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HomeMy WebLinkAboutMiscellaneous - 49 ORCHARD HILL ROAD 2/13/1998 CHRISTIANSEN & SERGI, INC. PROFESSIONAL ENGINEERS AND LAND SURVEYORS 160 SUMMER STREET HAVER14ILL.,MASSACHLJSETTS01830-6318 (978)373-0310 FAX: (978)372-3960 HYDROLOGIC ANALYSIS FOR LOT 1-2B-1 ORCHARD HILL ROAD IN NORTH ANDOVER, MASS. PREPARED FOR BAY HILL L.L.C. DATE: FEBRUARY 13,, 1998 LOT 1-2B-1 ORCHARD HILL ROAD HYDROLOGIC ANALYSIS A hydrologic analysis has been performed to determine the impact that the development on the lot has on off-site peak runoff rates. The "HydroCAD" Stormwater Modeling System has been used to compare the pre- and post-development runoff rates and to design the infiltration and detention facilities. The stormwater management system as designed will keep post-development peak rates equal to or less than the pre- development peak rates for the 2, 10, and 100 year storm events. Under existing(pre-development) conditions, the 3.7 acre project site lies at the bottom of an 8.9 acre contributing watershed. This watershed is shown as Drainage Area 1 on the enclosed "EXISTING DRAINAGE AREA MAP". The U.S.G.S. topographic Contours and the Soil Conservation Service Soil types around the project area are also shown on this plan. Under the proposed post-development conditions, the contributing watershed has been divided into 6 drainage areas for the purpose of the analysis. These drainage areas are shown on the enclosed "POST-DEVELOPMENT DRAINAGE AREA MAP", and may be summarized as follows: Drainage Area 2 consists of 5.2 acres of woodlands that lies upgradient of the project site. Any runoff from this area will flow onto Drainage Area 3 on the project site. Drainage Area 3 consists of 2.4 acres of the project site that will drain into the proposed drainage system that contributes the flow to Detention/Infiltration Area 1. This area includes most of the proposed pavement areas on the site. Drainage Area 4 is the 0.5 acre portion of the site that lies along the unimproved section of Orchard Hill Road. Runoff from this area, which will consist of lawn, planting areas, and undisturbed woodlands,will drain off of the project site uncontrolled. Drainage Area 5 lies in the northwest corner of the site between the paved cul-de- sac and the abutting lot to the west. Runoff from this 0.1 acre area will drain off of the project site uncontrolled. Drainage Area 6 consists of the roof area of the 21,600 square foot building. Runoff from the roof will be directed to Infiltration Area 2, which is a proposed 2400 square foot leaching facility to be located under the parking area to the west of the building. Drainage Area 7 is a 0.2 acre portion of the site that includes the portions of the proposed driveway and parking area that could not drain into Detention/infiltration Area 1 due to the topographical constraints. Runoff from this area will be collected by two catch basins located at the beginning of the driveway and directed into Infiltration Area 3, which is a proposed 1000 square foot leaching facility to be located under a lawn area to the west of the proposed driveway. It should be noted that the existing conditions in the watershed (well drained soils within a wooded area) result in very low runoff rates from the less intense storm events. For this reason, little or no surface runoff could be allowed to flow off the site during the 2 year and 10 year storm events. Infiltration Areas 2 and 3 were designed to recharge 100% of the runoff from Drainage Areas 6 and 7 in the all of the design storms. Detention/Infiltration Area 1 was designed to recharge 100% of the runoff from the two year design storm,but will allow some of the higher flows generated by the 10 and 100 year design storms to flow through the proposed outlet structure and be directed off site. The results of the hydrologic analysis are summarized as follows: TABLE t• PEAK OFFSITE FLOW RATES DESIGN STORM EXISTING POST-DEVELOPMENT CONDITIONS CONDITIONS _2 YEAR 0.0 C.F.S. 0.1 C.F.S. 10 YEAR 0.6 C.F.S. 0.6 C.F.S. 100 YEAR 5.7 C.F.S. 3.8 C.F.S. I Data for LOT 1-2B ORCHARD HILL ROAD, NORTH ANDOVER Page 1 TYPE II 24-HOUR RAINFALL= 6.4 IN 13 Feb 98 Prepared by CHRISTIANSEN & SERGI, INC. H droCAD 4.52 001057 c 1986-1996 A lied Microcomputer S stems WATERSHED ROUTING fXLS IIVG- C0M01T1(-) V S (D p pC3po,5F � C-u,,�J 0 ► / I D2 (D 50 (D 70 t01 102 tea Std MM tq i IG Ilb o tit IJ ( )SUBCATCHNENT F] REACH Q POND LINK Data for LOT 1-2B ORCHARD HILL ROAD, NORTH ANDOVER Page 3 TYPE II 24-HOUR RAINFALL= 3.1 IN 9 Jan 98 Prepared by CHRISTIANSEN & SERGI, INC. H droCAD 4.52 001057 c 1986-1996 Applied Microcom uter S stems SUBCATCHMENT 1 DRAINAGE AREA 1: EXISTING CONDITIONS PEAK= .02 CFS @ 18.75 HRS, VOLUME= .01 AF ACRES CN SCS TR-20 METHOD 4.25 30 H.S. GROUP A: WOODS, GOOD COND. TYPE II 24-HOUR 4 .34 55 H.S. GROUP B: WOODS, GOOD COND. RAINFALL= 3.1 IN .34 70 H.S. GROUP C: WOODS, GOOD COND. SPAN= 10-20 HRS, dt=.1 HRS 8 .93 44 Comment Tr lminl Method 6.1 TR-55 SHEET FLOW Woods: Light underbrush n=.4 L=50' P2=3.1 in s=.12 14.6 SHALLOW CONCENTRATED/UPLAND FLOW Woodland KV=5 L=980' s=.05 '/' V=1.12 fps Total Length= 1030 ft Total Tc= 20.7 SUBCATCHMENT 1 RUNOFF DRAINAGE AREA 1 : EXISTING CONDITIONS .022 A= 8.93 AC Tc= 20.7 MIN ,020 CN= 44 .018 r. .016 SCS TR-20 METHOD LO TYPE II 24-HOUR 4- .014 RAINFALL= 3. 