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Home My WebLink About1995-01-12 Engineer Review DEF SUB FEB--28-95 TU 1 a.48 ;ES ENGINEERING FAX NO,, 172467596 P. 01 t- HAYES ENGINEERING, INC. 603 SALEM STREET WAKEF15LO, MA 01860 NOA-0045 (617) 246-2800 REFER TO FILE #..... _ FAX (617) 246.7596 February 28, 1995 Mr. John Ghessia, P.E, Cofer & Colantonio, Inc, Post-11�" grand fax transmittal r)emo 7671 a,P�q�, From 101 Accord Park Drive, Suite #1 T° Norwell, MA 02061 6-VU. RE: East Pasture Circle r,x N r Fax k North Andover, MA ` ` FAX #((617) 982-5443 Dear John. In response to your letter dated February 6, 1996, we are providing you with the following information: /en1 No commend required. /em As discussed, this change is very small and of no consequence. Item 3 As discussed, this is the existing low area that is presently Pumped to the existing )low area in the vicinity of the 10" pipe, The existing low area in B is essentially self- contained, and it is recognized that the overflow from this area may not be to the low area in the watershed containing the 1 V pipe. However, the flow would still be tributary to the control point 2 comparison point, By assuming the low time of concentration and directing the flow to the head of the 10" pipe, as currently occurs with the pump situation, the existing conditions calculations provide a lower existing conditions outflow at comparison point 2. Therefore, the post development condition being compared at control point 2 is being compared against a conservatively low existing flow rate. The proposed design,mitigates this low flow, as shown in the post-development conditions outlined in TABLE il. The proposed plan incorporates improvements to this low area as part of the managed control of runoff to assist our abutter. This work his been discussed with the abutter, and he' is pleased with the proposal. ` It 4 The flow path has been modified as noted, and the revised time is attached. The change does not result in any significant change. 1 ],U GU JJ iU" iJ+ yV IMILO "11VIIUAL111111A 1 1111 11Vi 1VI IL4U14VV l VL Cofer & Colentonio, Inc. East Pasture Circle, North Andover, MA February 28, 1995 lte Requested information and back-up information has been provided along with a new summary run of the revised conditions, as shown on the revised TABLE I and TABLE II: No real net change resulted from the change. It r 6 The word "optional" will be removed from the sub-drain detail. Item rscussed with DPW- no problem. Ite I Discussed with DPW- no problem. item 9 The detention basin does not have a retaining wall. The tree well is comprised of .dry field masonry. See attached Commonwealth of Massachusetts Highway Department detail. item The proposed detention basin will be modified to include a rip rapped weir overflow section to the toe of the slope, The weir will be 5 feet wide, with 1;2 side slopes on each side. The bottom of the overflow will be set at 191.50, with a top of berm of l5 192.00, This will provide a flow capacity of 5.40 cubic feet per second (cfs). The peak outflow out of the basln, as designed, is 0.99 cfs. IIv"T Item 1 A section will be added to the plans indicating a 5-foot wide top section, with 1:2 ,A side slopes, for areas of the proposed basin needing to be created. vV Item/Discussed with DPW - no problem. �t These items