Reach� Lon d r�ink' Drainage Diagram for 166 Salem Street,Existing Conditions Prepared by Christiansen&Sergi, Inc., Printed 2/1912009 jdroCADV 9.00 s/n 011057 0 2G09 HydroCAD Software Sofutions LLC 166 Salem Street, Existing Conditions Type M 24-hr 9 Year Storm Rainfall=2.50" Prepared by Christiansen & Sergi, Inc. Printed 2/19/2009 H droCAD@ 9.00 sln 01057 O 2009 H droCAD Software Solutions LLC Pa e 2 Time span=0.00-36.00 hrs, dt=0.01 hrs, 3601 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Dyn-Stor-Ind method - Pond routing by Dyn-Stor-Ind method Subcatchment 1: South Runoff Area=60,560 sf 19.42% Impervious Runoff Depth=0.39" Flow Length=210' Tc=6.2 min CN=68 Runoff=0.43 cfs 0.045 of Subcatchment 2: East Runoff Area=21,735 sf 0.00% Impervious Runoff Depth=0.20" Flow Length=190' Tc=5.6 min CN=61 Runoff=0.04 cfs 0.008 of Subcatchment 3: North Runoff Area=49,176 sf 0.33% Impervious Runoff Depth=0.13" Flow Length=160' Tc=8.6 min CN=58 Runoff=0.04 cfs 0.013 of Total Runoff Area =3.018 ac Runoff Volume= 0.066 of Average Runoff Depth =0.26" 90.93% pervious =2.744 ac 9.07% Impervious =0.274 ac 166 Salem Street, Existing Conditions Type /1124-hr 9 Year Storm Rahifall=2.50" Prepared by Christiansen & Sergi, Inc. Printed 2/19/2009 H droCAD®9.00 s/n 01057 cU 2009 HyAroCAD Software Solutions LLC Pac ie3 Summary for Subcatchment 1: South Runoff — 0.43 cfs @ 12,12 hrs, Volume= 0.045 af, Depth= 0.39" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 1 Year Storm Rainfall=2.50" Area sf CN Description 11,759 98 Paved parking & roofs 48,801 61 >75% Grass cover, Good HSG B 60,560 68 Weighted Average 48,801 80.58% Pervious Area 11,769 19.42% Impervious Area Tc Length Slope Velocity Capacity Description min feet ft/f# ft/sec cfs 5.2 50 0.0250 0.16 Sheet Flow, Grass, Short n= 0.150 P2= 3.10" 1.0 160 0.0350 2.81 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 6.2 210 Total Summary for Subcatchment 2: East Runoff - 0.04 cfs @ 12.33 hrs, Volume= 0.008 af, Depth= 0.20" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-36.00 Iirs, dt= 0.01 hrs Type III 24-hr 1 Year Storm Rainfall=2.50" Areas ON Description 1,776 55 Woods, Good, HSG B 19,959 61 >75% Grass cover, Good, HSG B 21,735 61 Weighted Average 21,735 100.00% Pervious Area Tc Length Slope Velocity Capacity Description Amin) feet ft/ft ft/sec cfs 4.9 50 0.0300 0.17 Sheet Plow, Grass: Short n= 0.150 P2= 3.10" 0.7 140 0.0550 3.52 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 5.6 190 Total Summary for Subcatchment 3: North Runoff = 0,04 cfs @ 12.45 hrs, Volume= 0.013 af, Depth= 0.13" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0,00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 1 Year Storm Rainfall=2.50" 166 Salem Street, Existing Conditions Type ill 24-hr 1 Year Storin Rainfall=2.50" Prepared by Christiansen & Sergi, Inc. Printed 2/19/2009 H droCAM 9.00 s/n 01057 @ 2009 H droCAD Software SOlutions LLC Page 4 Area sf CN Description 164 98 Paved parking & roofs 28,511 55 Woods, Good, HSG B 20,501 61 >75% Grass cover, Good, HSG B 49,176 58 Weighted Average 49,012 99.67% Pervious Area 164 0.33% impervious Area Tc Length Slope Velocity Capacity Description min feet ft/f# ft/sec cfs 7.6 50 0.0700 0.11 Sheet Plow, Woods: Light underbrush n= 0.400 P2= 3.10" 1.0 110 0.1400 1.87 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 8.6 160 Total 166 Salem Street, Existing Conditions Type Iil 24-hr 2 Year Storm Rainfall=3.10" Prepared by Christiansen & Sergi, Inc. Printed 2/1912009 HYdjoCAD&9.00 s/n 01057 O 2009 H droCAD Software Solutions LLC Pap 5 Time span=0.00-36.00 hrs, dt=0.01 hrs, 3601 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Dyn-Stor-ind method - Pond routing by Dyn-Stor-Ind method Subcatchment 1: South Runoff Area=60,560 sf 19.42% Impervious Runoff Depth=0.68" Flow Length=210' Tc=6.2 min CN=68 Runoff=0.92 cfs 0.079 of Subcatchment 2: East Runoff Area=21,735 sf 0.00% Impervious Runoff Depth=0.40" Flow Length=190' Tc=5.6 rain CN=61 Runoff=0.14 cfs 0.017 of Subcatchment 3: North Runoff Area=49,176 sf 0.33% Impervious Runoff Depth=0.31" Flow Length=160' Tc=8.6 min CN=58 Runoff=0.16 cfs 0,029 of Total Runoff Area = 3.018 ac Runoff Volume =0.124 of Average Runoff Depth =0.49" 90.93% Pervious = 2.744 ac 9.07% Impervious = 0.274 ac 166 Salem Street, Existing Conditions Type lif 24-17r 2 Year Storm Rainfall=3.10" Prepared by Christiansen & Sergi, Inc, Printed 2/19/2009 H droCAD®9.00 sln 01057 O 2009 H droCAD Software Solutions LLC Pa_q e 6 Summary for Subcatchment 1: South Runoff = 0.92 cfs @ 12.11 hrs, Volume= 0.079 af, Depth= 0.68" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 2 Year Storm Rainfall=3.10" Area sf CN Description 11,759 98 Paved parking & roofs 48,801 61 >75% Grass cover, Good, HSG B 60,560 68 Weighted Average 48,801 80.58% Pervious Area 11,759 19.42% Impervious Area Tc Length Slope Velocity Capacity Description min feet ftlft ftlsec cfs 5.2 50 0.0250 0,16 Sheet Flow, Grass; Short n= 0.150 P2= 3.10" 1.0 160 0.0350 2.81 Shallow Concentrated Plow, Grassed Waterway Kv= 15.0 fps 6.2 210 Total Summary for Subcatchment 2: East Runoff = 0.14 cfs @ 12.12 hrs, Volume= 0.017 af, Depth= 0.40" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type Ill 24-hr 2 Year Storm Rainfall=3.10" Area sf CN Description 1,776 55 Woods, Good, HSG B 19,959 61 >75% Grass cover, Good, HSG B 21,735 61 Weighted Average 21,735 100.00% Pervious Area Tc Length Slope Velocity Capacity Description min feet ftift ftlsec cfs 4.9 50 0.0300 0.17 Sheet Flow, Grass: Short n= 0.150 P2= 3.10" 0.7 140 0.0550 3.52 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 5.6 190 Total Summary for Subcatchment 3: North Runoff = 0.16 cfs @ 12.32 hrs, Volume= 0.029 af, Depth= 0.31" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 2 Year Storm Rainfall=3.10" 166 Salem Street, Existing Conditions Tyne 11124-11r 2 Year Storm Rainfall=3.10" Prepared by Christiansen & Sergi, Inc. Printed 2/19/2009 H droCAD®9.00 sln 01057 ©2009 H droCAD Software Solutions LLC Page 7 Area sf CN Description 164 98 Paved parking & roofs 28,511 55 Woods, Good, HSG B 20,501 61 >75% Grass cover, Good, HSG B 49,176 58 Weighted Average 49,012 99.67% Pervious Area 164 0.33% Impervious Area Tc Length Slope Velocity Capacity Description min feet ftlfi ftlsec cfs 7.6 50 0.0700 0.11 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.10" 1.0 110 0.1400 1.87 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 8.6 160 Total — 166 Salem Street, Existing Conditions Type {l124-hr 10 Year Stonn Rainfall=4.50" Prepared by Christiansen & Sergi, Inc. Printed 2/19/2009 H droCAD®9,00 sln 01057 c0 2009 H droCAD Software Solutions LLC Pa e 8 Time span=0.00-36.00 hrs, dt=0.01 hrs, 3601 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Dyn-Star-Ind method - Pond routing by Dyn-Stor-Ind method Subcatchment 1: South Runoff Area=60,560 sf 19.42% Impervious Runoff Depth=1.53" Flow Length=210' Tc=6.2 Erin CN=68 Runoff=2.37 cfs 0.178 of Subcatchment 2: East Runoff Area=21,735 sf 0.00% Impervious Runoff Depth=1.08" Flow Length=190' Tc=5.6 min CN=61 Runoff=0.56 cfs 0.045 of Subcatchment 3: North Runoff Area=49,176 sf 0.33% Impervious Runoff Depth=0.90" Flow Length=160' Tc=8,6 min CN=58 Runoff=0.88 cfs 0.085 of Total Runoff Area = 3.018 ac Runoff Volume =0.308 of Average Runoff Depth =1.22" 90.93%Pervious =2.744 ac 9.07% Impervious = 0.274 ac 166 Salem Street, Existing Conditions Type 11124-hr 10 Year Storm Rainfall=4.50" Prepared by Christiansen & Sergi, Inc. Printed 2/19/2009 H droCAD®9.00 sin 01057 ©2009 H droCAD Software Solutions LLC page 9 Summary for Subcatchment 1: South Runoff = 2.37 cfs @ 12.10 hrs, Volume= 0.178 af, Depth= 1.53" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 10 Year Storm Rainfall=4.50" Area sf CN Descri tion 11,759 98 Paved parking & roofs 48,801 61 >75% Grass cover, Good, HSG B 60,560 68 Weighted Average 48,801 80.58% Pervious Area 11,759 19.42% Impervious Area Tc Length Slope Velocity Capacity Description min feet ftlft ftlsec cfs 5.2 50 0.0250 0.16 Sheet Flow, Grass: Short n= 0.150 P2= 3.10" 1.0 160 0.0350 2.81 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 6.2 210 Total Summary for Subcatchment 2: East Runoff — 0.56 cfs @ 12.10 hrs, Volume= 0.045 af, Depth= 1.08" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 10 Year Storm Rainfall=4.50" Area sf CN Description 1,776 55 Woods, Good, HSG B 19,959 61 >75% Grass cover, Good, HSG B 21,735 61 Weighted Average 21,735 100.00% Pervious Area Tc Length Slope