1 IN .012 PEAK= .02 CFS 3 ,010 e 16,75 HRS 0 008 UOLUME= .01 AF .006 .004 .002 0.000m N M v in r oo m m TIME (hours) Data for LOT 1-2B ORCHARD HILL ROAD, NORTH ANDOVER Page 4 TYPE II 24-HOUR RAINFALL= 3 .1 IN 9 Jan 98 Prepared by CHRISTIANSEN & SERGI, INC. H droCAD 4.52 001057 c ..1986-1996 A lied Microcom uter S stems SUBCATCHMENT 2 DRAINAGE AREA 2: PROPOSED CONDITIONS PEAK= .01 CFS @ 18 .67 HRS, VOLUME= .01 AF ACRES CN SCS TR-20 METHOD 2.56 30 H.S. GROUP A: WOODS, GOOD COND. TYPE II 24-HOUR 2.34 55 H.S. GROUP B: WOODS, GOOD COND. RAINFALL= 3.1 IN .32 70 H.S. GROUP C: WOODS, GOOD COND. SPAN= 10-20 HRS, dt=.1 HRS 5.22 44 Method Comment Tc (min) 6.1 TR-55 SHEET FLOW Woods: Light underbrush n=.4 L=50' P2=3.1 in s=.12 '/' 8.6 SHALLOW CONCENTRATED/UPLAND FLOW Woodland KV=5 L=580' s=.05 '/' V=1.12 fps Total Length= 630 ft Total Tc= 14.7 SUBCATCHMENT 2 RUNOFF DRAINAGE AREA 2 : PROPOSED CONDITIONS .013 A= 5.22 AC .012 Tc= 14.7 MIN .011 CN= 44 .010 SCS TR-20 METHOD j ,009 TYPE II 24-HOUR 4- .008 RAINFALL= 3. 1 IN L) 007 PEAK= .01 CFS 3 .006 e 16.67 HRS O .005 UOLUME= .01 AF 004 003 .002 .001 0.000 m � N f*7 �t t!) i0 I� 01) Ol m TIME (hours) Data for LOT 1-2B ORCHARD HILL ROAD, NORTH ANDOVER Page 5 TYPE II 24-HOUR RAINFALL= 3 .1 IN 9 Jan 98 Prepared by CHRISTIANSEN & SERGI, INC. H droCAD 4.52 001057 c 1986,-1996 A lied Microcom uter Systems SUBCATCHMENT 3 DRAINAGE AREA 3: PROPOSED CONDITIONS PEAK= 2.39 CFS @ 11.94 HRS, VOLUME= .13 AF ACRES CN SCS TR-20 METHOD .42 98 H.S. GROUP A: IMPERVIOUS TYPE II 24-HOUR .55 98 H.S. GROUP B: IMPERVIOUS RAINFALL= 3 .1 IN .48 39 H.S. GROUP A: LAWN SPAN= 10-20 HRS, dt=.1 HRS .45 61 H.S. GROUP B: LAWN .16 30 H.S. GROUP A: WOODS, GOOD COND. .36 55 H.S. GROUP B: WOODS, GOOD COND. 2.42 69 Comment Tc (min) Method 5.6 TR-55 SHEET FLOW Woods: Light underbrush n=.4 L=50' P2=3 .1 in s=.15 1 SHALLOW CONCENTRATED/UPLAND FLOW Unpaved Kv=16.1345 L=30' s=.3 ' /' V=8 .84 fps 1.4 SHALLOW CONCENTRATED/UPLAND FLOW Paved Kv=20.3282 L=240' s=.02 '/' V=2 .87 fps Total Length= 320 ft Total Tc= 7.1 SUBCATCHMENT 3 RUNOFF DRAINAGE AREA 3 . PROPOSED CONDITIONS 2.4 2.2 AREA= 2.42 AC Tc= 7. 1 MIN 2.0 CN= 69 1 .8 SCS TR-20 METHOD 1 .6 TYPE II 24-HOUR to (+ 1 .4 RAINFALL= 3. 1 IN L) " 1 .2 PEAK= 2.39 CFS 3 1 .0 e 11 .94 HRS 0 8 UOLUME= . 13 AF J 6 .4 .2 N TIME (hours) Data for LOT 1-2B ORCHARD HILL ROAD, NORTH ANDOVER Page 6 TYPE II 24-HOUR RAINFALL= 3 .1 IN 9 Jan 98 Prepared by CHRISTIANSEN & SERGI, INC. H droCAD 4.52 001057 c 1986-1 96 A li d Microcom1puter Systems SUBCATCHmENT 4 DRAINAGE AREA 4: PROPOSED CONDITIONS PEAK= .10 CFS @ 11.92 HRS, VOLUME= .01 AF ACRES CN SCS TR-20 METHOD .08 39 H.S. GROUP A: LAWN TYPE II 24-HOUR .22 61 H.S. GROUP B: LAWN RAINFALL= 3.1 IN .17 55 H.S. GROUP B: WOODS, GOOD COND. SPAN= 10-20 HRS, dt=.l HRS .02 74 H.S. GROUP C: LAWN .49 56 Method Comment Tc (min) 2.1 TR-55 SHEET FLOW Grass: Short n=.15 L=40' P2=3.1 in s=.15 '/' 9 SHALLOW CONCENTRATED/UPLAND FLOW Woodland KV=5 L=67' s=.06 '/' V=1.22 .fps Total Length= 107 ft Total Tc= 3.0 SUBCATCHMENT 4 RUNOFF DRAINAGE AREA 41 PROPOSED CONDITIONS .095 AREA= .49 AC .090 Tc= 3 MIN 080 CN= 56 .075 .070 SCS TR-20 METHOD .065 TYPE II 24-HOUR to .055 RAINFALL= 3. 1 IN .050 PEAK= . 10 CFS 3 ,040 e 11 .92 HRS 0 .035 VOLUME= .01 AF —J .030 LL .025 .020 .015 ,010 .005 O.OeO m N m OD N TIME (hours) _ Data for LOT 1-2B ORCHARD HILL ROAD, NORTH ANDOVER Page 7 TYPE II 24-HOUR RAINFALL= 3.1 IN 9 Jan 98 Prepared by CHRISTIANSEN & SERGI, INC. H droCAD 4.52 001057 c 1986-1 96 A li d Mi rocom uter Systems SUBCATCHMENT 5 DRAINAGE AREA 5: PROPOSED CONDITIONS PEAK= 0.00 CFS @ 0.00 HRS, VOLUME= 0.00 AF ACRES CN SCS TR-20 METHOD .09 39 H.S. GROUP A: LAWN TYPE II 24-HOUR RAINFALL= 3.1 IN SPAN= 10-20 HRS, dt=.1 HRS Method Comment Tr (min) 1.9 TR-55 SHEET FLOW Grass: Short n=.15 L=20' P2=3.1 in s=.05 ' /' 5 SHALLOW CONCENTRATED/UPLAND FLOW Unpaved Kv=16.1345 L=100' s=.05 '/' V=3.61 fps Total Length= 120 ft Total Tc= 2.4 SUBCATCHMENT 5 RUNOFF DRAINAGE AREA 5 ; PROPOSED CONDITIONS t0 AREA= .09 AC 9 Tc= 2.4 MIN 8 CN= 39 7 SCS TR-20 METHOD TYPE II 24-HOUR 4- 6 RAINFALL= 3. 1 IN U 5 PEAK= 0.00 CF5 4 E 0 HRS CD 1 UOLUME= 0.00 AF 3 2 1 Om N m v in r m T m TIME (hours) Data for LOT 1-2B ORCHARD HILL ROAD, NORTH ANDOVER Page 8 TYPE II 24-HOUR RAINFALL= 3.1 IN Prepared by CHRISTIANSEN & SERGI, INC. 9 Jan 98 HVdroCAD 4.52 001057 (c) 1986-1996 Applied Microcomputer Systems SUBCATCHMENT 6 DRAINAGE AREA 6: PROPOSED CONDITIONS PEAK= 2.00 CFS @ 11.84 HRS, VOLUME= .10 AF ACRES CN SCS TR-20 METHOD .22 98 H.S. GROUP A: IMPERVIOUS TYPE II 24-HOUR .28 98 H.S. GROUP B: IMPERVIOUS RAINFALL= 3.1 IN .50 98 SPAN= 10-20 HRS, dt=.1 HRS Method Comment T min .4 TR-55 SHEET FLOW Smooth surfaces n=.011 L=60' P2=3.1 in s=.15 ' /' .8 CIRCULAR CHANNEL 12" Diameter a=.79 sq-ft Pw=3.1' r=.25' s=.005 '/' n=.009 V=4.63 fps L=220' Capacity=3 .6 cfs Total Length= 280 ft Total Tc= 1.2 SUBCATCHMENT 6 RUNOFF DRAINAGE AREA 6 , PROPOSED CONDITIONS 2.0 1 .9 AREA- .5 AC 1 .8 Tc= 1 .2 MIN 1 .7 1 .6 CN= 96 1 .5 1 .4 SCS TR-20 METHOD j 1 .3 TYPE II 24-HOUR `+ 1 .2 RAINFALL= 3. 1 IN L) 1 . 1 1 .0 PEAK= 2.00 CFS 3 .8 L 11 .84 HRS 0 .7 UDLUME= . 10 AF J 6 LL 5 .4 .3 .2 . 