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HomeMy WebLinkAboutStormwater Report - 284 SALEM STREET 9/22/2004 Drainage Calculations r Residential Landscaping Improvements at 284 Salem Street Andover., S Submitted W . Town of North Andover Prepared ford David W. Palmer 284 Salem Street North Andover, Massachusetts 0 Prepared w: McKenzie Engineening Group, Inc. Professional Chit Engineering ® Project Management ® Land Planning 196 Central,Street,,Saugus,Massachusetts 01906 T'eb: (781) 941-2211 Facsimile: (781) 941-2662 SN OF Mgssgcy�® BRADLEY' ZIe s�� May 21,2004 O CIVIL (n No. 36917 P GIST�� �4 �FFSSIONM,�aG®®i° Proposed Residential Landscape Improvements 284 Salem Street, North Andover, Massachusetts Project Summary The project site is located at 284 Salem Street and consists of approximately 27,094 square feet and contains a three bedroom residential dwelling with a 2 car drive under garage. The drive under garage is located at the bottom of the driveway slope at elevation 174+/- and is approximately six feet(6')lower than the entrance at Salem Street. The current site conditions promote high runoff velocities, erosion of grassed areas adjacent to the wetlands and dangerous freezing of ponded runoff areas during the winter months. The proponent proposes to install a small subsurface infiltration facility complete with trench drains equipped with pre-treatment sumps in an attempt to mitigate the stormwater volumes,velocities, and melt runoff at the garage entrance This report contains calculations for the post-development stormwater runoff and includes sizing of the proposed subsurface infiltration facility. Post Development Condition The majority of the runoff slopes from the highest point at the front yard and driveway entrance(elevation 181.5 ft.NGVD)in a northerly direction down to the garage turn- around area and eventually to the rear of the property at the wetland (elevation 171.0 ft. NGVD). Soils information was obtained from the USDA Soils Conservation Service (SCS) Soils Survey of Middlesex County. The soils on the site are classified as Sutton Fine Sandy Loam(StB&StC, SCS Hydrologic Soil Group B) Refer to Figure 1, SCS Soils Map, for a delineation of the boundaries of the soil with respect to the subject parcel and the attached SCS soil description information. Technical Release 20(TR 20)Program for Project Formulation Hydrology developed by the Soil Conservation Service (SCS)was employed to develop post- development flows. Drainage calculations were performed for the 2, and 10-year type III storm events. Refer to the attached TR-20 computer results for soil characteristics, cover descriptions and the time of concentration for the watershed subarea. The proposed subsurface infiltration facility was analyzed using the SCS TR 20 computer program. Refer to the attached TR-20 computer results and calculation sheet for the storage characteristics of the infiltration facility. Refer to the Construction Plans and Details for more information on the layout and design of the stormwater management system. a'=�•-�- _ _. � fry _� �' ,�x� �� r "�- p ��,..r ,�,.