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HomeMy WebLinkAbout2015-01-06 Drainage Report DTO SP 4/7/2014 t :�r�•�3s ...�i: zur - :::�y :iH.•t: ;..! ...3. :-:fir' - - *:.i ^k _ - _ .�� ':Y=ra.- 5: - _ ..._ a-���_�-�.-,� �= r�;�;%-,sue..•r.'^y �` ... :11`yAM- ram^••.: �`...�.��• �i'� ,�� _ -, . t Ys Drainage Report Vilest Mill High Street North Andover, MA Submitted: 3/4/1.4 Revised: 4/7/14 Prepared For: RCG, LLC 17 Ivaloo Street Somerville, MA 02143 �s Prepared By: VYAYNE R. KEEFHER Design Consultants, Inc. CIVIL _ 120 Middlesex Avenue No- 41313 Suite 20 Somerville, MA 02145 ■ 1 / 1 + 1 7 West Mill, High Street, Andover, MA Table of Contents INTRODUCTION 1 EXISTING CONDITIONS 1 SOILS 1 PROPOSED CONDITIONS 2 HYDROLOGIC MODEL 2 TABLE 1 -- EXISTING vs PROPOSE❑ SUMMARY 3 CONCLUSION 3 Appendix A Pre and Post Project Hydrology 5 Appendix B NRCS Web Soil Survey 49 Appendix C Operation and Maintenance Plan 55 i West Mill, High Street, Andover, MA INTRODUCTION RCG, LLC proposes to construct additional parking spaces at the West Mill complex, in particular within the existing u-shaped courtyard area off High Street in North Andover. The proposed parking areas will be permeable pavement, utilizing concrete units pavers. To mitigate any increase in runoff rate or volume, several vegetated bioretention areas will be constructed. Pretreatment for the runoff is provided via gravel and grass combination. Each bio-retention area has been sized to mitigate the 100-year storm event. Taken as a whole, the proposed improvements decrease the runoff to the on-site drainage system, which is tributary to two large existing culverts which run under the existing mill buildings. EXISTING CONDITIONS The area of study is a portion of a much larger mill building complex. The entire complex covers an area of approximately 9.5 acres. The study area is limited to that portion of the u-shaped courtyard area off High Street which is between the existing building and the property line along High Street. The existing study area is a combination of paved walkways and outdoor patio areas, landscaped areas and grass meadow. There are currently 5 parking spaces located within the courtyard. The driveway is concrete with decorative brick banding. Within the courtyard are walkways connecting to a central outdoor patio. Many mature shade trees are located both inside the courtyard and also between the driveway and existing mill buildings. Two large diameter (60") reinforced concrete pipes traverse the courtyard running northwest connecting Mill Pond to Osgood Pond and eventually connecting to the Merrimac River. On-site drainage consists of catch basins which are collected at a drain manhole. This manhole has a gravity outlet (12") which is tributary to Mil Pond as well as an overflow outlet which is tributary to a 15,000 gallon overflow tank that pumps to one of the large diameter pipes in time of severe storm events. SOILS The NRCS Web Soil Survey characterizes the soil at the site as being Urban Land. This area is most likely a combination of fill, urban fill and construction debris dating from the time of the construction of the mills. West Mill, High Street, Andover, MA Nearby soils are classified as Woodbridge fine sandy loam, 3 to 8 percent slopes (HSG C), Charlton fine sandy loam, 3 to 8 percent slopes (HSG B) and Canton fine sandy loam, 3 to 8 percent slopes (HSG B). For the purpose of these calculations, the HSG for the underlying soils is assumed to be HSG C. PROPOSED CONDITIONS The proposed improvements include the construction of 30 parking spaces. These spaces will be constructed of concrete unit pavers on a sand setting bed which is a type of porous pavement. The proposed parking spaces are graded to drain away from the existing driveway and will drain to a low point within the parking area. Adjacent to the low point will be located a break in the vertical granite curbing that will allow stormwater runoff to travel across a pea stone strip, then across a sod filter strip and into a bioretention area. The bioretention areas have been sized to mitigate the increase in runoff rate and volume up to and including the 100 year storm event. The bioretention areas feature a one foot berm, which together with a broad crested weir and overflow inlet provide a ponding depth of approximately 8". The bloretention areas also contain 3 feet of soil medium to allow for storage and TSS removal. A broadcrested weir and overflow inlet provide for overflow protection while allowing stormwaterto pond and infiltrate the soil medium below. As part of the proposed work, the existing closed storm drain system will be completely cleaned and the pumps in the overflow tank tested to ensure proper functioning. HYDROLOGIC MODEL The hydrologic model used for this analysis is based upon the SCS Method. The SCS Method allows for variable rainfall intensity throughout the storm duration, peaking near the middle of the Type 111, 24-hour storm. Both existing and proposed conditions are modeled for the 2-year, 10-year, 25-year and 100-year storm events. As required by the North Andover Stormwater Management and Erosion Control Regulations, the 24-hour rainfall amounts are based on the Northeast Regional Climate Center "Atlas of precipitation Extremes for the Northeastern United States and Southeastern Canada. The specific rainfall amounts used are 3.2 inches (2-year), 4.8 inches (10-year), 6.0 inches (25-year) and 8.6 inches (100-year). The time of concentration (tJ for all catchment areas was taken as 5 minutes, due to the very small catchment areas in the study area. Complete calculations are included in Appendix A, see Table 1 for summary results. 2 Vilest Mill, High Street, Andover, MA TABLE 1 — EXISTING vs PROPOSED SUMMARY Total Mite Runoff Peak Discharges (CFS) and Volumes (AF) Description Existing Conditions Proposed Conditions Drainage Area 46,016 sf 46,01.6 sf Storm Event Offsite Peak Offsite Runoff Mite Peak Offsite Runoff Runoff (CFS) Volume (AF) Runoff (CFS) Volume (AF) 2 Yr (3.2") 2.06 0.142 1.85 0.127 10 Yr (4.8") 3.83 0.264 3.38 0.233 25 Yr (6.0") 5.1.9 0.360 4.55 0.317 100 Yr (8.6") 8.1.5 0.577 7.08 0.507 CONCLUSION The proposed site improvements have negligible impact on the existing hydrology of the site. Existing stormwater flow patterns are maintained. No increase in peals rate or volume to the on-site storm drainage system is proposed, resulting in no increase to peak rate and volume to the existing large diameter pipes traversing the site for the 2, 1.0, 25 and 1.00-year storm events. Based on DC1's analysis of the existing and proposed conditions, the proposed site condition meets the criteria set forth by the Town of North Andover Stormwater Management and Erosion Control Regulations. 3 West Mill, High Street, Andover, MA Appendix A Pre and Post-Project Hydrology cp 0 MO.MEA FLOC° xa`��OiIE x�upc-O�x . ME K 0 oaw r-7%*3 Kv-ri us(cte�rway-as:.n k Rss xLe G4 E �33 P] tsi cf..-Mt-3 3 y�IL(5 Fi �, �3tS55 -�71f17f74A Too I ns' w�..rr.ro ,c-cau , C C �vnnr x,uaatr .�. � tr3 Irn�7a�I 53f� Gv1s NT IrnL to Mr ` ,ax ca �X \ a-7aca ' 98' �SY owl ° GOSS r nv GRAM 1AiT£ p q f I IL7' ,ar WAM a Pp cr air Mott Coal wmuxr �tetivs HIGH STREET (PAVED PUBLIC RAW. — 50' WIDE) '77/7" f l ,`•LC 63S' OF.9' II ` S30' !IY i �E£RS.15E•;il d 7J' 7.x kSY HU&BttiG{;IR.D N SCALE: 1" = 50' i - a F I G. 1 WEST MILL S NIGH STREET EXISTING k NORTH ANDOVER, MA HYDROLOGY 2014-014.00 co ` n q 0 a U-00. AREA 1 1 Y� 493 SOYT.k now man zu~x zuz Ae x a DSss W,ti 0 MTLG.)-7i.3A lsx A-7a M � \ acass �4tik�sLt TAW 1 I hY 77.0 R-ftt$ {.. t. BtY•Tbl1 [�f _ rPRti. /E GNcA (��/��1■J 1 NT P0. 0 q f 1 R+7R75 iXW7169 Y 7 N t ram'\ W [aASs re '{{w 11.7 aas• ,� �aep y � � $ \ � � J/ Q S2Yi5 O a CRY P.�iYAYE �� 69im ' H'rC�Yr Fi1iR0.YT HIGH STREET (PAVED PUBLIC R.OX - 50' WIDE) l i�7 t7x —anaatt+7s 7e SCALE: V = 50` WEST MILL 2 N1GN STREET PROPOSED E ►� : k NORTH ANDOVER, MA HYDROLOGY kb k 2014-01 4.00 a 2S . Proposed Parking 1 P posed Parking 2 P 2P Rain G rden 1 ain Garden 2 0S 6S '[ R Q---- Existing Overland Flow Prop sed Rain Garden Troposed Parking 3&4 5P 4P Rain rden 5 Rain Garden 5S 4S Proposed Parking 7 Proposed Parking 5&6 Suk�cat Reach on [Clk Drainage Diagram for 2014-014 Hydrology Prepared by Design Consultants, Inc., Printed 3/13/2014 HydroCAD®9.10 s/n 00884 0 2010 HydroCAD Software Solutions LLC 11 2014-014 Hydrology Type 11124-hr 2-Yr Rainfall=3.20" Prepared by Design Consultants, Inc. Printed 3/13/2014 H droCAD® 9.10 s/n 00884 U 2010 H droCAD Software Solutions LLC Pa e 2 Time span=0.00-48.00 hrs, dt=0,01 hrs, 4801 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method SubcatchmentOS: Existing Runoff Area=46,016 sf 36.00% Impervious Runoff ❑epth=1.61" Tc=5.0 min CN=83 Runoff=2.06 cfs 0.142 of SubcatchmentlS: Proposed Parking 1 Runoff Area=858 sf 0.00% Impervious Runoff Depth=1.09" Tc=5.0 min CN=75 Runoff 0.03 cfs 0.002 of Subcatchment2S: Proposed Parking 2 Runoff Area=1,482 sf 0.00% Imperious Runoff Depth=1.09" Tc=5.0 min CN=75 Runoff=0.04 cfs 0.003 of Subcatchment3S: Proposed Parking 3&4 Runoff Area=1,714 sf 0.00% Impervious Runoff Depth=1.09" Tc=5.0 min CN=75 Runof=0.05 cfs 0.004 of Subcatchment4S: Proposed Parking 5&6 Runoff Area=1,546 sf 0.00% Impervious Runoff Depth=1.09" Tc=5.0 min CN=75 Runoff 0.05 cfs 0.003 of Subcatchment5S: Proposed Parking 7 Runoff Area=960 sf 0.00% Impervious Runoff Depth=1.09" Tc=5.0 min CN=75 Runoff=0.03 cfs 0.002 of Subcatchment6S: Overland Flow Runoff Area=39,456 sf 41.98% Impervious Runoff Depth=1.68" Tc=5.0 min CN=84 Runoff-1.85 cfs 0.127 of Reach 1 R: Proposed Inflow=1.85 cfs 0.127 of Outflow=1.85 cfs 0.127 of Pond 1 P: Rain Garden 1 Peak Elev=0.63' Storage=39 cf Inflow=0.03 cfs 0.002 of Discarded=0.00 cfs 0.002 of Primary=0.00 cfs 0.000 of Outflow=0.00 cfs 0.002 of