1 in r m rn m TIME (hours) Data for LOT 1-2B ORCHARD HILL ROAD, NORTH ANDOVER Page 9 TYPE II 24-HOUR RAINFALL= 3.1 IN Prepared by CHRISTIANSEN & SERGI, INC. 9 Jan 98 HydroCAD 4 52 001057 (c) 1986-1996 Applied Microcomputer Svs ems SUBCATCHMENT 7 DRAINAGE AREA 7: PROPOSED CONDITIONS PEAK= .38 CFS @ 11.87 HRS, VOLUME= .02 AF ACRES CN SCS TR-20 METHOD .14 98 H.S. GROUP A: IMPERVIOUS TYPE II 24-HOUR .10 39 H.S. GROUP A: LAWN RAINFALL= 3 .1 IN .24 73 SPAN= 10-20 HRS, dt=.1 HRS Method Comment Tr (min) .8 TR-55 SHEET FLOW Grass: Short n=.15 L=15' P2=3.1 in s=.25 '/' SHALLOW CONCENTRATED/UPLAND FLOW 5 Paved Kv=20.3282 L=150' s=.06 '/' V=4.98 fps Total Length= 165 ft Total Tc= 1.3 SUBCATCHMENT 7 RUNOFF DRAINAGE AREA 7 ; PROPOSED CONDITIONS .38 .36 AREA= .24 AC .34 Tc= 1 .3 MIN •32 CN= 73 .30 .28 .26 SCS TR-20 METHOD .24 TYPE II 24-HOUR 4- .22 RAINFALL= 3. 1 IN .20 , 18 PEAK= .38 CFS 3 . 16 e 11 .87 HRS o . 14 UOLUME= .02 AF -i . 12 LL . 10 .08 .06 .04 .02 0.00m T N m ,r- in w r a> rn N TIME (hours) Data for LOT 1-2B ORCHARD HILL ROAD, NORTH ANDOVER Page 10 TYPE II 24-HOUR RAINFALL= 3 .1 IN 9 Jan 98 Prepared by CHRISTIANSEN & SERGI, INC. H droCAD 4.52 001057 1 6-1 96 A lied Microcom uter tems POND 101 DETENTION/INFILTRATION AREA 1 Qin = 2.39 CFS @ 11.94 HRS, VOLUME= .14 AF Qout= .05 CPS @ 20.00 HRS, VOLUME= .03 AF, ATTEN= 98%, LAG= 483 .3 MIN Qpri= .05 CFS @ 20.00 HRS, VOLUME= .03 AF Qsec= 0.00 CFS @ 0.00 HRS, VOLUME= 0.00 AF ELEVATION AREA INC.STOR CUM.STOR STOR-IND METHOD (FTl (SF) (CF) (CF) PEAK STORAGE = 4472 CF 102 .0 1500 0 0 PEAK ELEVATION= 103.6 FT 103 .0 2950 2225 2225 FLOOD ELEVATION= 106.0 FT 104.0 4400 3675 5900 START ELEVATION= 102.0 FT 105.0 5250 4825 10725 SPAN= 10-20 HRS, dt=.1 HRS 106 .0 6100 5675 16400 Tdet= 261.5 MIN ( .03 AF) ROUTE INVERT OUTLET DEVICES 1 P 102.0' ENFILTRATION V= .001389 FPM over (SURFACE AREA - 1500 SF) 2 S 103.7' 4" ORIFICE/GRATE Q=.6 PI r-2 SQR(2g) SQR(H-r) 3 S 104.5' 12° ORIFICE/GRATE Q=.6 PI r^2 SQR(2g) SQR(H-r) Primary Discharge 1--1=Exfiltration Secondary Discharge --2=Orif ice/Grate I 3=0rifice/Grate POND 101 INFLOW & OUTFLOW DETENTION/INFILTRATION AREA 1 2.,4 2.2 STOR-IND METHOD PEAK STOR= 4472 CF 2.0 PEAK ELEU= 103.6 FT 1 .8 Gin= 2.39 CFS 1 .6 Qout= .05 CFS c} 1 Qpri= .05 CF5 l7 Qsec= 0.00 CFS 1 .2 LAG= 483.3 MIN 3 1 .0 O 8 J 6 4 .2 0, N -- --------------- --�--�--�--- 0)0 m - m TIME (hours) Data for LOT 1-2B ORCHARD HILL ROAD, NORTH ANDOVER Page 11 TYPE II 24-HOUR RAINFALL= 3.1 IN 9 Jan 98 Prepared by CHRISTIANSEN & SERGI, INC. H droCAD 4.52 0010 7 c 19 6-1996 Applied Microcom u er S stems POND 102 INFILTATION AREA 2 Qin = 2 .00 CFS @ 11.84 HRS, VOLUME= .10 AF Qout= .03 CFS @ 16 .48 HRS, VOLUME= .02 AF, ATTEN= 980, LAG= 278.3 MIN ELEVATION CON.AREA INC.STOR CUM.STOR WET.AREA STOR-IND METHOD (FT) (SF) (CF) (CF) (SF) PEAK STORAGE = 3362 CF 106.0 2400 0 0 2400 PEAK ELEVATION= 107.4 FT 110.0 2401 9602 9602 3095 START ELEVATION= 106.0 FT SPAN= 10-20 HRS, dt=.1 HRS Tdet= 281.2 MIN ( .02 AF) ROUTE INVERT OUTLET DEVICES 1 P 106.0' EXFILTRATION V= .008333 FPM over (WETTED AREA - 2400 SF) POND 102 INFLOW & OUTFLOW INFILTATION AREA 2 2.0 1 .9 STOR-IND METHOD 1 .8 PEAK 5TOR= 3362 CF 1 .7 PEAK ELEU= 107.4 FT 1 .6 1 .5 1 .4 Din= 2.00 CFS j 1 .3 Dout= .03 CFS �+ 1 .2 LAG= 278.3 MIN U 1 . 1 C 1 ,7 .9 3 .B O .7 6 L� 5 ,4 3 .2 . 1 0.0m _ ��-- --b -- to �o r m rn m TIME (hours) Data for LOT 1-2B ORCHARD HILL ROAD, NORTH ANDOVER Page 12 TYPE II 24-HOUR RAINFALL= 3.1 IN Prepared by CHRISTIANSEN & SERGI, INC. 9 Jan 98 HydroCAD 4.52 001057 (c) 1986-1996 Applied Microcomputer Svstems POND 103 INFILTRATION AREA 3 Qin = .38 CFS @ 11.87 HRS, VOLUME= .02 AF Qout= .01 CFS @ 18.06 HRS, VOLUME= .01 AF, ATTEN= 980, LAG= 371.4 MIN ELEVATION CON.AREA INC.STOR CUM.STOR WET.AREA STOR-IND METHOD (FT) (SF) (CF) (CF) (SF) PEAK STORAGE = 510 CF 105.0 1000 0 0 1000 PEAK ELEVATION= 105.5 FT 108.0 1001 3001 3001 1336 FLOOD ELEVATION= 108.0 FT START ELEVATION= 105.0 FT SPAN= 10-20 HRS, dt=.1 HRS Tdet= 259.5 MIN (0 AF) ROUTE INVERT OUTLET DEVICES 1 P 105.0' EXFILTRATION V= .008333 FPM over (WETTED AREA - 1000 SF) POND 103 INFLOW & OUTFLOW INFILTRATION AREA 3 .38 •36 STOR-IND METHOD .34 PEAK STOR= 510 CF '32 PEAK ELEU= 105.5 FT .30 .26 Qin= .38 CFS 24 Dout= .01 CFS �+ .22 LAG= 371 .4 MIN 20 . 18 3 . 16 o . 12 ' 10 - .08 - .06 .04 .02 TIME (hours) Data for LOT 1-2B ORCHARD HILL ROAD, NORTH ANDOVER Page 13 TYPE II 24-HOUR RAINFALL= 3.1 IN Prepared by CHRISTIANSEN & SERGI, INC. 9 Jan 98 HydroCAD 4 52 001057 (c) 1986-1996 Applied Microcomputer Systems POND 104 sv MM ll T10\y 0�� Not described Qin = .10 CFS @ 11.92 HRS, VOLUME= .01 AF Qout= .10 CFS @ 11.92 HRS, VOLUME= .01 AF, ATTEN= 0%-, LAG= 0.0 MIN ELEVATION AREA INC.STOR CUM.STOR - METHOD (FT) (AC) (AF) (AF) PEAK STORAGE = 0.00 AF PEAK ELEVATION= 0.0 FT FLOOD ELEVATION= 0.0 FT START ELEVATION= 0.0 FT SPAN= 10-20 HRS, dt=.1 HRS ROUTE INVERT OUTLET DEVICES POND 104 INFLOW & OUTFLOW Not described .095 - METHOD ,090 .085 PEAK STDR= 0.00 AF 088 PEAK ELEU= 0 FT .075 ,070 Qin= . 10 CFS .065 Qout= . 10 CFS .055 LAG= 0 MIN 050 3 .040 cl .035 ' .030 .025 .020 .015 ,010 .005 O.Oee m N m v m o' N TIME (hours) Data for LOT 1-2B ORCHARD HILL ROAD, NORTH ANDOVER Page 14 TYPE II 24-HOUR RAINFALL= 4.5 IN 9 Jan 98 Prepared by CHRISTIANSEN & SERGI, INC. H droCAD 4.52 001057 1 86-lqqA Applied Microcom uter Systems SUBCATCHMENT 1 DRAINAGE AREA 1: EXISTING CONDITIONS PEAK= .60 CFS @ 12.27 HRS, VOLUME= .15 AF ACRES CN SCS TR-20 METHOD 4 .25 30 H.S. GROUP A: WOODS, GOOD COND. TYPE II 24-HOUR 4 .34 55 H.S. GROUP B: WOODS, GOOD COND. RAINFALL= 4.5 IN .34 70 H.S. GROUP C: WOODS, GOOD COND. SPAN= 10-20 HRS, dt=.1 HRS 8 .93 44 Method Comment Tr (min) 6.1 TR-55 SHEET FLOW Woods: Light underbrush n=.4 L=50' P2=3.1 in s=.12 14.6 SHALLOW CONCENTRATED/UPLAND FLOW Woodland KV=5 L=980' s=.05 '/' V=1.12 fps Total Length= 1030 ft Total Tc- 20.7 SUBCATCHMENT 1 RUNOFF DRAINAGE AREA 1 : EXISTING CONDITIONS .60 .55 AREA= 8.93 AC To= 20.7 MIN .50 CN= 44 .45 40 SCS TR-20 METHOD TYPE II 24-HOUR <+ 35 RAINFALL= 4.5 IN L) 30 PEAK= .60 CFS 3 .25 e 12.27 HR5 0 20 UDLUME= . 