� s�� ���.�•'�- `��' �`.cw. x�'e��::� -cHy�,e� spa i N i•-� � � �"+r-v! •mss •. <. �, ��*•-fir,;€" �t�'S•a4� m t, `� � -s�? t>v'i��;���,_"'�-:, �w��`�•c. '7� - 1.,- ..,53 g.C�3 �,Sri. '?>'• •r3- `� ,Kty 'K y�F `-�a� -.� � ��.'� � ..;tczr ra�{y''#•��IG'�f. ��'� c�y� a3-� w.y�,.�-�T�3•Li"'La� 4} �i2r.•-� '�� +} � 9� �t. �;..Y '4•�,�.-ys•�'3-k �E.t�s1'�-•a!�'�'sTF,y�sr� t1 —'+.Y". -� s_. `far• F-�� h `�"• t •' � �► <`�'va .�-.. � -fie a- � �'i z' < .-�,�.. *�Y >�wT�-4V�.�?• �ia.-�.. NO SRI- igg;X1, bwr� SCS SOILS MAP n t r M � { Salem Massachusetts North Andover, h 2 k yTV Drainage Diagram for 24-140-POST S�lbcaf= feacl pn L[nk Prepared by Mckenzie Engineering Group, Inc. 5/21/2004 HydroGAD®6.00 s/n 000452 ®1986-2001 Applied Microcomputer Systems 24-140-POST Type Ill 24-hr Ralnfall=3.10"(2 year storm event) Prepared by Mckenzie Engineering Group, Inc. HydroCADO 6.00 s/n 000452 01986-2001 Applied Microcomputer Systems 5/21/2004 ubcatchrnent Al: SUBAREA Al Runoff - 0.21 cfs @ 12.09 hrs, Volume= 0.015 of Runoff by SCS TR-20 method, UH=SCS, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs Type III 24-hr Rainfall=3.10'1 Area (sf) CN Description 2,230 98 Paved parking & roofs 1,707 61 >75% Grass cover, Good, HSG B 11190 85 Pavers, HSG B 5,127 83 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6,0 _ Direct Entry, Subcatchrnent Al: SUBAREA Al Hydrograph Plot 0.23 -----------I--- ! . - � Runo 0.22:.' 1 I 1 1 ! ! -:D:2l�dr I 1 1 I t 1 I 0.21 ' _____I__-__y__�__.�__..__Y__r__I_ __y__ -_r_____r-_r.--i__---- I ! 1 I t--7 t t I 0.19' ---+--- +--s--+-- --�--+- - +-- --i-- -- -- --+-- -- +--�-- I I I ! ! 1 0.18 -- --r--t-- -- --r-----r-- --1- -�-- !--r--r--r--r--r--:--�-- --�-- 0.17 --'-- ---1-- ---i J---' --�--! -!- -- --I---'---'---!--'--'--J-- 1 1 I ! ! I I I 1 1 ! I t 1 1 ! 1 ! 1 0.16 -- --+-- +---+--+--�--� --� --!- - +-- -- -- --�--�-- --E-- +-- +-- +-- � 0.15 0.14- I. L_-L_ i -, -, I 7 ! 1 1 4 0.13. --,---i---:-- t-- !--t-- -- --r: --I--y--.- *--r--r-- r--E-- !-- -- 1-- v ! ! 1 '-- ! -- ! --! --i---1- -- '-----1 --I --' --!---I---1---i- - 0.12 � -- --,---,---,--� i i f i 0 0.11 ,..__a___I___I__- J__1__1-_L__L_-1_ J__ M 0.1 __,_-_,___,__.y__y__t__t__,___F__,_ :•. _ 1__y__�__,.__r__r__i_____�__j__1__ . 1 t I 1 1 ! ! I 1 t t t 1 I 1 ___ i- 0.09- /, _____'___t___'___ i3 � � I_ I_________________' I ___I__ 0.08- ', --t---!---1-- ----- --_--+ -- --1- - +-- ;-- -- -- --!---+---+-- ; --�- -`T-- --r-`I .: --1--�---f--r--f--;-----I---i--i--'!-- 0.07 -i---i--,-- --: : 0.06 . ! ---'---`--=-- F-----If -'--'--'--=--'---'---'---'--'---'--�-- -_i-_-1 1 ! 1 ( I 0.05 1 1 1 0.04 -_,___I___t__,_,�__s__F__r__r__I ^; __Z__F__r.