will be incorporated into the final plan as part of the overall approval process. Based upon our discussion and this information, it is our opinion that further review is not required, Please feel free to call if you have any questions regarding this matter. Very truly yours, William R. Bergeron, P.E. Project Engineer WRBldab Enclosures cc: Mike Howard - FAX # (508) 682-299G FEB-28-95 `SUE 15;49 HAYES ENGINEERING FAX NO. ,16172467596 i' 03 .J 1 Mitigative Drainage Analysis East Pastore Circle, North Andover, MA January 5, 1995 DETENTION BASIN PERFORMANCE SUMMARY PROPOSED CONDITION EAST PASTURE CIRCLE NORTH ANDOVER, MASSACHUSETTS TABLE I STORM EVENT PEAK FLOW IN PEAK FLOW OUT MAXIMUM cfs ofs WATER LEVEL 1 Yr. 0.20 � 187.92 Yr 1,18 ' 0.28 '' 1$8.16 10 Yr, 2,96 0,48 189.11 } 14"3 ,85 Outlet control structure: 4" diameter orifice discharge at elevation 187,50 Manhole overflow weir at elevation 190.83 Emergency overflow at elevation 191,50 Top of berm at elevation 192.00 ` ` l ?i- 1,\ .•+:.:i is i` •` `�` - ' • .ti ',1:y,,,it L.'.;,,,j._ ;.':' .h.� �} ', r . FEB-28-95 TUE 15:50 HAYES ENGINEERING FAX N0, 16172467596 P104 Mitigative Drainag6 Analysis � East Pasturo Circle, North Andover, MA �' ! January 5, 1995 COMPARATIVE ANALYSIS EAST PASTURE CIRCLE NORTH ANDOVER, MASSACHUSETTS SUMMARY OF FLOWS TABLE lI STORM COMPARISON EXISTING PROPOSED CHANGE EVENTS POINTS CONDITION CONDITION cfs cfs oft 1 0.06 `' 0,03e - 0.03 1 Yr. 2 0.94710 0--m {6$ -Q-43-0,it e 2.6"124 hr. 3 0.23 0.27 + 0.04 4 0.08 0.08 0.0 1 0.10 .f 0.07 - 0.03 2 Yr. 2 4,u I.zs 4-.4a(3� 1-OZ - 0�-.�a 3.1"/24 hr. 3 0,61 0.65 « + 0.04 4 0,19 -� 0.19 - 0.0 • i 1 0.25 0.20 - 0.05 ' 10 Yr. 2 21"3151 2:26 211Gv ,�•t. F� 4,6"/24 hr. 3 2.38 - 2,33 v' - 0.05 4 0.63 0.63 0.0 100 Yr. 1 0.54 v 0.47 -' - 0.07 7.0"124 hr. 2 7-461.40 4-42 4-M 3 6.20 u 5.89 ✓ - 0.31 r 4 1,51 1,51 0.0 Cnm ariso0,.�aints ; n � 1 Flow to westerly watershed off slte 2 Flow to northerly watershed off site 3 Flow to northeasterly watershed off site FEB-28-95 TUE 15:50 HAYES ENGINEERING FAX N0, 16172467596 P. 05 TR20 Xt4 02-ZB-95 07,.29 EAST PASTURB ESTATES EXISTING CONDITION JOB 1 SUMHARY R1.V PC 09/03(.2) TTP6 III STORM DISTRIBUTION 24 HOUR DURATION PAGE 37 SUMMARY TA41.0 1 • SELECTED RESULTS OF STANDARD AND EKECUTIVC CONTROL. 1NSTkUCTIONS IN THE ORDER PERFORMED (A STAR(*) AFTER THE PEAK DISCHARGE TIME AND RATE (CFE) VALUES INDICATED A FLAT TAP HYOROCRAPH A QUESTION HAPK(?) INDICATES A HYCROGRAPH 9ITH PEAT: AS LAST POINT,) SECTIOu/ STANDARD RR IN ANTEC MAIN PRECIPITATION PEAK DISCHAPGE STRUCTURE CONTROI. DRAINAGE TABLE MOIST TIME ..-- ------••• RtlHOFF ---------------- Ib OPERATION AREA 0 COAD IRCREM BEGIN AMOUNT DURATION AMOUNT CLEVATICN TIME PATE RATE (Sa MI) (HR) (HR) (IN) (HR) (IN) (FT) (HR) (CFS) (CSM) ALTERNATE 1 STC.Rm 1 XSECTION 1 RUNOFF 100 9 2 .08 .0 2.60 24.00 '33 --- 12,24 .06 202.6 XSECTION Z RUNOFF .00 9 2 .08 .0 2.60 24,00 .22 --- 12.64 .05 46.3 XSECTION 3 RUNOFF .00 9 2 .08 .0 2..6m 24.00 .t6 --- 12.48 07 3515 W.C7,10N 4 AODHYD .00 9 2 .08 .0 2.60 Z4.00 .19 ... 12.56 .12 35.5 STRUCTURE i RESVOR 100 9 2 .08 ,0 2.60 24,00 .19 186.31 12,56 .12 38.4 XSECTION 5 RUNOFF ,00 9 2 .O9 .0 2.60 24.00 .95 ••• 12.24 .47 489.Z XSECTIAN 6 ADDHYD ,00 9 2 .0$ .0 Z.61) 24.00 .38 --- 12.32 .