15 OF Li- 15 . 10 .05 0.00m T N r*, U) 'D r Co rn m TIME (hour5) Data for LOT 1-2B ORCHARD HILL ROAD, NORTH ANDOVER Page 15 TYPE II 24-HOUR RAINFALL= 4.5 IN Prepared by CHRISTIANSEN & SERGI, INC. 9 Jan 98 H droCAD 4 .52 001057 c 1986-1.996 Applied Microcom uter Systems SDBCATCHMENT 2 DRAINAGE AREA 2: PROPOSED CONDITIONS PEAK= .42 CFS @ 12.14 HRS, VOLUME= .09 AF ACRES CN SCS TR-20 METHOD 2.56 30 H.S. GROUP A: WOODS, GOOD COND. TYPE II 24-HOUR 2.34 55 H.S. GROUP B: WOODS, GOOD COND. RAINFALL= 4.5 IN .32 70 H.S. GROUP C: WOODS, GOOD COND. SPAN= 10-20 HRS, dt=.1 HRS 5.22 44 Method Comment Tc (min) 6.1 TR-55 SHEET FLOW Woods: Light underbrush n=.4 L=50' P2=3 .1 in s=.12 '/' 8.6 SHALLOW CONCENTRATED/UPLAND FLOW Woodland KV=5 L=580' s=.05 '/' V=1.12 fps Total Length= 630 ft Total Tc= 14.7 SUBCATCHMENT 2 RUNOFF DRAINAGE AREA 2 ; PROPOSED CONDITIONS .40 AREA= 5.22 AC 35 Tc= 14.7 MIN CN= 44 30 SCS TR-20 METHOD `l TYPE II 24-HOUR c, 25 RAINFALL= 4.5 IN U v •20 PEAK= .42 CFS 3 e 12. 14 HRS o . 15 UDLUME= .09 AF J � . 10 .05 0.0 m v to r OD rn m TIME (hour5) Data for LOT 1-2B ORCHARD HILL ROAD, NORTH ANDOVER Page 16 TYPE II 24-HOUR RAINFALL= 4.5 IN Prepared by CHRISTIANSEN & SERGI, INC. 9 Jan 98 HVdroCAD 4 52 001057 (c) 1986-1996 Applied Microcomputer Systems SIIBCATCHMENT 3 DRAINAGE AREA 3: PROPOSED CONDITIONS PEAK= 5.77 CFS Q 11.93 HRS, VOLUME= .29 AF ACRES CN SCS TR-20 METHOD .42 98 H.S. GROUP A: IMPERVIOUS TYPE II 24-HOUR .55 98 H.S. GROUP B: IMPERVIOUS RAINFALL= 4.5 IN .48 39 H.S. GROUP A: LAWN SPAN= 10-20 HRS, dt=.1 HRS .45 61 H.S. GROUP B: LAWN .16 30 H.S. GROUP A: WOODS, GOOD COND. .36 55 H.S. GROUP B: WOODS, GOOD COND. 2.42 69 Method Comment Tr- (min) TR-55 SHEET FLOW 5.6 Woods: Light underbrush n=.4 L=50' P2=3 .1 in s=.15 SHALLOW CONCENTRATED/UPLAND FLOW .1 Unpaved Kv=16 .1345 L=30' s=.3 '/' V=8 .84 fps SHALLOW CONCENTRATED/UPLAND FLOW 1.4 Paved Kv=20.3282 L=240' s=.02 '/' V=2.87 fps Total Length= 320 ft Total Tc= 7.1 SUBCATCHMENT 3 RUNOFF DRAINAGE AREA 3 . PROPOSED CONDITIONS 5.5 AREA-- 2.42 AC 5,0 Tc= 7. 1 MIN 4.5 CN= 69 4.0 SCS TR-20 METHOD o 3.5 TYPE II 24-HOUR RAINFALL= 4.5 IN v 3.0 3 2.5 - PEAK= 5.77 CFS e 11 ,93 HRS 0 2.0 VOLUME= .29 AF LL 1 ,5 - 1 .0 .5 0,0m N m d Ln r ® rn m TIME (hours) Data for LOT 1-2B ORCHARD BILL ROAD, NORTH ANDOVER Page 17 TYPE II 24-HOUR RAINFALL= 4.5 IN Prepared by CHRISTIANSEN & SERGI, INC. 9 Jan 98 H droCAD 4.52 001057 c 1 86-1 6 A lied Microcom uter S stems SUBCATCmMNT 4 DRAINAGE AREA 4: PROPOSED CONDITIONS PEAK= .63 CFS @ 11.90 HRS, VOLUME= .03 AF ACRES CN SCS TR-20 METHOD .08 39 H.S. GROUP A: LAWN TYPE II 24-HOUR .22 61 H.S. GROUP B: LAWN RAINFALL= 4.5 IN .17 55 H.S. GROUP B: WOODS, GOOD COND. SPAN= 10-20 HRS, dt=.1 HRS 02 74 H.S. GROUP C: LAWN .49 56 Method Comment Tc (min) 2.1 TR-55 SHEET FLOW Grass: Short n=.15 L=40' P2=3 .1 in s=.15 '/' 9 SHALLOW CONCENTRATED/UPLAND FLOW Woodland KV=5 L=67' s=.06 '/' V=1.Z2 fps Total Length= 107 ft Total Tc= 3.0 SUBCATCHMENT 4 RUNOFF DRAINAGE AREA 4 : PROPOSED CONDITIONS .6e AREA-- .49 AC .55 Tc= 3 MIN .58 CN= 56 •45 SCS TR-20 METHOD .40 TYPE II 24-HDUR - 35 RAINFALL= 4.5 IN .30 PEAK= .63 CFS 3 ,25 C 11 .9 HR5 OJ 20 UDLUME= .03 AF LL 15 . 10 ,05 0,00m N m � T r m rn m TIME (hours) - Data for LOT 1-2B ORCHARD HILL ROAD, NORTH ANDOVER Page 18 TYPE II 24-HOUR RAINFALL= 4.5 IN Prepared by CHRISTIANSEN & SERGI, INC. 9 Jan 98 HydroCAD 4 52 001057 (c) 1986-1996 Applied Microcomputer Systems SUBCATCHMENT 5 DRAINAGE AREA 5: PROPOSED CONDITIONS PEAK= 0.00 CFS @ 13.30 HRS, VOLUME= 0.00 AF ACRES CN SCS TR-20 METHOD .09 39 H.S. GROUP A: LAWN TYPE II 24-HOUR RAINFALL= 4.5 IN SPAN= 10-20 HRS, dt=.1 HRS Method Comment Tc (min) TR-55 SHEET FLOW 1.9 Grass: Short n=.15 L=20' P2=3.1 in s=.05 SHALLOW CONCENTRATED/UPLAND FLOW .5 Unpaved Kv=16.1345 L=100' s=.05 '/' V=3.61 fps Total_Length= 120 ft Total Tc= 2.4 SUBCATCHMENT 5 RUNOFF DRAINAGE AREA 5 : PROPOSED CONDITIONS .0011 0010 AREA= .09 AC Tc= 2.4 MIN 0009 = 39 .0008 SCS TR-20 ME D .0007 TYPE II 24-HOU `+ RAINFALL= 4.5 IN L) .0006 v 0005 PEAK= 0.00 CFS 0 0004 G 13.3 HRS J UOLUME= 0.00 AF L .0003 .0002 .0001 0.0000 m N frJ V ln 01 N TIME (hours) Data for LOT 1-2B ORCHARD HILL ROAD, NORTH ANDOVER Page 19 TYPE II 24-HOUR RAINFALL= 4.5 IN Prepared by CHRISTIANSEN & SERGI, INC. 9 Jan 98 H droCAD 4.52 001057 c 1986-1996 A lied Microcom uter Systems SUBCATCHMENT 6 DRAINAGE AREA 6: PROPOSED CONDITIONS PEAK= 2.92 CFS @ 11.84 HRS, VOLUME= .14 AF ACRES CN SCS TR-20 METHOD .22 98 H.S. GROUP A: IMPERVIOUS TYPE II 24-HOUR 28 98 H.S. GROUP B: IMPERVIOUS RAINFALL= 4.5 IN .50 98 SPAN= 10-20 HRS, dt=.1 HRS Method Comment Tr- (min) .4 TR-55 SHEET FLOW Smooth surfaces n=.011 L=60' P2=3.1 in s=.15 '/' 8 CIRCULAR CHANNEL 1211 Diameter a=.79 sq-ft Pw=3.1' r=.25' S=.005 '/' n=.009 V=4.63 fps L=220' Capacity=3 .6 cfs Total Length= 280 ft Total Tc= 1.2 SUBCATCHMENT 6 RUNOFF DRAINAGE AREA 6 : PROPOSED CONDITIONS 2.8 AREA= .5 AC 2.6 Tc= 1 .2 MIN 2.4 CN= 98 2.2 r. 2.0 SCS TR-20 METHOD TYPE II 24-HOUR i '8 RAINFALL= X1.5 IN L) 1 .6 1 .4 PEAK= 2.92 CFS 3 1 .2 G 11 .84 HRS 001 1 .0 UDLUME= . 