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HomeMy WebLinkAbout1998-07-09 Drainage Calculations DEF SUB 1 4 � I Drainage calculations for Rose Meadow Subdivision Winter Street North Andover, Mass May 1998 l a JOSEP ! � SERWATKA C1.YK �n o,3k981® ?o� �lsg TibP�. ti4` Narrative The following drainage analysis is presented to quantify the amount of runoff associated with the proposed improvement of Winter Street associated with the construction of a single family dwelling, in North Andover, Ma. The existing and proposed roadway conditions are analyzed to determine peak rates and volumes of runoff associated with the 25 and 100 year, 24 hour storm. The analysis is performed using "Hydrocad", a computer program for generating peak rates of runoff and hydrographs, based on the TR-55 and TR-20 methods developed by the United States Soil Conservation Service. A system of leaching catchbasins, leaching drain pipe, and vegetated buffer strip is proposed and sized to capture the runoff associated with the proposed paving of Winter Street. The method of runoff mitigation treatment is based on the BMP's (i.e. Best Management Practices) developed and recommended by the Massachusetts Department of Environmental Protection. The existing Winter Street roadway consists of a portion of crushed gravel from South Bradford Street to the existing dwellings, with the remainder of the study area being wooded. Runoff from the site is calculated as 1 .1 cfs and 2.1 cfs for the 25 and 100 year, 24 hour storms. The volumes associated with these events are 0.07 and 0.14 acre-feet, respectively. It is proposed to improve the existing roadway with 22 feet of bituminous pavement and a leaching drainage system. The increase in runoff and volume is proposed to be collected, infiltrated and treated by the installation of leaching catchbasins connected by a perforated drainage pipe which will capture runoff from impervious surfaces and allow it to infiltrate into the ground. This method will provide both mitigation and treatment of runoff. Runoff associated with the improvements is calculated as 1 .8 cfs and 2.8 for the 25 and 100 year, 24 hour storms. The volumes associated with these events are 0.11 and 0.18 acre-feet, respectively. In conclusion, the proposed improvements will not produce a substantial increase in the rate or volume of runoff from the site, The proposed leaching basins and perforated drainage pipe will serve to mitigate the runoff generated from the improvements as well as provide treatment. 