Velocity Capacity Description min feet ft/ft ftlsec cfs 4.9 50 0.0300 0.17 Sheet Flow, Grass: Short n= 0.150 P2= 3.10" 0.7 140 0.0550 3.52 Shallow Concentrated Flow, Grassed Waterway Kv-- 15.0 fps 5.6 190 Total Summary for Subcatchment 3: North Runoff = 0.88 cfs @ 12.14 hrs, Volume= 0.085 af, Depth= 0.90" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 10 Year Storm Rainfall=4.50" i 166 Salem Street, Existing Conditions Type lil 24-hr 10 Year Storin Rainfall=4.50" Prepared by Christiansen & Sergi, Inc. Printed 2/19/2009 H droCAD®9.00 s/n 01057 e0 2009 H droCAD Software Solutions LLC Page 10 sf) CN Description Area(... ._ 164 98 Paved parking & roofs 28,511 55 Woods, Good, HSG B 20,501 61 >75% Grass cover, Good, HSG B 49,176 58 Weighted Average 49,012 99.67% Pervious Area 164 0.33% Impervious Area To Length Slope Velocity Capacity Description min feet ftJft ft/sec cfs 7.6 50 0.0700 0.11 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.10" 1.0 110 0.1400 1.87 Shallow Concentrated Flow, _ Woodland Kv= 5.0 fps 8.6 160 Total it I 166 Salem Street, Existing Conditions Type IIJ 24-hr 100 Year Storm Rainfall=6.50" Prepared by Christiansen & Sergi, Inc. Printed 2/19/2009 HydroCAD®9.00 sln 01057 ©2009 HydroCAD Software Solutions LLC _Page 11 Time span=0.00-36.00 hrs, dt=0.01 hrs, 3601 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Dyn-Stor-Ind method - Pond routing by Dyn-Stor-Ind method Subcatchment 1: South Runoff Area=60,560 sf 19.42% Impervious Runoff Depth=3.01" Flow Length=210' Tc=6.2 min CN=68 Runoff=4.85 cfs 0.349 of Subcatchment 2: East Runoff Area=21,735 sf 0.00% Impervious Runoff Depth=2.35" Flow Length=190' Tc=5.6 min CN=61 Runoff=1.35 cfs 0.098 of Subcatchment 3: North Runoff Area=49,176 sf 0.33% Impervious Runoff Depth=2.08" Flow Length=160' Tc=8.6 min CN=58 Runoff=2,37 cfs 0.195 of Total Runoff Area =3.018 ac Runoff Volume= 0.642 of Average Runoff Depth =2.55" 90.93% Pervious =2.744 ac 9.07% Impervious =0.274 ac 166 Salem Street, Existing Conditions Type !II 24-hr 100 Year Storin Rainfall=6.50" Prepared by Christiansen & Sergi, Inc. Printed 2/19/2009 H droCAD0 9.00 sin 01057 ©2009 H droCAD Software Solutions LLC Pacie 12 Summary for Subcatchment 1: South Runoff = 4.85 cfs @ 12.09 hrs, Volume= 0.349 af, Depth= 3.01" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 100 Year Storm Rainfall=6.50" Area sf CN Description 11,759 98 Paved parking & roofs 48,801 61 >75% Grass cover, Good, HSG B 60,560 68 Weighted Average 48,801 80.58% Pervious Area 11,759 19.42% Impervious Area Tc Length Slope Velocity Capacity Description min feet ftlft ftlsec cfs 5.2 50 0.0250 0.16 Sheet Flow, Grass: Short n= 0.150 P2= 3.10" 1.0 160 0.0350 2.81 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 f s 6.2 210 Total Summary for Subcatchment 2: East Runoff - 1.35 cfs @ 12.09 hrs, Volume= 0.098 af, Depth= 2.35" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 100 Year Storm Rainfall=6.50" Area sf CN Descri tion i 1,776 55 Woods, Good, HSG B 19,959 61 >75% Grass cover, Good, HSG B 21,735 61 Weighted Average 21,735 100.00% Pervious Area Tc Length Slope Velocity Capacity Description min feet ftlft ftlsec cfs 4.9 50 0.0300 0.17 Sheet Flow, Grass: Short n= 0.150 P2= 3.10" 0.7 140 0.0550 3.52 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 5.6 190 Total Summary for Subcatchment 3: North Runoff = 2.37 cfs @ 12.13 hrs, Volume= 0.195 af, Depth= 2.08" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 100 Year Storm Rainfall=6.50" 166 Salem Street, Existing Conditions Type iil 24-fir 100 Year Storm Rainfall=6.50" Prepared by Christiansen & Sergi, Inc. Printed 2/19/2009 H droCAD®9.00 s/n 01057 p 2009 H droCAD Software Solutions LLC Page 13 Area sf CN Description 164 98 Paved parking & roofs 28,511 55 Woods, Good, HSG B 20,501 61 >75% Grass cover, Good, HSG B 49,176 58 Weighted Average 49,012 99.67% Pervious Area 164 0.33% Impervious Area Tc Length Slope Velocity Capacity Description min feet ftlft ft/sec cfs 7.6 50 0.0700 0.11 Sheet Plow, Woods: Light underbrush n= 0.400 P2= 3.10" 1.0 110 0.1400 1.87 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 8.6 160 Total 3B North T 3 L R2 Nort otal Roof Runoff Infiltration Roof Runoff Infiltration R2 Area 2 Area 3 R3 Roof 2 RG Roof 3 3A Rain Garden (Infiltration Basin) Flow to Rain Garden R1 1 2 Ro f 1 So th East R1 NZT\-1 Roof Runoff Infiltration South Total Area 1 SUbca# [Reach Pand Lind( Drainage Diagram for 166 Salem Street,Proposed Conditions _____ Prepared by Christiansen&Sergi, Inc., Printed 211912009 — HydroCADD 9.00 s1n 01057 O2009 HydroCAD Software Solutions LLC 166 Salem Street, Proposed Conditions Type 11124-hr 9 Year Storm Rainfai1=2.50" Prepared by Christiansen & Sergi, Inc. Printed 2/19/2009 H droCAD®9.00 sin 01057 0 2009 H droCAD Software Solutions LLC Page 15 Time span=0.00-36.00 hrs, dt=0.01 hrs, 3601 points x 3 Runoff by SCS TR-20 method, UH=SCS Reach routing by Dyn-Stor-Ind method - Pond routing by Dyn-Stor-Ind method Subcatchment 1: South Runoff Area=50,295 sf 21.05% Impervious Runoff Depth=0.42" Flow Length=175' Slope=0.0300'1' Tc=5.5 min CN=69 Runoff=0.42 ofs 0.040 of i Subcatchment 2: East Runoff Area=14,126 sf 0.00% Impervious Runoff Depth=0.20" Flow Length=190' Tc=6.3 min CN=61 Runoff=0.03 cfs 0.005 of Subcatchment 3A: Flow to Rain Garden Runoff Area=16,790 sf 19.89% Impervious Runoff Depth=0.39" Flow Length=125' Tc=3.1 min CN=68 Runoff=0.13 cfs 0.012 of Subcatchment 313: North Runoff Area=44,802 sf 0,00% Impervious Runoff Depth=0.12" Flow Length=160' Tc=8.6 min CN=57 Runoff=0.03 cfs 0.010 of Subcatchment R1: Roof 1 Runoff Area=2,779 sf 100.00% Impervious Runoff Depth=2.27" Tc=1.0 min CN=98 Runoff=0.18 cfs 0.012 of Subcatchment R2: Roof 2 Runoff Area=960 sf 100.00% Impervious Runoff Depth=2.27" Tc=1.0 min CN=98 Runoff=0,06 cfs 0.004 of Subcatchment R3: Roof 3 Runoff Area=2,400 sf 100.00% Impervious Runoff Depth=2.27" Tc=1.0 min CN=98 Runoff=0.16 cfs 0.010 of Pond RG: Rain Garden (Infiltration Basin) Peak Elev=222.00' Storage=0 cf Inflow=0.13 cfs 0.012 of Outflow=0.13 cfs 0.012 of Pond RR1: Roof Runoff Infiltration Area 1 Peak Elev=220.59' Storage=144 cf Inflow=0.18 cfs 0.012 of Discarded=0.02 ofs 0.012 of Primary=0.00 cfs 0.000 of Outflow=0.02 cfs 0.012 of Pond RR2: Roof Runoff Infiltration Area 2 Peak Elev=222.89' Storage=35 cf Inflow=0.06 cfs 0.004 of Discarded=0.01 cfs 0.004 of Primaty=0.00 cfs 0.000 of Outflow=0,01 cfs 0.004 of Pond RR3: Roof Runoff Infiltration Area 3 Peak Elev=215.43' Storage=114 cf Inflow=0.16 cfs 0.010 of Discarded=0.02 cfs 0.010 of Primary=0.00 cfs 0.000 of Outflow=0.02 cfs 0.010 of Pond T 1: South Total Inflow=0.42 cfs 0.040 of Primary=0.42 cfs 0.040 of Pond T 3: North Total Inflow=0.03 cfs 0.010 of Primary=0.03 cfs 0.010 of Total Runoff Area = 3.034 ac Runoff Volume =U.U95 of Average Runoff Depth = 0.37" 84.82% Pervious =2.573 ac 15.18% Impervious =0.461 ac 166 Salem Street, Proposed Conditions Type lit 24-17r 9 Year Storm Rainfall=2.50" Prepared by Christiansen & Sergi, Inc. Printed 2/19/2009 H dl"oCAD®9.00 sln 01057 O 2009 H droCAD Software Solutions LLC Page 16 Summary for Subcatchment 1: South Runoff — 0.42 cfs @ 12.11 hrs, Volume= 0.040 af, Depth= 0.42" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 1 Year Storm Rainfall=2.50" Area sf CN Description 10,585 98 Paved parking & roofs 39,710 61 >75% Grass cover, Good HSG S 50,295 69 Weighted Average 39,710 78.95% Pervious Area 10,585 21.05% Impervious Area To Length Slope Velocity Capacity Description min feet ftlft ftlsec cfs 4.9 50 0.0300 0.17 Sheet Flow, Grass: Short n= 0.150 P2= 3.10" 0.6 125 0.0300 3.52 Shallow Concentrated Flow, Paved Kv= 20.3 fps 5.5 175 Total Summary for Subcatchment 2: East Runoff — 0.03 cfs @ 12.34 hrs, Volume= 0.005 af, Depth= 0.20" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-36.00 hrs, dt= 0.01 Iirs Type Ill 24-hr 1 Year Storm Rainfall=2.50" Area (sf) CN Description 126 61 >75/a Grass cover, Good, H ., 14, ° SG 8 14,126 100.00% Pervious Area Tc Length Slope Velocity Capacity Description min feet ftlft ft/sec cfs 5.7 50 0.0200 0.15 Sheet Flow, Grass: Short n= 0.150 P2= 3.10" 0.6 140 0.0600 3.67 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 6.3 190 Total Summary for Subcatchment 3A: Flow to Rain Garden Runoff = 0.13 cfs @ 12.07 hrs, Volume= 0.012 af, Depth= 0.39" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 1 Year Storm Rainfall=2.50" 166 Salem Street, Proposed Conditions Type 11124-hr 1 Year Storm Rainfall=2.50" Prepared by