__r__1___,__,__ -'--�--1--1--1-- --L--!---- - --1--''--i---L--'---I--'J--=--'J-- 0.03 0.02' 0.01= , 0' . . , , .. . . ,..., .., . 1 2 3 4 5 6""T' 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) 24-140-POST Type 111 24-hr Rainfall-3.10"(2 year storm event) Prepared by Mckenzie Engineering (croup, Inc. HydroCADO 6.00 s/n 000452 ©1986-2001 Applied Microcomputer Systems 5/21/2004 Pond 1 Po subsurface infiitration/detention Inflow - 0.21 cfs @ 12.09 hrs, Volume= 0.015 of Outflow = 0.06 cfs @ 11.90 hrs, Volume= 0.015 af, Atten=71°/a, Lag= 0.0 min Primary = 0.06 cfs @ 11.90 hrs, Volume= 0.015 of Routing by Stor-Ind method, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 171.47' Storage= 119 cf Plug-Flow detention time= (not calculated: outflow precedes inflow) Elevation Inc.Store Cum.Store (feet) (cubic-feet) (cubic-feet) 170.50 0 0 171.00 39 39 172.00 170 209 Primary OutFlow (Free Discharge) 1=Exfiltration w/Darcy's Law # Routing Invert Outlet Devices 1 Primary 0,00' Exfiltration w/Darcy's Law Elev. (feet) 0.00 0.50 1.50 Disch. (cfs) 0.00 0.03 0.06 Pond 1 P. subsurface infiltration/detention Hydrograph Plot ! I 1 ? I i ! 1 1 t ! ! ! ? ? 1 I 1 i 1 I FEi inflow i I ! ! ! 0.22 ----------- ------ --r--r- E r--� 7 - 7-----r--i-- --I---1-- --! ? I I , ! / s F 0.2.' --'---I--r--r--:-- r-- t--r--r- -----r- -- -- -!- r- --I-----r--r-- I 0.16` __y__y._---_,__y__y-_!-__r__i_ __.,.__ ----_y__r__,..__1__y__y__,.__,__ 3 ! 1 1 1 I 1 1 ! ! ! I 1 1 ! I 0.16' ----'=--}-- --1-- +-->--=--t --t __ / r 0.14- .per„ 0.12-' --F--�--=- --1--�-- -- --" -1 �-=-- --' --I--� --1-- / ! f I t I F ! 1 1 ! ! 1 1 I I I I ? i 0.08- -- -- -r-- z--�-- r--r -=--r--!-----_--r--�--t--�--r--,--- 0.0 T ----- T r -- --1- 0.04 --!--e--t--r-- y-- --r--! -=-- --*--r--t-- --^--1 --!-- I / 0.02, 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 18 20 21 22 23 24 Time (hours) 4-140-POT Type 111 24-hr Rainfall=4.50"(10 year storm event) Prepared by Mckenzie Engineering Group, Inc. HydroCADO 6.00 s/n 000452 © 1986-2001 Applied Microcomputer Systems 5121/2004 ucatchrment Al: SUBAREA Al Runoff = 0.37 cfs @ 12.09 hrs, Volume= 0.027 of Runoff by SCS TR-20 method, UH=SCS, Time Span= 1.00-24.00 hrs, dt=0.05 hrs Type III 24-hr Rainfall=4.50!' Area (sf) CN Description 2,230 98 Paved parking & roofs 1,707 61 >75%Grass cover, Good, HSG B 1,190 85 Pavers, HSG B 5,127 83 Weighted Average Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 - Direct Entry, Subcatchment Al: SUBAREA Al Hydrograph Plot F i 1 F i F I F 1 1 1 F 1 '.. 0.4-" --r--!---!-- I-- --r--r— r--;-- --:--�-- l-- r--r--r--r` r— ----- r-- ----l---t-- --�-- —1---� _- '0.37 cis --'--=--�— F , L I ! 0.38. -1- - --------- I I 1 f i I 0.341:: ---1-- a-- -- -- --�--� --I- -- '--=-- --=-- -- --!-- '- --�=- 1 1 1 1 I ! 1 ! I - I 0.32, --I---!--- 1-- --+--r--Y--r--I- ---+--*--*--� --Y--I --!-- �--y-- 1 - 0.28 __!