Pond 2P: Rain Garden 2 Peak Elev=0.67' Storage=69 cf Inflow=0.04 cfs 0.003 of Discarded=0.00 cfs 0.003 of Primary=0.00 cfs 0.000 of Outflow=0.00 cfs 0.003 of Pond 3P: Rain Garden 3 Peak Elev=0.64' Storage=79 cf Inflow=0.05 cfs 0.004 of Discarded=0.00 cfs 0.004 of Primary=0.00 cfs 0.000 of Outflow=0.00 cfs 0.004 of Pond 4P: Rain Garden 4 Peak Elev=0.57' Storage=68 cf Inflow=0.05 cfs 0.003 of Discarded=0.00 cfs 0.003 of Primary=0.00 cfs 0.000 of Outflow=0.00 cfs 0.003 of Pond 5P: Rain Garden 5 Peak Elev=0.42' Storage=38 cf Inflow=0.03 cfs 0.002 of Discarded=0.00 cfs 0.002 of Primary=0.00 cfs 0.000 of Outflow=0.00 cfs 0.002 of 12 2014-014 Hydrology Type t1124-hr 2-Yr Rarnfaf1=3.20" Prepared by Design Consultants, Inc. Printed 3/13/2014 H droCADO 9.10 sln 00884 ©2010 H droCAD Software Solutions LLC Page 3 Summary for Subcatchment OS: Existing Runoff — 2.06 cfs @ 12.08 hrs, Volume= 0.142 af, Depth= 1 .61" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Type III 24-hr 2-Yr Rainfall=3.20" Area (so CN Description 16,564 98 Paved parking, HSG C 29,452 74 >75% Grass cover, Good HSG C 46,016 83 Weighted Average 29,452 64.00% Pervious Area 16,564 36.00% Impervious Area Tc Length Slope Velocity Capacity Description min feet ftlft) (ftlsec) cfs 5.0 Direct Entry, Direct Entry Summary for Subcatchment IS: Proposed Parking 1 Runoff = 0.03 cfs @ 12.08 hrs, Volume= 0.002 af, Depth= 1 .09" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Type III 24-hr 2-Yr Rainfall=3.20" Area (so CN Descri Lion 651 75 Porous Pavers 207 74 >75% Grass cover, Good, HSG C 858 75 Weighted Average 858 100.00% Pervious Area Tc Length Slope Velocity Capacity Description min feet fuft) (ft/sec) (cfs 5.0 Direct Entry, Dirent Entry Summary for Subcatchment 2S: Proposed Parking 2 Runoff -- 0.04 cfs @ 12.08 hrs, Volume= 0.003 af, Depth= 1 .09" Runoff by SCS TR--20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Type III 24-hr 2-Yr Rainfall=3.20" Area (so CN Description 1,138 75 Porous Pavers 344 74 >75% Grass cover, Good, HSG C 1,482 75 Weighted Average 1,482 100.00% Pervious Area 13 2014-014 Hydrology Type I1124Whr 2-Yr Rainfall=3.20" Prepared by Design Consultants, Inc. Printed 3/13/2014 H droCAD0 9.10 sin 00884 0 2010 H droCAD Software Solutions LLC Page 4 Tc Length Slope Velocity Capacity Description min feet ftlft ftlsec cfs 5.0 Direct Entry, Dirent Entry Summary for Subcatchment 3S: Proposed Parking 3&4 Runoff 0.05 cfs @ 12.08 hrs, Volume= 0.004 af, Depth= 1.09" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Type III 24Whr 2--Yr Rainfall=3.20" Area fso CN Description 654 75 Porous Pavers 652 75 Porous Pavers 408 74 >75% Grass cover, Good HSG C 1,714 75 Weighted Average 1,714 100.00% Pervious Area Tc Length Slope Velocity Capacity Description min feet fUft ftlsec cfs 5.0 Direct Entry, Dirent Entry Summary for Subcatchment 4S: Proposed Parking 5&6 Runoff 0.05 cfs @ 12.08 hrs, Volume= 0.003 af, ❑epth= 1.09" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Type III 24-hr 2-Yr Rainfall=3.20" Area (sD CN Description 330 75 Porous Pavers 814 75 Porous Pavers 402 74 >75% Grass cover, Good HSG C 1,546 75 Weighted Average 1,546 100.00% Pervious Area Tc Length Slope Velocity Capacity Description min feet fU ft/sec cfs 5.0 Direct Entry, Dirent Entry Summary for Subcatchment 5S: Proposed Parking 7 Runoff 0.03 cfs @ 12.08 hrs, Volume= 0.002 af, ❑epth= 1.09" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Type III 24-hr 2-Yr Rainfall=3.20" 14 2014-014 Hydrology Type /// 24-hr 2-Yr Rainfall=3.24" Prepared by Design Consultants, Inc. Printed 3113/2014 H droCADO 9.10 s/n 00884 ©2010 H droCAD Software Solutions L.LC Page 5 Areas CN Description * 652 75 Porous Pavers 308 74 >75% Grass cover Good HSG C 960 75 Weighted Average 960 100.00% Pervious Area Tc Length Slope Velocity Capacity Description min (feet) ft/ft) (ftlsec) (cfs 5.0 Direct Entry, ❑irent Entry Summary for Subcafchment 6S: Overland Flow Runoff = 1.85 cfs @ 12.08 hrs, Volume= 0.127 af, Depth= 1.68" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Type III 24-hr 2-Yr Rainfall=3.20" Area (sD CN Description 16,564 98 Paved parking, HSG C 22,892 74 >75% Grass cover, Good HSG C 39,456 84 Weighted Average 22,892 58.02% Pervious Area 16,564 41 .98% Impervious Area Te Length Slope Velocity Capacity Description min feet ftlft ftlsec cfs 5.0 Direct Entry, Direct Entry Summary for Reach 1 R: Proposed Inflow Area = 1.056 ac, 36.00% Impervious, Inflow Depth = 1.44" for 2-Yr event Inflow 1.85 cfs a@7 12.08 hrs, Volume= 0.127 of Outflow — 1 .85 cfs @ 12.08 hrs, Volume= 0.127 af, Aften= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Summary for Pond 'I P: Rain Garden 1 Inflow Area = 0.020 ac, 0.00% Impervious, Inflow Depth = 1 .09" for 2-Yr event Inflow 0.03 cfs a@ 12.08 hrs, Volume= 0.002 of Outflow = 0.00 cfs @ 11 .67 hrs, Volume= 0.002 af, Atten= 95%, Lag= 0.0 min Discarded = 0.00 cfs @ 11 .67 hrs, Volume= 0.002 of Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Peak Elev= 0.63' @ 15.51 hrs Surf.Area= 207 sf Storage= 39 cf Plug-Flow detention time= 325.8 min calculated for 0.002 of (100% of inflow) Center-of-Mass det. time= 325.8 min ( 1,183.7 - 857.9 } Is 2014-014 Hydrology Type 11124-hr2-Yr Rarnfa11=3.20" Prepared by Design Consultants, Inc. Printed 3/13/2014 H droCAD0 9.10 s/n 00884 02010 H droCAD Software Solutions LLC Page 6 Volume Invert Avail.Stora a Storage Description #1 0.00, 337 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Voids Inc.Store Cum.Store (feej) (sq-ft) (%) (cubic-feet) (cubic-feet) 0.00 207 0.0 0 0 0.01 207 30.0 1 1 1.00 207 30.0 61 62 2.00 207 30.0 62 124 3.00 207 30.0 62 186 3.01 95 100.0 2 188 4.00 207 100.0 149 337 Device Routing Invert Outlet Devices #1 Discarded 0.00' 0.270 iinlhr Exfiltration over Surface area #2 Primary 3.80' 5.0' long x 1.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1 .40 1.60 1 .80 2.00 2.50 3.00 Coef. (English) 2.69 2.72 2.75 2.85 2.98 3.08 3.20 3.28 3.31 3.30 3.31 3.32 #3 Primary 3.90' 6.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Qiscarded OutFlow Max=0.00 cfs c@ 11.67 hrs HW=0.01' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.00 cfs) Primary OutFlow Max=0.00 cfs cr 0.00 hrs HW=0.00' (Free Discharge) 'IE2=Broad-Crested Rectangular Weir( Controls 0.00 cfs) 3=Orifice/Grate ( Controls 0.00 cfs) Summary for Pond 2P: Rain Garden 2 Inflow Area = 0.034 ac, 0.00% Impervious, Inflow Depth = 1.09" for 2-Yr event Inflow _ 0.04 cfs @ 12.08 hrs, Volume= 0.003 of Outflow = 0.00 cfs @ 11 .66 hrs, Volume= 0.003 af, Men= 95%, Lag= 0.0 min Discarded = 0.00 cfs @ 11.66 hrs, Volume= 0.003 of Primary - 0.00 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Peak Elev= 0.67' @ 15.62 hrs Surf.Area= 344 sf Storage= 69 cf Plug-Flow detention time= 344.9 min calculated for 0.003 of(100% of inflow) Center-of-Mass det. time= 344.9 min ( 1,202.8 - 857.9 ) Volume Invert Avail.Stora e Storage Description #1 0.00, 571 cf Custom Stage Data (Prismatic)Listed below (Recalc) 16 2014-014 Hydrology Type li! 24-hr 2-Yr Rainfall=3.20" Prepared by Design Consultants, Inc. Printed 3/13/2014 H droCAD® 9.10 sln 00884 D 2010 H droCAD Software Solutions LLC Page 7 Elevation Surf.Area Voids Inc.Store Cum.Store fleet s -ft °/8 cubic-feet cubic-feet 0.00 344 0.0 0 0 0.01 344 30.0 1 1 1.00 344 30.0 102 103 2.00 344 30.0 103 206 3.00 344 30.0 103 310 3.01 178 100.0 3 312 4.00 344 100.0 258 571 Device Routing_ Invert Cutlet Devices #1 Discarded 0.00' 0.270 inlhr Exfiltration over Surface area #2 Primary 3.80' 6.0' long x 1.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1 .00 1 .20 1.40 1.60 1.80 2.00 2.50 3.00 Coef. (English) 2.69 2.72 2.75 2.85 2.98 3.08 3.20 3.28 3.31 3.30 3.31 3.32 #3 Primary 3.90' 6.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads �Diiscarded OutFlow Max=0.00 cfs @ 11.66 hrs HW=0.01' (Free Discharge) 1=Exf1ltration (Exfiltration Controls 0.00 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=0.00' (Free Discharge) �2=Broad-Crested Rectangular Weir( Controls 0.00 cfs) 3-Orifice/Grate ( Controls 0.00 cfs} Summary for Pond 3P: Rain Garden-3 Inflow Area = 0.039 ac, 0.00% Impervious, Inflow Depth = 1.09" for 2-Yr event nflow = 0.05 cfs @ 12.08 hrs, Volume= 0.004 of Outflow -- 0.00 cfs @ 11 .66 hrs, Volume= 0.004 af, Atten= 95%, Lag= 0.0 min Discarded = 0.00 cfs @ 11 .66 hrs, Volume- 0.004 of Primary - 0.00 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Peak Elev= 0.64' ar 15.55 hrs Surf.Area= 408 sf Storage= 79 cf Plug-Flow detention time= 332.4 min calculated for 0.004 of (100% of inflow) Center-of-Mass det. time= 332.4 min ( 1 .190.3 - 857.9 } Volume Invert Avail.Stora a Storage Description #1 0.00, 686 cf Custom Stage Data (Prismatic)Listed below (Recalc) 17 2014-014 Hydrology Type Ill 24-hr 2-Yr Rainfall=3.20" Prepared by Design Consultants, Inc. Printed 3/13/2014 H droCADO 9.10 sln 00884 Q 2010 H droCA❑ Software Solutions LLC Pa e 8 Elevation Surf.Area Voids Inc.Store Cum.Store feet s -ft °/fl cubic-feet cubic--feet 0.00 408 0.0 0 0 0.01 408 30.0 1 1 1.00 408 30.0 121 122 2.00 408 30.0 122 245 3.00 408 30.0 122 367 3.01 229 100.0 3 370 4.00 408 100.0 315 686 Device Routing Invert Cutlet Devices #1 Discarded 0.00' 0.270 inlhr Exfiltration over Surface area #2 Primary 3.80' 5.0' long x 1.