$1 128.2 SIRUGIURE 2 RESVOR .00 9 2 .08 D 2.60 24.00 .38 184-53 12.32 .46 116.4 XSECTION 7 RUNOFF .00 9 2 .08 .0 2.60 24.00 .46 --- 12,32 .33 222,1 XSECTION 8 ADT5NYD .01 9 2 .08 10 2.60 24.00 .40 --- 1'2.52 .79 145.2 XSECTION 9 RUNOFF .01 9 2 .06 .0 2.60 24,00 .20 --- 12.48 .25 43.5 XSECTION 10 RUNOFF .00 9 2 '08 .0 2.60 Z4,00 .22 ••• 12.32 10$ 79.9 ALTERNATE 1 !,]ORM 2 XSECTION 1 RUNOFF .00 9 2 .08 .0 3.10 24.00 .56 12.,24 ,10 341,9 XSECTION 2 RUNOFf .00 9 2 .08 .0 3.10 24.00 .4Q --- 12.56 .13 11015 XSECTION 3 RUNOFF .00 9 2 08 .0 3.10 24.00 .33 - - 12.40 .20 105.9 XSEM ON 4 ADOHYO .00 9 2 .08 .0 3.10 24.00 .36 12.48 .3S 1D1.8 STRUCTURE 1 RESVOR .00 9 2 108 .0 3.10 24.00 .36 186.41 12.48 .31 102.7 XSECTION 5 RUNOFF .00 9 2 .08 ,0 3.10 Z4,00 '.32 12,24 .65 676.8 X5tCT19N 6 ADOHYO ,UO 9 2 OA 0 3.10 24,00 .59 17_132 .85 214.7 STRUCTURE 2 RESVOR .00 9 2 Q$ .0 3.10 24,00 59 Ift4.55 12.40 .77 1V1.I XSECTTON Y RUNOFF .00 9 2 As .0 3.10 24.00 .72 -- 12.24 .54 363.2 YSECTION 0 ADDHYD .01 9 2 .08 .0 3.10 24.00 .62 --- 12.31 1.28 233.7 XSECTION 9 RUNOFF .01 9 2 .08 .0 3.10 24.00 .37 --- 12.40 .6t 114.3 XSECTION 10 RUNOFF .00 9 2 -08 .0 3.10 24.00 .40 --- 12.24 .19 1ga.b ALTERNATE 1 STORM 3 XSECT;ON 1 RUNOFF .00 9 2 .Ott .0 4.60 24.00 1.59 •• 12.24 .25 840.0 XSECTION 2 RUNOFF .00 9 2 .08 .0 .4,60 24.00 1.12 12.48 .47 407,7 XSECTION 3 RUNOFF 100 9 2 .08 .0 4.60 24.00 1.01 •-- 12.3z .80 MCTION 4 ADOHYD .00 9 Z .08 .0 4-60 24.00 1.05 12,38 1.25 414.2 STRUCTURE 1 RE WOO .00 9 2 .08 -0 4.60 24,00 1.05 156.90 12.40 1.25 413.8 FEB-28-95 TUE 15:61 ; 7S ENGINEERING FAX NO. f172467596 P. 06 TR20 XVO 02-26-95 07:2.9 EAST PASTURE ESTATES EXISTIND CONDITION JOB 1 SUMMARY R[:V PC 04/83(.2) TYPE III £YORM DISTRIBUTION 24 HOUR DURATION PAGE �8 SUMMARY TABLE 1 - SELECTFD RFIWLTS OF STANDARD AND EXECUTIVE CONTROL INgTRUCT10NS IN THE ORDER PCRFORMCD (A STAR(') AFTER THE PEAK DISCHARGE TIME AND RATE (CFS) VALUES INDICATES A FLAT TL)P HYDROGRAUH A QUESTION MARK(?) INDICATES: A HYDROGRAP8 WITH PEAK AS LAST POINT.) 5ECTf0N/ STANDARD RAIN ANTEC MAIN PRECIPITATION PEAK DISCHARGE STRUCTURE CONTRDL DRAINAGE TABLE MOIST TIME ............ ------- RUNOFF -------- ^•••••.•. .. ID OPERATION AREA 11 C00 INCREM BEGIN AMWNT DURATION AMOUNT ELEVATION TINE RATE RATF (SO HI) (HR) (HR) (IN) (HR) (IN) (FT) (HR) (CFS) (CSM) ALTERNATE 1 STORM 3 XSECTION 5 RUNOFF ,00 9 2 .08 .0 4.60 24.00 2.54 --- 12,7,4 1.23 1279,7 XSECTION 6 ADDHYO .00 9 2 .08 .0 4.60 24.00 1.41 --- 12,30 2.32 584.0 STRUCTURE 2 R£5VOR .00 9 2 .08 .0 4.m 24.00 1.41 184.6? 12.33 2.27 570.4 X&ECTION 7 RUNOFF .00 9 2 .08 .0 4.60 24,00 1.66 --- 12.25 1.30 870.2 XSECTION 8 ADDHYD .01 9 2 D8 0 4.60 24.OD 1,48 --• 12.29 3.51 642.5 XSECTION 9 RUNOFF .01 9 2 .08 .0 4.60 24,00 1,07 ... 12.38 2.38 444,E XSECIION 10 RUNOFF .00 9 2 .08 .0 4.0 24,00 1,13 --- 12.24 .63 613.0 ALTtRNATII 1 _STORN 4 XSCCTION 1 RUNOFF S .00 9 2 .05 .0 7.06 24.U0 3.39 --- 12.24 .54 1767.7 XSECTION Z RUNOFF .00 9 2 .08 .0 7.00 24.00 2,68 --- 12.43 1.23 1054.5 XSECTION 3 RUNOFF ,00 9 2 .08 .0 7.00 24.00 2.49 --- 12.32 2.16 1165.0 XSECTION 4 ADDHYP .00 9 2 .08 .0 7.00 24.00 2156 --- 12.35 3.32 1098.9 STRUCTURE I RESVOR .00 9 2 .08 .0 7.00 24,00 2.56 188.00 12.4.4 3.O6 1012.1 XSEC11OR 5 RUNOFF .00 9 2 .08 .0 7.00 24.00 4,68 --- 12.22. 2.20 2290.5 XSECTION 6 ADDHTO .00 9 2 .08 .0 7.00 24.00 3.07 - 12.29 4.88 1226.6 STRUCTURE 2 RESVOR .00 9 2 .0$ 0 7.00 24.00 3.07 184.68 12.31 4.82 1211.6 ?