__3 = _-_r__I___!__,__�__r__.!.__r__r__r � _,_-_ r__r__r 0.26 --,_ --,---1---,--,--T--r-- --r--,- - -- --;--r--r--r--!---,---,-- -- q 0.24-: .24 ---;--'---' _L__L__L__}_ _J__?__S__?__!__L_J___?__ __J__J__. 0.22_ J__1___1 __- 0.2. i 4,!__4__. { iL 0.18. y I 1 1 ! I 1 1 E 1 '°-. I 1 t E t 1 1 0.16 i ! i : 0.14- '_ �' --;--;---!---,--,--z--;--,---,---I - --F--E--s--�--: r--i---!---F--;-- 0.12' - F I ! I ! 1 ----�--I - , -j__ __i E i ! 0.08 --------4--------I---!---�---+---�-- ( F I f I 1 I i 1 i I i I i i 0.06 -,_--1---l---1--y_--------- I -_ _'. ___!-_K--*'--r---l---I---I-"_!__-i__-i_-. 1 I i 1 i f ! 0.04- _-..1__Y-__rt.__Y__r-_ -� __r__r__r__r 0.02 , 1 2 S 4 5 6 7 8 9 10 11l 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) 24-140-POST Type ill 24-hr Rainfa11=4.501 10 year storm event) Prepared by Mckenzie Engineering Group, Inc. HydroCAD®6.00 s/n 000452 01986-2001 Applied Microcomputer Systems 5/21/2004 Pond 1 P: subsurface infiltration/detention Inflow = 0.37 cfs-@ 12.09 hrs, Volume= 0.027 of Outflow - 0.06 cfs C 11.70 hrs, Volume= 0.427 af, Atten= 84%, Lag=0.0 min Primary = 0.06 cfs C 11.70 hrs, Volume= 0.027 of Routing by Stor-Ind method,Time Span= 1.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 172.75' Storage=336 cf Plug-Flow detention time=(not calculated: outflow precedes inflow) Elevation Inc.Store Cum.Store (feet) (cubic-feet) (cubic-feet) 170.50 0 0 171.00 39 39 172.00 170 209 Primary OutFlow (Free Discharge) 't-1=Exf iltration w/Darcy's Law # - Routing Invert Outlet Devices 1 Primary 0.00' Exfiltration w/Darcy's Law Elev. (feet) 0.00 0.50 1.50 Disch. (cfs) 0.00 0.03 0.06 Pond 1 P: subsurface infiltration/detention Hydrograph Plot 1 i , 1 ! 1 ! 1 ! , !__ 0 inflow -;---!--;--;- --,-- f--;--,--------- -,-- - ---,--;-- ---, Prima 1 0.38.. j--+--� -- - +--*--+ --r- - --+-- - -- t-- --!-- --=--�--�- ' 0.36- : --{-- t--r--r--r- 1-- t--r--r- --r-- - -----r--r--r- -----,---r- f- 1 __I I ! I 3 1 I ! I 1 F I 0.34," , i --,--T--r--C-,__�_____1 t __r__r__f ______� 0.32-: '--'--- '--=--'---'- -` 1 ---I---'-- --'--`---'-- E_ 0.28°_ ' = --�--t--r- -r -,---1--�--r--r--/- --t--r-----�- r--r- --t---r--r--r- ' r' I 1 v t I 0.26 -, 'l--T".-i'--�--1--?--1•--r , --1---I---1--T--r--r- 024• - i -------- � ----------- - 0.2 O 0.18 1 I ! i f---- --I I I f f 1 r--I--�--T--r--r- 0.16°"' ' ' f I__I i-- I I-_`---`--5 -=--'-'"----'--'-�--'--'--'--I--- ! 0.14- -1---4-- --1 -- 0.12` ! 1 ! { 1 I 1 1 0.1- -1- T r ,-- --r--r-- r--r--t-- r --r- -r-I-- -r--r- -- _ 0.08. :' - --' -=--'---'--`-----1- 06Ofr : ------------------ 1 1 1 0.06 _____�__{__�________�_ 0.04. . 0.02 01 2 3 4 5 6 7 8 10 1�1 12 13 14 15 16 17 18 1�9 20 21 22 23 24 Time (hours) && Jim WQ`OI�Rv a n jdgx w g� q� w g IPA � t `4 y , a R d U W Ltj AMEMOM VU LIN groom a It $r qq5 "' 5 � 3ga ��s .