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1 .20 1 .40 1.60 1.80 2.00 2.50 3.00 Coef. (English) 2.69 2.72 2.75 2.85 2.98 3.08 3.20 3.28 3.31 3.30 3.31 3.32 #3 Primary 3.90' 6.0" Vert. Orifice/Grate C= 0.600 Discarded OutFlow Max=0.00 cfs @ 11 .66 hrs HW=0.01' (Free Discharge) I-' -1=Exfiltration (Exfiltration Controls 0.00 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=0.00' (Free Discharge) �2=Broad-Crested Rectangular Weir( Controls 0.00 cfs) 3=Orifice/Grate ( Controls 0.00 cfs) Summary for Pond 4P; Rain Garden 4 Inflow Area = 0.035 ac, 0.00% Impervious, Inflow Depth = 1.09" for 2-Yr event Inflow -- 0.05 cfs @ 12.08 hrs, Volume= 0.003 of Outflow = 0.00 cfs @ 11.68 hrs, Volume= 0.003 af, Atten= 94%, Lag= 0.0 min Discarded = 0.00 cfs @ 11 .68 hrs, Volume= 0.003 of Primary -- 0.00 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Peals Elev= 0.57' @ 15.27 hrs Surf.Area= 402 sf Storage= 68 cf Plug-Flow detention time= 290,9 min calculated for 0.003 of (100% of inflow) Center-of-Mass det. time= 290.9 min ( 1 ,148.8 - 857.9 ) Volume Invert Avail.Stora a Storage Description #1 0.00, 684 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Voids inc.Store Cum.Store feet s -ft % cubic-feet cubic-feet 0.00 402 0.0 0 0 0.01 402 30.0 1 1 1 .00 402 30.0 119 121 2.00 402 30.0 121 241 3.00 402 30.0 121 362 3.01 243 100.0 3 365 4.00 402 100.0 319 684 18 2014-014 Hydrology Type /II 24-hr 2-Yr Rar'nfall=3.20" Prepared by Design Consultants, Inc. Printed 3/13/2014 H droCADO 9.10 sln 00884 @ 2010 H droCAD Software Solutions LLC Page 9 Device Routing Invert Outlet Devices #1 Discarded 0.00' 0.270 inlhr Exfiltration over Surface area #2 Primary 3.80' 5.0' long x 1.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1 .00 1.20 1.40 1.60 1 .80 2.00 2.50 3.00 Coef. (English) 2.69 2.72 2.75 2.85 2.98 3.08 3.20 3.28 3.31 3.30 3.31 3.32 #3 Primary 3.90' 6.0" Vert. Orifice/Grate C= 0.600 Discarded OutFlow Max=0.00 cfs @ 11.68 hrs HW=0.01' (Free Discharge) T- 1=Exfiltration (Exfiltration Controls 0.00 cfs) Primary ❑utFlow Max=0.00 cfs @ 0.00 hrs HW=0.00' (Free Discharge) �2=Broad-Crested Rectangular Weir( Controls 0.00 cfs} 3=OrificelGrate ( Controls 0.00 cfs} Summary for Pond 5P: Rain Garden 5 Inflow Area = 0.022 ac, 0.00% Impervious, Inflow Depth = 1.09" for 2-Yr event Inflow 0.03 cfs @ 12.08 hrs, Volume= 0.002 of Outflow 0.00 cfs @ 11.72 hrs, Volume= 0.002 af, Atten= 93%, Lag= 0.0 min Discarded = 0.00 cfs @ 11.72 hrs, Volume= 0.002 of Primary -- 0.00 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Peak Elev= 0.42' @ 14.51 hrs Surf.Area= 305 sf Storage= 38 cf Plug-Flow detention time= 209.7 min calculated for 0.002 of (100% of inflow) Center-of-Mass det. time= 209.7 min ( 1 ,067.6 - 857.9 } Volume Invert Avail.Stora a Storage Descri tion #1 0.00, 517 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Voids Inc.Store Cum.Store feet s ft °/o cubic-feet cubic-feet 0.00 305 0.0 0 0 0.01 305 30.0 1 1 1.00 305 30.0 91 92 2.00 305 30.0 92 183 3.00 305 30.0 92 275 3.01 178 100.0 2 277 4.00 308 100.0 241 517 Device Routing Invert Outlet Devices #1 Discarded 0.00' 0.270 inthr Exfiltration over Surface area #2 Primary 3.80' 5.0' long x 1.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1 .00 1 .20 1 .40 1.60 1 .80 2.00 2.50 3.00 Coef. (English) 2.69 2.72 2.75 2.85 2.98 3.08 3.20 3.28 3.31 3.30 3.31 3.32 #3 Primary 3.90' 6.0" Vert, Orifice/Grate C= 0.600 '19 2014-014 Hydrology Type /I124-hr2-Yr Rainfall=3.20" Prepared by Design Consultants, Inc. Printed 3/13/2014 H droCAD@ 9.10 sln 00884 U 2010 H droCAD Software Solutions LLC Pa e 10 Qiscarded GutFlow Max=0.0€3 cfs a@ 11.72 hrs HW=0.01' (Free Discharge) =Exfiltration (EAltration Controls 0.00 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=0.00' (Free ❑ischarge) L2=13road-Crested Rectangular Weir( Controls 0.00 cfs) 3=CrificelGrate ( Controls 0.00 cfs) 20 2014-014 Hydrology Type /I/ 24-hr 10-Yr Rainfall=4.80" Prepared by Design Consultants, Inc. Printed 3/13/20 4 H droCADS 9.10 s/n 00884 ©2010 H droCA❑ Software Solutions LLC Page 11 Time span=0.00-48.00 hrs, dt=0.01 hrs, 4801 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Star-Ind method SubcatchmentaS: Existing Runoff Area=46,016 sf 36,00% Impervious Runoff Depth=2.99" Tc=5.0 min CN=83 Runoff=3.83 cfs 0.264 of SubcatchmentlS: Proposed Parking 1 Runoff Area=858 sf 0.00% Impervious Runoff Depth=2.29" Tc=5.0 min CN=75 Runoff=0.05 cfs 0.004 of Subcatchment2S: Proposed Parking 2 Runoff Area=1,482 sf 0.00% impervious Runoff Depth=2.29" Tc=5.0 min CN=75 Runoff=0.09 cfs 0.006 of Subcatchment3S: Proposed Parking 3&4 Runoff Area=1,714 sf 0.00% Impervious Runoff Depth=2.29" Tc=5.0 min CN=75 Runoff=0.'I 1 cfs 0.008 of Subcatchment4S: Proposed Parking 5&6 Runoff Area=1,546 sf 0.00% Impervious Runoff Depth=2.29" Tc=5.0 min CN=75 Runoff=0.10 cfs 0.007 of Subcatchment5S: Proposed Parking 7 Runoff Area=960 sf 0.00% Impervious Runoff Depth=2.29" Tc=5.0 min CN=75 Runoff=0.06 cfs 0.004 of Subcatchment6S: Overland Flow Runoff Area=39,456 sf 41.98% Impervious Runoff Depth=3.09" Tc=5.0 min CN=84 Runoff=3.38 cfs 0.233 of Reach 1 R: Proposed Inflow=3.38 cfs 0.233 of Outflow=3.38 cfs 0.233 of Pond 1P: Rain Garden 1 Peak Elev=1.73' Storage=107 cf Inflow=0.05 cfs 0.004 of ❑iscarded=0.00 cfs 0.004 of Primary=0.00 cfs 0.000 of Outflow=0.00 cfs 0.004 of Pond 2P: Rain Garden 2 Peak EIev=1.81' Storage=187 cf Inflow=0.09 cfs 0.006 of Discarded=0.00 cfs 0.006 of Primary=0.00 cfs 0.000 of Outflow=0.00 cfs 0.006 of Pond 3P: Rain Garden 3 Peak Elev=1.76' Storage=215 cf Inflow=0.11 cfs 0.008 of Discarded=0.00 cfs 0.008 of Primary=0.00 cfs 0.000 of Outflow=0.00 cfs 0.008 of Pond 4P: Rain Garden 4 Peak EIev=1.56' Storage=189 cf Inflow=0.10 cfs 0.007 of Discarded=0.00 cfs 0.007 of Primary=0.00 cfs 0.000 of Outflow=0.00 cfs 0.007 of Pond 5P: Rain Garden 5 Peak EIev=1.20' Storage=110 cf Infiow=0.06 cfs 0.004 of Discarded=0.00 cfs 0.004 of Primary=0.00 cfs 0.000 of Outflow=0.00 cfs 0.004 of 21 2014-014 Hydrology Type 11124-hr 10-Yr Rainfall=4.80" Prepared by Design Consultants, Inc. Printed 3/13/2014 H droCAD0 9.1 0 sin a0884 02010 H droCA❑ Software Solutions LLC Page 12 Summary for Subcatchment OS: Existing Runoff = 3.83 cfs @ 12.07 hrs, Volume= 0.264 af, Depth= 2.99" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Type III 24-hr 10-Yr Rainfall=4.80" Area (so CN Description 16,564 98 Paved parking, HSG C 29,452 74 >75% Grass cover, Good, HSG C 46,016 83 Weighted Average 29,452 64.00% Pervious Area 16,564 36.00% Impervious Area Tc Length Slope Velocity Capacity Description min feet ftlft ft/sec cfs 5.0 Direct Entry, Direct Entry Summary for Subcatchment IS: Proposed Parking I Runoff -- 0.05 cfs @ 12.08 hrs, Volume= 0.004 af, Depth= 2.29" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Type III 24-hr 10-Yr Rainfall=4.80" Areas CN Description 651 75 Porous Pavers 207 74 >75% Grass cover, Good, HSG C 858 75 Weighted Average 858 100.00% Pervious Area Tc Length Slope Velocity Capacity Description min feet ft/ft ftlsec cfs 5.0 Direct Entry, ❑irent Entry Summary for Subcatchment 2S: Proposed Parking 2 Runoff - 0.09 cfs @ 12.08 hrs, Volume= 0.006 af, Depth= 2.29" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Type Ill 24-hr 10-Yr Rainfall=4.80" Area (so CN Description 1 ,138 75 Porous Pavers 344 74 >75% Grass cover, Good, HSG C 1,482 75 Weighted Average 1,482 100.00% Pervious Area 22 2014-014 Hydrology Type tii 24-hr 10-Yr Rainfaii=4.80" Prepared by Design Consultants, Inc. Printed 3/13/2014 H droCAD0 9.10 sln 00884 @ 2010 H droCA❑ Software Solutions LLC Page 13 Tc Length Slope Velocity Capacity Description min feet ftlft fUsec cfs 5.0 Direct Entry, Dirent Entry Summary for Subcatchment 3S: Proposed Parking 3&4 Runoff -- 0.11 cfs a@ 12.08 hrs, Volume= 0.008 af, Depth= 2.29" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Type III 24-hr 10-Yr Rainfall=4.80" Area (so CN Description 654 75 Porous Pavers 652 75 Porous Pavers 408 74 >75% Grass cover, Good HSG C 1,714 75 Weighted Average 1,714 100.00% Pervious Area Tc Length Slope Velocity Capacity Description min feet ft/ft f#Isec cfs 5.0 Direct Entry, Dirent Entry Summary for Subcatchment 4S: Proposed Parking 6&6 Runoff - 0.10 cfs @ 12.08 hrs, Volume= 0.007 af, ❑epth= 2.29" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Type III 24-hr 10-Yr Rainfall=4.80" Areas CN Description ` 330 75 Porous Pavers 814 75 Porous Pavers 402 74 >75% Grass cover, Good, HSG C 1,546 75 Weighted Average 1,546 100.00% Pervious Area Tc Length Slope Velocity Capacity Description min feet ft/ft) (ft/sec) (cfs 5.0 Direct Entry, Dirent Entry Summary for Subcatchment 6S: Proposed Parking 7 Runoff = 0.06 cfs @ 12.08 hrs, Volume= 0.004 af, Depth= 2.29" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Type Ill 24-hr 10-Yr Rainfall=4.80" 23 2014-014 Hydrology Type /it 24-hr 10-Yr Rainfall=4.80" Prepared by Design Consultants, Inc. Printed 3/13/2014 H droCADO 9.10 sln 00884 © 2010 H droCAD Software Solutions LLC Page 14 Areas CN Description 652 75 Porous Pavers 308 74 >75% Grass cover, Good HSG C 960 75 Weighted Average 960 100.00% Pervious Area Tc Length Slope Velocity Capacity Description min (feet)-___ ft/ft) (ft/sec) (cfs 5.0 Direct Entry, Dirent Entry Summary for Subcatchment 6S: Overland Flow Runoff -- 3.38 cfs @ 12.07 hrs, Volume= 0.233 af, Depth= 3.09" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Type III 24-hr 10-Yr Rainfall=4.80" Area (so CN Description 16,564 98 Paved parking, HSG C 22,892 74 >75% Grass cover, Good HSG C 39,456 84 Weighted Average 22,892 58.02% Pervious Area 16,564 41 .98% Impervious Area Tc Length Slope Velocity Capacity Description min feet ftlft) (ftlsec) (cfs 5.0 Direct Entry, Direct Entry Summary for Reach 1 R: Proposed Inflow Area = 1.056 ac, 36.00% Impervious, Inflow Depth = 2.65" for 10-Yr event Inflow = 3.38 cfs @ 12.07 hrs, Volume= 0.233 of Outflow = 3.38 cfs @ 12.07 hrs, Volume= 0.233 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Summary for Pond 'I P; Rain Garden 1 Inflow Area = 0.020 ac, 0.00% Imperious, Inflow Depth = 2.29" for 10-Yr event Inflow = 0A5 cfs @ 12.08 hrs, Volume= 0.004 of Outflow -- 0.00 cfs @ 10.86 hrs, Volume= 0.004 af, Atten= 98%, Lag= 0.0 min Discarded = 0.00 cfs @ 10.86 hrs, Volume= 0.004 of Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Peak Elev= 1 .73' [7a 17.80 hrs Surf.Area= 207 sf Storage= 107 cf Plug-Flow