14 AF LL '8 .6 .4 .2 0.0m N M v 'n r ao rn N TIME (hours) Data for LOT 1-2B ORCHARD HILL ROAD, NORTH ANDOVER Page 20 TYPE II 24-HOUR RAINFALL= 4.5 IN Prepared by CHRISTIANSEN & SERGI, INC. 9 Jan 98 H droCAD 4.52 001057 c 1986-19 6 A lied microcomputer S terns SUBCATCHMENT 7 DRAINAGE AREA 7: PROPOSED CONDITIONS PEAK= .78 CFS @ 11.87 HRS, VOLUME= .03 AF ACRES CN SCS TR-20 METHOD .14 98 H.S. GROUP A: IMPERVIOUS TYPE II 24-HOUR 10 39 H.S. GROUP A: LAWN RAINFALL= 4.5 IN .24 73 SPAN= 10-20 HRS, dt=.l HRS Method Comment Tr- (min) .8 TR-55 SHEET FLOW Grass: Short n=.15 L=15' P2=3.1 in s=.25 '/' 5 SHALLOW CONCENTRATED/UPLAND FLOW Paved Kv=20.3282 L=150' s=.06 '/' V=4.98 fps Total Length= 165 ft Total Tc= 1.3 SUBCATCHMENT 7 RUNOFF DRAINAGE AREA 7 ; PROPOSED CONDITIONS .75 AREA= .24 AC .70 Tc= 1 .3 MIN .65 CN= 73 .60 .55 SCS TR-20 METHOD ,50 TYPE II 24-HOUR 4- ,45 RAINFALL= 4.5 IN 40 PEAK= .78 CFS p 30 e 11 ,87 HR5 J 25 UDLUME= .03 AF L- .20 . 15 . 10 .05 0,000 N m 't to co rn N TIME (hour5) Data for LOT 1-2B ORCHARD HILL ROAD, NORTH ANDOVER Page 21 TYPE II 24-HOUR RAINFALL= 4.5 IN 9 Jan 98 Prepared by CHRISTIANSEN & SERGI, INC. H droCAD 4.52 001057 c 1986-1 6 A lied Microcom uter S s em POND 101 6 DETENTION/INFILTRATION AREA 1 AF Qin = 5.82 CFS @ 11.93 HRS, VOLUME= .24 AF, ATTEN= 930, LAG= 120.1 MIN Qout= .42 CFS @ 13.94 HRS, VOLUME= Qpri= .08 CFS @ 13.94 HRS, VOLUME= .05 AF Qsec= .34 CFS @ 13.94 HRS, VOLUME= .19 AF STOR-IND METHOD ELEVATION AREA INC.STOR CUM.STOR PEAK STORAGE = 8366 CF (FT) SF� «'F1 (C 0 PEAK ELEVATION= 104.5 FT 102.0 1500 0 2225 2225 FLOOD ELEVATION= 106 .0 FT 103.0 2950 START ELEVATION= 102.0 FT 104.0 4400 3675 5900 4825 10725 SPAN= 10-20 HRS, dt=.1 HRS 5250 105.0 Tdet= 217.1 MIN ( .24 AF) 106.0 6100 5675 16400 ROUTE INVERT OUTLET DEVICES 1 P 102 .0' EXFILTRATION V= .001389 FPM over (SURFACE AREA - 1500 SF) 2 S 103 .7' 4" ORIFICE/GRATE Q=.6 PI r-2 SQR(2g) SQR(H-r) 3 S 104 .5' Q=.6pPIgr^2 SQRT2g) SQR(H-r) Primary Discharge I 1=Exf i ltrat ion Secondary Discharge �--2=Orifice/Grate �--3=Orifice/Grate PON OUTFLOW DETENTION/INFILTRATION AREA 1 5.5 STOR-IND METHOD 5.0 PEAK STOR= 6366 CF PEAK ELEU= 104.5 FT 4,5 4.0 Din= 5.82 CFS Qout= .42 CFS y� 3,5 Qpri= .08 CFS u 3,0 Qsec= .34 CF5 LAG= 120. 1 MIN 3 2.5 OJ 2.0 1 .0 0,em T N In - m N TIME (hours) Data for LOT 1-2B ORCHARD HILL ROAD, NORTH ANDOVER Page 22 TYPE II 24-HOUR RAINFALL= 4.5 IN 9 Jan 98 Prepared by CHRISTIANSEN & SERGI, INC. H droCAD 4.52 001057 c 1986-1996 A lied microcomputer Systems POND 102 INFILTATION AREA 2 Qin = 2.92 CFS @ 11.84 HRS, VOLUME= .14 AF Qout= .05 CFS @ 16.42 HRS, VOLUME= .03 AF, ATTEN= 98e, LAG= 274.7 MIN ELEVATION CON.AREA INC.STOR CUM.STOR WET.AREA PEAK STOR-IND METHOD 4927 CF (FT) (SF) (CF) (CF) SF 106.0 2400 0 0 2400 PEAK ELEVATION= 108.1 FT 110.0 2401 9602 9602 3095 START ELEVATION= 106.0 FT SPAN= 10-20 HRS, dt=.1 HRS Tdet= 281.5 MIN ( .03 AF) ROUTE INVERT OUTLET DEVICES 1 P 106.0' EXFILTRATION V= .008333 FPM over (WETTED AREA - 2400 SF) POND 102 INFLOW & OUTFLOW INFILTATION AREA 2 2,8 STOR-IND METHOD 2.6 PEAK STOR= 4927 CF 2.4 PEAK ELEU= 108. 1 FT 2.2 Din= 2.92 CFS 2.0 Qcut= .05 CFS LAG= 274.7 MIN L) 1 .6 " 1 ,4 3 1 .2 0 1 .0 Li- '8 .6 4 .2 0 lam N-- rn -- -- tD r m m TIME (hours) Data for LOT 1-2B ORCHARD HILL ROAD, NORTH ANDOVER Page 23 TYPE II 24-HOUR RAINFALL= 4.5 IN Prepared by CHRISTIANSEN & SERGI, INC. 9 Jan 98 H droCAD 4.52 001057 c 1986-1996 An lied Microcom uter S stems POND 103 INFILTRATION AREA 3 Qin = .78 CFS @ 11.87 HRS, VOLUME= .03 AF Qout= .02 CFS @ 16.64 HRS, VOLUME= .01 AF, ATTEN= 980, LAG= 286.3 MIN ELEVATION CON AREA INC.STOR CUM.STOR WET.AREA STOR-IND METHOD (FT) (SF) (CF) (CF) (SF) PEAK STORAGE = 1074 CF 105.0 1000 0 0 1000 PEAK ELEVATION= 106.1 FT 108 .0 1001 3001 3001 1336 FLOOD ELEVATION= 108 .0 FT START ELEVATION= 105.0 FT SPAN= 10-20 HRS, dt=.1 HRS Tdet= 262.1 MIN ( .01 AF) ROUTE INVERT OUTLET DEVICES 1 P 105.0' EXFILTRATION V= .008333 FPM over (WETTED AREA - 1000 SF) POND 103 INFLOW & OUTFLOW INFILTRATION AREA 3 ,75 STOR-IND METHOD ,70 PEAK STOR= 1074 CF .65 PEAK ELEU= 106. 1 FT .60 r .55 QIn= .78 CF5 50 Qout= .02 CFS 45 LAG= 286.3 MIN v 40 3 .35 CD .30 -1 ,25 L- .20 , 15 . 10 .05 0,00m T N ------------ ----- --� r w rn m TIME Chours) Data for LOT 1-2B ORCHARD HILL ROAD, NORTH ANDOVER Page 24 TYPE II 24-HOUR RAINFALL= 4.5 IN 9 Jan 98 Prepared by CHRISTIANSEN & SERGI, INC. m H dro 4 52 0010 1 6-1 A li d Mi r m POND 104 Not described Qin = .63 CFS @ 11.90 HRS, VOLUME= .22 AF Qout= .63 CFS @ 11.90 HRS, VOLUME= .22 AF, ATTEN= 0%, LAG= 0.0 MIN ELEVATION AREA INC.STOR CUM.STOR - METHOD PEAK STORAGE = 0 .00 AF (FT) (AC) (AF) (AF) PEAK ELEVATION= 0.0 FT FLOOD ELEVATION= 0.0 FT START ELEVATION= 0.0 FT SPAN= 10-20 HRS, dt=.l HRS ROUTE INVERT OUTLET DEVICES POND 104 INFLOW & OUTFLOW Not described .60 - METHOD .55 PEAK STOR= 0.00 AF .50 PEAK ELEU= 0 FT .45 Qin= .63 CFS j 40 Dout= .63 CFS 35 LAG= 0 MIN .30 .25 CD J .20 LL 15 , 10 .05 0.00( T N m �r �n r o� rn m TIME (hour5) Data for LOT 1-2B ORCHARD HILL ROAD, NORTH ANDOVER Page 25 TYPE II 24-HOUR RAINFALL= 6.4 IN 9 Jan 98 Prepared by CHRISTIANSEN & SERGI, INC. H droCAD 4.52 001057 c 1986-1996 A