�7 � 6 �`' � •�•. ••iii:• `` � �_s—€ '. @ems � o� a •a J i' ` `2 i iLLU cq zit-� / .ems '\ b• Pi- \ n R Li gig 9 Ell! I 4 McKenzie /7 in rin f' u , Inc. 5/21/2004 Detention Facitiy m Rainstore-3 Infiltration Units REVISES: PROJECT: 234 Salen Street JOB No.: 23140 . LOCATION: North Andover, MA BY: W.S.N. CALCULATE SUBSURFACE DETENTION LEACHING FACILTY VOLUME: Void Ratio = 0.40 Enter subsurface Stone envelope length in feet: 14.00 Enter subsurface Stone envelope width in feet: 14.00 Enter storage per Ram5tore-3 unit in cubic feet: 3.53 Enter total number of Ram5tore-3 units: 45.00 Enter width of Ram5tore-3 units: 13.32 Enter length of Ram5tore-3 units: 13•32 Ram5tore-3-storage in (c.f.) 15: _ Stone storage in (c.f.) 15: 0 0.0 0 0.0 0.50 0.0 0.50 39.2 1 .50 1 G9.4 1 .50 0.8 Total storage in (c.f.) 15: Total leaching area m (5.f.) 15: 0 0 0 196.0 0.50 39.2 0.50 224.0 1 .50 170.3 1 .50 280.0 CALCULATE SUBSURFACE DKYWELL LEACHING CAPACITY: Enter Hydraulic Conductivity (K) from guideline table based on 5C5 Soil type m/hr.: 2.41 k= 0.000056 feet per. second Enter Separation from ba5m bottom to ground water in ft: ).50 Calculated IS the hydrualic gradient: I @ 0.0': 1 .0 I @ 0.5': 2.0 1 @ 1 .5': 4.0 Elev. (ft) k I Area (5f) Q (cf5) 0.00 0.000056 1 .0 19G 0.0109 0.50 0.000056 2.0 224 0.0250 1 .50 0.000056 4.0 280 O.OG25 Saturated hydraulic conductivity K depends on site-specific soil types. It c oe estimated from soil borings or in situ tests such as with double-barrel infil- trometers. Such tests involve expenses, and do not al ways give consitent results. An alternative method is to identify soil types from SCS soil surnreys or (prefera bly) on-site examination, and then to estimate I by association with soil texture: The table below lists average conductivities found in the laboratory by highway drainage engineers and USDA soil scientists. When on-site data are extremely lim- ited,only very conservative assumptions would be prudent: for a wet pond,assume soil texture with permeability as high as can be found in the region, for a dry basin, issume.texture with permeability as low as can be found. Mvdrraulic conductivity K in/hr tlda Crashed stone•AS r4 stone sire: No. 3 stone 50,000 100,000 No. 4 stone 40,000 80,000 No. 5 stone 25,000 50,000 No. 6 stone 15,000 30,000 Natural soil° SCS texture class: Sand 827 16.54 Loamy sand 141 4.82 Sandy loam 1.02 2.04 Loam 0.52 1.04 Silt loam 0.27 0.54 Sandy clay loam 0.17 0.34 Clay loam 0.09 0.18 Silty clay loam 0.06 0.12 Sandy clay 0.05 0.10 Silty clay 0.0 0.08 � Clay 0.02 0.04 i SIme eau Waal V=MR.Cedcwm ad dhom 1974Gradr4rnerlor LU addgn of Sab aafaee Drainage Syx&.ms forHighway S hffaSw inns. Repan No.FHWAAD30.WasFskMM:Federd High--'!A as Ofr=cf Research std a Ya hh:2.1ofH-R.Cedsagrat.l9'li.Seepage,D►a"ra and Flaw Nam.PISYalcW&I. Soil oon&.d j=fmm WJ.Rawls.D.L.Srskatsi&sad KR S=M.19n E4 1=110a S4 Wl=Lies. rrwwwcions�yrkeAwrieanSadaygf IEng v&25,mS.M"1316-13Wand1325. �°' 75 Waterl alance