(SECTION 7 RUNOFF 00 9 2 .08 .0 7.00 24.00 3.50 --- 12.23 2,69 IB07.1 YSs:CTION 8 A60HYD .01 9 2 .08 10 7.00 24.00 3.18 --- 12.27 7.40 1352.8 XRECTION 9 RUNOFF ,01 9 2 .08 .0 7.00 24.00 2.59 ... 12.35 6.20 1156.7 XSECIIoN 10 RUNOFF 00 9 2 .03 0 7.00 24.00 2.69 --- 12.22 1.51 1473.9 FEB-28-95 TUE 15:51 HAYES ENGINEERING FAX NO. 16172467596 Pr07 TR20 XE4 02-2a-95 07;29 EAST PASTURE: ESTATES EXISTING CONOTTION JOB 1 S REV PC 04/83(.2) TYPE III STORES D[ST4IsuTION 24 HOUR WW I% M,1kY PACE 39 SUMNAkY TABLE 3 DISCIEARGE (CFS) AT XSECTIONS AND STRUCTURES FOR ALL STORMS AND ALTERNATES XSECT[ON/ DRAINAGE STRKT€JRE AREA STORES WJPIBER5......,.,, 1D (so Ml) 1 2 3 4 STRUCTURG 2 _ .00 ALTERNATE 1 .46 177 Z.27 4,82 STRUCTURE 1 .00 ALTEPUAtf 1 .1Z .31 1.25 3.06 XSECTMN 1yw .00 ALTERNATE? 1 .06 .10 .25 .54 XSECCv101 2 .00 AI.TE'RNATE 1� .05 .13 .47 1.23 XSEGTION 0r1 ALTERNATE 1 .07 .20 .80 2.16 XSECTION 4 _ GO A€TERRATE 1 112 .31 1.25 332 XSECTION. 5_� ,OG ALTERNATE 1 .47 .65 1,23 2.20 XSEr ION 5 .04 ALTERNATE 1 .51 '85 Z.32 4.88 XSECT 1 ON 7 .. .00 ALTERNA'BE 1 33 .54 1.30 2.69 XSECT I ON .., 8 .. ..__ ..01 AtTERNAYE 1 .79 1.2$ 3.51 7.40 XSECT[ON 9 _ .01 ALTERNATE 1 .23 .61 2.38 6.20 X&UTI01{_ To „ .00 ALTERNATE 1 .06 .19 .63 1.51 � � .• til .. - i• / , }' ♦ I I f. i {` [1 * .. ate• •.L �__�..�.3_ ,._...._....,.... .,t. .:>~.._1_,._�...t. .f.'�s•�-'i�..�....._�'.t .a.,....... �. _.'S\ _:u_".i`..i_+u'_...wic.l.�laYt_._:.A" a _.u_'�a-.r.�_\ ..\__. ._ _ FEB-28-95 TUE 15 F 52 IIAYES ENGINEERING FAX N41 16172467596 P. 08 II, IR20 XSQ 02-28-95 07:35 EAST PASTURE ESTATES PROPOSED CON01110N JOB 1 SUMHARY RCV PC 09/83(,2) TYPE 111 STORM AISTRIBUT[ON 24 HOUR DURATION PATE 42 SUMHARY TA8t.E 1 . SELECTED RESULTS OF STANOARD AND EXECUTIVE CONTROL INSTRUCTIONS IN THE ORDER PN.RFORMf:T) (A STAR(*) AFTER TUE PEAK DISC11ARt1L' TIME AND RATE (CPS) VALUES INDICATES A FLAT TOP NYDROGRAPH A OUGSTION MARK(?) INDICATES A HYDROGRAPK 11ITH PW AS LAST FlOtHl.) $ECiIOIY/ STANDARO RA[k ANTEC MAIN PRECIPITATION PEAT; DISCHARGE STRUCTUfi[i CONTROL DRAINAGE TABLE MOIST TIME •------••••-------------- RUNOFF ---------- ......•--.--•------------- .. tb OPERATION AREA 9 COND INCREM 6EGIH AMOUNT DURATION AMOUNT ELEVATION TIME RATF RATE (SO MI) (I10 (HR) (IN) (HP) (1N) (FT) (8R) (CFS) (C5M) ALTERNATE 1 STORF! 1 XSECTION 1 RUNOFF .00 9 2 .05 ,0 2.60 24.00 17 -- 12,3P. '03 113.2 X51CTION 2 RVNQFf .00 9 •2 ,08 .0 2.60 24.00 .50 •• 12.48 .26 167.4 )(SECTION 3 RUNOFF .00 9 2 .08 .0 2.60 24.00 .46 12.40 .41 185.8 XSECTION 4 ADDNYD .00 9 Z .08 .0 2,60 24.00 .48 1Z,40 .65 174.4 XSECTION 5 RUNOFF .00 9 2 .08 .0 7..60 24.00 .23 12.24 .07 140.0 XSECTION 6 AODHYD .00 9 2 .08 .0 2.60 24.00 .45 12.40 .69 161.7 STRUCTURE 1 RESVOR .00 9 2 .08 .0 2.60 24.00 .39 187.92 13.297 .20? 47.3 XSECTION 7 RUNOFF .00 9 2 .08 .0 2.60 24,00 1.12 --- 12.24 M 577.7 XSECTION 6 ADDWD ,00 9 2 .03 .0 2.60 24.00 50 --- 12.32 .40 80.8 SYR11r,.TIIRE 2 RESVOR .00 9 2 .08 .0 2.60 24,00 .49 184,53 12.32 .38 16.7 XSEC11ON 9 RUNOFF 100 9 2 .08 .0 2.60 Z4,00 .62 •-• 12.24 .31 31.3.6 XSECTION 10 ADDHYO .01 9 2 .08 0 2.60 24.00 .52 --- 12.32 .68 114.7 XSECTION 11 RUNOFF .00 9 2 .08 .0 2.60 24.00 .22 --" 12.48 .27 54.7 XSECTION 12 RUNOFF .00 4 2 .08 .0 2.60 24.00 .22 --- 12.32 .08 79.9 ALTERNATE 1 _STTORM 2 XSECT104 1 RUNOFF .00 9 2 OS ,t) 3.10 24.00 35 --- 12.32 .07 218.8 X$ECTtON 2 RUNCIPF DO 9 2 .08 .0 3.10 24.00 .76 ••• 12.4 8 .43 277.1 XSECTION 3 RUNOFF 100 9 2 .08 .0 3,10 24.00 .72 - 12,32 .69 314.4 XSECT[ON 4 ADDHYD .00 9 2 .08 .0 3.10 24.00 .Y4 12,40 1.0E 290.2 XSECTION S RUNOFF .00 9 2 .O8 10 3.10 24.00 .47 --- 12.24 .14 265,3 XSECTION 6 AODHYD .00 9 Z .08 .0 3.10 24.00 70 --- 1Z,35 1.18 276.9 STRUCTURE 1 RE$VOR .00 9 2 .08 4 3,10 24.00 .64 1A8,16 13.44? 