Christiansen & Sergi, Inc. Printed 2/19/2009 H droCAD�)9.00 sln 01057 ©2009 H droCAD Software Solutions LLC Page 17 Area sf CN Description 3,339 98 Paved parking & roofs 13,451 61 >75% Grass cover, Good, HSG B 16,790 68 Weighted Average 13,451 80.11% Pervious Area 3,339 19.89% Impervious Area i To Length Slope Velocity Capacity Description train feet ftlft ftlsec cfs 2.8 50 0.1200 0.30 Sheet Flow, Grass: Short n= 0.150 P2= 3.10" 0.2 50 0.0440 4.26 Shallow Concentrated Flow, Paved Kv=20.3 fps 0.1 25 0.0400 3.00 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 3.1 125 Total Summary for Subcatchment 313: North Runoff = 0.03 cfs @ 12.49 hrs, Volume= 0.010 af, Depth= 0.12" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 1 Year Storm Rainfall=2.50" Area (so CN Description 27,800 55 Woods, Good, HSG B 17,002 61 575% Grass cover, Good, HSG B 44,802 57 Weighted Average 44,802 100.00% Pervious Area To Length Slope Velocity Capacity Description min feet ftift ftlsec cfs 7.6 50 0.0700 0.11 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.10" 1.0 110 0,1400 1.87 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 8.6 160 Total Summary for Subcatchment R1: Roof 1 Runoff — 0.18 cfs @ 12,01 hrs, Volume= 0.012 af, Depth= 2.27" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 1 Year Storm Rainfall=2.50" Area sf CN Description 2,779 98 Paved parking & roofs 2,779 100.00% Impervious Area 166 Salem Street, Proposed Conditions Type I/l 24-hr I Year Storin Rainfall=2.50" Prepared by Christiansen & Sergi, Inc. Printed 2/19/2009 HydroCADV 9.00 s/n 01057 O 2009 HydroCAD Software Solutions LLC Page 18 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.0 Direct Entry, Summary for Subcatchment R2: Roof 2 Runoff - 0.06 cfs @ 12.01 hrs, Volume= 0.004 af, Depth= 2.27" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 1 Year Storm Rainfall=2.50" Area (sf) ON Description 960 98 Paved parking & roofs 960 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min)- (feet) (ft/fl) (ft/sec) (cfs) 1,0 Direct Entry, Summary for Subcatchment R3: Roof 3 Runoff 0.16 cfs @ 12.01 hrs, Volume= 0.010 af, Depth= 2.27" Runoff by SOS TR-20 method, UH=SCS, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 1 Year Storm Rainfall=2.50" Area (sf) CN Description 2,400 98 Paved parking & roofs 2,400 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (fl/ft) (ft/sec) (cfs) 1.0 Direct Entry, - Summary for Pond RG: Rain Garden (Infiltration Basin) Inflow Area = 0.385 ac, 19.89% Impervious, Inflow Depth = 0.39" for 1 Year Storm event Inflow - 0.13 cfs @ 12.07 hrs, Volume= 0.012 of Outflow = 0.13 cfs @ 12.07 hrs, Volume= 0.012 af, Atten= 0%, Lag= 0.0 min Discarded = 0.13 cfs @ 12.07 hrs, Volume= 0.012 of Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs/3 Peak Elev= 222.00' @ 12.07 hrs Surf.Area= 860 sf Storage= 0 cf Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 0.0 min ( 904.8 - 904.7 ) 166 Salem Street, Proposed Conditions Type If!24-hr 1 Year Stonn Rainfall=2.50" Prepared by Christiansen & Sergi, Inc. Printed 2/19/2009 H droCAD®9.00 s/n 01057 02009 H droCAD Software Solutions LLC page 19 Volume Invert Avail,Storage Storage Description #1 222.00' 1,300 cf Custom Stage Data Prismatic Listed belo"°._.._ g (Prismatic) w (Recalc) Elevation Surf.Area Inc.Store Cum.Store feet s -ft cubic-feet cubic-feet 222.00 860 0 0 223.00 1,740 1,300 1,300 Device Routing Invert Outlet Devices #1 Discarded 222.00' 7.500 inlhr Exfiltration over Surface area Discarded OutFlow Max=0.15 cfs @ 12.07 hrs HW=222.00' (Free Discharge) L1=Exfiltration (Exfiltration Controls 0.15 cfs) Summary for Pond RR1: Roof Runoff Infiltration Area 1 Inflow Area = 0,064 ac,100.00% Impervious, Inflow Depth = 2.27" for 1 Year Storm event Inflow — 0.18 cfs @ 12.01 hrs, Volume= 0.012 of Outflow = 0.02 cfs @ 11,69 hrs, Volume= 0.012 af, Atten= 87%, Lag= 0.0 min Discarded = 0.02 cfs @ 11.69 hrs, Volume= 0.012 of Primary — 0.00 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs 13 Peak Elev= 220.59' @ 12.48 hrs Surf.Area= 136 sf Storage= 144 cf Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 33.9 min ( 791.2 - 757.3 ) Volume Invert Avail.Stora e Sto e Description #1 218.80' 85 cf Crushed Stone Around Chambers (Prismatic) Listed below (Recalc) 301 cf Overall - 87 cf Embedded = 213 cf x 40.0%Voids #2 219.30' 87 cf Cultec R-180 x 4 Inside#1 Effective Size= 33.6"W x 20.0"H => 3.44 sf x 6.331 = 21.8 cf Overall Size= 36.0"W x 20.5"H x 7.331 with 1.00' Overlap #3 220.47' 1 of 0.33'D x 6.50'H Vertical Cone/Cylinder-Impervious 173 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store feet s -ft cubic-feet cubic-feet 218.80 136 0 0 221.01 136 301 301 Device Routing invert Outlet Devices #1 Discarded 218.80' 7.500 inlhr Exfiltration over Surface area #2 Primary 221.01' Special & User-Defined Head (feet) 0.00 0.10 Disch. (cfs) 0.000 10.000 166 Salem Street, Proposed Conditions Type H/ 24-hr 9 Year Storm Rainfall=2.50" Prepared by Christiansen & Sergi, Inc. Printed 2/19/2009 H droCAD®9A0 sin 01057 OO 2009 H droCAD Software Solutions LLC Page 20 Discarded OutFlow Max=0.02 cfs @ 11.69 hrs HW=218.88' (Free Discharge) 'L1=Exfiltration (Exfiltration Controls 0.02 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=218.80' TW=0.00' (Dynamic Tailwater) L2=Special & User-Defined ( Controls 0.00 cfs) Summary for Pond RR2: Roof Runoff Infiltration Area 2 Inflow Area = 0.022 ac,100.00% Impervious, Inflow Depth = 2.27" for 1 Year Storm event Inflow - 0.06 cfs @ 12.01 hrs, Volume= 0.004 of Outflow - 0.01 cfs @ 11.71 hrs, Volume= 0.004 af, Atten= 79%, Lag= 0.0 min Discarded = 0.01 cfs @ 11.71 hrs, Volume= 0.004 of Primary - 0,00 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Dyn-Star-Ind method, Time Span= 0.00-36.00 hrs, df= 0.01 hrs i 3 Peak Elev= 222.89' @ 12.38 hrs Surf.Area= 76 sf Storage=35 cf Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 11.9 min ( 769.2 - 757.3 } Volume Invert Avail.Stora e Storage Description #1 222.00' 50 of Crushed Stone Around Chambers (Prismatic) Listed below(Recalc) 168 cf Overall-44 cf Embedded= 124 cf x 40.0%Voids #2 222.50' 44 cf Cultec R-180 x 2 Inside#1 Effective Size= 33,6"W x 20.0"H => 3.44 sf x 6.33% = 21.8 cf Overall Size= 36.0"W x 20.5"H x 7.331 with 1.00' Overlap #3 223,67' 0 cf 0.33'D x 4.00'H Vertical Cone/Cylinder-Impervious 94 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store feet s -ft cubic-feet cubic-feet 222.00 76 0 0 224.21 76 168 168 Device Routing Invert Outlet Devices #1 Discarded 222.00' 7.500 inthr Exfiltration over Surface area #2 Primary 226.10' 4.0" Round Culvert L= 2.0' CPP, square edge headwall, Ke= 0.500 Outlet Invert= 226.00' S= 0.0500 '1' Cc= 0.900 n= 0.010 PVC, smooth interior Discarded OutFlow Max=0.01 cfs @ 11.71 hrs HW=222.01' (Free Discharge) t--1=Exfiltration (Exfiltration Controls 0.01 cfs) Primary OutFlow Max=0,00 cfs @ 0.00 hrs HW=222.00' TW=0.00' (Dynamic Tailwater) t-2=Culvert ( Controls 0.00 cfs) 166 Salem Street, Proposed Conditions Type 1l1 24-hr I Year Storm Rainfall=2.50" Prepared by Christiansen & Sergi, Inc. Printed 2/19/2009 H droCAD®9A0 s/n 01057 4 2009 H droCAD Software Solutions LLC Page 21 Summary for Pond RR3: Roof Runoff Infiltration Area 3 Inflow Area = 0.055 ac,100.00% Impervious, Inflow Depth = 2.27" for 1 Year Storm event Inflow 0.16 cfs @ 12.01 hrs, Volume= 0.010 of Outflow = 0.02 cfs @ 11.62 hrs, VOILII-ne= 0.010 af, Men= 85%, Lag= 0.0 min Discarded = 0.02 cfs @ 11,62 hrs, Volume= 0.010 a€ !. Primary -- 0.00 ofs @ 0.00 hrs, Volume= 0.000 of Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs 13 Peak Elev= 215.43' @ 12.46 hrs Surf.Area= 136 sf Storage= 114 of Plug-Flow detention time= (not calculated; outflow precedes inflow) Center-of-Mass det. time= 25.2 min ( 782.4- 757.3 ) Volume Invert Avail.Stora a Storage Description #1 214.00' 85 of Crushed Stone Around Chambers (Prismatic) Listed below(Recalc) 301 of Overall - 87 of Embedded = 213 of x 40.0%Voids #2 214.50' 87 of Cultec R-180 x 4 Inside#1 Effective Size= 33.6"W x 20.0"H => 3.44 sf x 6.331= 21.8 of Overall Size= 36.0"W x 20.5"H x 7.33'L with 1.00' Overiap #3 215,67' 0 cf 0.33'D x 4.00'H Vertical Cone/Cylinder-Impervious 173 of Total Available Storage Elevation Surf.Area Inc.Store Cum.Store feet s -ft cubic-feet cubic-feet 214.00 136 0 0 216.21 136 301 301 Device Routing Invert Outlet Devices #1 Discarded 214.00' 7.500 inthr Exfiltration over Surface area #2 Primary 215.67' Special & User-Defined Head (feet) 0.00 0.10 Disch. (cfs) 0.000 1.000 Discarded