1 I II Calculate infiltration rate from the proposed leaching catchbasins and perforated drainage pipe: Use percolation rate of 15 minutes per inch (conservative) Area available for infiltration is approximately 3000 s.f. Perc rate: 15 min/in = 180 min/c.f. = 10,800 sec/ft. 3000 s.f. area/(10800 sec/ft) = 0.3cfs out of structures and pipe it Data' f'or -SAN LAU - WINTER STREET (EXISTING) i TYPE III 24-HOUR RAINFALL= 7 .0 IN Prepared by Applied Microcomputer Systems 16 Aug 96 K droCAD 4 00 000821 c 1986--1995 Applied. MicrocoLnputer Systems WATERSHED ROUTING i I 'I I I 0 SUBCATCHHENT REACH Q POND LINK SUSCATCHMENT 1 = WINTER STREET - EXISTING -� )ata ,fdr SAN LAU - WINTER STREET {EXISTING} TYPE III 24-HOUR RAINFALL= 7 .0 IN ?repared by Applied Microcomputer Systems 16 Aug 96 droCAD 4 . 00 000821 c 198 -1995 Applied Microcomputer Systems RUNOFF BY SCS TR--20 METHOD: TYPE III 24-HOUR RAINFALL 7 .0 IN, SCS U.H. I RUNOFF SPAN = 10-20 HRS, dt= . 10 HRS, 101 POINTS I 3-UBCAT AREA Tc WGT'D PEAK Tpeak VOL 1UMBER ACRE MIN --GROUND COVERS .CN --- CN C CFS HRS AF 1 .40 3 . 5 50081 50a74 - - 78 2 . 1 12 . 01 . 14 )ata• for SAN LAU - WINTER STREET (EXISTING) TYPE III 24-HOUR RAINFALL= 7 .0 IN 16 Aug 96 ?repared by Applied Microcomputer Systems 4 . 00 000821 c 198 -1995 A 1.i d Microcam uter Systems i droCAD ;USCATCHMENT 1 WINTER STREET - EXISTING PEAK= 2 .1 CFS @ 12 . 01 HRS, VOLUME= .14 AV 1, CN SCS TR-20 METHOD ACRES . 20 81 GRAVEL ROAD TYPE III 24-HOUR . 20 74 WOODS, DIRT PATH RAINFALL= 7 . 0 IN .40 78 SPAN= 10-20 HRS, dt= . 1 HRS lethod Comment Tc min rR-55 SHEET FLOW Segment ID: . 8 Smooth surfaces n= . 011 L=100 ' P2=3 . 2 in s= . 056 ' / ' 2 . 7 ;HALLOW CONCENTRATED/UPLAND FLOW Segment ID: inpaved Kv=16 . 1345 L=700 ' s= .07 1 / 1 V=4 .27 fps ---------- Total. Length= 800 ft Total Tc= 3 . 5 SUBCATCHMENT 1 RUNOFF MINTER STREET - EXISTING 2 .0 AREA= . 4 AC 1 . 8 Tc= 3. 5 MIN 1 .6 CN= 78 1 .4 SCS Tft-20 METHOD u f 2 TYPE III 24-HOUR i .0 RAINFALL? 7 .0 IN 3 .8 S PEAK= 2 . 1 CFS e 12 .01 HRS . 4 VOLUME= 14 AF . 2 0 .0 cv M I- to �0 r oa rn m TIME (hours) SUBCATCHMENT 1 RUNOFF PEAK= 2 .1 CFS @ 12 . 01 HOURS HOUR 0 . 00 . 10 . 20 . 30 .41 .50 . 60 . 70 . 80 90 10 . 00 . 1 . l . 1 . 1 11 . 00 . l . 1 . 1 . 2 . 2 . 2 . 3 3 . 3 . 2 . 2 . 2 12 . 00 2 . 1 1 . 3 . 9 • 7 • 5 . .1 . 1 .2 . 1 13 . 00 .2 . 2 .2 . 2 . 2 . 1 1 . 1 . 1 . 1 . 1 . 1 14 . 00 • 1 . 1 15 . 00 .1 . 1 . 1 .1 . 1 . 1 .1 16 . 00 . 1 1 . 1. . 1 . 1 . 1 17 . 00 . 1 . 1 . 1 0 .0 0 .0 0 .0 0 . 0 0 .0 0 .0 0 .0 18 . 00 0 . 0 D . 0 0 . 0 0 . 0 0 . 0 0 . 0 0 . 0 0 . 0 0 . 0 0 . 0 19 . 00 0 . 0 0 . 0 0 . 0 0 . 0 0 . 0 0 .0 0 . 0 0 . 0 0 .0 0 . 0 20 .00 0 . 0 1 )ata- for SAN LAU - WINTER STREET (EXISTING) { TYPE III 24-HOUR RAINFALL= 4 .5 IN -)repared by Applied Microcomputer Systems 16 Aug 96 l droCAD 4 . 00 000821 c 19$6-1995 A om lied Microc cater stems ;UBCATCHMSNT 1 WINTER STREET - EXISTING PEAK= 1 . 1 CFS @ 12 . 01 HRS, VOLUME= . 07 AF ACRES CN SCS TR-20 METHOD . 20 81 GRAVEL ROAD TYPE III 24-HOUR .20 74 WOODS, DIRT PATH RAINFALL= 4 . 5 IN . 40 78 SPAN= 10-20 HRS, dt= .1 HRS Method Comment Tc Cmin) CR-55 SHEET FLOW Segment ID: . 8 Smooth surfaces n= .011 L=100 ' P2=3 . 