detention time= 825.9 min calculated for 0.004 of (100% of inflow) Center-of-Mass det. time= 825.9 min ( 1,661 .8 - 835.9 } 24 2014-014 Hydrology Type 11124-hr 10-Yr Rainfall=4.80" Prepared by Design Consultants, Inc. Printed 3/13/2014 H droCAD® 9.10 sln 00884 Q 2010 H droCAD Software Solutions LLC Page 15 Volume Invert Avail.Stora a Storage Description #1 0.00' 337 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Voids Inc.Store Cum.Store feet s --ft °/v cubic-feet cubic--feet 0.00 207 0.0 0 0 0.01 207 30.0 1 1 1.00 207 30.0 61 62 2.00 207 30.0 62 124 3.00 207 30.0 62 186 3.01 95 100.0 2 188 4.00 207 100.0 149 337 Device -Routing Invert Outlet Devices #1 Discarded 0.00' 0.270 inthr Exfiltration over Surface area #2 Primary 3.80' 5.0' long x 1.0` breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1 .00 1.20 1.40 1.60 1 .80 2.00 2.50 3.00 Coef. (English) 2.69 2.72 2.75 2.85 2.98 3.08 3.20 3.28 3.31 3.30 3.31 3.32 #3 Primary 3.90' 6.0" Horiz, Orifice/Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=0.00 cfs @ 10.86 hrs HW=0.01' (Free Discharge) t--'l=Exfiltration (Exfiltration Controls 0.00 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=0.00' (Free Discharge) T- 2=13road-Crested Rectangular Weir( Controls 0.00 cfs) 3=Orifice/Grate ( Controls 0.00 cfs} Summary for Pond 2P: Rain Garden 2 Inflow Area = 0.034 ac, 0.00% Impervious, Inflow Depth ^ 2.29" for 10-Yr event Inflow - 0.09 cfs @ 12.08 hrs, Volume= 0.006 of Outflow 0.00 cfs @ 10.82 hrs, Volume= 0.006 af, Atten= 98%, Lag= 0.0 min Discarded = 0.00 cfs @ 10.82 hrs, Volume= 0.006 of Primary -- 0.00 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Peak Elev= 1.81' @ 17.93 hrs Surf.Area= 344 sf Storage= 187 cf Plug-Flow detention time= 865.6 min calculated for 0.006 of(100% of inflow) Center-of-Mass det. time= 865.7 min ( 1,701 .7 -- 835.9 } Volume Invert Avail.Stora a Storage Description #1 0.00, 571 cf Custom Stage Data (Prismatic)Listed below (Recale) 25 2014-014 Hydrology Type 11124-hr 10-Yr Rainfall=4.80" Prepared by Design Consultants, inc. Printed 3/13/2014 H droCADO 9.10 sln 00884 0 2010 H droCAD Software Solutions LLC Pacie 16 Elevation Surf.Area Voids Inc.Store Cum.Store (feet) s -ft °/a cubic-feet cubic--feet 0.00 344 0.0 0 0 0.01 344 30.0 1 1 1.00 344 30.0 102 103 2.00 344 30.0 103 206 3.00 344 30.0 103 310 3.01 178 100.0 3 312 4.00 344 100.0 258 571 Device Routing Invert Outlet Devices #1 Discarded 0.00' 0.270 inlhr Exfiltration over Surface area #2 Primary 3.80' 5.0' long x 1.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1 .40 1.60 1 .80 2.00 2.50 3.00 Coef. (English) 2.69 2.72 2.75 2.85 2.98 3.08 3.20 3.28 3.31 3.30 3.31 3.32 #3 Primary 3.90' 6.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Qiscarded OutFlow Max=0.00 cfs @ 10.82 hrs HW=0.01' (Free Discharge) T-•-1=Exfiltration (Exfiltration Controls 0.00 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=0.00' (Free Discharge) N =Broad-Crested Rectangular Weir( Controls 0.00 cfs) =OrificelGrate ( Controls 0.00 cfs) Summary for Pond 3P: Rain Garden 3 Inflow Area = 0.039 ac, 0.00% Impervious, Inflow Depth = 2.29" for 10-Yr event Inflow = 0.11 cfs @ 12.08 hrs, Volume= 0.008 of Outflow = 0.00 cfs @ 10.85 hrs, Volume= 0.008 af, Atten= 98%, Lag= 0.0 min Discarded = 0.00 cfs @ 10.85 hrs, Volume= 0.008 of Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Peak Elev= 1.76' a@ 17.84 hrs Surf.Area= 408 sf Storage= 215 cf Plug-Flow detention time= 839.5 min calculated for 0.008 of (100% of inflow) Center-of--Mass det. time= 839.6 min ( 1,675.5 - 835.9 ) Volume I nvert Avaii.Stora a Storage Description #1 0.00, 686 cf Custom Stage Data (Prismatic)Listed below (Recalc) 26 2014-014 Hydrology Type 11124-hr 107Yr Rainfall=4.80" Prepared by Design Consultants, Inc. Printed 3/13/2014 H droCADO 9.10 s/n 00884 C 2010 H droCA❑ Software Solutions LLC Page 17 Elevation Surf.Area Voids 1nc.Store Cum.Store feet s -ft °/o cubic--feet cubic-feet 0.00 408 0.0 0 0 0.01 408 30.0 1 1 1.00 408 30.0 121 122 2.00 408 30.0 122 245 3.00 408 30.0 122 367 3.01 229 100.0 3 370 4.00 408 100.0 315 686 Device Routing Invert Outlet Devices #1 Discarded 0.00' 0.270 inlhr Exfiltration over Surface area #2 Primary 3.80' 5.0' long x 1.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1 .00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 Coef. (English) 2.69 2.72 2.75 2.85 2.98 3.08 3.20 3.28 3.31 3.30 3.31 3.32 #3 Primary 3.90' 6.0" Vert. Orifice/Grate C=Discarded OutFlow Max=0.00 cfs @ 10.85 hrs HW=0.01' (Free Discharge) l-Exfiltration (Exfiltration Controls 0.00 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=0.00' (Free Discharge) �2=Broad-Crested Rectangular Weir( Controls 0.00 cfs) 3=Orifice/Grate ( Controls 0.00 cfs} Summary for Pond 4P: Rain Garden 4 Inflow Area = 0.035 ac, 0.00% Impervious, Inflow Depth = 2.29" for 10-Yr event Inflow = 0.10 cfs @ 12.08 hrs, Volume= 0.007 of Outflow -- 0.00 cfs @ 10.94 hrs, Volume= 0.007 af, Atten= 97%, Lag= 0.0 min Discarded = 0.00 cfs @ 10.94 hrs, Volume= 0.007 of Primary = 0.00 cfs a@ 0.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Peak Elev= 1.56' @ 17.52 hrs Surf.Area= 402 sf Storage= 189 cf Plug-Flow detention time= 753.0 min calculated for 0.007 of(100% of inflow) Center-of-Mass det. time= 753.1 min ( 1 ,589.0 - 835.9 } Volume Invert Avail.Stora a Storage Description #1 0.00, 684 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Voids Inc.Store Curn.Store feet s -ft °/° cubic-feet cubic--feet 0.00 402 0.0 0 0 0.01 402 30.0 1 1 1 .00 402 30.0 119 121 2.00 402 30.0 121 241 3.00 402 30.0 121 362 3.01 243 100.0 3 365 4.00 402 100.0 319 684 27 2014-014 Hydrology Type lf124-hr 90-Yr Rainfall=4.80" Prepared by Design Consultants, Inc. Printed 3/13/2014 H droCAD@ 9.10 sln 00884 02010 H droCAD Software Solutions LLC Pa e 18 Device Routing_____ Invert Outlet Devices #1 Discarded 0,00' 0.270 inlhr Exfiltration over Surface area #2 Primary 3.80' 5.0' long x 1.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1 .00 1,20 1.40 1.60 1.80 2.00 2.50 3.00 Coef. (English) 2.69 2.72 2.75 2.85 2.98 3.08 3.20 3.28 3.31 3.30 3.31 3.32 #3 Primary 3.90' 6,0" Vert. Orifice/Grate C= 0.600 Qiscarded OutFlow Max=0.00 cfs @ 10.94 hrs HW=0.01' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.00 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=0.00' (Free Discharge) 12=Broad-Crested Rectangular Weir( Controls 0.00 cfs) 3=OrificelGrate ( Controls 0.00 cfs) Summary for Pond 5P: Rain Garden 5 Inflow Area = 0.022 ac, 0.00% Impervious, Inflow Depth = 2.29" for 10-Yr event Inflow = 0.06 cfs @ 12.08 hrs, Volume= 0.004 of Outflow 0.00 cfs @ 11 .14 hrs, Volume= 0.004 af, Atten= 97%, Lag= 0.0 min Discarded = 0.00 cfs @ 11 .14 hrs, Volume= 0.004 of Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Peak Elev= 1.20' @ 16.65 hrs Surf.Area= 305 sf Storage= 110 cf Plug-Flow detention time= 584.6 min calculated for 0.004 of (100% of inflow) Center-of-Mass det. time= 584.7 min ( 1 ,420.6 - 835.9 ) Volume Invert Avail.Stora a Storage Description #1 0.00` 517 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Voids Inc.Store Cum.Store feet s -ft °/° cubic-feet cubic-feet 0.00 305 0.0 0 0 0.01 305 30.0 1 1 1 .00 305 30.0 91 92 2.00 305 30.0 92 183 3.00 305 30.0 92 275 3.01 178 100.0 2 277 4.00 308 100.0 241 517 Device Routing Invert Outlet Devices #1 Discarded 0.00' 0.270 inlhr Exfiltration over Surface area #2 Primary 3.80' 5.0' long x 1.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1 .00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 Coef. (English) 2.69 2.72 2.75 2.85 2.98 3.08 3.20 3.28 3.31 3.30 3.31 3.32 #3 Primary 3.90' 6.0" Vert. Orifice/Grate C= 0.600 28 2014-014 Hydrology Type 11124-hr 10-Yr Rainfall=4.80" Prepared by Design Consultants, Inc. Printed 3/13/2014 H droCAD0 9.10 s/n ❑0884 @ 2010 H droCAD Software Solutions LLC Page 19 Q!1=Exfiltration carded DutFlow Max=0.00 cfs @a 11 .14 hrs HW=0.01' (Free Discharge) (Exfiltration Controls 0.00 cfs) Primary OutFlow Max=0.00 cfs a@ 0.00 hrs HW=0.00' (Free Discharge) t2=Broad-Crested Rectangular Weir( Controls 0.00 cfs) 3=OrificelGrate Controls 0.00 cfs) 29 2014-014 Hydrology Type /// 24-hr 25-Yr Rainfall=6.00" Prepared by Design Consultants, Inc. Printed 3/13/2014 H droCAD0 9.10 sln 00884 ©2010 H droCAD Software Solutions LLC Page 20 Time span=0.00-48.00 hrs, dt=0.01 hrs, 4801 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method SubcatchmentOS: Existing Runoff Area=46,016 sf 36.00% Impervious Runoff Depth=4.09" Tc=5.0 min CN=83 Runoff=5.19 cfs 0.360 of Subcatchment'IS: Proposed Parking 1 Runoff Area=858 sf 0.00% Impervious Runoff Depth=3.28" Tc=5.0 min CN=75 Runoff=0.08 cfs 0.005 of Subeatchment2S: Proposed Parking 2 Runoff Area=1,482 sf 0.00% Impervious Runoff Depth=3.28" Tc=5.0 min CN=75 Runoff=0.14 cfs 0.009 of Subcatchment3S: Proposed Parking 3&4 Runoff Area=1,714 sf 0.00% Impervious Runoff Depth=3.28" Tc=5.0 min CN=75 Runoff=0.16 cfs 0.011 of Subcatchment4S: Proposed Parking 5&6 Runoff Area=1,546 sf 0.00% Impervious Runoff Depth=3.28" Tc=5.0 min CN=75 Runoff=0.14 cfs 0.010 of Subcatchment5S: Proposed Parking 7 Runoff Area=960 sf 0.00% Impervious Runoff ❑epth=3.28" Tc=5.0 min CN=75 Runoff=0.09 cfs 0.006 of Subcatchment6S: Overland Flow Runoff Area=39,456 sf 41.98% Impervious Runoff ❑epth=4.20" Tc=5.0 min CN=84 Runoff=4.55 cfs 0.317 of Reach IR: Proposed Inflow=4.55 cfs 0.317 of Outflow=4.55 cfs 0.317 of Pond I P: Rain Garden I Peak Elev=2.72' Storage=169 cf Inflow=0.08 cfs 0.005 of Discarded=0.00 cfs 0.004 of Primary=0.00 cfs 0.000 of Outflow=0.00 cfs 0.004 of Pond 2P: Rain Garden 2 Peak Elev=2.86' Storage=295 cf Inflow=0.14 cfs 0.009 of Discarded=0.00 cfs 0.007 of Primary=0.00 cfs 0.000 of Outflow=0.00 cfs 0.007 of Pond 3P: Rain Garden 3 Peak Elev=2.77' Storage=339 cf Inflow=0.16 cfs 0.011 of ❑iscarded=0.00 cfs 0.008 