2$? 64.9 XEECTION 7 RUNOFF .00 9 2 D8 .0 3.10 24.00 1.52 12,24 .53 775.3 X$E(;TION 8 ADOHYD .00 9 Z .08 .0 3.10 24.00 .77 12.3Z .63 127.3 STRUCTURE. 2 RESVOR .00 9 2 .08 .0 3.10 24.110 .76 184.54 12.40 .57 116.3 XSECTION 9 RUNOFF .00 9 2 .08 .0 3.10 24.00 .91 --- 12.24 .47 474.4 W CTION 10 WHYD .01 9 2 .08 .0 3.10 24.W .79 = 12.n 1.02 171.3 XSECTION 11 RUNOFF .00 9 1 .08 10 3.10 24.00 .40 --- 12.40 .65 132.3 XSECTION 12 RUNOFF -00 9 2 .00 .0 3110 24.G0 .40 --• 12.24 .19 188.6 ALTERNATE i STORM 3 XSECTION 1 RUNOFF .00 9 2 .08 .0 4.60 24.00 1.25 --- 12..24 .20 654.7 voE,•Y I.110 ') GNtt.n[[ AA O O %a n . - w n11 1 7Y -__ A4 /A - . ns - . .�.._.�.-.. t_�_ _... ..� ,.._ -_..l__. .�.___.• _-..._._1. i_..�._._.., ._..... :,. ._,..,. -.nf.3.e.�1�-F..JC .._._. .._..•... <. .� s, -s l t� � 1 '�... FEB-28-96 TIIE 15:52 HAYES ENGINEERING FAX NO. 16172467596 p. 09 TRTO XEG 02.28-95 07:3S EASY PASTURE ESTATES PROPOSCD CquDITION RCY PC 09/83(.2) TYPE III STORM DISTRIBUTION 24 HOUR DURATION JOB 1 SUMMARY PAGE 43 SUMMARY TABLE 1 - SELECTEA RESULTS OF STANDARD ANC EXECUTIVE CONTROL, INSTRUCTIONS IN THE NM PERFORMED (A STAR(*) AFTER III[ PEAK DISCHARGE TIRE AND RATE (CFS) VALUES INDICATES A FLAT TOP HYDROGRAPN A QUFSTIOH NARK(?) INDICATE, A HYDROCRAPH WITH PEAK AS LAST POINT.) SECTION! STANDARD RAIN ANTEC MAIN PRECIPITATION PEAK DISCHARGE STRUCTURE CONTROL DRAINAGE TAKE MOIST TIME ...••-- ----------------- RUNOFF -- ID OPERATION AREA # CONO IHCREM BEGIN AM(XJYT DURATION AMOUNT ELEVATION TIME RAte RATE (SO MI) 0R) (HR) (IN) (HR) (IN) (FT) (HR) (CFS) AI_TLRNATE 1 STORM 3 XSECTIDN 3 RUNDpP ,00 9 2 .08 .0 4,60 24.00 1.66 ••• 12.52 1.70 XSECTIDN 4 ADDHYD ,00 9 .2 106 .0 4.60 24,00 1.69 --- 12,35 2,69 720.8 XSECTIDN 5 RUNOFF .00 9 2 .06 .0 4.60 24.00 1.32 •-- 12.24 38 728.9 XSECTIDN 6 ADDHYD .00 9 2 .08 .0 4.60 24,00 1,64 ••• 12.32 2,96 695.6 STRUCTURE 1 RESVOR .00 9 2 .08 .0 4.60 24.00 1.54 189.11 13.6,°? 148? 114,0 XSECTIDN 7 RUNOFF D0 9 2 .08 .0 4.0 24.00 2.80 •- 12.24 .96 1394.7 XSFCTION 8 ADDHYD DO 9 2 .08 _0 4.60 24,00 1.71 12.24 1.25 252.5 STRUCTURE 2 RESVOR .00 9 Z .08 .0 4.60 24.00 1.71 184.58 12.32 1.19 240.0 XSECTIOV 9 RUNOFF .00 9 2 .08 .0 4.60 24.00 1,96 12, XSECTIDN 10 ADO HYD .01 9 2 24 1364. •08 .0 4.hD 24,A0 1,75 --- 12,27 2-16 16 64,2 XSECTIDN 11 RUNOFF .00 9 2 .08 .0 4.60 24,00 1.13 12.37 2.33 475.8 XSECTIDN 12 RUNOFF .00 9 2 .08 ,0 4.60 24,00 1.13 - t�.Z4 .63 613.0 ALTERNATE, t STORM 4 XSECTION I RUNOFF .00 9 2 .08 .0 7.00 24.00 Z,88 ••• 12.24 .47 1519,2 XSECTIDN 2 RUNOFF .00 9 2 .08 .0 7,00 24.00 3.