OutFlow Max=0.02 cfs @ 11.62 hrs HW=214.01' (Free Discharge) t-1=Exfiltration (Exfiltration Controls 0,02 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=214.00' TW=0.00' (Dynamic Tailwater) t-2=Special & User-Defined ( Controls 0.00 cfs) Summary for Pond T 1: South Total Inflow Area = 1.218 ac, 25.18% Impervious, Inflow Depth = 0.40" for 1 Year Storm event Inflow -- 0.42 cfs @ 12.11 hrs, Volume= 0.040 of Primary = 0.42 cfs @ 12.11 hrs, Volume= 0.040 af, Men= 0%, Lag= 0.0 min Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs 13 166 Salem Street, Proposed Conditions Type 11124-hr 1 Year Storm Rainfall=2.50" Prepared by Christiansen & Sergi, Inc. Printed 2/19/2009 Hy droCAD0 9.00 s1n 01057 02009 H droCAD Software Solutions LLC Pa e 22 Summary for Pond T 3: North Total Inflow Area 1.491 ac, 10.31% Impervious, Inflow Depth = 0.08" for 1 Year Storm event Inflow — 0.03 cfs @ 12.49 hrs, Volume= 0.010 of Primary — 0.03 cfs @ 12.49 hrs, Volume= 0.01Oaf, Atten= 0%, Lag= 0.0 min Routing by Dyn-Stor-Ind method, Time Span= 0,00-36.00 hrs, dt= 0.01 hrs/3 166 Salem Street, Proposed Conditions Type 11124-hr 2 Year Storm Rainfall=3.10" Prepared by Christiansen & Sergi, Inc. Printed 2/19/2009 H droCAQ®9.00 sJn 01057 2009 H droCAD Software Solutions LLC Page 23 Tine span=0.00-36.00 firs, dt=0.01 hrs, 3601 points x 3 Runoff by SCS TR-20 method, UH=SCS Reach routing by Dyn-Stor-Ind method - Pond routing by Dyn-Stor-Ind method Subcatchment 1: South Runoff Area=50,295 sf 21.05% Impervious Runoff Depth=0.72" Flow Length=175' Slope=0.0300'f Tc=5.5 min CN=69 Runoff=0.86 cfs 0.070 of Subcatchment 2: East Runoff Area=14,126 sf 0.00% Impervious Runoff Depth=0.40" Flow Length=190' Tc=6.3 min CN=61 Runoff=0.09 cfs 0.011 of Subcatchment 3A: Flow to Rain Garden Runoff Area=16,790 sf 19.89% Impervious Runoff Depth=0.68" Flow Length=125' Tc=3.1 min CN=68 Runoff=0.29 cfs 0.022 of Subcatchment 3B: North Runoff Area=44,802 sf 0.00% Impervious Runoff Depth=0.28" Flow Length=160' Tc=8.6 min CN=57 Runoff=0.13 cfs 0.024 of Subcatchment R1: Roof 1 Runoff Area=2,779 sf 100.00% Impervious Runoff Depth=2.87" Tc=1.0 mIn CN=98 Runoff=0.23 cfs 0.015 of Subcatchment R2: Roof 2 Runoff Area=960 sf 100.00% Impervious Runoff Depth=2.87" Tc=1.0 min CN=98 Runoff=0.08 cfs 0.005 of Subcatchment R3: Roof 3 Runoff Area=2,400 sf 100.00% Impervious Runoff Depth=2.87" Tc=1.0 min CN=98 Runoff=0.20 cfs 0.013 of Pond RG: Rain Garden (Infiltration Basin) Peak Elev=222.06' Storage=50 cf Inflow=0.29 cfs 0.022 of Outflow=0.16 cfs 0.022 of Pond RR1: Roof Runoff Infiltration Area 1 Peak Elev=221.01' Storage=173 cf Inflow=0.23 cfs 0.015 of ❑iscarded=0.02 cfs 0.015 of Pr1mary=0.07 cfs 0,001 of Outflow=0.10 cfs 0.015 of Pond RR2: Roof Runoff Infiltration Area 2 Peak Elev=223.25' Storage=53 of Inflow=0.08 cfs 0.005 of Discarded=0.01 cfs 0.005 of Primary=0.00 cfs 0,000 of Outflow=0.01 ofs 0.005 of Pond RR3: Roof Runoff Infiltration Area 3 Peak Elev=215.68' Storage=135 cf Inflow=0.20 cfs 0.013 of Discarded=0.02 cfs 0.013 of Primary=0.05 cfs 0.001 of Outflow=0.08 cfs 0.013 of Pond T 1: South Total Inflow=0.86 cfs 0.070 of Primary=0.86 cfs 0.070 of Pond T 3: North Total Inflow=0.16 cfs 0.024 of Primary=0.16 cfs 0.024 of Total Runoff Area =3.034 ac Runoff Volume =0.160 of Average Runoff Depth =0.63" 84.82%Pervious =2.573 ac 15.18% Impervious =0.461 ac 166 Salem Street, Proposed Conditions Type 11124-hr 2 Year Storm Rainfall=3.10" Prepared by Christiansen & Sergi, Inc. Printed 2/19/2009 Hydro CAN)9.00 sln 01057 C 2009 H droCA©Software Solutions LLC Page 24 Summary for Subcatchment 1: South Runoff = 0.86 cfs @ 12.09 firs, Volume 0.070 af, Depth= 0.72" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-36.00 hrs, dt= 0.01 firs Type III 24-hr 2 Year Storm Rainfall=3.10" Area sf CN Description 10,585 98 Paved parking & roofs 39,710 61 >75% Grass cover, Good, HSG B 50,295 69 Weighted Average 39,710 78.95% Pervious Area 10,585 21.05% Impervious Area Tc Length Slope Velocity Capacity Description min fee# ftlf# ftfsec cfs 4.9 50 0.0300 0.17 Sheet Flow, Grass: Short n= 0.150 P2= 3.10" 0.6 125 0.0300 3.52 Shallow Concentrated Flow, Paved Kv=20.3 fps 5.5 175 Total Summary for Subcatchment 2: East Runoff — 0.09 cfs @ 12.13 hrs, Volume= 0.011 af, Depth= 0.40" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 2 Year Storm Rainfall=3.10" Area sf CN Description 14,126 61 >75% Grass cover, Good, HSG B 14,126 100.00% Pervious Area Te Length Slope Velocity Capacity Description min feet fUf# ftlsec cfs 5.7 50 0.0200 0.15 Sheet Flow, Grass: Short n= 0.150 P2= 3.10" 0.6 140 0.0600 3.67 Shallow Concentrated Flow, Grassed Waterwa Kv= 15.0 f s 6.3 190 Total Summary for Subcatchment 3A: Flow to Rain Garden Runoff = 0.29 cfs @ 12.06 hrs, Volume= 0.022 af, Depth= 0.68" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-36.00 firs, dt= 0.01 hrs Type III 24-hr 2 Year Storm Rainfall=3.10" 4" 166 Salem Street, Proposed Conditions Type 1i124-hr 2 Year Storm Rainfall=3.1 Prepared by Christiansen & Sergi, Inc. Printed 2/19/2009 H droCAD®9.00 sin 01057 ©2009 H droCAD Software Solutions LLC Page 25 Area sf CN Description 3,339 98 Paved parking & roofs 13,451 61 >75% Grass cover, Good, HSG B 16,790 68 Weighted Average 13,451 80.11% Pervious Area 3,339 19.89% Impervious Area Tc Length Slope Velocity Capacity Description min feet ftlft ftlsec cfs 2.8 50 0.1200 0.30 Sheet Flow, Grass: Short n= 0.150 P2= 3.10" 0.2 50 0.0440 4.26 Shallow Concentrated Flow, Paved Kv=20.3 fps 0.1 25 0.0400 3.00 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 3.1 125 Total Summary for Subcatchment 36: North Runoff = 0.13 cfs @ 12.34 hrs, Volume= 0.024 af, Depth= 0,28" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 2 Year Storm Rainfall=3.10" Area sf CN Description 27,800 55 Woods, Good, HSG B 17,002 61 >75% Grass cover, Good, HSG B 44,802 57 Weighted Average 44,802 100.00% Pervious Area Tc Length Slope Velocity Capacity Description grin feet ftlff ftlsec cfs 7.6 50 0.0700 0.11 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.10" 1.0 110 0.1400 1.87 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 8.6 160 Total Summary for Subcatchment R1: Roof 1 Runoff — 0.23 cfs @ 12.01 hrs, Volume= 0.015 af, Depth= 2.87" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 2 Year Storm Rainfall=3.10" Area sf CN Descri tion 2,779 98 Paved_parking & roofs 2,779 100.00% Impervious Area 166 Salem Street, Proposed Conditions Type ill 24-hr 2 Year Storm Rainfall=3.10" Prepared by Christiansen & Sergi, Inc. Printed 2/19/2009 H droCAD®9.00 s!n 01057 02009 H droCAD Software Solutions LLC Page 26 To Length Slope Velocity Capacity Description min feet ftlft ftlsec cfs 1.0 Direct Entry, Summary for Subcatchment R2: Roof 2 Runoff 0,08 cfs @ 12.01 hrs, Volume= 0.005 af, Depth= 2,87" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0,00-36.00 Mrs, dt= 0.01 hrs Type III 24-hr 2 Year Storm Rainfall=3.10" Areas CN Description 960 98 Paved parking & roofs _ 960 100.00% Impervious Area To Length Slope Velocity Capacity Description min feet ftlft ftlsec cfs 1.0 Direct Entry, Summary for Subcatchment R3: Roof 3 Runoff = 0.20 cfs @ 12.01 hrs, Volume= 0.013 af, Depth= 2.87" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 2 Year Storm Rainfall=3.10" Area (sf) CN Description 2,400 98 Paved parking & roofs 2,400 100.00% Impervious Area Tc Length Slope Velocity Capacity Description min feet ftlft ftlsec cfs 1.0 Direct Entry, Summary for Pond RG: Rain Garden (Infiltration Basin) Inflow Area = 0.385 ac, 19.89% Impervious, Inflow Depth = 0.68" for 2 Year Storm event Inflow = 0.29 cfs @ 12.06 hrs, Volume= 0.022 of Outflow — 0.16 cfs @ 12.20 hrs, Volume= 0,022 af, Atten= 45%, Lag= 8.3 min Discarded = 0.16 cfs @ 12.20 hrs, Volume= 0.022 of Routing by Dyn-Stor-Ind method, Time Span= 0,00-36,00 hrs, dt= 0.01 hrs!3 Peak Elev= 222.06' @ 12.20 hrs Surf.Area= 910 sf Storage= 50 cf Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 1.2 min ( 884.3 - 883.1 } 166 Salem Street, Proposed Conditions Type llf 24-hr 2 Year Stonn Rainfall=3.10" Prepared by Christiansen & Sergi, Inc. Printed 2/19/2009 H droCAD@ 9.00 sln 01057 O 2009 H droCAD Software Solutions LLC Page 27 Volume Invert Avail.Storage Storage Description #1 222.00' 1,300 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store feet s -fk cubic-feet cubic-feet 222,00 860 0 0 j 223.00 1,740 1,300 1,300 Device Routing Invert Outlet Devices #1 Discarded 222,00' 7.500 inlhr Exfiltration over Surface area Discarded OutFlow Max=0.16 cfs @ 12.20 hrs HW=222.06' (Free Discharge) 'L1=Exfiltration (Exfiltration Controls 0.16 cfs) Summary for Pond RR1: Roof Runoff Infiltration Area 1 Inflow Area = 0,064 ac,100.00% Impervious, Inflow Depth = 2.87" for 2 Year Storm event Inflow - 0.23 cfs @ 12.01 hrs, Volume= 0.015 of Outflow — 0.10 cfs @ 12.23 hrs, Volume= 0.015 af, Atten= 58%, Lag= 12.9 min Discarded = 0.02 cfs @ 11.64 hrs, Volume= 0.015 of Primary = 0.07 cfs @ 12.23 hrs, Volume= 0.001 of Routing by Dyn-Stor-Ind method, Time Spam 0.00-36.00 hrs, dt= 0.01 hrs 13 Peak Elev= 221.01' @ 12.23 hrs Surf.Area= 136 sf Storage= 173 of Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 41.6 min ( 794.0- 752.4 ) Volume Invert Avail.Stora e Storage Description #1 218.80' 85 of Crushed Stone Around Chambers (Prismatic) Listed below (Recalc) 301 of Overall - 87 of Embedded W 213 of x 40.0%Voids #2 219,30' 87 of Cultec R-180 x 4 Inside#1 Effective Size= 33.6"W x 20.0"H => 3.44 sf x 6.331 = 21.8 of Overall Size= 36.0"W x 20.5"H x 7.331 with 1.00' Overlap #3 220.47' 1 of 0.33'D x 6.50'H Vertical ConelC linden-Impervious 173 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store feet (sq-ft) (cubic-feet) (cubic-feet) 218.80 136 0 0 221.01 136 301 301 Device Routing Invert Outlet Devices #1 Discarded 218.80' 7.500 inlhr Exfiltration over Surface area #2 Primary 221.01' Special & User-Defined Head (feet) 0.00 0.10 Disch. (cfs) 0.000 10.000 166 Salem Street, Proposed Conditions Type ill 24-hr 2 Year Storm Rainfall=3,10" Prepared by Christiansen & Sergi, Inc. Printed 2/19/2009 H droCAD®9.00 sln 01057 ©2009 H droCAD Software Solutions LLC Pa e 28 Discarded OutFlow Max=0.02 cfs @ 11.64 hrs HW=218.88' (Free Discharge) t-1=Exfiltration (Exfiltration Controls 0.02 cfs) Primary OutFlow Max=0.07 cfs @ 12.23 hrs HW=221.01' TW=0.00' (Dynamic Tailwater) t-2=Special & User-Defined (Custom Controls 0.07 cfs) Summary for Pond RR2: Roof Runoff Infiltration Area 2 Inflow Area = 0.022 ac,100.00% Impervious, Inflow Depth = 2.87" for 2 Year Storm event Inflow - 0.08 cfs @ 12.01 hrs, Volume= 0.005 of Outflow - 0.01 cfs @ 11.65 hrs, Volume= 0.005 af, Atten= 83%, Lag= 0.0 min Discarded = 0.01 cfs @ 11.65 hrs, Volume= 0.005 of Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs f 3 Peak Elev= 223.25' @ 12.43 hrs Surf.Area= 76 sf Storage= 53 cf Plug-Flow detention time= (not calculated; outflow precedes inflow) Censer-of-Mass det. time= 19.5 min ( 772.0 - 752.4 ) Volume Invert Avail.Stora e Storage Description #1 222.00' 50 cf Crushed Stone Around Chamfers (Prismatic) Listed below(Recalc) 168 cf Overall- 44 of Embedded= 124 cf x 40.0% Voids #2 222,50' 44 cf Cultec R480 x 2 Inside#1 Effective Size= 33.6"W x 20.0"H => 3.44 sf x 6.331= 21.8 cf Overall Size= 36.0"W x 20.5"H x 7.33'L with 1.00' Overlap #3 223.67' 0 cf 0.33'D x 4.00'H Vertical Cone/Cylinder-Impervious 94 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store feet s -f# (cubic-feet) cubio-feet) 222.00 76 0 0 224.21 76 168 168 Device Routing Invert Outlet Devices #1 Discarded 222.00' 7.500 inihr Exfiltration over Surfac e area #2 Primary MAO' 4.0" Round Culvert L= 2.0' CPP, square edge headwall, Ke= 0.500 Outlet Invert= 226.00' S= 0.0500 7' Cc= 0.900 n= 0.010 PVC, smooth interior Discarded OutFlow Max=0.01 cfs @ 11.65 hrs HW=222.01' (Free Discharge) t-1=Exfiltration (Exfiltration Controls 0.01 cfs) Primary Outflow Max=0.00 cfs @ 0.00 hrs HW=222.00' TW=0.00' (Dynamic Tailwater) 't-2=Culvert (Controls 0A0 cfs) 166 Salem Street, Proposed Conditions Type J// 24-fir 2 Year Stonn Raintalf=3.10" Prepared by Christiansen & Sergi, Inc. Printed 2/19/2009 HydroCAD®9.00 sln 01057 ©2009 HydroCAD Software Solutions LLC Page 29 Summary for Pond RR3: Roof Runoff Infiltration Area 3 inflow Area = 0.055 ac,100.00% Impervious, Inflow Depth = 2.87" for 2 Year Storm event Inflow - 0.20 cfs @ 12,01 hrs, Volume= 0,013 of Outflow - 0.08 cfs @ 12,19 hrs, Volume= 0,013 af, Atten= 61%, Lag= 10.6 min Discarded = 0.02 cfs @ 11.58 lirs, Volume: 0.013 of Primary = 0.05 cfs @ 12.19 hrs, Volume= 0.001 of Routing by Dyn-Stor-Ind method, Time Span= 0.00-36,00 hrs, dt= 0.01 hrs J 3 Peak Elev= 215.68' @ 12.19 hrs Surf.Area= 136 sf Storage= 135 cf Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 29.8 min ( 782.3 - 752.4 ) Volume Invert Avail.Stora e Storage Descri Lion #1 214.00' 85 cf Crushed Stone Around Chambers (Prismatic) Listed below(Recalc) 301 cf Overall - 87 cf Embedded = 213 of x 40.0%Voids #2 214.50' 87 cf Cultec R-180 x 4 Inside#1 Effective Size= 33.6"W x 20.0"H => 3A4 sf x 6.331= 21.8 cf Overall Size= 36.0"W x 20.5"H x 7.331 with 1.00' Overlap #3 215.67' 0 cf 0.33'D x 4.00'H Vertical Cone/Cylinder-impervious 173 cf Total Available Storage Elevation Surf.Area inc.Store Cum.Store feet s -ft cubic-feet cubic-feet 214.00 136 0 0 216.21 136 301 301 Device Routing Invert Outlet Devices #1 Discarded 214,00' 7.500 inthr Exfiltration over Surface area #2 Primary 215.67' Special & User-Defined Head (feet) 0.00 0.10 Disch, (cfs) 0,000 1.000 Discarded OutFlow Max=0.02 cfs @ 11.58 hrs HW=214.01' (Free Discharge) Z-1=Exfiltration (Exfiltration Controls 0.02 cfs) Primary OutFlow Max=0.05 cfs @ 12,19 hrs HW=215.68' TVV=0.00' (Dynamic Tailwater) 'L2=Special & User-Defined (Custom Controls 0.05 cfs) Summary for Pond T 1: South Total Inflow Area = 1.218 ac, 25.18% Impervious, Inflow Depth = 0.69" for 2 Year Storm event Inflow - 0.86 cfs @ 12.09 hrs, Volume= 0.070 of Primary = 0.86 cfs @ 12.09 hrs, Volume= 0.070 af, Atten= 0%, Lag= 0.0 min Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs 13 166 Salem Street, Proposed Conditions Type I// 24-hr 2 Year Storm Rainfall=3,90" Prepared by Christiansen & Sergi, Inc,. Printed 2/19/2009 H droCAD®9.00 sln 01057©2009 H droCAD Software Solutions LLC Pa e 30 Summary for Pond T 3: North Total Inflow Area = 1.491 ac, 10.31% Impervious, Inflow Depth = 0.20" for 2 Year Storm event Inflow — 0.16 cfs @ 12,19 hrs, Volume= 0.024 of Primary -- 0,16 cfs @ 12.19 hrs, Volume= 0.024 af, Atten= 0%, Lag= 0.0 min Routing by Dyn-Stor-Ind method, Time Span= 0,00-36.00 hrs, dt= 0,01 hrs!3 166 Salem Street, Proposed Conditions Type /1124-hr 10 Year Storm Rainfall=4,50" Prepared by Christiansen & Sergi, Inc. Printed 2/19/2009 H droCAD®9.00 s/n 01057 ©2009 H droCAD Software Solutions LLC Page 31 Time span=0,00-36.00 hrs, dt=0.01 hrs, 3601 points x 3 Runoff by SCS TR-20 method, UH=SCS Reach routing by Dyn-Stor-Ind method - Pond routing by Dyn-Stor-Ind method Subcatchment 1: South Runoff Area=50,295 sf 21.05% Impervious Runoff Depth=1.60" Flow Length=175' Slope=0.0300 7' Tc=5.5 min CN=69 Runoff=2.13 cfs 0.154 of Subcatchment 2: East Runoff Area=14,126 sf 0.00% Impervious Runoff Depth=1.08" Flow Length=190' Tc=6.3 min CN=61 Runoff=0.35 cfs 0.029 of Subcatchment 3A: Flow to Rain Garden Runoff Area=16,790 sf 19.89% ImperVlous Runoff Depth=1.53" Flow Length=125' Tc=3.1 min CN=68 Runoff=0.74 cfs 0,049 of Subcatchment 3B: North Runoff Area=44,802 sf 0.00% Impervious Runoff Depth=0.85" Flow Length=160' Tc=8.6 min CN=57 Runoff=0.73 cfs 0.073 of Subcatchment R1: Roof 1 Runoff Area=2,779 sf 100.00% Impervious Runoff Depth=4.26" Tc=1.0 min CN=98 Runoff=0.33 cfs 0,023 of Subcatchment R2: Roof 2 Runoff Area=960 sf 100.00% Impervious Runoff Depth=4.26" Tc=1.0 min CN=98 Runoff=0.12 cfs 0.008 of Subcatchment R3: Roof 3 Runoff Area=2,400 sf 100.00% Impervious Runoff Depth=4.26" Tc=1.0 min CN=98 Runoff=0.29 cfs 0.020 of Pond RG: Rain Garden (infiltration Basin) Peak Elev=222.39' Storage=399 cf Inflow=0.74 cfs 0.049 of Outflow=0.21 cfs 0.049 of Pond RR1: Roof Runoff Infiltration Area 1 Peak Elev=221.01' Storage=173 cf Inflow=0.33 cfs 0.023 of Discarded=0.02 cfs 0.019 of Primary=0.31 cfs U04 of Outflow=0.33 cfs 0.023 of Pond RR2: Roof Runoff Infiltration Area 2 Peak Elev=226.17' Storage=94 cf Inflow=0.12 cfs 0.008 of Discarded=0.01 cfs 0.008 of Primary=0.01 cfs 0.000 of Outflow=0.03 cfs 0.008 of Pond RR3: Roof Runoff Infiltration Area 3 Peak Elev=215.71' Storage=137 cf lnflow=0.29 cfs 0.020 of Discarded=0.02 cfs 0.016 of Primary=0.37 cfs 0.003 of Outflow=0.39 cfs 0.020 of Pond T 1: South Total Inflow=2.31 cfs 0.158 of Primary=2.31 cfs 0.158 of Pond T 3: North Total Inflow=0.81 cfs 0.076 of Primary=0.81 cfs 0.076 of Total Runoff Area =3.034 ac Runoff Volume=0.355 of Average Runoff Depth = 1.41" 84.82% Pervious =2.573 ac 15.18% Impervious =0.461 ac i 0" 166 Salem Street, Proposed Conditions Type H/ 24-hr 10 Year Storm Rainfall=4.5 Prepared by Christiansen & Sergi, Inc. Printed 2/19/2009 