of Primary=0.00 cfs 0.000 of Outflow=0.00 cfs 0.008 of Pond 4P: Rain Garden 4 Peak Elev=2.47' Storage=298 cf Inflow=0.14 cfs 0.010 of Discarded=0.00 cfs 0.008 of Primary=0.00 cfs 0.000 of Outflow=0.00 cfs 0.008 of Pond 5P: Rain Garden 5 Peak Elev=1.91' Storage=175 cf Inflow=0.09 cfs 0.006 of Discarded=0.00 cfs 0.006 of Primary=0.00 cfs 0.000 of Outflow=0.00 cfs 0.006 of 30 2014-014 Hydrology Type Ill 24-hr 25-Yr Rainfall=6.00" Prepared by Design Consultants, Inc. Printed 3113/2014 H droCADO 9.10 sin 00884 ©2010 H droCAD Software Solutions LLC Page 21 Summary for Subcatchment OS: Existing Runoff = 5.19 cfs a� 12.07 hrs, Volume= 0.360 af, ❑epth= 4.09" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Type III 24-hr 25--Yr Rainfall=6.00" Area (sD CN Description 16,564 98 Paved parking, HSG C 29,452 74 >75% Grass cover, Good, HSG C 46,016 83 Weighted Average 29,452 64.00% Pervious Area 16,564 36.00% Impervious Area Tc Length Slope Velocity Capacity Description min feet ft/ft ftlsec cfs 5.0 Direct Entry, Direct Entry Summary for Subcatchment '1S: Proposed Parking I Runoff -- 0.08 cfs a[�7 12.08 hrs, Volume= 0.005 af, Depth= 3.28' Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Type III 24-hr 25-Yr Rainfall=6.00" Area (sD CN Description * 651 75 Porous Pavers 207 74 >75% Grass cover, Good HSG C 858 75 Weighted Average 858 100.00% Pervious Area Tc Length Slope Velocity Capacity Description min feet ftfft) (fUsec) (cfs 5.0 Direct Entry, Dirent Entry Summary for Subcatchment 2S: Proposed Parking 2 Runoff -- 0.14 cfs @ 12.08 hrs, Volume= 0.009 af, Depth= 3.28" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Type III 24-hr 25-Yr Rainfall=6.00" Area (so CN Description * 1 ,138 75 Porous Pavers 344 74 >75% Grass cover, Good, HSG C 1 ,482 75 Weighted Average 1,482 100.00% Pervious Area 31 2014-014 Hydrology Type 11124-hr 25-Yr Rainfall=6.00" Prepared by Design Consultants, Inc. Printed 3/13/2014 H droCADO 9.10 sin 00884 ©2010 H droCAD Software Solutions LLC Pa e 22 Tc Length Slope Velocity Capacity Description rnin feet ftlft) (fUsec) (cfs 5.0 Direct Entry, Dirent Entry Summary for Subcatchment 3S: Proposed Parking 3&4 Runoff -- 0.16 cfs a@ 12.08 hrs, Volume= 0.011 af, Depth= 3.28" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Type III 24-hr 25-Yr Rainfall=6.00" Area (so CN Description 654 75 Porous Pavers 652 75 Porous Pavers 408 74 >75% Grass cover, Good, HSG C 1,714 75 Weighted Average 1 ,714 100.00% Pervious Area Tc Length Slope Velocity Capacity Description min feet ft/ft ftlsec cfs 5.0 Direct Entry, Dirent Entry Summary for Subcatchment 4S: Proposed Parking 5&6 Runoff - 0.14 cfs @ 12.08 hrs, Volurne= 0.010 af, Depth= 3.28" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Type III 24-hr 25-Yr Rainfall=6.00" Area (sD CN Description 330 75 Porous Pavers 814 75 Porous Pavers 402 74 >75% Grass cover, Good, HSG C 1,546 75 Weighted Average 1,546 100.00% Pervious Area Tc Length Slope Velocity Capacity Description min feet ft/ft ft/sec cfs 5.0 Direct Entry, Dirent Entry Summary for Subcatchment 5S: Proposed Parking 7 Runoff -- 0.09 cfs @ 12.08 hrs, Volume= 0.006 af, Depth= 3.28" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Type III 24-hr 25-Yr Rainfall=6.00" 32 2014-014 Hydrology Type 11124-hr 25-Yr Rainfall=6.00" Prepared by Design Consultants, Inc. Printed 3/13/2014 H droCAo® 9.10 s/n 00884 02010 H droCAD Software Solutions LL.0 Page 23 Areas CN Description ` 652 75 Porous Pavers 308 74 >75% Grass cover, Good HSG C 960 75 Weighted Average 960 100.00% Pervious Area Tc Length Slope Velocity Capacity Description min feet ft/ft fUsec cfs 5.0 Direct Entry, Direct Entry Summary for Subcatchment 6S: Overland Flow Runoff = 4.55 cfs @ 12.07 hrs, Volume= 0.317 af, Depth= 4.20" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Type III 24-hr 25-Yr Rainfall=6.00" Areas CN Description 16,564 98 Paved parking, HSG C 22,892 74 >75% Grass cover, Good, HSG C 39,456 84 Weighted Average 22,892 58,02% Pervious Area 16,564 41.98% Impervious Area Tc Length Slope Velocity Capacity Description (min)- feet fUft ftlsec cfs 5.0 Direct Entry, Direct Entry Summary for Reach I R. Proposed Inflow Area = 1.056 ac, 36.00% Impervious, Inflow Depth = 3.60" for 25-Yr event Inflow = 4.55 cfs @ 12.07 hrs, Volume= 0.317 of Outflow -- 4.55 cfs @ 12.07 hrs, Volume= 0.317 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Summary for Pond 'I P. Rain Garden 'i Inflow Area = 0.020 ac, 0.00% Impervious, Inflow Depth = 3.28" for 25-Yr event Inflow = 0.08 cfs @ 12.08 hrs, Volume= 0.005 of Outflow -- 0.00 cfs @ 10.15 hrs, Volume= 0.004 af, Atten= 98%, Lag= 0.0 min Discarded = 0.00 cfs @ 10.15 hrs, Volume= 0.004 of Primary -- 0.00 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Peak Elev= 2.72' @ 20.19 hrs Surf.Area= 207 sf Storage= 169 cf Plug-Flow detention time= 978.8 min calculated for 0.004 of (77% of inflow) Center-of-Mass det. time= 894.1 min ( 1 ,719.6 - 825.5 ) 33 2014-014 Hydrology Type 11124-hr 25-Yr Rainfall=6.00" Prepared by Design Consultants, Inc. Printed 3/13/2014 H droCAD® 9.10 sln 00884 Q 2010 H droCAD Software Solutions LLC Page 24 Volume Invert Avail.Stora a Storage Description #1 0.00, 337 cf Custom Stage Data (Prismatic)Listed below (Recale) Elevation Surf.Area Voids Inc.Store Cum.Store feet s -ft °/a cubic-feet cubic-feet 0.00 207 0.0 0 0 0.01 207 30.0 1 1 1 .00 207 30.0 fit 62 2.00 207 30.0 62 124 3.00 207 30.0 62 186 3.01 95 100.0 2 188 4.00 207 100.0 149 337 Device Routing Invert Outlet Devices #1 Discarded 0A0' 0.270 infhr Exfiltration over Surface area #2 Primary 3.80' 5.0' long x 1.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 Coef. (English) 2.69 2.72 2.75 2.85 2.98 3.08 3.20 3.28 3.31 3.30 3.31 3.32 #3 Primary 3.90' 6.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads iscarded DutFlow Max=0.00 cfs @ 10.15 hrs HW=0.01' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.00 cfs) Primary QutFlow Max=0.00 cfs a7 0.00 hrs HW=0.00' (Free Discharge) �2=13road-Crested Rectangular Weir( Controls 0.00 cfs) 3=4rificelGrate ( Controls 0.00 cfs) Summary for Pond 2P: Rain Garden 2 Inflow Area = 0.034 ac, 0.00% Impervious, Inflow Depth = 3.28" for 25-Yr event Inflow 0.14 cfs @ 12.08 hrs, Volume= 0.009 of Outflow = 0.00 cfs @ 10.11 hrs, Volume= 0.007 af, Atten= 98%, Lag= 0.0 min Discarded = 0.00 cfs @ 10.11 hrs, Volume= 0.007 of Primary 0.00 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Peak Elev= 2.86' @ 20.64 hrs Surf.Area= 344 sf Storage= 295 cf Plug-Flow detention time= 983.1 min calculated for 0.007 of (74% of inflow) Center-of-Mass det. time= 893.1 min ( 1,718.6 - 825.5 ) Volume Invert Avail.Stora a Storage Descri lion #1 0.00, 571 cf Custom Stage Data (Prismatic)Listed below (Recalc) 34 2014-014 Hydrology Type 11124-hr 25-Yr Rainfall=6.00" Prepared by Design Consultants, Inc. Printed 3/13/2014 H droCADO 9.10 s1n 00884 ©2010 H droCAD Software Solutions LLC Page 25 Elevation Surf.Area Voids Inc.Store Cum.Store feet s -ft % cubic--fee# cubic-feet 0.00 344 0.0 0 0 0.01 344 30.0 1 1 1 .00 344 30.0 102 103 2.00 344 30.0 103 206 3.00 344 30.0 103 310 3.01 178 100.0 3 312 4.00 344 100.0 258 571 Device Routing Invert Outlet Devices #1 Discarded 0.00' 0.270 inlhr Exfiltration over Surface area #2 Primary 3.80' 6.0" long x 1.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1 .00 1.20 1 .40 1 .60 1 .80 2.00 2.50 3.00 Coef. (English) 2.69 2.72 2.75 2.85 2.98 3.08 3.20 3.28 3.31 3.30 3.31 3.32 #3 Primary 3.90' 6.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads iiscarded OutFlow Max=0.00 cfs @ 10.11 hrs HW=0.01' (Free Discharge) 9=Exfiltration (Exf€ltration Controls 0.00 cfs) Primary OutFlow Max=0.00 cfs a@ 0.00 hrs HW=0.00' (Free Discharge) �2=Broad-Crested Rectangular Weir( Controls 0.00 cfs) 3 OrificelGrate ( Controls 0.00 cfs) Summary for Pond 3P: Rain Garden 3 Inflow Area : 0.039 ac, 0.00% Impervious, Inflow Depth = 3.28" for 25-Yr event Inflow = 0.16 cfs @ 12.08 hrs, Volume= 0.011 of Outflow 0.00 cfs @ 10.14 hrs, Volume= 0.008 af, Atten= 98%, Lag= 0.0 min Discarded = 0.00 cfs @ 10.14 hrs, Volume= 0.008 of Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Peak Elev= 2.77' @ 20.35 hrs Surf.Area= 408 sf Storage= 339 cf Plug-Flow detention time= 980.3 min calculated for 0.008 of (76% of inflow) Center-of-Mass det. time= 893.7 min ( 1,719.2 - 825.5 ) Volume Inver# Avail.Stora a Storage Descri #ion #1 0.00 686 cf Custom Stage Data (Prismatic)Listed below (Recalc) 35 2014-014 Hydrology Type !1124-hr 25-Yr Rainfall=6.00" Prepared by Design Consultants, Inc. Printed 3/13/2014 H droCAD@ 9.10 s/n 00884 02010 H droCA❑ Software Solutions LLC Page 26 Elevation Surf.Area Voids Inc.Store Cum.Store feet s -ft °/o cubic-feet cubic-feet 0.00 408 0.0 0 0 0.01 408 30.0 1 1 1.00 408 30.0 121 122 2.00 408 30.0 122 245 3.00 408 30.0 122 367 3.01 229 100.0 3 370 4.00 408 100.0 315 686 Device Routing____ Invert Outlet Devices #1 Discarded 0.00' 0.270 inlhr Exfiltration over Surface area #2 Primary 3.80' 5.0' long x 1.