2 in s= . 056 ' / ' 2 .7 3HALLOW CONCENTRATED/UPLAND FLOW Segment ID: 7npaved Kv=16 . 1345 L=700 ' s= .07 ' / ' V=4 . 27 fps ---------- Total. Length 800 ft Total Tc= 3 .5 SUBCATCHMENT I RUNOFF WINTER STREET - EXISTING 1 .0 AREA= . 4 AC .9 Tc= 3 . 5 MIN .g CN= 78 .7 SCS TR-2O METHOD . 6 TYPE III 24-HOUR .5 RAINFALL= 4 .5 IN 0 4 - . 3 PEAK= 1 . 1 CFS @ 12 .01 HRS UOLUME= . 07 AF . 1 U Om cv m rn Uj r- ca m TIME (hours) SUBCATCHMENT 1 RUNOFF PEAK= 1 . 1 CFS @ 12 . 01 HOURS HOUR 0 . 00 . 10 . 20 .30 .40 . 50 . 60 . 70 . 80 . 90 10 . 00 0 . 0 0 .0 0 . 0 0 . 0 0 . 0 0 . 0 0 .0 0 .0 0 .3 0 .0 11 .00 0 . 0 0 . 0 . 1 . 1 . 1 . 1 . 2 . 1 12 . 00 1 . 1 . 7 .5 .4 .3 . 2 . 1 . 1 13 .00 . 1 . 1 .1 . 1 . 1 . 1 . 1 . 1 14 . 00 . 1 . 1 . 1 . 1 . 1 . 1 . 1 . 1 15 . 00 . 1 . 1 . 1 0 . 0 0 . 0 0 .0 0 . 0 0 .0 0 .0 0 .0 16 . 00 0 . 0 0 . 0 0 . 0 0 .0 0 . 0 0 . 0 0 . 0 0 . 0 0 . 0 0 . 0 17 . 00 0 . 0 0 . 0 0 . 0 0 .0 0 . 0 0 . 0 0 . 0 0 . 0 0 . 0 0 .0 18 . 00 0 . 0 0 . 0 0 . 0 0 . 0 0 . 0 0 . 0 0 . 0 0 . 0 0 . 0 0 . 0 19 . 00 0 . 0 0 . 0 0 . 0 0 . 0 0 . 0 0 . 0 0 . 0 0 . 0 0 .0 0 . 0 20 . 00 0 . 0 )ata' fbr 'SAN LAU REALTY - WINTER STREET TYPE III 24-HOUR RAINFALL= 7 .0 IN ?repared by Applied Microcomputer Systems 16 Aug 96 droCAD 4 . 00 000821 c 1986-1995 A m lied Microco uter Systems I 4ATERSHED ROUTING 4 5UBCATCHM£Nr REACH Z�,POND LINK SUBCATCHMENT 1. = WINTER STREET (WITH IMPROVEMENTS) -> 3ata- for -SAN LAU REALTY -- WINTER STREET TYPE III 24-HOUR RAINFALL= 7 .0 IN ?repared by Applied Microcomputer Systems 16 Aug 95 i droCAD 4 . 00 000821 c 1986-1995 Applied Microcom uter S stems RUNOFF BY SCS TR--20 METHOD: TYPE III 24-HOUR RAINFALL= 7 .0 IN, SCS U.H. RUNOFF SPAN = 10-20 HRS, dt= .10 HRS, 101 POINTS i 3UBCAT AREA Tc WGT'D PEAK Tpeak VOL NUMBER ACRE MIN --GROUND COVERS aCN --- CN C CFS HRS AF i .40 2 . 2 100%98 - - 98 - 2 . $ 11 .99 . 1$ i )ata• f'or ,SAN LAU REALTY - WINTER STREET TYPE III 24--HOUR RAINFALL= 7 .0 IN ?repared by Applied Microcomputer Systems 16 Aug 96 droCAD 4 . 00 000821 c 1986-1995 A lied Microcom cater Systems i a 3UBCATCHMENT 1 WINTER STREET (WITH IMPROVEMENTS) i PEAK= 2 . 8 CFS @ 11 .99 HRS, VOLUME= . 18 AF ACRES CN SCS TR-20 METHOD .40 98 22 ' ROADWAY TYPE III 24-HOUR RAINFALL= 7 . 0 IN SPAN= 10-20 HRS, dt= . l HRS jethod _ Comment _ Tc (min) IR-55 SHEET FLOW Segment ID: . 8 Smooth surfaces n= . 011 L=100 ' P2=3 .2 in s= .056 SHALLOW CONCENTRATED/UPLAND FLOW Segment ID: 1 . 0 ?aved Kv=20 . 3282 L=300 ' s= .056 ' / ' V=4 . 81 fps �-IRCULAR CHANNEL Segment ID: .4 t2" Diameter a= .79 sq-ft Pw=3 . 1 ' r= .25 ' 3= . 076 ' / ' n= .01 V=16 . 26 fps L=400 ' Capacity=12 . 8 cfs Total Length= 800 ft Total Tc= 2 . 2 SUBCATCHMENT 1 RUNOFF WINTER STREET (WITH IMPROVEMENTS) 2 . 0 2 .6 AREA= . 4 AC 2 .4 Tc-- 2 . 2 MIN 2 . 2 CN= 98 2 .0 4- 1 .6 SCS TR--20 METHOD 1 4 TYPE III 24-HOUR 1 .2 RAINFALL-- 7 .0 IN .g PEAK-- 2 . 