$9 12,41 2.22 1437.6 XSECTIDN 3 RUNOFF -00 9 2 .08 ,0 7.00 24.00 3.50 12,31 3.61 1647,0 XSECTIDN 4 A00KY0 Do 9 2 .08 .0 7.00 24.00 3.54 --- 12.33 5.72 1531.1 XSCCTION 5 RUNOFF 00 9 2 .08 .0 7,00 24.00 2,99 ••• 12.24 .84 1621.9 XSECTIDN 6 ADDHYD .00 9 2 .06 .0 7.00 24.00 3.47 --• 12.30 6.35 1492.5 STRUCTURE 1 RESVOR .00 9 2 .08 .0 7.00 2.4,00 2.93 100.85 13.607 .907 233.4 XSECTIDN 7 RUNOFF .00 9 2 .08 .0 7.00 24.00 5.01 •• 12.22 1,66 2414,1 XSECTION 8 ADDHYD .00 9 2 .08 .0 7.00 24.00 3.22 - 12.25 2.15 435.0 STRUCTURE 2 RgSVOR .00 9 2 .08 .0 7,00 24.00 3.20 184.62 12.28 2.14 434,1 XSECTIDN 9 RUNOFF 60 9 2 108 .0 7.00 2440 3.92 --• 12.23 €.99 2000.4 XSECTIDN 10 ADIIHYD .01 9 2 .08 .0 7,00 24.00 3.32 --- 12.24 4.09 688.5 XSECTIDN 11 RQR0FF .00 9 2 .08 .0 7.00 24.00 2,68 --- 12,34 5,89 1203.7 XSECTIDN 12 RUNOFF .00 9 2 .08 .0 7.00 24.00 2.69 -- 12.22 1.51 i4Y3.9 FEB-28-95 TUE 15;53 6�ES ENGINEERING FAX N0,� i617246759E P. 10 T920 XEQ 02-28-95 07:35 EAST PASTURE ESTATES PROPOSER CONDITION .)OE I SUMMARY RtV PC 09/83(.2) TYPE III STORM DISTRIBUTION 24 HOUR DURATION PAQE 44 SUMMARY TABLE 3 • PIWIARCE (CPS) AT XSECTIONS AW STkUCTURES FOR ALL STORMS ANO ALTERNATES XSECTION/ DRAINAGE STRUCTURE AREA STORK HUM@ER$.......... ID (54 MI) 1 2 3 4 STRUCTORE 2 .00 ALTERNATE _.,1 .38 6'l 1.19 2.14 STRUCTURE 1 1,00 ALTERNATE 1 . .20 .28 .48 XSrCTION 1.. . .00 ALTERNAT{ 1 .03 G7 .7,0 .47 XSECTION 2 00 ALfkRNATI 1 .26 .43 1.04 2.22 XSECTION 3 .00 ALTERNATE 1 .41 .69 1.70 3.61 XSECTION 4 00 ALTERNATE 1 65 1.68 Z.69 5,72 XSECT I ON 5,.r W .00 ALTERNATC 1 .07 .16, .3g .84 XaECTION 6 00 ~ALTERNATE 1 .69 1.10 2.)6 6.35 XSECTION 7 `.00 ALTERNATC S 140 .53 .96 1.66 XSECTION 8 .00 ALTERNATE 1 .40 .63 1.25 2.15 XSECTION 9 .00 . ALTERNATE 1..� .31 .47 1.02 1.99 XSECTION 10 .01 ALTERNATE 1 .68 1.02 5.16 4.09 XSECTION �1.1 .00 AITERNATE 1 .2Y .65 2.33 5.89 XSECTION 12 .00 ALTERNATE 1 .08 .19 63 1.51 n :54 HAYES ENGINEERING FAX N0, 16172467596 P, 11 FEB-28-95 TUE 15 �9kv1sk� TR--55 To and Tt THRU SUBAREA COMPUTATION VERSION 1. 11 Project : tAST PASTURIk ESTATES User: wrb Date: 01-0.3-95 CoQnt<y State: Checked: Date: _ Subtitle.: EXISTING CONDITION WATERSHED ASSESSMENT --- '------------ -------------- subarea #1 -- A ----_---------------------------- Plow Tyne 2 year Length Slope Surface n Aroa Wp Velocity Time rain (ft) (ft/ft) code (sq/ft) (ft) (ft/sec) (hr) sr,ect 3 . 1 �5 . 0� �, --__ ,-___-_---0. 163 Time of Concentration = 0. 16* -------------------------------- Subaru #2 - Flow Type 2 year Length Slope Surface n Area Wp Velocity Time rain (ft) (ft/ft) code (scl/ft) (ft) (ft/seo) (ter) T^^ Sheet 3 . 1. 100 . 008 H 0. 525 Shallow Conce.nt:'d 60 . 005 U 0.015 Time of Concentration = 0. 54* -------------------------------- Subarea #3 --- . ----------------------------- FloW Type 2 year Length Slope Surface n Area Wp Velocity Time rain (ft) (ft/ft) code (sq/ft) (ft) (ft/sec) (hr) ------------------------------------------------------------------------------- Skeet 3 . 1 100 .03 H 0. 309 Shallow Conoent'd 260 .0625 U 0.018 Time of Content~ration = 0 . 33* --------------------------------- Subarea #4 - D Flow Type 2 year Length Slope Surface n Area Wp Velocity Time rain (ft.) (.fit/ft) code (sq/ft) (ft) (ft./sec) (hr) -------------------------------------------------------------------------------- Sheet; 3 . 1 100 . 037 F 01189 shallow Concent'd 65 . 18 U 0. 003 Time of Concentration - 0. 1.9* FEB-28-95 TUE 15:54 HAYES ENGINEERING FAX NO, 16172467596 1' 1� lUvIsUb i t TR-55 Tc and Tt THRU- SUBAREA COMPUTATION VERSrON 1 . 11 Projtctr t EAST PASTURE ESTATES User: wrb Date: 01 .03-95 County state: Checked: Date: Subtitle; EXISTING CONDITION WATERSHED ASSESSMENT -------------------------------- Subarea #5 - E -____- _--W --- _-_ Flow Type 2 year Length Slope Surface n Area WpVelocity Time rain (ft) (ft/ft) code (sq/ft) (ft) (ft/sec) (hr) ----------------------------------------- Sheet_ 3 . 