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1 .00 1 .20 1.40 1 M 1 .80 2.00 2.50 3.00 Coef. (English) 2.69 2.72 2.75 2.85 2.98 3.08 3.20 3.28 3.31 3.30 3.31 3.32 #3 Primary 3.90' 6.0" Vert. Orifice/Grate C= 0.600 Discarded OutFlow Max=0.00 cfs @ 10.14 hrs HW=0.01' (Free Discharge) t--1=Exfiltration (Exfiltration Controls 0.00 cfs) Primary OutFlow Max=0.00 cfs a@ 0.00 hrs HW=0.00' (Free Discharge) t.Z=Broad-Crested Rectangular Weir( Controls 0.00 cfs) 3=OrificelGrate ( Controls 0.00 cfs) Summary for Pond 4P: Rain Garden 4 Inflow Area = 0.035 ac, 0.00% Impervious, inflow Depth = 3.28" for 25-Yr event Inflow = 0.14 cfs @ 12.08 hrs, Volume= 0.010 of Outflow - 0.00 cfs @ 10.23 hrs, Volume= 0.008 af, Atten= 98%, Lag= 0.0 miry Discarded = 0.00 cfs @ 10.23 hrs, Volume= 0.008 of Primary = 0.00 cfs @ 0.00 hrs, Volurne= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Peak Elev= 2.47` @a7 19.47 hrs Surf.Area= 402 sf Storage= 298 cf Plug-Flow detention time= 967.5 min calculated for 0.008 of(83% of inflow) Center-of-Mass det. time= 895.9 min ( 1,721 .4 - 825.5 ) Volume Invert Avail.Stora a Storage Descri Lion #1 0.00, 684 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Voids Inc.Store Cum.Store feet s -ft °/o cubic-feet cubic-feet 0.00 402 0.0 0 0 0.01 402 30.0 1 1 1.00 402 30.0 119 121 2.00 402 30.0 121 241 3.00 402 30.0 121 362 3.01 243 100.0 3 365 4.00 402 100.0 319 684 36 2014-014 Hydrology Type 11124-hr 25-Yr Rainfall=6.00" Prepared by Design Consultants, Inc. Printed 311312014 H droCAD0 9.10 s/n 00884 02010 H droCAD Software Solutions LLC Pa e 27 Device Routing invert Cutlet Devices #1 Discarded 0.00' 0.270 inlhr Exfiltration over Surface area #2 Primary 3.80' 5.0' tong x 1.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1 .00 1.20 1.40 1.60 1 .80 2.00 2.50 3.00 Coef. (English) 2.69 2.72 2.75 2.85 2.98 3.08 3.20 3.28 3.31 3.30 3.31 3.32 #3 Primary 3.90' 6.0" Vert. Orifice/Grate C= 0.600 Discarded OutFlow Max=0.00 cfs @ 10.23 hrs HW=0.01' (Free Discharge) L1=Exfiltration (Exfiltration Controls 0.00 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=0.00' (Free Discharge) �2=Broad-Crested Rectangular Weir( Controls 0.00 cfs) 3=Orifice/Grate ( Controls 0.00 cfs} Summary for Pond 5P. Rain Garden 5 Inflow Area = 0.022 ac, 0.00% Impervious, Inflow Depth = 3.28" for 25-Yr event Inflow = 0.09 cfs @ 12.08 hrs, Volume= 0.006 of Outflow = 0.00 cfs @ 10.45 hrs, Volume= 0.006 af, Atten= 98%, Lag= 0.0 min Discarded = 0.00 cfs a@ 10.45 hrs, Volume= 0.006 of Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Peak Elev= 1.91' @ 17.85 hrs Surf.Area= 305 sf Storage= 175 cf Plug-Flow detention time= 895.2 min calculated for 0.006 of (100% of inflow) Center-of-Mass det. time= 895.2 min ( 1 ,720.7 - 825.5 } Volume Invert Avail.Stora a Storage Description #1 0.00, 517 cf Custom Stage Data (Prismatic)Listed below (Recatc) Elevation Surf.Area Voids Inc.Store Cum.Store feet s -ft °/° cubic-feet cubic-feet 0.00 305 0.0 0 0 0.01 305 30.0 1 1 1.00 305 30.0 91 92 2.00 305 30.0 92 183 3.00 305 30.0 92 275 3.01 178 100.0 2 277 4.00 308 100.0 241 517 Device Routing invert Outlet Devices #1 Discarded 0.00' 0.270 inlhr Exfiltration over Surface area #2 Primary 3.80' 5.0' long x 1.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1 .00 1.20 1.40 1.60 1 .80 2.00 2.50 3.00 Coef. (English) 2.69 2.72 2.75 2.85 2.98 3.08 3.20 3.28 3.31 3.30 3.31 3.32 #3 Primary 3.90' 6.0" Vert. Orifice/Grate C= 0.600 37 2014-014 Hydrology Type 11124-hr25-Yr Rainfall=6.00" Prepared by Design Consultants, Inc. Printed 3/13/2014 H droCADO 9.10 sln 00884 Q 2010 H droCAD Software Solutions LLC Pa e 28 ,]iscarded OuMow Max=0.00 cfs @ 10.45 hrs HW 0.01' (Free c-11=1EMiltration (Exfiltration Controls 0.00 cfs) Primary OufFtow Max=0.00 cfs @ 0.00 hrs HW=0.00' (Free Discharge) t..2=13road-Crested Rectangular Weir( Controls 0.00 cfs) 3=Orifice/Grate ( Controls 0.00 cfs) 38 2014-014 Hydrology Type /I/ 24-hr 100--Yr Rarnfafi=8.60" Prepared by Design Consultants, Inc. Printed 3/13/2014 H droCADO 9.10 sln 00884 U 2010 H droCAD Software Solutions LLC Page 29 Time span=0.00-48.00 hrs, dt=0.01 hrs, 4801 points Runoff by SCS TR--20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Star-Ind method SubcatchmentOS: Existing Runoff Area=46,016 sf 36.00% Impervious Runoff Depth=6.55" Tc=5.0 min CN=83 Runoff=8.15 cfs 0.577 of Subcatchment9S: Proposed Parking 1 Runoff Area=858 sf 0.00 Impervious Runoff Depth=5.59" Tc=5.0 min CN=75 Runoff=0.13 cfs 0.009 of Subcatchment2S: Proposed Parking 2 Runoff Area=1,482 sf 0.00% Impervious Runoff Depth=5.59" Tc=5.0 min CN=75 Runoff=0.23 cfs 0.016 of Subcatchment3S: Proposed Parking 3&4 Runoff Area=1,714 sf 0.00% Impervious Runoff Depth=5.59" Tc=5.0 min CN=75 Runoff 0.27 cfs 0.018 of Subcatchment4S: Proposed Parking 5&6 Runoff Area=1,546 sf 0.00% Impervious Runoff Depth=5.59" Tc=5.0 min CN=75 Runoff 0.24 cfs 0.017 of Subcatchment5S: Proposed Parking 7 Runoff Area=960 sf 0.00% Impervious Runoff Depth=5.59" Tc=5.0 min CN=75 Runoff=0.15 cfs 0.010 of Subcatchment6S: Overland Flow Runoff Area=39,456 sf 41.98% Impervious Runoff Depth=6.67" Tc=5.0 min CN=84 Runoff=7.08 cfs 0.504 of Reach 1 R: Proposed Inflow=7.08 cfs 0.507 of Outflow=7.08 cfs 0.507 of Pond 4 P: Rain Garden 1 Peak Elev=3.80' Storage=298 cf Inflow=0.13 cfs 0.009 of ❑iscarded=0.00 cfs 0.003 of Primary=0.00 cfs 0.001 of Outflow=0.00 cfs 0.004 of Pond 2P: Rain Garden 2 Peak Elev=3.80' Storage=506 cf Inflow=0.23 cfs 0.016 of ❑iscarded=0.00 cfs 0.006 of Primary=0.01 cfs 0.002 of Outflow=0.01 cfs 0.008 of Pond 3P: Rain Garden 3 Peak Elev=3.80' Storage=609 cf Inflow=0.27 cfs 0.018 of Discarded=0.00 cfs 0.007 of Primary=0.00 cfs 0.001 of Outflow=0.01 cfs 0.008 of Pond 4P: Rain Garden 4 Peak Efev=3.75' Storage=590 of Inflow=0.24 cfs 0.017 of ❑iscarded=0.00 cfs 0.007 of Primary=0.00 cfs 0.000 of Outflow=0.00 cfs 0.007 of Pond 5P: Rain Garden 5 Peak Elev=3.41' Storage=358 cf Inflow=0.15 cfs 0.010 of Discarded=0.00 cfs 0.005 of Primary=0.00 cfs 0.000 of Outflow=0.00 cfs 0.005 of 39 2014-014 Hydrology Type /// 24-hr 100-Yr Rainfall=8.60" Prepared by Design Consultants, Inc. Printed 3/13/2014 H droCADO 9.10 s/n 00884 Q 2010 H droCAD Software Solutions LLC Page 30 Summary for Subcatchment 0S: Existing Runoff -- 8.15 cfs @ 12.07 hrs, Volume= 0.577 af, ❑epth= 6.55" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Type ill 24-hr 100-Yr Rainfall=8.60" Areas CN Description 16,564 98 Paved parking, HSG C 9,452 74 >75% Grass cover, Good HSG C 46,016 83 Weighted Average 29,452 64.00% Pervious Area 16,564 36.00% Impervious Area Tc Length Slope Velocity Capacity Description min feet ftift) (ftlsec) (cfs 5.0 Direct Entry, Direct Entry Summary for Subcatchment IS: Proposed Parking 1 Runoff - 0.13 cfs @ 12.07 hrs, Volume= 0.009 af, ❑epth= 5.59" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Type III 24-hr 100-Yr Rainfall=8.60" Area (so CN Description 651 75 Porous Pavers 207 74 >75% Grass cover, Good, HSG C 858 75 Weighted Average 858 100.00% Pervious Area Tc Length Slope Velocity Capacity Description min feet ftlft ftlsec cfs 5.0 Direct Entry, Dirent Entry Summary for Subcatchment 2S: Proposed Parking 2 Runoff = 0.23 cfs @ 12.07 hrs, Volume= 0.016 af, ❑epth= 5.59" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Type III 24-hr 100-Yr Rainfall=8.60" Area (so CN Description 1,138 75 Porous Pavers 344 74 >75% Grass cover, Good, HSG C 1,482 75 Weighted Average 1,482 100.00% Pervious Area 40 2414-014 Hydrology Type 11124-hr 1 nn-Yr Rainfa11=8.60" Prepared by Design Consultants, Inc. Printed 3/13/2014 H droCAD0 9.10 sln 00884 U 2010 H droCA❑ Software Solutions LLC Pa e 31 Tc Length Slope Velocity Capacity ❑escription min feet ftlft fUsec cfs 5.0 Direct Entry, Dirent Entry Summary for Subcatchment 3S: Proposed Parking 3&4 Runoff - 0.27 cfs @ 12.07 hrs, Volume= 0.018 af, Depth= 5.59" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Type Ill 24-hr 100-Yr Rainfall=8.60" Area (sq CN Description * 654 75 Porous Pavers * 652 75 Porous Pavers 408 74 >75% Grass cover, Good, HSG C 1,714 75 Weighted Average 1,714 100.00% Pervious Area Tc Length Slope Velocity Capacity ❑escription min (feet)__ ft/ft ft/sec cfs 5.0 ❑irect Entry, ❑irent Entry Summary for Subcatchment 4S: Proposed Parking SM Runoff -- 0.24 cfs @ 12.07 hrs, Volume= 0.017 af, ❑epth= 5.69" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Type 111 24-hr 100-Yr Rainfall=8.60" Areas CN Description * 330 75 Porous Pavers * 814 75 Porous Pavers 402 74 >75% Grass cover, Good HSG C 1,546 75 Weighted Average 1,546 100.00% Pervious Area Tc Length Slope Velocity Capacity Description min feet ft/ft ftlsec cfs 5.0 Direct Entry, Dirent Entry Summary for Subcatchment 5S: Proposed Parking 7 Runoff -- 0.15 cfs @ 12.07 hrs, Volume= 0.010 af, Depth= 5.59" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Type III 24-hr 100-Yr Rainfall=8.60" 41 2014-014 Hydrology Type Ill 24-hr 100-Yr Rainfa&8.60" Prepared by Design Consultants, Inc. Printed 3/13/2014 H droCADO 9.10 sln 00884 O 2010 H droCAD Software Solutions LLC Page 32 Areas CN Description ' 652 75 Porous Pavers 308 74 >75% Grass cover, Good HSG C 960 75 Weighted Average 960 100.00% Pervious Area Tc Length Slope Velocity Capacity Description min feet ft/ft ftlsec cfs 5.0 Direct Entry, ❑irent Entry Summary for Subcatchment 6S: Overland Flow Runoff - 7.08 cfs @ 12.07 hrs, Volume= 0.504 af, Depth= 6.67" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Type III 24-hr 100-Yr Rainfall=8.60" Areas CN Description 16,564 98 Paved parking, HSG C 22,892 74 >75% Grass cover, Good HSG C 39,456 84 Weighted Average 22,892 58.02% Pervious Area 16,564 41.98% impervious Area Tc Length Slope Velocity Capacity Description min feet ft/ft ftlsec cfs 5.0 Direct Entry, Direct Entry Summary for Reach I R: Proposed Inflow Area = 1.056 ac, 36.00% Impervious, Inflow Depth = 5.76" for 100-Yr event Inflow = 7.08 cfs @ 12.07 hrs, Volume= 0.507 of Outflow - 7.08 cfs @ 12.07 hrs, Volume= 0.507 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Summary for Pond 1 P: Rain Garden 1 Inflow Area = 0.020 ac, 0.00% Impervious, Inflow Depth = 5.59" for 10❑-Yr event Inflow = 0.13 cfs @ 12.07 hrs, Volume= 0.009 of Outflow - 0.00 cfs @ 15.83 hrs, Volume= 0.004 af, Atten= 97%, Lag= 225.6 min Discarded = 0.00 cfs @ 8.81 hrs, Volume= 0.003 of Primary = 0.00 cfs @ 15.83 hrs, Volume= 0.001 of Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Peak Elev= 3.80' @ 15.83 hrs Surf.Area= 185 sf Storage= 298 cf Plug-Flow detention time= 809.2 min calculated for 0.004 of (46% of inflow) Center-of-Mass det. time= 692.9 min ( 1 ,503.2 - 810.3 } 42 2014-014 Hydrology Type/1/ 24-hr 100-Yr Rainfall=8.64" Prepared by Design Consultants, Inc. Printed 3/13/2014 H droCAD® 9.1❑ sln Oa884 @ 2010 H droCAD Software Solutions LLC Page 33 Volume Invert Avail.Stora a Storage Description #1 0.00, 337 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Voids Inc.Store Cum.Store feet s -ft °/° cubic-feet cubic-feet 0.00 207 0.0 0 D 0.01 207 30.0 1 1 1.00 207 30.0 61 62 2.00 207 30.0 62 124 3.00 207 30.0 62 186 3.01 95 100.0 2 188 4.00 207 100.0 149 337 Device Routing Invert Outlet Devices #1 Discarded 0.00' 0.270 inlhr Exfiltration over Surface area #2 Primary 3.80' 5.0' long x 1.