HydroCAD&9.00 sin 01057 ©2009 HydroCAD SOftware,Solutions LLC Page 32 Summary for Subcatclunent 1: South Runoff = 2.13 cfs @ 12.09 hrs, Volume= 0.154 af, Depth= 1.60" Runoff by SOS TR-20 method, UH=SCS, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 10 Year Storm Rainfall=4.50" Area sf ON Description 10,585 98 Paved parking & roofs 39,710 61 >75% Grass cover, Good, HSG B 50,295 69 Weighted Average 39,710 78.95% Pervious Area 10,585 21.05% Impervious Area Te Length Slope Velocity Capacity Description min feet ft/ft ftlsec cfs 4.9 50 0.0300 0.17 Sheet Plow, Grass; Short n= 0,150 P2= 3.10" 0.6 125 0.0300 3.52 Shallow Concentrated Flow, Paved Kv=20.3 fps 5.5 175 Total Summary for Subcatchment 2: East Runoff = 0.35 cfs @ 12.11 hrs, Volume= 0.029 af, Depth= 1.08" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 10 Year Storm Rainfall=4.50" Area sf ON Description 14,126 61 >75% Grass cover, Good, HSG B 14,126 100.00% Pervious Area Tc Length Slope Velocity Capacity Description rnin feet ft/ft ftlsec cfs 5.7 50 0.0200 0.15 Sheet Flow, Grass: Short n= 0.150 P2= 3.10" 0.6 140 0.0600 3.67 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 6.3 190 Total Summary for Subcatchment 3A: Flow to Rain Garden Runoff — 0.74 cfs @ 12.05 hrs, Volume= 0.049 af, Depth= 1.53" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 10 Year Storm Rainfall=4.50" I i 0" 166 Salem Street, Proposed Conditions Type III 24-hr 10 Year Storrn Rainfall=4.5 Prepared by Christiansen & Sergi, Inc. Printed 2/19/2009 H droCAM 9.00 s/n 01057 ©2009 H di-oCAD Software Solutions LLC Pa e 33 Area (so CN Description 3,339 98 Paved parking & roofs 13 451 61 >75% Grass cover, Good, HSG B 16,790 68 Weighted Average 13,451 80.11% Pervious Area 3,339 19.89% Impervious Area Tc Length Slope Velocity Capacity Description min feet ft/ft ft/sec cfs 2.8 50 0.1200 0.30 Sheet Flow, Grass: Short n= 0.150 P2= 3.10" 0.2 50 0.0440 4.26 Shallow Concentrated Flow, Paved Kv= 20.3 fps 0.1 25 0.0400 3.00 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 3.1 125 Total Summary for Subcatchment 3B: North Runoff — 0.73 cfs @ 12.15 hrs, Volume= 0,073 af, Depth= 0.85" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 10 Year Storm Rainfall=4.50" Area sf CN Description 27,800 55 Woods, Good, HSG B 17,002 61 >75% Grass cover, Good, HSG I3 44,802 57 Weighted Average 44,802 100.00% Pervious Area Tc Length Slope Velocity Capacity Description min feet ft/ft f#/sec cfs 7.6 50 0.0700 0.11 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.10" 1.0 110 0.1400 1.87 Shallow Concentrated Flow, Woodland Kv= 5.0 fps_ 8.6 160 Total Summary for Subcatchment R1: Roof 1 Runoff = 0.33 cfs @ 12.01 hrs, Volume= 0.023 af, Depth= 4,26" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0,00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 10 Year Storm Rainfall=4.50" Area sf CN Description 2,779 98 Paved parking & roofs 2,779 100.00% Impervious Area i 166 Salem Street, Proposed Conditions Type H/ 24-hr 10 Year Storm Ralnfall=4.50" Prepared by Christiansen & Sergi, Inc. Printed 2/19/2009 H droCAD0 9.00 s/n 01057 02009 H droCAD Software Solutions LLC Page 34 Tc Length Slope Velocity Capacity Description min feet ft/ft ft/sec cfs 1.0 Direct Entry, j Summary for Subcatchment R2: Roof 2 Runoff — 0.12 cfs @ 12.01 hrs, Volume= 0.008 af, Depth= 4.26" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0,00-36.00 hrs, dt= 0.01 lirs Type III 24-hr 10 Year Storm Rainfall=4.50" Area sf CN Description 960 98 Paved parking & roofs 960 100.00% Impervious Area Tc Length Slope Velocity Capacity Description min fee# ftlft) (ftlsec) (cfs 1.0 Direct Entry, Summary for Subcatchment R3: Roof 3 Runoff = 0.29 cfs @ 12.01 hrs, Volume= 0.020 af, Depth= 4.26" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 10 Year Storm Rainfall=4.50" Area sf CN Descri Lion 2,400 98 Paved parking & roofs 2,400 100.00% Impervious Area Te Length Slope Velocity Capacity Description (min) feet ft/ft ft/sec cfs 1.0 Direct Entry, Summary for Pond RG: Rain Garden (Infiltration Basin) Inflow Area = 0.385 ac, 19.89% Impervious, Inflow Depth = 1.53" for 10 Year Storm event Inflow — 0.74 cfs @ 12.05 hrs, Volume= 0.049 of Outflow -- 0.21 cfs @ 12.42 hrs, Volume= 0.049 af, Atten= 72%, Lag= 22.3 min Discarded = 0.21 cfs @ 12.42 hrs, Volume= 0.049 of Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs 13 Peak Elev= 222.39' @ 12.42 hrs Surf.Area= 1,201 sf Storage= 399 cf Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 10.7 min ( 867.1 - 856.4 ) i 166 Salem Street, Proposed Conditions Type III 24-fir 10 Year Storm Rainfall=4.50" Prepared by Christiansen & Sergi, Inc. Printed 2/19/2009 H droCAD®9.00 sin 01057 ©2009 H droCAD Software Solutions LLC Page 35 Volume Invert Avail.Stora e Stora e Description #1 222.00' 1,300 cf Custom Stage Data (Prismatic) Listed below(Recalc) Elevation Surf.Area Inc.Store Curn.Store feet s -ft cubic-feet cubic-feet 222.00 860 0 0 223.00 1,740 1,300 1,300 Device Routing Invert Outlet Devices #1 Discarded 222.00' 7.500 inlhr Exfiltration over Surface area Discarded OutFlow Max=0.21 cfs @ 12.42 hrs HW=222.39' (Free Discharge) t--1=Exfiltration (Exfiltration Controls 0.21 cfs) Summary for Pond RR1: Roof Runoff Infiltration Area 1 Inflow Area = 0.064 ac,100.00% Impervious, Inflow Depth = 4.26" for 10 Year Storm event Inflow -- 0.33 cfs @ 12.01 hrs, Volume= 0.023 of Outflow = 0.33 cfs @ 12.03 hrs, Volume= O,023 af, Atten= 0%, Lag= 0.8 min Discarded = 0.02 cfs @ 11.44 hrs, Volume= 0.019 of Primary = 0.31 cfs @ 12.03 hrs, Volume= 0.004 of Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs!3 Peak Elev= 221.01' @ 12.03 hrs Surf.Area= 136 sf Storage= 173 cf Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 37.2 min ( 782A - 745.2 ) Volume Invert Avail.Stora e Storage Description #1 218.80' 85 cf Crushed Stone Around Chambers (Prismatic) Listed below(Recalc) 301 cf Overall - 87 cf Ernbedded = 213 cf x 40.0%Voids #2 219.30' 87 cf Cultec R-180 x 4 Inside#1 Effective Size= 33.6"W x 20.0"H => 3.44 sf x 6.331= 21.8 cf Overall Size= 36.0"W x 20.5"H x 7.331 with 1.00' Overlap #3 220.47' 1 of 0.33'D x 6.50'H Vertical Cone/Cylinder-Impervious 173 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store feet s -ft cubic-feet cubic-feet 218.80 136 0 0 221.01 136 301 301 Device Routing Invert Outlet Devices _ #1 Discarded 218.80 7.50 nlhr Exfiltration over 0 i' r Surface area #2 Primary 221.01' Special & User-Defined Head (feet) 0.00 0.10 Disch. (cfs) 0.000 10.000 166 Salem Street, Proposed Conditions Type 11124-hr 10 Year Stamm Rainfall=4.50" Prepared by Christiansen & Sergi, Inc. Printed 2/19/2009 H droCAD0 9.00 sin 01057 O 2009 H droCAD Software Solutions LLC Page 36 Discarded OutFlow Max=0.02 cfs @ 11.44 hrs HW=218.88' (Free Discharge) 'L1=Exfiltration (Exfiltration Controls 0.02 cfs) Primary OutFlow Max=0.30 cfs @ 12.03 hrs HW=221.01' TW=0.00' (Dynamic Tailwater) t-2=Special & User-Defined (Custom Controls 0.30 cfs) Summary for Pond RR2: Roof Runoff Infiltration Area 2 Inflow Area = 0.022 ac,100.00% Impervious, Inflow Depth = 4.26" for 10 Year Storm event Inflow = 0.12 cfs @ 12.01 hrs, Volume= 0.008 of Outflow - 0.03 cfs @ 12.37 hrs, Volume= 0.008 af, Atten= 77%, Lag= 21.3 min Discarded = 0.01 cfs @ 11.57 hrs, Volume= 0.008 of Primary = 0.01 cfs @ 12.37 hrs, Volume= 0.000 of Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs 13 Peak Elev= 226.17' @ 12.37 hrs Surf.Area= 76 sf Storage= 94 cf Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 39.9 min ( 785.0 -745.2 ) Volume Invert Avail.Stora e Storage Description #1 222,00' 50 cf Crushed Stone Around Chambers (Prismatic) Listed below (Recalc) 168 cf Overall -44 cf Embedded= 124 cf x 40.0%Voids #2 222.50' 44 cf Cultec R-180 x 2 Inside#1 Effective Size= 33.6"W x 20.0"H => 3.44 sf x 6.331= 21.8 cf Overall Size= 36.0"W x 20.5"H x 7.331 with 1.00'Overlap #3 223.67' 0 cf 0.33'D x 4.00'H Vertical Cone1C tinder-Impervious 94 of Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft)_ _ (cubic-feet) (cubic-feet) 222.00 76 0 0 224.21 76 168 168 Device Routing Invert Outlet Devices #1 Discarded 222.00' 7.500 inlhr Exfiltrati on over Surface a. ..rea #2 Primary 226.10' 4.0" Round Culvert L= 2.0' CPP, square edge headwall, Ke= 0.500 Outlet Invert=226.00' S= 0.0500 I Cc= 0.900 n= 0.010 PVC, smooth interior Discarded OutFlow Max=0.01 cfs @ 11.57 hrs HW=222.01' (Free Discharge) t1=Exfil(ration (Exfiltration Controls 0.01 cfs) Primary OutFlow Max=0.01 cfs @ 12.37 hrs HW=226.17' TW=0.00' (Dynamic Tailwater) t-2=Culvert (inlet Controls 0.01 cfs @ 0.92 fps) 166 Salem Street, Proposed Conditions Type 11124-17r 10 Year Storm Rainfall=4.50" Prepared by Christiansen & Sergi, Inc. Printed 2/1912009 H droCAD®9.00 s/n 01057 ©2009 H droCAD Software Solutions LLC Page 37 Summary for Pond RR3: Roof Runoff Infiltration Area 3 Inflow Area = 0.055 ac,100.00% Impervious, Inflow Depth = 4.26" for 10 Year Storm event Inflow = 0,29 cfs @ 12.01 hrs, Volume= 0.020 of Outflow = 0.39 cfs @ 12.02 hrs, Volume= 0.020 af, Atten= 0%, Lag= 0.5 min Discarded = 0.02 cfs @ 11.36 hrs, Volume= 0.016 of Primary = 0.37 cfs @ 12.02 hrs, Volume= 0.003 of Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0,01 lirs 13 Peak Elev= 215.71' @ 12.02 Iirs Surf.Area= 136 sf Storage= 137 of Plug-Flow detention time= (not calculated; outflow precedes inflow) Center-of-Mass det, time= 27.0 min ( 772.2- 745.2 } Volume Invert Avail,Stora a Storage Description #1 214,00' 85 cf Crushed Stone Around Chambers (Prismatic) Listed below (Recale) 301 of Overall- 87 of Embedded = 213 of x 40.0% Voids #2 214.50' 87 cf Cultec R-180 x 4 Inside#1 Effective Size= 33.6"W x 20.0"H => 3.44 sf x 6.331 = 21.8 of Overall Size= 36,0"W x 20.5"H x 7.33'L with 1.00' Overlap #3 215.67' 0 of 0.33'D x 4.00'H Vertical Cone/C finder-Impervious 173 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store feet s -ft cubic-feet cubic-feet 214.00 136 0 0 216.21 136 301 301 Device Routing Invert Outiet Devices #1 Discarded 214.00' 7.500 inlhr Exfiltration over Surface area #2 Primary 215.67' Special & User-Defined Head (feet) 0.00 0.10 Disch. (cfs) 0.000 1,000 Discarded OutFlow Max=0.02 cfs @ 11.36 hrs HW=214.01' (Free Discharge) t-1=Exfiltration (Exfiltration Controls 0.02 cfs) Primary Outflow Max=0.33 cfs @ 12.02 hrs HW=215,70' TW=0.00' (Dynamic Tailwater) t-2=Special &User-Defined (Custom Controls 0.33 cfs) Summary for Pond T 1: South Total Inflow Area = 1.218 ac, 25.18% Impervious, Inflow Depth = 1.56" for 10 Year Storm event Inflow -- 2.31 cfs @ 12.09 hrs, Volume= 0.158 of Primary = 2.31 cfs @ 12.09 hrs, Volume= 0.158 af, Atten= 0%, Lag= 0.0 min Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs/3 166 Salem Street, Proposed Conditions Type 11124-hr 10 Year Storm Rainfall=4.50" Prepared by Christiansen & Sergi, Inc. Printed 2/19/2009 H droCAD®9.00 sln 01057 02009 h droCAD Software Solutions LLC Page 38 j Summary for Pond T 3: North Total Inflow Area = 1.491 ac, 10,31% Impervious, Inflow Depth = 0.61" for 10 Year Storm event Inflow — 0.81 cfs @ 12.14 hrs, Volume= 0.076 of Primary — 0.81 cfs @ 12.14 hrs, Volume= 0.076 af, Atten= 0%, Lag= 0.0 min Routing by Dyn-Star-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs 13 166 Salem Street, Proposed Conditions Type ill 24-hr 100 Year Storm Rainfall=6.50" Prepared by Christiansen & Sergi, Inc. Printed 2/19/2009 H droCAM 9.00 s1n 01057 ©2009 H droCAD Software Solutions LLC Page 39 Time span=0.00-36.00 hrs, dt=0.01 hrs, 3601 points x 3 Runoff by SCS TR-20 method, UH=SCS Reach routing by Dyn-Stor-Ind rnethod - Pond routing by Dyn-Star-Ind method Subcatchment 1: South Runoff Area=50,295 sf 21.05% Impervious Runoff Depth=3.11" Flow Length=175' Slope=0.0300'P Tc=5.5 min CN=69 Runoff=4.27 cfs 0.299 of Subcatchment 2: East Runoff Area=14,126 sf 0.00% Impervious Runoff Depth=2.35" Flow Length=190' Tc=6.3 min CN=61 Runoff=0.85 cfs 0.063 of Subcatchment 3A: Flow to Rain Garden Runoff Area=16,790 sf 19.89% Impervious Runoff Depth=3.01" Flow Length=125' Tc=3.1 min CN=68 Runoff=1.50 cfs 0.097 of Subcatchment 3B: North Runoff Area=44,802 sf 0.00% Impervious Runoff Depth=1.99" Flow Length=160' Tc=8.6 min CN=57 Runoff=2.04 cfs 0.170 of Subcatchment R1: Roof 1 Runoff Area=2,779 sf 100.00% Impervioris Runoff Depth=6.26" Tc=1,0 min CN=98 Runoff=0.48 cfs 0.033 of Subcatchment R2: Roof 2 Runoff Area=960 sf 100.00% Impervious Runoff Depth=6.26" Tc=1.0 min CN=98 Runoff=0.177 cfs 0.011 of Subcatchment R3: Roof 3 Runoff Area=2,400 sf 100.00% Impervious Runoff Depth=6.26" Tc=1.0 min CN=98 Runoff=0.42 cfs 0.029 of Pond RG: Rain Garden (Infiltration Basin) Peak Elev=222.93' Storage=1,177 of Inflow=1.50 cfs 0.097 of Outflow=0.29 cfs 0.097 of Pond RR1: Roof Runoff Infiltration Area 1 Peak Elev=221.01' storage=173 of Inflow=0.48 cfs 0.033 of Discarded=0.02 cfs 0.024 of Primary=0.46 cfs 0.010 of Outflow=0.49 cfs 0.033 of Pond RR2: Roof Runoff Infiltration Area 2 Peak Elev=226.38' Storage=94 of Inflow=0.17 cfs 0.011 of Discarded=0.01 cfs 0.010 of Primary=0.14 cfs 0.002 of Outflow=0.16 cfs 0.012 of Pond RR3: Roof Runoff Infiltration Area 3 Peak Elev=215.71' Storage=138 of Inflow=0.42 cfs 0.029 of Discarded=0.02 cfs 0.021 of Primary=0.39 cfs 0.008 of Outflow=0,42 cfs 0.029 of Pond T 1: South Total Inflow=4.54 cfs 0.309 of Primary=4.54 cfs 0.309 of Pond T 3: North Total Inflow=2.26 cfs 0.180 of Primary=2.26 cfs 0.180 of Total Runoff Area =3.034 ac Runoff Volume =0,703 of Average Runoff Depth =2.78" 84.82% Pervious =2.573 ac 15.18% Impervious = 0.461 ac 166 Salem Street, Proposed Conditions Type ill 24-hr 100 Year Storm Rainfall-650" Prepared by Christiansen & Sergi, Inc. Printed 2/19/2009 y H droGAD®9.©0 s1n 01057 a 2009 H d,_.roCAD Software Solutions LLC ,, _Page 40 Summary for Subcatchment 1: South Runoff - 4.27 cfs @ 12.08 hrs, Volume= 0.299 af, Depth= 3.11" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0,00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 100 Year Storm Rainfall=6.50" Area (so CN Descri lion 10,585 98 Paved parking & roofs 39,710 61 >75% Grass cover, Good, HSG B 50,295 69 Weighted Average 39,710 78.95% Pervious Area 10,585 21.05% Impervious Area Tc Length Slope Velocity Capacity Description min feet ft/ft ft/sec cfs 4.9 50 0.0300 0.17 Sheet Flow, Grass: Short n= 0.150 P2= 3.10" 0.6 125 0.0300 3.52 Shallow Concentrated Flow, Paved Kv=20.3 fps 5.5 175 Total Summary for Subcatchment 2: East Runoff _ 0.85 cfs @ 12.10 hrs, Volume= 0.063 af, Depth= 2.35" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 100 Year Storm Rainfall=6.50" Areas CN Description 14,126 61 >75% Grass cover, Good, HSG B 14,126 100,00% Pervious Area Tc Length Slope Velocity Capacity Description inin feet fllft ft/sec cfs 5.7 50 0.0200 0.15 Sheet Flow, Grass: Short n= 0.150 P2= 3.10" 0,6 140 0.0600 3.67 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 6.3 190 Total Summary for Subcatchment 3A: Flow to Rain Garden Runoff = 1.50 cfs @ 12.05 hrs, Volume 0.097 af, Depth= 3.01" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 100 Year Storm Rainfall=6.50" i 0" 166 Salem Street, Proposed Conditions Tyne ilf 24-hr 100 Year Storm Rainfall=6.5 Prepared by Christiansen & Sergi, Inc. Printed 2/19/2009 H droCAD®9.00 s/n 01057 a 2009 H droCAD Software Solutions LLC Pacie 41 Area (so CN Descriplion 3,339 98 Paved parking & roofs 13,451 61 >75% Grass cover, Good HSG B 16,790 68 Weighted Average 13,451 80.11% Pervious Area 3,339 19.89% Impervious Area Tc Length Slope Velocity Capacity Description min feet ft/ft ft/sec cfs 2.8 50 0.1200 0.30 Sheet Flow, Grass: Short n= 0.150 P2= 3.10" 0.2 50 0.0440 4.26 Shallow Concentrated Flow, Paved Kv=20.3 fps 0.1 25 0.0400 3.00 Shallow Concentrated Flow, Grassed Waterway Kv= 15.0 fps 3.1 125 Total Summary for Subcatchment 3113: North Runoff 2.04 cfs @ 12.13 hrs, Volume= 0.170 af, Depth= 1.99" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 100 Year Storm Rainfall=6.50" Area sf CN Description 27,800 55 Woods, Good, HSG B 17,002 61 >75% Grass cover, Good, HSG B 44,802 57 Weighted Average 44,802 100,00% Pervious Area Tc Length Slope Velocity Capacity Description min feet ft/ft ft/sec cfs 7.6 50 0.0700 0.11 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.10" 1.0 110 0.1400 1.87 Shallow Concentrated Flow, Woodland Kv= 5.0 fps 8.6 160 Total Summary for Subcatchment R1: Roof 1 Runoff — 0.48 cfs @ 12.01 hrs, Volume= 0.033 af, Depth= 6.26" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 100 Year Storm Rainfall=6.50" Area sf CN Description 2,779 98 Paved Varking & roofs 2,779 100,00% Impervious Area 166 Salem Street, Proposed Conditions Type it/ 24-hr 100 Year Storm Rainfaii=6.50" Prepared by Christiansen & Sergi, Inc. Printed 2/19/2009 H droCAM 9.00 s/n 01057 02009 H droCAD Software Solutions LLC Page 42 Tc Length Slope Velocity Capacity Description in in feet ftfft ftlsec cfs 1.0 Direct Entry, Summary for Subcatchment R2: Roof 2 Runoff - 0,17 cfs @ 12.01 hrs, Volume= 0.011 af, Depth= 6.26" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 100 Year Storm Rainfall=6.50" Area (so CN Descri lion 960 98 Paved parkin2 & roofs 960 100,00% Impervious Area Tc Length Slope Velocity Capacity Description min feet ftlft ftlsec cfs 1.0 Direct Entry, Summary for Subcatchment R3: Roof 3 Runoff = 0.42 cfs @ 12.01 hrs, Volume= 0.029 af, Depth= 6.26" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs Type III 24-hr 100 Year Storm Rainfall=6.50" Area sf CN Description 2,400 98 Paved arkin & roofs 2,400 100.00% Impervious Area Tc Length Slope Velocity Capacity Description min feet ft/ft ftlsec cfs 1.0 Direct Entry, Summary for Pond RG: Rain Garden (Infiltration Basin) Inflow Area = 0.385 ac, 19.89% Impervious, Inflow Depth = 3.01" for 100 Year Storm event Inflow -- 1.50 cfs @ 12.05 hrs, Volume= 0.097 of Outflow = 0.29 cfs @ 12.49 hrs, Volume= 0.097 af, Atten= 81°1°, Lag= 26.4 min Discarded = 0.29 cfs @ 12.49 hrs, Volume= 0.097 of Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 firs 13 Peak Elev= 222.93' @ 12.49 hrs Surf.Area= 1,677 sf Storage= 1,177 cf Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass del. time= 30.0 min ( 866.2 - 836.2 ) 166 Salem Street, Proposed Conditions Type Il! 24-hr 100 Year Storm Rainfall=6.50" Prepared by Christiansen & Sergi, Inc, Printed 2/19/2009 H droCAD(@ 9.00 sin 01057 a 2009 H droCAD Software Sahitions LLC Page 43 Volume Invert Avail.Stora e Storage Description #1 222.00' 1,300 cf Custom Stage Data (Prismatic) Listed below(Recaic) Elevation Surf,Area Inc.Store Cum.Store feet s -ft cubic-feet cubic-feet 222.00 860 0 0 223.00 1,740 1,300 1,300 Device Routina Invert Outlet Devices #1 Discarded 222.00' 7.500 infhr Exfiltration over Surface area Discarded OutFlow Max=0.29 cfs @ 12.49 hrs HW=222.93' (Free Discharge) t-1=Exfiltration (Exfiltration Controls 0.29 cfs) Summary for Pond RR1: Roof Runoff Infiltration Area 1 Inflow Area = 0.064 ac,100.00% Impervious, Inflow Depth = 6.26" for 100 Year Storm event Inflow = 0.48 cfs @ 12.01 hrs, Volume= 0.033 of Outflow 0,49 cfs @ 12.01 hrs, Volume= OA33 af, Atten= 0%, Lag= 0.0 min Discarded = 0.02 cfs @ 10,87 hrs, Volume= 0.024 of Primary - 0.46 cfs @ 12.01 hrs, Volume= 0.010 of Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs !3 Peak Elev= 221.01'@ 12.01 hrs Surf.Area= 136 sf Storage= 173 of Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 34.4 min ( 773.7- 739.3 } Volume Invert Avail.Stora e Storage Description #1 218.80' 85 cf Crushed Stone Around Chambers(Prismatic) Listed below(Recaic) 301 cf Overall- 87 cf Embedded = 213 cf x 40.0% Voids #2 219.30' 87 cf Cultec R-180 x 4 Inside#1 Effective Size= 33.6"W x 20.0"H => 3.44 sf x 6.331 =21.8 cf Overall Size= 36.0"W x 20.5"H x 7.331 with 1.00'Overlap #3 220,47' 1 cf 0.33'D x 6.50'H Vertical ConelC tinder-Impervious 173 of Total Available Storage Elevation Surf.Area Inc.Store Cum.Store feet s -ft cubic-feet cubic-feet 218,80 136 0 0 221,01 136 301 301 Device Routing Invert Outlet Devices #1 Discarded 218.80' 7.500 inihr Exfiltration over Surface area #2 Primary 221.01' Special & User-Defined Head (feet) 0.00 0.10 Disch. (cfs) 0.000 10.000 Oil 166 Salem Street, Proposed Conditions Type 1i124-hr 100 Year Storm Rainfall=6.5 Prepared by Christiansen & Sergi, Inc. Printed 2/19/2009 H droCADO 9.00 sin 01057 ©2009 H droCAD Software Solutions LLC Page 44 Discarded OutFlow Max=0.02 cfs @ 10.87 hrs HW=218.88' (Free Discharge) t-1=Exfiltration (Exfiltration Controls 0.02 cfs) Primary OutFlow Max=0.46 cfs @ 12.01 hrs HW=221.01' TW=0.00' (Dynamic Tailwater) t-2=Special &User-Defined (Custom Controls 0.46 cfs) Summary for Pond RR2: Roof Runoff Infiltration Area 2 Inflow Area = 0.022 ac,100.00% Impervious, Inflow Depth = 6.26" for 100 Year Storm event Inflow = 0.17 cfs @ 12.01 hrs, Volume= 0.011 of Outflow = 0.16 cfs @ 12.05 hrs, Volume= 0.012 af, Atten= 6%, Lag= 2.1 min Discarded = 0.01 cfs @ 11.31 hrs, Volume= 0.010 of Primary - 0.14 cfs @ 12.05 hrs, Volume= 0.002 of Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs f 3 Peak Elev= 226.38' @ 12.05 hrs Surf.Area= 76 sf Storage= 94 cf Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det, time= 36.0 min ( 775.3- 739.3 ) Volume Invert Avail.Stora e Storage Description #1 222.00' 50 cf Crushed Stone Around Chambers (Prismatic) Listed below (Recalc) 168 cf Overall - 44 cf Embedded = 124 cf x 40.0% Voids #2 222.50' 44 cf Cultec R-180 x 2 Inside#1 Effective Size= 33.6"W x 20.0"H => 3.44 sf x 6.331 = 21.8 cf Overall Size= 36.0"W x 20.5"H x 7.33'L with 1.00' Overlap #3 223.67' 0 of 0.33'D x 4.00'H Vertical Cone/Cylinder-Impervious 94 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store feet s -ff cubic-feet cubic-feet 222.00 76 0 0 224.21 76 168 168 Device Routing Invert Outlet Devices #1 Discarded 222.00' 7.500 inlhr Exfiltration over Surface area #2 Primary 226.10' 4.0" Round Culvert L= 2.0' CPP, square edge headwall, Ke= 0.500 Outlet Invert= 226.00' S= 0.0500 '/' Cc= 0.900 n= 0.010 PVC, smooth interior Discarded OutFlow Max=0,01 cfs @ 11.31 hrs HW=222.01' (Free Discharge) t-1=Exfiltra#ion (Exfiltration Controls 0.01 cfs) Primary OutFlow Max=0.14 cfs @ 12.05 hrs HW=226.38' TW=0.00' (Dynamic Tailwater) t-2=Culvert (inlet Controls 0.14 cfs @ 1.80 fps) 1 166 Salem Street, Proposed Conditions Type II! 24-hr 100 Year Storm Rainfall=6.50" Prepared by Christiansen & Sergi, Inc. Printed 2/19/2009 H droCADO 9.00 s/n 01057 ©2009 H droCAD Software Solutions LLC Page 45 Summary for Pond RR3: Roof Runoff Infiltration Area 3 Inflow Area = 0.055 ac,100.00% Impervious, Inflow Depth = 6.26" for 100 Year Storm event Inflow - 0.42 cfs @ 12.01 hrs, Volume= 0.029 of Outflow = 0.42 cfs @ 12,02 hrs, Volume= 0.029 af, Atten= 0%, Lag= 0.2 min Discarded = 0.02 cfs @ 10,87 hrs, Volume= 0.021 of Primary 0.39 cfs @ 12.02 hrs, Volume= 0A08 of Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs 13 Peak Elev= 215.71'�7a 12.02 hrs Surf.Area= 136 sf Storage= 138 cf Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 25.5 min ( 764.8 - 739.3 ) Volume Invert Avail.Stora e Storage Description #1 214,00' 85 of Crushed Stone Around Chambers (Prismatic) Listed below(Recalc) 301 cf Overall - 87 cf Embedded= 213 cf x 40.0% Voids #2 214.50' 87 cf Cultec R-180 x 4 Inside#1 Effective Size= 33.6"W x 20.0"H => 3.44 sf x 6.331=21.8 of Overall Size= 36.0"W x 20.5"H x 7.331 with 1.00' Overlap #3 215.67' 0 cf 0.33'D x 4.00'H Vertical Cone/Cylinder-Impervious 173 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store feet s -ft cubic-feet cubic-feet 214.00 136 0 0 216.21 136 301 301 Device Routing Invert Outlet Devices #1 Discarded 214.00' 7.500 inthr Exfiitration over Surface area #2 Primary 215.67' Special & User-Defines{ Head (feet) 0.00 0.10 Disch. (cfs) 0.000 1.000 Discarded OutFlow Max=0.02 cfs @ 10.87 hrs HW=214.01' (Free Discharge) t-1=Exfiltration (Exfiitration Controls 0.02 cfs) Primary OutFlow Max=0.39 cfs @ 12.02 hrs HW=215.71' TW=0.00' (Dynamic Tailwater) t-2=Special &User-Defined (Custom Controls 0.39 cfs) Summary for Pond T 1: South Total Inflow Area = 1.218 ac, 25.18% Impervious, Inflow Depth = 3.04" for 100 Year Storm event Inflow = 4.54 cfs @ 12.08 hrs, Volume= 0309 of Primary - 4.54 cfs @ 12.08 hrs, Volume= 0.309 af, Atten= 0%, Lag= 0.0 min Routing by Dyn-Stor-Ind method, Time Span= 0.00-36,00 hrs, dt= 0.01 hrs 13 166 Salem Street, Proposed Conditions Type ill 24-hr 100 Year Storm Rainfall=65T Prepared by Christiansen & Sergi, Inc. Printed 2/19/2009 H droCAD®9.00 s!n 01057 O 2009 H droCAD Software Solutions LLC Page 46 Summary for Pond T 3: North Total Inflow Area = 1.491 ac, 10.31% Impervious, Inflow Depth = 1.45" for 100 Year Storm event Inflow — 2.26 cfs @ 12.13 hrs, Volume= 0.180 of Primary — 2.26 cfs @ 12.13 hrs, Volume= 0.180 af, Atten= 0%, Lag= 0.0 min Routing by Dyn-Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.01 hrs 13 Section III: Soils Analysis Stormwater Management Report for "Tire Captain Nathaniel Berry Homestead",North Andover,Mass, HI} Soils Analysis According to the Soil Conservation Service Soil (S.C.S.) Survey of Essex County, Massachusetts,the following soil type is found on the project site: CmB Charlton fine sandy loam, 3 to 8 percent slopes Hydrologic Soil Group B Figure 3: Soil Conservation Service Soil Map shows the portion of the Soil Survey map that includes the project site. The results and locations of the test pits and infiltration tests performed on the site are included on Sheet 2 of the Definitive Subdivision Plan. F119URF 3: S.C.S. SOILS MAP SCALE: I" = 200' DATE: 12118108 y vT, r ox UZ MW Pz- -� 3 � . = � N W 31 Fh ko� 5. Y ry S �