1 100 . 03 F 0. 205 Shallow Concent 'd 100 . 03 U 0. 010 Shallow Concent'd 140 . 048 U 0. 01.1 Time of Concentration = 0. 23* - --------_- ------ Subarea f 6 - F ---------------------------------- Flow Type 2 year Length Slope surface n Area wp Velocity Time raln (ft) (ft/ft) code (sq/ft) (ft) (it/sec) (hr) --------------------------------------------- Sheet 3 ' l 100 . 029 H 0. 318 Shallow Concent'd 200 . 009 U 0. 036 $hallow Concent 'd 250 . 034 U 0. 023 Time of Concentration = 0. 38* -------------------------------- Subarea #7 - G - T- Flow Type 2 year Length Slope Surface n Area Wp Velocity Time rain (ft) (ft/ft) code (sq/ft) (ft) (ft/sec) (hr) --------------------------_----------------------------------------------------- Sheet 3 . 1 100 .12 F 0. 118 Shallow Concent 'd 60 . 12 U 0. 003 Time of Concentration = 0. 12* ---- Sheet~ Flow Surface Codes A Smooth Surface F Grass, Dense --- Shallow Concentrated -- - D Fallow (No Res. ) G Grass, Hurmuda --- Surface Codes --W C Cultivated < 20 % Reis. H Woods, Light P Paved 0 Cultivated > 20 % Res. I Woods, Dense U Unpaved E Grass-Range, Short FEB-28-95 TUE 15,.55 H1-11LS ENGINEERING FAX NO, ,472467596 P, 13 The following are the discharge equations used by the flood routing program: Definition of terms for the following equations: Q = Flow rate; c. f .s .- D = Pipe diameter; feet A = Area; square feet H = Ileadl measured from the flow line; feet h = affective Weir height, feet L = Weir length; feet g = Gravitational acceleration, 32. 2 ft/sec2 C = an emperically derived factor A. PIPE PLOW EQUATIONS: i ) Horizontal. pipe - 0. j �� -' OOS(l2 P) '' '��C� F e 0 < P 4 ? CA {25,q).5 F'oP ti=1.2 0 ii) Stand pipe: �2 A P. B_ WEIR FLOW EQUATIONS; Q : C !-fir i) Sharp crested weir: C r- 3,2 7 ii ) Broad crested weir: iii) Roadway section weir; C = C.7 ...._..:..i:. �5...,.. ..... _�....::�'.�_.«�.�...�..._. •f ...._..__.,._.._�..�._.-....e��._i._.:..._.,.�� ...�.1.y_,�� ...i.,,.:..,u.L��y:shl.in.:......._.i.�.,....?......-.«.....:a,:..S1.uiL..:.�. �s I FEB-28-95 TUE 15:55 HAYES ENGINEERING FAX NO, 16172467596 P, 14 REFER TO FILE # NAME DATE HAYES ENGINEERING, INC. 603 SALE`M STREET' MADE BY WAKE;EIELD, MA 01880 MEMO TEL.: (617) 246.2800 FAX: (617) 246-7596 � CALCULATION do�" 1 �I , o &DOO © ,0kS-f I � aS�oo � 1��,.. a.o��a ��Z,. v , c��.'1 �►5� U ,u3S�2�1 � v. �,� } IV �a 0 �f'`Y O r 1 3 1 ""O .�,:,;� ! �p . �3 (p '� j j c� 3 1 � lD�c,� S� � , 1 '�. 1"'1 ��•� d � 3 43 9 � Cc"� a •?� 4 is 1co c�a►33 _ �1 USc wva 1 Plik u4Tt0 set �WZ.h Lin r t-c FEB 28 95 TUE 15:56 HAYES ENGINEEK1NU I'BA NU, 1blfeg0(08b r io REFER TO FYLE # N6 —oo = NAME DATE -� HAYES ENGINEERING, INC. MACE BY 603 SALE"M STREET .- WAKEFIELD, MA 01880 ❑ MEMO TEE,.: (617) 246-2800 FAX: (617) 246.7596 �' CALCULATION IN 1 J 4('�4 'o,Otc)5('6 0, G .,c>'.1 ,?.4-7— a. u,•�•` �.� � �SulLb � 1 �0 O,CLJ !,.�> © • GU�'�G11 �nc�,��{�7°,. •gip r'63 10 3�4'a 77 ` F e 1 �.� . �i,d 7. � {)+?�' �11`�j4 k. �cnS rc i' C?�—• f vG n fro,. E�[� A4-a +�G: � � t� r�G(�•� .. _�. .,u.,.. ..� . _.._ i,.��.4..�_.� _ ... 1 ._ .-. _ ._..... ... .�.,. .., .•i..._5.�..�.z..aj.i.:.s� .,..:.,:�.�'..�.i...�.ix.se;.:d..._.�..._.__..,....