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 Coef. {English} 2.69 2.72 2.75 2.85 2.98 3.08 3.20 3.28 3.31 3.30 3.31 3.32 #3 Primary 3.90' 6.0"' Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Discarded GutFlow Max=0.00 cfs a@ 8.81 hrs HW=0.01' (Free Discharge) Z---1=Exf11tration (Exfltration Controls 0.00 cfs) Primary GutFlow Max=0.00 cfs @ 15.83 hrs HW=3.80' (Free Discharge) N3=Broad-C rested Rectangular Weir(Weir Controls 0.00 cfs @ 0.09 fps) =GrificelGrate ( Controls 0.00 cfs) Summary for Pond 2P: Rain Garden 2 Inflow Area = 0.034 ac, 0.00% impervious, Inflow ❑epth = 5.59" for 100-Yr event Inflow - 0.23 cfs @ 12.07 hrs, Volume= 0.016 of Outflow -- 0.01 cfs @ 15.43 hrs, Volume= 0.008 af, Atten= 96%, Lag= 201.4 min Discarded = 0.00 cfs @ 8.77 hrs, Volume= 0.006 of Primary -- 0.01 cfs a@ 15.43 hrs, Volume= 0.002 of Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Peak Elev= 3.80' @ 15.43 hrs Surf.Area= 311 sf Storage= 506 cf Plug-Flow detention time= 794.0 min calculated for 0.008 of (47% of inflow) Center-of-Mass det. time= 679.1 min 1,489.4 - 810.3 } Volume Invert Avail.Stora a Storage Description #1 0.00` 571 cf Custom Stage Data (Prismatic)Listed below (Recalc) 43 2014-014 Hydrology Type 11124-hr 100-Yr Rainfall=8.60" Prepared by Design Consultants, Inc. Printed 3/13/2014 H droCAD® 9.10 sin 00884 02010 H droCAD Software Solutions LLC Page 34 Elevation Surf.Area Voids Inc.Store Cum.Store feet s -ft % cubic-feet cubic-feet 0.00 344 0.0 0 0 0.01 344 30.0 1 1 1.00 344 30.0 102 103 2.00 344 30.0 103 206 3.00 344 30.0 103 31❑ 3.01 178 100.0 3 312 4.00 344 100.0 258 571 Device Routing_- Invert Outlet Devices #1 Discarded 0.00' 0.270 inlhr Exfiltration over Surface area #2 Primary 3.80` 5.0' tong x 1.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1 .00 1 .20 1 .40 1.60 1 .80 2.00 2.50 3.00 Coef. (English) 2.69 2.72 2.75 2.85 2.98 3.08 3.20 3.28 3.31 3.30 3.31 3.32 #3 Primary 3.90' 6.0" Horia. Orifice/Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=0.00 cfs @ 8.77 hrs HW=0.01' (Free Discharge) t1-Exfiltration (Exfiltration Controls 0.00 cfs) Primary OutFlow Max=0.00 cfs a@ 15.43 hrs HW=3.80' (Free Discharge) �__2=Broad-Crested Rectangular Weir(Weir Controls 0.00 cfs @ 0.14 fps) 3=OrificelGrate ( Controls 0.00 cfs) Summary for Pond 3P: Rain Garden 3 Inflow Area = 0.039 ac, 0.00% Impervious, Inflow Depth = 5.59" for 100-Yr event Inflow = 0.27 cfs @ 12.07 hrs, Volume= 0.018 of Outflow = 0.01 cfs @ 16.52 hrs, Volume= 0.008 af, Atten= 97%, Lag= 266.9 min Discarded = 0.00 cfs @ 8.80 hrs, Volume= 0.007 of Primary = 0.00 cfs @ 16.52 hrs, Volume= 0.001 of Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Peak Elev= 3.80' @ 16.52 hrs Surf.Area= 372 sf Storage= 609 cf Plug-Flow detention time= 847.2 min calculated for 0.008 of (46% of inflow) Center-of-Mass det. time= 730.8 min ( 1,541.1 - 810.3 ) Volume Invert Avail.Stora a Stora a Description_ #1 0.00, 686 cf Custom Stage Data (Prismatic)Listed below (Recalc) 44 2014-014 Hydrology Type 11124-hr 100-Yr Rainfali=8.60" Prepared by Design Consultants, Inc. Printed 3/13/2014 H droCAD0 9.10 sln 00884 Q 2010 H droCAD Software Solutions LLC Page 35 Elevation Surf.Area Voids Inc.Store Cum.Store feet s -f % cubic-feet cubic-feet 0.00 408 0.0 0 0 0.01 408 30.0 1 1 1.00 408 30.0 121 122 2.00 408 30.0 122 245 3.00 408 30.0 122 367 3.01 229 100.0 3 370 4.00 408 100.0 315 686 Device Routing Invert Outlet Devices #1 Discarded 0.00' 0.270 inlhr Exfiltration over Surface area #2 Primary 3.80' 5.0' long x 1.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1 .00 1.20 1 .40 1.60 1 .80 2.00 2.60 3.00 Coef. (English) 2.69 2.72 2.75 2.85 2.98 3.08 3.20 3.28 3.31 3.30 3.31 3.32 #3 Primary 3.90' 6.0" Vert. Orifice/Grate C= 0.600 Discarded OutFlow Max=0.00 cfs @ 8.80 hrs HW=0.01' (Free Discharge) t I=Exfiltration (Exfiltration Controls 0.00 cfs) Primary OutFlow Max=0.00 cfs @ 16.52 hrs HW=3.80' (Free Discharge) N=Broad-Crested Rectangular Weir(Weir Controls 0.00 cfs @ 0.13 fps) =Orifice/Grate ( Controls 0.00 cfs) Summary for Pond 4P: Rain Garden 4 Inflow Area = 0.035 ac, 0.00% Impervious, Inflow Depth = 5.59" for 100-Yr event Inflow -- 0.24 cfs @ 12.07 hrs, Volume= 0.017 of Outflow = 0.00 cfs @ 8.90 hrs, Volume= 0.007 af, Atten= 99%, Lag= 0.0 min Discarded = 0.00 cfs @ 8.90 hrs, Volume= 0.007 of Primary -- 0.00 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Peak Elev= 3.75' @ 24.03 hrs Surf.Area= 362 sf Storage= 590 cf Plug-Flow detention time= 934.3 min calculated for 0.007 of(42% of inflow) Center-of-Mass det. time= 814.5 min { 1 ,624.8 - 810.3 } Volume Invert Avall.Stora a Storage Description #1 0.00, 684 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Voids Inc.Store Cum.Store feet s -ft cubic--feet cubic-feet 0.00 402 0.0 0 ❑ 0.01 402 30.0 1 1 1.00 402 30.0 119 121 2.00 402 30.0 121 241 3.00 402 30.0 121 362 3.01 243 100.0 3 365 4.00 402 100.0 319 684 45 2014-014 Hydrology Type 11124-hr 100-Yr Rarnfa11=8.fia" Prepared by Design Consultants, Inc. Printed 3/13/2014 H droCADO 9.10 sin 00884 D 2010 H droCA❑ Software Solutions LLC Page 36 Device Routing Invert Outlet Devices #1 Discarded 0.00' 0.270 inlhr Exfiltration over Surface area #2 Primary 3.80' 5.0' long x 1.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1 .40 1.60 1 .80 2.00 2.50 3.00 Coef. (English) 2.69 2.72 2.75 2.85 2.98 3.08 3.20 3.28 3.31 3.30 3.31 3.32 #3 Primary 3.90' 6.0" Vert. Orifice/Grate C= 0.600 P carded OutFlow Max=0.00 cfs a@ 8.90 hrs HW=0.01' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.00 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=0.00' (Free Discharge) �2=13 road-Crested Rectangular Weir( Controls 0.00 cfs) 3=OrificelGrate ( Controls 0.00 cfs) Summary for Pond 5P: Rain Garden 5 Inflow Area = 0.022 ac, 0.00% Impervious, Inflow Depth = 5.59" for 100-Yr event Inflow - 0.15 cfs a@ 12.07 hrs, Volume= 0.010 of Outflow = 0.00 cfs @ 9.16 hrs, Volume= 0.005 af, Atten= 99%, Lag= 0.0 min Discarded = 0.00 cfs @ 9.16 hrs, Volume= 0.005 of Primary -- 0.00 cfs @ 0.00 hrs, Volume= 0.000 of Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.01 hrs Peak Elev= 3.41' [7a 24.03 hrs Surf.Area= 230 sf Storage= 358 cf Plug-Flow detention time= 979.6 min calculated for 0.005 of(47% of inflow) Center-of-Mass det. time= 864.4 min ( 1 ,674.7 - 810.3 ) Volume Invert Avail.Stora a Storage Descri tion #1 0.00, 517 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Voids Inc.Store Cum.Store feet s -ft °/a cubic-feet cubic-feet 0.00 305 0.0 0 0 0.01 305 30.0 1 1 1 .00 305 30,0 91 92 2.00 305 30.0 92 183 3.00 305 X0 92 275 3.01 178 100.0 2 277 4.00 308 100.0 241 517 Device Routing Invert Outlet Devices #1 Discarded 0.00' 0.270 inlhr Exfiltration over Surface area #2 Primary 3.80' 5.0' long x 1.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1 .40 1.60 1.80 2.00 2.50 3.00 Coef. (English) 2.69 2.72 2.75 2.85 2.98 3.08 3.20 3.28 3.31 3.30 3.31 3.32 #3 Primary 3.90' 6.0" Vert. Orifice/Grate C= 0.600 46 2014-014 Hydrology Type 11124-hr 100-Yr Rainfall=8.60" Prepared by Design Consultants, Inc. Printed 3/13/2014 H droCAD0 9.10 sln 00884 ©2010 H droCAD Software Solutions LLC Page 37 Qiscarded GutFlow Max=0.00 cfs u 9.16 hrs. HW=0.01' (Free Discharge) '--I=Exfiltration {Exfiltration Controls 0.00 cfs} Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=0.00' (Free Discharge) .2=B road-C rested Rectangular Weir Controls 0.00 cfs} 3=Orifice/Grate Controls 0.00 cfs} 47 West Mill, High Street, Andover, MA Appendix B NRCS Web Soil Survey 49 a LO Hydrologic Soil Group—Essex County, Massachusetts, Northern Part o w n r. �i 325670 325730 325790 325850 325910 325970 326030 326M 3261M 326210 42°42'12"N « r. 4r 42 It N v u." ad ate°,T,•., •!..�r:.i';:;r !` _f y��f77,lriC4 P, "0. Y :lk•,, n y;. is uktix 'p shy •`, n � sr. � �r a, '� , d`lYu�[ yam. •i-�y, - ,�i - w 1 I _ _ a.. M �li.�j '' ,Q•r '<:: ;•<:�. � r a�` .:_ gym, o a•:r �' • �.�,,� �...i1'" CSC u: C fV v i' T a ui. rV � 42'41•,W'N 42°R1 59"N 325610 325670 32573fl 325790 3258m 325%0 325970 326030 325090 326M 326210 h Mp Scale:1:2,770 Wp4rftd ail A larxkape(11"x 8.5'�Shut. r: Meters °. 