li d Microcom uter Systems SUBCATCHMENT 1 DRAINAGE AREA l: EXISTING CONDITIONS PEAK= 5.68 CFS @ 12.14 HRS, VOLUME= .57 AF ACRES CN SCS TR-20 METHOD 4.25 30 H.S. GROUP A: WOODS, GOOD COND. TYPE II 24-HOUR 4 .34 55 H.S. GROUP B: WOODS, GOOD COND. RAINFALL= 6 .4 IN 34 70 H.S. GROUP C: WOODS, GOOD COND. SPAN= 10-20 HRS, dt=.1 HRS 8 .93 44 Comment Tr Method 6 .1 TR-55 SHEET FLOW Woods: Light underbrush n=.4 L=50' P2=3 .1 in s=.12 14.6 SHALLOW CONCENTRATED/UPLAND FLOW Woodland Kv=5 L=980' s�.05 '/' V=1.12 fps Total Length= 1030 ft Total Tc= 20.7 SUBCATCHMENT 1 RUNOFF DRAINAGE AREA 1 : EXISTING CONDITIONS 5.5 AREA- 8.93 AC 5.0 Tc= 20.7 MIN 4.5 CN= 44 4.0 SCS TR-20 METHOD TYPE II 24-HOUR 3.5 RAINFALL= 6.4 IN v 3.0 PEAK= 5.68 CFS 3 2.5 e 12, 14 HRS CD 2.0 VOLUME= .57 AF 1 ,5 1 .0 .5 TIME (hours) Data for LOT 1-2B ORCHARD HILL ROAD, NORTH ANDOVER Page 26 TYPE II 24-HOUR RAINFALL= 6.4 IN Prepared by CHRISTIANSEN & SERGI, INC. 9 Jan 98 HydroCAD 4.52 001057 (c) 1986-1996 Applied Microcomputer Systems SUBCATCHMENT 2 DRAINAGE AREA 2: PROPOSED CONDITIONS PEAK= 3 .93 CFS @ 12.07 HRS, VOLUME= .33 AF ACRES CN SCS TR-20 METHOD 2 .56 30 H.S. GROUP A: WOODS, GOOD COND. TYPE II 24-HOUR 2 .34 55 H.S. GROUP B: WOODS, GOOD COND. RAINFALL= 6.4 IN .32 70 H.S. GROUP C: WOODS, GOOD COND. SPAN= 10-20 HRS, dt=.1 HRS 5.22 44 Method Comment Tr- (min TR-55 SHEET FLOW 6.1 Woods: Light underbrush n=.4 L=50' P2=3.1 in s=.12 '/' SHALLOW CONCENTRATED/UPLAND FLOW 8'6 Woodland Kv-5 L=580' s=.05 '/' V=1.12 fps Total Length= 630 ft Total Tc= 14.7 SUBCATCHMENT 2 RUNOFF DRAINAGE AREA 2 ; PROPOSED CONDITIONS 3.8 3.6 AREA= 5.22 AC 3,4 Tc= 14.7 MIN 3.2 CN= 44 3.0 2.8 SCS TR-20 METHOD 2.6 TYPE II 24-HOUR 2.4 RAINFALL= 6.4 IN 2.2 2.0 1 .8 PEAK= 3.93 CFS 3 1 .6 C 12.07 HRS 0 1 .4 UOLUME= .33 AF 1 .2 .e .6 .4 .2 0.0� N (T7 V Ifl t0 I� m 6� m TIME (hours) Data for LOT 1-2B ORCHARD HILL ROAD, NORTH ANDOVER Page 27 TYPE II 24-HOUR RAINFALL= 6.4 IN 9 Jan 98 Prepared by CHRISTIANSEN & SERGI, INC. Hydr)CAD 4.52 001057 1986-1996 A lied Microcom ut r S teas SUBCATCHMENT 3 DRAINAGE AREA 3: PROPOSED CONDITIONS PEAK= 11.16 CFS @ 11.92 HRS, VOLUME= .56 AF ACRES CN SCS TR-20 METHOD .42 98 H.S. GROUP A: IMPERVIOUS TYPE II 24-HOUR .55 98 H.S. GROUP B: IMPERVIOUS RAINFALL= 6.4 IN .48 39 H.S. GROUP A: LAWN SPAN= 10-20 HRS, dt=.l HRS .45 61 H.S. GROUP B: LAWN .16 30 H.S. GROUP A: WOODS, GOOD COND. .36 55 H.S. GROUP B: WOODS, GOOD COND. 2.42 69 Comment Tc (min) Method 5.6 TR-55 SHEET FLOW Woods: Light underbrush n=.4 L=50' P2=3.1 in s=.15 1 SHALLOW CONCENTRATED/UPLAND FLOW Unpaved Kv=16.1345 L=30' s=.3 '/' V=8.84 fps 1.4 SHALLOW CONCENTRATED/UPLAND FLOW Paved Kv=20.3282 L=240' s=.02 '/' V=2.87 fps Total Length= 320 ft Total Tc= 7.1 SUBCATCHMENT 3 RUNOFF DRAINAGE AREA 3 : PROPOSED CONDITIONS 11 AREA= 2.42 AC 10 Tc= 7. 1 MIN 9 CN= 69 8 SCS TR-20 METHOD j 7 TYPE II 24-HOUR 4- RAINFALL= 6.4 IN U 6 5 PEAK= 11 . 16 CFS 3 O 11 .92 HRS 0 4 VOLUME= ,56 AF -i L. 3 2 to W m rn m TIME (hours) Data for LOT 1-2B ORCHARD HILL ROAD, NORTH ANDOVER Page 28 TYPE II 24-HOUR RAINFALL= 6.4 IN Prepared by CHRISTIANSEN & SERGI, INC. 9 Jan 98 HydroCAD 4 52 001057 (c) 1986-1996 Applied Microcomputer Systems SUBCATCHMENT 4 DRAINAGE AREA 4: PROPOSED CONDITIONS PEAK= 1.60 CFS @ 11.89 HRS, VOLUME= .07 AF ACRES CN SCS TR-20 METHOD .08 39 H.S. GROUP A: LAWN TYPE II 24-HOUR .22 61 H.S. GROUP B: LAWN RAINFALL= 6.4 IN .17 55 H.S. GROUP B: WOODS, GOOD COND. SPAN= 10-20 HRS, dt=.1 HRS .02 74 H.S. GROUP C: LAWN .49 56 Method Comment Tc (min) TR-55 SHEET FLOW 2.1 Grass: Short n=.15 L=40' P2=3 .1 in s=.15 SHALLOW CONCENTRATED/UPLAND FLOW •9 Woodland Kv=5 L=67 ' s=.06 '/' V=1.22- fps Total Length= 107 ft Total Tc= 3.0 SUBCATCHMENT 4 RUNOFF DRAINAGE AREA 4 ; PROPOSED CONDITIONS 1 .6 1 .5 AREA= .49 AC 1 .4 Tc= 3 MIN 1 .3 CN= 56 1 .2 1 . 1 SCS TR-20 METHOD 1 .0 TYPE II 24-HDUR 4- g RAINFALL= 6.4 IN U 7 PEAK= 1 .60 CFS <a 11 .89 HRS � ;5 UDLUME= .07 AF li 4 .3 .2 . 1 0,0m N r*� d to �n r m rn m TIME (hours) Data for LOT 1-2B ORCHARD HILL ROAD, NORTH ANDOVER Page 29 TYPE II 24-HOUR RAINFALL= 6.4 IN Prepared by CHRISTIANSEN & SERGI, INC. 9 Jan 98 H droCAD 4.52 001057 c 1986-1996 ADDlied Microcom uter S tems SUBCATCHMENT 5 DRAINAGE AREA 5: PROPOSED CONDITIONS PEAK= .05 CFS @ 11.91 HRS, VOLUME= 0.00 AF ACRES CN SCS TR-20 METHOD .09 39 H.S. GROUP A: LAWN TYPE II 24-HOUR RAINFALL= 6 .4 IN SPAN= 10-20 HRS, dt=.l HRS Method Comment Tc (min) 1.9 TR-55 SHEET FLOW Grass: Short n=.15 L=20' P2=3 .1 in s=.05 '/' 5 SHALLOW CONCENTRATED/UPLAND FLOW Unpaved Kv=16.1345 L=100' s=.05 '/' V=3.61 fps -_ ----- Total Length= 120 ft Total Tc= 2.4 SUBCATCHMENT 5 RUNOFF DRAINAGE AREA 5 ; PROPOSED CONDITIONS .050 AREA= .09 AC .045 Tc= 2.4 MIN CN= 39 .040 035 LRTASINF R-20 METHOD II 24-HOUR `+ .030 ALL= 6.4 IN u .025 AK= .05 CFS p 020 G 11 ,91 HRS ME= 0.00 AF 015 .0tH .005 0.000 m to m a in �o r m m m TIME (hours) Data for LOT 1-2B ORCHARD HILL ROAD, NORTH ANDOVER Page 30 TYPE II 24-HOUR RAINFALL= 6.4 IN Prepared by CHRISTIANSEN & SERGI, INC. 9 Jan 98 c 1 86-19 6 A lied Microcom uter S s ems H droCAD 4.52 0010 SUBCATCHMNT 6 DRAINAGE AREA 6: PROPOSED CONDITIONS PEAK= 4.17 CFS @ 11.84 HRS, VOLUME= .21 AF ACRES CN SCS TR-20 METHOD .22 98 H.S. GROUP A: IMPERVIOUS TYPE II 24-HOUR 28 98 H.S. GROUP B: IMPERVIOUS RAINFALL= 6.4 IN .50 98 SPAN= 10-20 HRS, dt=.1 HRS Method Comment Tc (min) .4 TR-55 SHEET FLOW Smooth surfaces n=.011 L=60' P2=3 .1 in s=.15 '/' 8 CIRCULAR CHANNEL 12" Diameter a=.79 sq-ft Pw=3 .1' r=.25' s=.005 '/' n=.009 V=4.63 fps L=220' Capacity=3.6 cfs Total Length= 280 ft Total Tc= 1.2 SUBCATCHMENT 6 RUNOFF DRAINAGE AREA 6 . PROPOSED CONDITIONS 4.0 AREA= .5 AC Tc= 1 .2 MIN 3.5 CN= 98 3.0 SCS TR-20 METHOD TYPE II 24-HOUR c� 2.5 RAINFALL= 6.4 IN u " 2.0 PEAK= 4. 