8 CPS .6 e 11 .99 HRS . 4 QGLUME= . 18 AF 2 U Om It Ln 0 r- ao M CD TIME (hours) i )ata • for SAN LAU REALTY - WINTER STREET � TYPE III 24-HOUR RAINFALL= 7 .0 IN Irepared by Applied Microcomputer Systems 16 Aug 96 j I droCAD 4 .00 000821 (c)... 1986-1995. Applied Microcomputer Systems i SUBCATCHMENT 1 RUNOFF PEAK= 2 . 8 CFS @ 11 . 99 HOURS HOUR 0 . 00 1 . 20 30 40 . 50 . 60 . 70 180 . 9 10 . 00 . 1 . 1 .2 . 2 .2 . 2 . 2 . 2 .2 . 2 11 . 00 .2 . 2 . 3 . 3 . 3 .4 . 6 . 9 1.1 1 . 8 12 .00 2 . 8 1 .4 1 .0 .8 . 5 . 3 . 3 . 3 .3 . 2 13 . 00 . 2 . 2 .2 .2 .2 . 2 . 2 . 2 .2 . 1 14 .00 . 1 . 1 .1 . 1 . 1 . 1 . 1 . 1 .1 .1 15 . 00 . 1 . 1 . 1 . 1 . 1 . 1 . 1 . 1 . 1 . 1 16 . 00 .1 . 1 .1 . 1 . 1 . 1 . 1 . 1 . 1 .1 17 . 00 . 1 . 1 . 1 . 1 . 1 . 1 . 1 0 . 0 0 . 0 0 . 0 18 . 00 0 . 0 0 . 0 0 . 0 0 .0 0 .0 0 . 0 0 . 0 0 . 0 0 . 0 0 .0 19 . 00 0 . 0 0 .0 0 . 0 0 .0 0 . 0 0 . 0 0 . 0 0 . 0 0 . 0 0 . 0 20 . 00 0 . 0 )ataefer GAN LAU REALTY - WINTER STREET TYPE III 24--HOUR RAINFALL= 4 .5 IN )repared by Applied Microcomputer Systems 16 Aug 96 i droCAD 4 00 000821 c 1986-1995 Applied Microcomputer Systems �UBCATCHMENT 1 WINTER STREET (WITH IMPROVEMENTS) PEAK= 1 . 8 CFS @ 11 . 99 HRS, VOLUME= . 11 AF ACRES CN SCS TR-20 METHOD .40 98 22 ' ROADWAY TYPE III 24-HOUR RAINFALL= 4 . 5 IN SPAN= 10--20 HRS, dt 1 HRS lethod Comment Tc min UR-55 SHEET FLOW Segment ID: . 8 ;month surfaces n= . 011 L=100 ' P2=3 .2 in s= . 056 >HALLOW CONCENTRATED/UPLAND FLOW Segment ID: 1 . 0 ?aved KV=20 . 3282 L=300 ' s= . 056 1 / ' V=4 . 81 fps =CULAR CHANNEL Segment ID: .4 _2" Diameter a= .79 sq-ft Pw=3 . 1 ' r= . 25 ' = .076 ' / ' n= . 01 V=16 . 26 fps L=400 ' Capacity=12 . 8 cfs Total Length= 800 £t Total Tc= 2 . 2 SUBCATCHMENT 1 RUNOFF WINTER STREET (WITH IMPROVEMENTS) 1 . 7 1 . 6 AREA= . 4 AC 1 . 5 Tom= 2 . 2 MIN 1 4 CN= 98 f . 3 i . 2 u 1 .0 SCS TR--20 METHOD g TYPE III 24-HOUR .8 RAINFALL-- 4 . 5 IN 3 LL 5 PEAK= 1 . 8 CFS @ 11 .99 HRS . 2 UOLUME= . 11 AF . 1 Mm �t- u) 0 co M @ TIME (hour's) )ata° fbrcSAN LAU REALTY - WINTER STREET TYPE III 24--HOUR RAINFALL= 4 .5 IN Irepared by Applied Microcomputer Systems 16 Aug 96 { droCAD 4 00 000821 c 1986-1995 Ap plied Microcomputer Systems S AT HMENT 1 R FF PEAK= 1 . 8 CF 11 HOURS HOUR 0 .00 . 10 20 30 40 . 50 . 60 . 70 8 g 10 . 00 . 1 . 1 . 1 . 1 . 1 . l .1 . 1 . 1 . 1 11 . 00 . 1 . 1 . 2 .2 . 2 . 2 .4 . 6 . 7 1 . 1 12 .00 1 . 8 . 9 .7 .5 . 3 .2 .2 .2 .2 . 1 13 . 00 . 1 . 1 . 1 . 1 . 1 . 1 .1 . 1 . 1 . 1 14 .00 . 1 . 1 .1 . 1 . 1 . 1 .1 . 1 .1 . 1 15 . 00 . 1 . 1 . 1 . 1 . 1 . 1 . 1 .1 . 1 0 . 0 16 .00 0 . 0 0 . 0 0 .0 0 . 0 0 . 0 0 .0 0 .0 0 . 0 0 .0 0 .0 17 . 00 0 . 0 0 .0 0 . 0 0 . 0 0 . 0 0 . 0 0 .0 0 . 0 0 .0 0 . 0 18 .00 0 . 0 0 . 0 0 .0 0 . 0 0 . 0 0 . 0 0 .0 0 . 0 0 .0 0 . 0 19 . 00 0 . 0 0 . 0 0 . 0 0. 0 0 . 0 0 . 0 0 .0 0 . 0 0 .0' 0 . 0 20 . 00 0 . 0