0 40 so 160 Q lOQ 200 400 600 Map pm3ecbon:Web Men=r Carnermordh-Aes:WGS54 Edge tks:UM Zone 19N WGS84 UsQA Natural Resources Web Sail Survey 3/1'1/2014 20—M Conservation Service National Cooperative Soil Survey Page 4 of 4 Hydrologic Soil Group--Essex County, Massachusetts, Northern Part Cm ti MAP LEGEND MAP INFORMATION Area of Interest(A0Q ® C The soil surveys that comprise your AOf were mapped at 1:15,800. Area of Interest(ADI) ® CID Warning: Soil Map may not be valid at this scale. Soils Soil Rating Polygons ® n Enlargement of maps beyond the scale of mapping can cause ED A 13 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 AID water Features sails that could have been shown at a more detailed scale. Streams and Canals Please ref on the bar scale on each ma sheet far ma Transportation Y p p BID t-#-I. Rails measurements. C v►� Interstate Highways Source of Map: Natural Resources Conservation Service ED CID Web Soil Survey URL: http:/ANebsoilsurvey.nres.usda.gov CIS Routes Coordinate System: Web Mercator(EPSG:3857) t] Major Roads Maps from the Wets Soil Survey are based on the Web Mercator 0 Not rated or not available Local goads projection,which preserves direction and shape but distorts distance and area.A projection that preserves area, such as the Snit Rating lines Background Albers equal-area conic projection,should be used if more accurate A Aerial Photography calculations of distance or area are required. A/D This product is generated from the USDA-MRCS certified data as of B the version date(s) fisted below. BID Soil Survey Area: Essex County, Massachusetts, Northern Part C Survey Area Data: Version 9, Dec 17,2013 CID Soil map units are labeled(as space allows)for map scales 1:50,000 or larger. n Date(s)aerial images were photographed: Mar 30,2011—May 1, 'W'01 Not rated or not available 2011 Soil Rating Points The orthophoto or other base map on which the soil lines were ® A compiled and digitized probably differs from the background imagery displayed on these maps.As a result,some minor shifting ® A/D of map unit boundaries may be evident. ® B BID ,usDA Natural Resources Web Soil Survey 3/11/2014 Conservation Service National Cooperative Soil Survey Page 2 of 4 Hydrologic Soil Group—Essex County, Massachusetts, Northern Part Hydrologic Soil Group Hydrologic Soll.Group -Summary by Map Unit---.Essex County,Massachusetts, Northern Part(MABOS) Map unit symbol Map unit name Rating Acres In AOl Percent of AOI 1 Water 1.6 5.8% 310E Woodbridge fine sandy C 2.1 7.6% loam, 3 to 8 percent slopes 405E Charlton fine sandy B 1.4 5.1% loam, 3 to 8 percent slopes 420E Canton fine sandy loarn, B 0.1 0.2% 3 to 8 percent slopes 602 Urban land 23.0 81.3% Totals for Area of Interest 28.3 1011.0% UsDA Natural Resources Web Soil Survey 311112014 Conservation Service National Cooperative Soil Survey rage 3 of 4 53 Hydrologic Soil Group—Essex County, Massachusetts, Northern Part 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 (AID, BID, and CID). 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 (AID, BID, or CID), 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. Rating Options Aggregation Method: Dominant Condition Component Percent Cutoff., None Specified Tie-break Rule: Higher USDA Natural Resources Web Soil Survey 3/11/2014 Conservation Service National Cooperative Sal Survey Page 4 of 4 54 West Mill, High Street, Andover, MAM"„ Appendix C T Operation and Maintenance Plan 55 STORMWATER MANAGEMENT OPERATION AND MAINTENANCE PLAN West Mills High Street North Andover, Massachusetts The following Stormwater Management operation and Maintenance (O&M) Plan has been prepared to operate and maintain the stormwater management system for the proposed improvements at the West Mil facility located on High Street. Owner/Operator: RCG, LLC 17 Ivaloo Street Somerville, MA 02143 Inspection and Maintenance Schedule Personnel entrusted by RCG, LLC with stormwater maintenance shall inspect the stormwater management system on a routine basis not less than once per month for the first 6 months of operation and semi-annually thereafter. Refer to plans for drainage structure locations. Inspection and maintenance shall be performed as follows: 1. Landscaped Areas shall be inspected and maintained on a monthly basis. Areas which may be subject to erosion will be stabilized and reseeded immediately. These operations will be performed as part of ongoing routine grounds maintenance operations, and shall be the responsibility of the Owner/Operator. 2. Street Sweeping of the roadway shall be the responsibility of the Owner/Operator and shall be conducted bimonthly between the months of April and November. Care should be taken to remove any built up sediments within the curb openings associated with the bioretention areas. Removed sediment will be disposed off site by a qualified waste disposal contractor in accordance with state and federal regulations. 3. Catch Basins/Drainage Overflow Tank: Catch basins and the drainage overflow tank shall be inspected after every major storm event for the first few months to ensure proper stabilization and function. Thereafter, the catch basins and tank shall be inspected at least twice per year. Sediment levels in the catch basins shall not be allowed to accumulate within 1 foot of the pipe invert. Catch Basins and tank shall be cleaned out as required. All sediments and hydrocarbons shall be properly handled in accordance with local, state, and federal guidelines (See Mass. DEP Stormwater Management Policy Volume Two 3.1-6). 57 4. Bloretention Areas : Maintenance of the Bioretention Areas shall be the responsibility of the Owner/Operator, Premature failure of bioretention areas is a significant issue caused by a lack of regular maintenance. Ensuring long-term maintenance involves sustained public education. Bioretention areas require careful attention while plants are being established and seasonal landscaping maintenance thereafter. Inspect pretreatment devices and bioretention cells regularly for sediment build-up, structural damage and standing water. Inspect soil and repair eroded areas monthly. Re-mulch void areas as needed. Remove litter and debris monthly. Treat diseased vegetation as needed. Remove and replace dead vegetation twice per year (spring and fall). Remove invasive species as needed to prevent these species from spreading into the bioretention areas. Replace mulch every two years, in the early spring. Upon failure, excavate bioretention area, scarify bottom and sides, replace soil, replant and mulch. Vegetation shall be inspected monthly for disease or pest problems. If treatment is warranted, a non- toxic approach is the only allowed method. Promptly replace any vegetation that is beyond treatment. During times of extended drought, inspect vegetation for signs of stress including wilting or spotted or brown leaves. Watering of bioretention planting is required until all plantings are established. Bloretention areas shall be weeded at least twice a year or as required. Inspect soil and repair eroded areas monthly. Re-plant void areas as needed. Remove litter and debris monthly. Remove and replace dead vegetation twice peryear in spring and fall. Replace soil media if ponding is witnessed more than 48 hours after rainfall event, and remove any accumulated sediments. The Engineered Soil Mix for Bioretention Systems Designed to Exfiltrate should consist of the following mixture: -40%sand -20-30%topsoil -3❑-40% compost 5. Permeable Pavers: Permeable pavers require inspection after a major storm event to ensure that infiltration is occurring. Vacuum sweeping of the paver surface shall be performed Z- 4 times per year and inspection of the paver blocks for deterioration shall be performed annually. Periodic replacement of the sand may be necessary, In the event that the infiltration spaces are filled with grass and/or weeds, the growth shall be removed to prevent clogging. There shall not be any winter time salting in the permeable paver area. 6. Snow Removal and Storage: During the winter months, snow shall be plowed from the roadway and not stored or piled in the biorentention areas. Special care shall be taken to ensure that the curb openings are kept clear of snow and that any rain and/or melt water can properly drain into the bioretention areas to prevent water ponding and freezing within the road. This should be accomplished using manual means, since plowing will not be adequate to keep these openings clear. Snow removal within the roadway and bioretention/stormwater areas shall be the responsibility of the Owner/Operator. 58 7, A summary of maintenance activities is included in this table. Bioretention Area Maintenance Schedule Activity Time of Year Frequency Inspect and remove trash Year round Monthly Mulch Spring Annually Remove dead vegetation Fall or Spring Annually Replace dead vegetation Spring Annually Prune Spring of Fall Annually Replace entire media & all Late Spring/early Summer As needed vegetation .19 Stormwater System Inspection Report General Information Location:West Mill, High Street, North Andover Date of Inspection Start/End Time Inspector's Name(s) Inspector's Title(s) Inspector's Contact Information Purpose of Inspection Weather Information Has it rained since the last inspection? ❑Yes ❑No Weather at time of this inspection? Site-Specific Stormwater Devices Installed and Date for Corrective Operating Aetion/Resppnsibie Description Properly;? Corrective Action Needed Person 1 ❑Yes ❑No 2 ❑Yes ❑No 3 ❑Yes ❑No 4 ❑Yes ❑No 5 ❑Yes ❑No 6 ❑Yes ❑No 7 ❑Yes ❑No 8 ❑Yes ❑No 9 ❑Yes ❑No 60 Installed and bate for Corrective Operating ResvonMble Description Properly? Corrective Action Needed Person 10 ❑Yes ❑No 11 ❑Yes ❑No 12 ❑Yes ❑No 13 ❑Yes ❑No 14 ❑Yes ❑No 15 ❑Yes ❑No 16 ❑Yes ❑No 17 ❑Yes ❑No 18 ❑Yes ❑No 19 ❑Yes ❑No 20 ❑Yes UNo 21 ❑Yes ❑No 22 ❑Yes ❑No 23 ❑Yes ❑No 24 ❑Yes ❑No 25 ❑Yes ❑No 26 ❑Yes ❑No 27 ❑Yes ❑No 28 ❑Yes ❑No 61 Overall Site Issues Date for Corrective ActionlResponsible Description Corrective Action Person I Are all slopes properly Dyes ❑No stabilized? 2 Are natural resource ❑Yes ❑No areas (e.g., streams, wetlands, etc.) being subjected to erosion? 3 Are discharge points free ❑Yes ❑No of sediment deposits? Certification Statement: "I certify under penalty of law that this document and all attachments were prepared under my direction} or supervision in accordance with a system designed to assure that qualified personnel properly gathered and evaluated the information submitted. Based on my inquiry of the person or persons who manage the system, or those persons directly responsible for gathering the information, the information submitted is, to the best of my knowledge and belief, true, accurate, and complete. I am aware that there are significant penalties for submitting false information, including the possibility of fine and imprisonment for knowing violations." Print name: Signature: Date: lb 62