17 CFS 3 f 11 .84 HRS 0 1 .5 UOLUME= .21 AF � 1 ,0 .5 N M � lfl t0 h M rn m TIME (hour5) Data for LOT 1-2B ORCHARD HILL ROAD, NORTH ANDOVER Page 31 TYPE II 24-HOUR RAINFALL= 6.4 IN 9 Jan 98 Prepared by CHRISTIANSEN & SERGI, INC. H drOCAD 4.52 001057 c 1986-1996 A lied Microcom uter S terns SUBCATCHMNT 7 DRAINAGE AREA 7 : PROPOSED CONDITIONS PEAK= 1.39 CFS @ 11.86 HRS, VOLUME= .06 AF ACRES CN SCS TR-20 METHOD .14 98 H.S. GROUP A: IMPERVIOUS TYPE II 24-HOUR .10 39 H.S. GROUP A: LAWN RAINFALL= 6.4 IN .24 73 SPAN= 10-20 HRS, dt=.1 HRS Method Comment Tc lm8n) .TR-55 SHEET FLOW Grass: Short n=.15 L=15' P2=3 .1 in s=.25 5 SHALLOW CONCENTRATED/UPLAND FLOW Paved Kv=20.3282 L=150' s=.06 '/' V=4 .98 fps Total Length= 165 ft Total Tc= 1.3 SUBCATCHMENT 7 RUNOFF DRAINAGE AREA 7 : PROPOSED CONDITIONS 1 .4 1 .3 AREA= .24 AC 1 .2 - Tc= 1 .3 MIN CN= 73 1 . i 1 .0 SCS TR-20 METHOD j .9 TYPE II 24-HOUR �+ .g RAINFALL= 6.4 IN u .7 PEAK= 1 .39 CFS 3 •6 e 11 .86 HRS o .5 VOLUME= .06 AF J 4 .3 .2 . I 0.0m T m v �o r m m m TIME (hour5) Data for LOT 1-2B ORCHARD HILL ROAD, NORTH ANDOVER Page 32 TYPE II 24-HOUR RAINFALL= 6.4 IN 9 Jan 98 Prepared by CHRISTIANSEN & SERGI, INC. c 1 86-1 6 A lied Microcom uter S stems H droCAD 4.52 00105 POND 101 DETENTION/INFILTRATION AREA 1 Qin = 12.99 CFS @ 11.96 HRS, VOLUME= .89 AF Qout= 3.70 CFS @ 12.28 HRS, VOLUME= .70 AF, ATTEN= 720, LAG= 19.1 MIN Qpri= .10 CFS @ 12.28 HRS, VOLUME= .06 AF Qsec= 3.60 CFS @ 12.28 HRS, VOLUME= .64 AF ELEVATION AREA INC.STOR CUIvI.STOR STOR-IND METHOD PEAK STORAGE = 14383 CF (FT) (SF) (CF1 (CFl PEAK ELEVATION= 105.6 FT 102.0 1500 0 0 103.0 2950 2225 2225 FLOOD ELEVATION= 106.0 FT START ELEVATION= 102.0 FT 104.0 4400 3675 5900 105.0 5250 4825 10725 SPAN= 10-20 HRS, dt=.1 HRS Tdet= 114.2 MIN ( .69 AF) 106.0 6100 5675 16400 ROUTE INVERT OUTLET DEVICES 1 P 102.0' ENFILTRATION V= .001389 FPM over (SURFACE AREA - 1500 SF) 2 S 103.7' 4" ORIFICE/GRATE Q=.6 PI r-2 SQR(2g) SQR(H-r) 3 S 104.5' 12° ORIFICE/GRATE Q=.6 PI r"2 SQR(2g) SQR(H-r) Primary Discharge i--1=Exf i ltrat ion Secondary Discharge f--2=Orif ice/Grate I 3=Orifice/Grate POND 101 INFLOW & OUTFLOW DETENTION/INFILTRATION AREA 1 13 12 STOR-IND METHOD 11 PEAK STOR= 14383 CF PEAK ELEU= 105.6 FT 10 9 Qin= 12.99 CFS Qout= 3.70 CFS c� 8 Qpri= . 10 CFS L) 7 Qsec= 3.60 CFS 6 LAG= 19. 1 MIN 3 5 O _I 4 3 i 2 Om N-- -- -- Ln r m rn mN TIME (hours) Data for LOT 1-2B ORCHARD HILL ROAD, NORTH ANDOVER Page 33 TYPE II 24-HOUR RAINFALL= 6.4 IN 9 Jan 98 Prepared by CHRISTIANSEN & SERGI, INC. H droCAD 4.52 001057 c 1 86-1996 A lied Mi rococo uter stems POND 102 INFILTATION AREA 2 Qin = 4.17 CFS @ 11.84 HRS, VOLUME= .21 AF Qout= .07 CFS @ 16 .39 HRS, VOLUME= .05 AF, ATTEN= 980, LAG= 272 .9 MIN ELEVATION CON.AREA INC.STOR CUM.STOR WET.AREA STOR-IND METHOD (FT) (SF) (CF) (CF) (SF) PEAK STORAGE = 7040 CF 106.0 2400 0 0 2400 PEAK ELEVATION= 108.9 FT 110.0 2401 9602 9602 3095 FLOOD ELEVATION= 110.0 FT START ELEVATION= 106.0 FT SPAN= 10-20 HRS, dt=.1 HRS Tdet= 283.8 MIN ( .05 AF) ROUTE INVERT OUTLET DEVICES 1 P 106.0' EBFILTRATION V= .008333 FPM over (WETTED AREA - 2400 SF) POND 102 INFLOW & OUTFLOW INFILTATION AREA 2 4.0 STOR-IND METHOD PEAK STDR= 7040 CF 3.5 PEAK ELEU= 108.9 FT 3.0 Din= 4, 17 CFS `l Qout= .07 CFS to 2.5 LAG= 272.9 MIN u " 2.0 3 O 1 .5 -i LL .5 Li 0.0 0 N-- M --'--Ln �0 r m M 0 TIME (hours) Data for LOT 1-2B ORCHARD HILL ROAD, NORTH ANDOVER Page 34 TYPE II 24-HOUR RAINFALL= 6.4 IN 9 Jan 98 Prepared by CHRISTIANSEN & SERGI, INC. H drOCAD 4.52 001057 c 1 86-1996 Applied Microcom uter S stems POND 103 INFILTRATION AREA 3 Qin = 1.39 CFS @ 11.86 HRS, VOLUME= .06 AF Qout= .03 CFS @ 15.81 HRS, VOLUME= .02 AF, ATTEN= 980, LAG= 236.7 MIN ELEVATION CON.AREA INC.STOR CUM.STOR WETSAREA PEAK STORAGE THOD 1955 CF (FT) (SF) (CF) (CF 105.0 1000 0 0 1000 PEAK ELEVATION= 107.0 FT 108 .0 1001 3001 3001 1336 START ELEVATION= 105.0 FT SPAN= 10-20 HRS, dt=.1 HRS Tdet= 261.2 MIN ( .02 AF) ROUTE INVERT OUTLET DEVICES 1 P 105.0, ENFILTRATION V= .008333 FPM over (WETTED AREA - 1000 SF) POND 103 INFLOW & OUTFLOW INFILTRATION AREA 3 1 .4 1 .3 STOR-IND METHOD 1 .2 PEAK STOR= 1955 CF 1 1 PEAK ELEU= 107 FT 1 .0 Din= 1 ,39 CFS � .9 Dout= .03 CFS c., B LAG= 236.7 MIN L) .7 3 .6 0 5 LL .3 .2 TIME (hours) Data for LOT 1-2B ORCHARD HILL ROAD, NORTH ANDOVER Page 35 TYPE II 24-HOUR RAINFALL= 6.4 IN 9 Jan 98 Prepared by CHRISTIANSEN & SERGI, INC. H droCAD 4. 2 001057 c 198 -1 96 A lied Microcom uter S tems POND 104 Not described Qin = 3 .82 CFS @ 12.25 HRS, VOLUME= .72 AF Qout= 3.82 CFS @ 12.25 HRS, VOLUME= .72 AF, ATTEN= 0%, LAG= 0.0 MIN ELEVATION AREA INC.STOR CUM.STOR - METHOD (FT) (AC) (AF) (AF) PEAK STORAGE = 0.00 AF PEAK ELEVATION= 0.0 FT FLOOD ELEVATION= 0.0 FT START ELEVATION= 0.0 FT SPAN= 10-20 HRS, dt=.1 HRS ROUTE INVERT OUTLET DEVICES POND 104 INFLOW- & OUTFLOW Not deacrlbed 3.6 3.6 - METHOD 3.4 PEAK STDR= 0.00 AF 3.2 PEAK ELEU= 0 FT 3.0 2.8 Din= 3.82 CFS r` 2.6 Qout= 3.82 CFS 0) 2.4 c,_ 2 2 LAG= 0 MIN v 2.0 1 .8 O 1 .4 J 1 .2 L- 1 .0 .8 .6 ,4 .2 0.0m N m v to r m rn m TIME (hours) CHRISTIANSN & SERGI, INC. PROFESSIONAL ENGINEERS AND LAND SURVEYORS 160 SUMMER STREET HAVERHILL, MASSACHUSETTS 01830-6318 (978)373-0310 FAX: (978)372-3960 SOIL TEST RESULTS LOT 1-26 ORCHARD HILL ROAD: TEST PIT RESULTS DATE OF TESTS:OCTOBER 15,1997 TEST PIT#1 DEPTH SOIL HORIZON SOIL TEXTURE SOIL COLOR SOIL MOTTLING COMMENTS p_ Ap FINE SANDY LOAM 10YR3/1 MASSIVE,FRIABLE 6'-28„ Bw LOAMY FINE SAND 2.5Y5/6 MASSIVE,FRIABLE 28"-46' Cl GRAVELLY FINE 2.5Y5/5 MASSIVE TO TO MEDIUM SAND GRANULAR,FRIABLE, FEW ROOTS TO 45" 45'-123' C2 LOAMY SAND WITH 2.5Y5/4 REDOX. MASSIVE,FRIABLE POCKETS OF SANDY BELOW 45" LOAM AND SAND 123"-140" C3 SANDY LOAM 5Y5/1 MASSIVE,FRIABLE ESTIMATED SEASONAL HIGH WATER TABLE=45' NO GROUNDWATER SEEPAGE,NO REFUSAL TEST PIT#2 DEPTH SOIL HORIZON SOIL TEXTURE SOIL COLOR SOIL MOTTLING COMMENTS 0-1p" Ap FINE SANDY LOAM 10YR3/1 MASSIVE,FRIABLE I CY'-31" Bw FINE SANDY LOAM 2.5Y5/6 MASSIVE,FRIABLE 31"-138" C1 SANDY LOAM 2.5Y5/4 REDOX. MASSIVE,FRIABLE BELOW 30" TO FIRM FEW ROOTS TO 35' 138"-154' 1 C2 SANDY LOAM 5Y5/1 MASSIVE,FRIABLE ESTIMATED SEASONAL HIGH WATER TABLE=30" NO GROUNDWATER SEEPAGE,NO REFUSAL TEST PIT#3 DEPTH SOIL HORIZON SOIL TEXTURE SOIL COLOR SOIL MOTTLING COMMENTS 0-91 A FINE SANDY LOAM 10YR3/1 MASSIVE,FRIABLE 10"-23' Bw FINE SANDY LOAM 2.5Y5/6 MASSIVE,FRIABLE 23"-150" Cl STRATIFIED SANDS AND 2.5Y5/4 REDOX. GRANULAR TO LOAMY SANDS WITH BELOW 45" MASSIVE,FRIABLE, POCKETS OF GRAVELLY FEW ROOTS TO 54' SAND AND SANDY LOAM ESTIMATED SEASONAL HIGH WATER TABLE=46' NO GROUNDWATER SEEPAGE,NO REFUSAL LOT 1-2B ORCHARD HILL ROAD: TEST PIT RESULTS TEST PIT#4 DEPTH SOIL HORIZON SOIL TEXTURE SOIL COLOR SOIL MOTTLING COMMENTS 0-8" A FINE SANDY LOAM 10YR3/1 MASSIVE,FRIABLE 8"-31" Bw FINE SANDY LOAM 2.5Y5/6 MASSIVE FRIABLE 31"-50" Cl GRAVELLY LOAMY 2.5Y5/5 REDOX. GRANULAR TO SAND BELOW 48" MASSIVE FRIABLE, FEW ROOTS TO 54' 5a'-124' C2 SANDY LOAM WITH 2.5Y5/4 MASSIVE,FRIABLE POCKETS OF LOAMY SAND ESTIMATED SEASONAL HIGH WATER TABLE=48" NO GROUNDWATER SEEPAGE,NO REFUSAL TEST PIT#5 DEPTH SOIL HORIZON SOIL TEXTURE SOIL COLOR SOIL MOTTLING COMMENTS 0-8" A FINE SANDY LOAM MASSIVE,FRIABLE 8"-25' Bw FINE SANDY LOAM 2.5Y5/5 MASSIVE,FRIABLE 267-33- Cl GRAVELLY SAND 2.5Y5/6 REDOX. GRANULAR,LOOSE BELOW 34' SANDY LOAM 2.5Y5/4 MASSIVE,FRIABLE -� C2 TO FIRM ESTIMATED SEASONAL HIGH WATER TABLE=34' NO GROUNDWATER SEEPAGE,NO REFUSAL TEST PIT#6 DEPTH SOIL HORIZON SOIL TEXTURE SOIL COLOR SOIL MOTTLING COMMENTS A FINE SANDY LOAM MASSIVE,FRIABLE la'-27' Bw FINE SANDY LOAM MASSIVE,FRIABLE 27'_47H Cl GRAVELLY LOAMY REDOX. GRANULAR TO SAND BELOW 36' MASSIVE,FRIABLE, FEW ROOTS TO 36' 47-132" C2 SANDY LOAM MASSIVE FRIABLE ESTIMATED SEASONAL HIGH WATER TABLE=36' NO GROUNDWATER SEEPAGE,NO REFUSAL LOT 1-213 ORCHARD HILL ROAD: TEST PIT RESULTS TEST PIT#7 DEPTH SOIL HORIZON SOIL TEXTURE SOIL COLOR SOIL MOTTLING COMMENTS 0-111, A FINE SANDY LOAM MASSIVE,FRIABLE 1'1"-27 Bw FINE SANDY LOAM MASSIVE FRIABLE 2T'-62" Cl GRAVELLY LOAMY REDOX. GRANULAR TO SAND BELOW 42" MASSIVE FRIABLE, FEW ROOTS TO 42" 62"-136" C2 SANDY LOAM MASSIVE,FRIABLE ESTIMATED SEASONAL HIGH WATER TABLE=42" NO GROUNDWATER SEEPAGE,NO REFUSAL TEST PIT#8 DEPTH SOIL HORIZON SOIL TEXTURE SOIL COLOR SOIL MOTTLING COMMENTS 0-61 A FINE SANDY LOAM MASSIVE,FRIABLE 5'-26' Bw FINE SANDY LOAM MASSIVE,FRIABLE 26'-85' Cl LOAMY SAND REDOX. GRANULAR TO BELOW 72" MASSIVE,FRIABLE, FEW ROOTS TO 72" a&'-12T-L C2 SANDY LOAM MASSIVE,FRIABLE ESTIMATED SEASONAL HIGH WATER TABLE=72" NO GROUNDWATER SEEPAGE,NO REFUSAL TEST PIT#9 DEPTH SOIL HORIZON SOIL TEXTURE SOIL COLOR SOIL MOTTLING COMMENTS 0-101, A FINE SANDY LOAM MASSIVE,FRIABLE la'-39' Bw LOAMY FINE SAND MASSIVE,FRIABLE 3a'-115' Cl FINE TO MEDIUM GRANULAR,LOOSE SAND 115'-150" C2 LOAMY SAND MASSIVE,FRIABLE ESTIMATED SEASONAL HIGH WATER TABLE=115" GROUNDWATER SEEPAGE AT 135',NO REFUSAL LOT 1-2B ORCHARD HILL ROAD: TEST PIT RESULTS TEST PIT#10 DEPTH SOIL HORIZON SOIL TEXTURE SOIL COLOR SOIL MOTTLING COMMENTS Ap FINE SANDY LOAM MASSIVE,FRIABLE 19'-27' Bw LOAMY FINE SAND MASSIVE FRIABLE 27'-90" Cl FINE TO MEDIUM HIGH CHROMA GRANULAR,LOOSE SAND BAND AT 48" REDOX. 99'-126' C2 LOAMY SAND BELOW 90" MASSIVE,FRIABLE ESTIMATED SEASONAL HIGH WATER TABLE=90" NO GROUNDWATER SEEPAGE,NO REFUSAL TEST PIT#11 DEPTH SOIL HORIZON SOIL TEXTURE SOIL COLOR SOIL MOTTLING COMMENTS 0-8" Ap FINE SANDY LOAM MASSIVE,FRIABLE 8^-24° Bw LOAMY FINE SAND MASSIVE,FRIABLE E422 Cl FINE TO MEDIUM GRANULAR,LOOSE SAND REDOX. C2 SANDY LOAM BELOW 42" MASSIVE,FRIABLE ESTIMATED SEASONAL HIGH WATER TABLE=42" NO GROUNDWATER SEEPAGE,NO REFUSAL TEST PIT#12 DEPTH SOIL HORIZON SOIL TEXTURE SOIL COLOR SOIL MOTTLING COMMENTS Ap FINE SANDY LOAM MASSIVE,FRIABLE 10"-27' Bw FINE SANDY LOAM MASSIVE,FRIABLE 27"-40" Cl LOAMY SAND MASSIVE,FRIABLE REDOX. qp"-g0" C2 SANDY LOAM BELOW q0" MASSIVE,FRIABLE ESTIMATED SEASONAL HIGH WATER TABLE=40" NO GROUNDWATER SEEPAGE,NO REFUSAL LOT 1-213 ORCHARD HILL ROAD: TEST PIT RESULTS PERC TEST#1 DEPTH OF TEST=52"(IN C2 HORIZON) SOAK 11:03 12" 11:18 9" 11:26 5' 11:38 PERC RATE=4 MINUTES PER INCH PERC TEST#3 DEPTH OF TEST=61"(IN Cl HORIZON) SOAK 11:40 12" 11:55 9" 12:15 5' 12:38 PERC RATE=8 MINUTES PER INCH NOTES: 1. SOIL EVALUATION PERFORMED BY DANIEL O'CONNELL 2. TEST PITS 1, 2, AND 3 WERE WITNESSED BY HEALTH AGENT SUSAN FORD 3. PERC TESTS 1 AND 3 WERE WITNESSED BY HEALTH AGENT RUDY ROTOLO