�....s .__...,..:,,�.y�L.'r,�.+.. ', �Eg-28-95 TUE 15:56 HAYES ENGINEERING FAX NO, 16172467596 A116 REFER TO FILE # NAME T DATE HAYES ENGINEERING, INC. MADE BY 603 SALRM STREET WAKEFIELD, MA Ci$$0 MEMO TEU., (617) 246-2800 FAX; (617) 246-7596 CALCULATION to oZ Eyoq.Ti4 o `R u, two s F-s O .6 45 1 35� �,(P. ;7 7L% o. ! "� .75(a o .0(001(1 b D,0(001(45 Z4 [0� It 3 (o Z' o � 152-6510 .0 043G?-)'Z_ 0, )o� l� i J GJC�dS it! U)C11`. {//d�lp? :xi rt::.�.�..-.,...... FEB-28-96 TUE 15a67 HAYES ENGINEERING FAX NO. 16172467596 P. 17 TREE WELL OPEN A 1�y ul ? NOTE Ya 12y WOO oT �1= LEIS ► PLAN 0+�1r A1�E11 DRY FIELb ATON[r idAS0N*Y r � 00 WELL ., , �� I FELL TO K 39L.EcTED 'Pi"EAkZ MATERIAL TABLE SHOWING CUBIC YARDS OF DRY STONE MASONRY DiAm. OF DEPTH OF WELL IN FEET TREE IN INCHES I US Z. 2,5 3 33 4 1 S 4 0.51 0.7% 1.01 1.26 1,51 I.76 2,02 2.5z 6 0.53 *.n 1.05 1.31 1.57' t.33 2,10 2.6Z a 0." 0.82 1.09 1,36 1.63 1.90 2.17 2,72 i0 0.56 Q84 1.12 1.41 1.69 1.97 225 2.81 12 OSa 0.$I 1.16 tA6 1.75 Z04 233 2.91 14 0.1><0 0&0 I.20 1.50 1.50 2.10 2.40 3DO IS 0.62 0.93 134 1.55 t e6 2.17 2.48 3.10 I 0.64 0.% 1.25 1,W 192 2.24 2.56 3.20 20 CLAS 099 1.32 1,65 1," 231 2.64 3.30 22 0,60 1,02 US I.70 2D4 234 2.72 3.39 24 0.7q I.05 1.40 L75 U* 2A4 279 3,49 30 0.79 1.13 1,51 IA9 2.27 2.65 3.Ce 3.79 3,6 042 1.22 1.63 2.04 2. '2.a5 326 407 42 OAT 1.31 1.75 lie z.42 3D$ 3.45 4.34 441 OS3 t.40 1 233 2.7! $26 372 4A$ I 54 OAS 1.48 1" 2.41 2.97 3.46 S.l16 493 i0 1.03 1.57 2L►1p 242 3.14 3.4 4 t S 524 _ ..+.....,..�.. --A ter" �AWW ft WUAIM MAY fW tW!! i kN�N \, ,V.,�1" 1 j ti x I V P02 1,vw �v e", COLER & COLANTONIOuz FEB I go RI_JtAtt(�qV ER MISSION 7CONSERVATION cOM February 20, 1995 Mr. Michael Howard Natural Resources/Land Usc Planner Conservation Commission 120 Main Street North Andover, MA 01845 R F,. Engineering Re-view East Pasture Estates Residentiai Development Dear T\lr, Howard: Coler &. Colantonio, Inn, has visited the above site and reviewed the $Ubmittal package as described in our proposal of Febivar), 6, 1995. Our review specifically addressed drainage and storniwater runoff aspects, of the design. It is our undcrstanding that conformance with offior' aspects of the regulations Wolttd be handled by Town stuff. We also compared thle, design assumptions and calculations with standard practiues ou(linod in SCS runoff calculation documents and other standard engineering references. This correspondence is a result of the above review and includes our coinnients on the submittal package. The following information was reviewed: Plans Entitled: 0 "Definitive Plan East Pasture Estates" Sheets I through 4 dated 12/14/94, Prepared by I-layes Eagine-ering, blo, 9 "Existing Walet-shed Map-" 0 "Proposed Watershed 'lYlap" A I o )v i oved wa s the "Mitigative Drainage Analysis" dated January t995 We offer the following coni.ment,N: I The site is located on the easterly side of.Boston Street near the intersection of Boston Street and the Salem Turnpike, The site currently Qoilsijts, of an existing residence ,And outbuildings, together with a dug pond, Most of t1le site is open pasture witl) wooded areas near the northern part of the site. Calculations were perfoillied w5inu'FR-55, TR-20 and other standard wxepiable methodologies. 101 Accord Park Drive, Suite Oiie 617.982-6400 .1 'si Sl , � S ll I t •\�`j .ti` '`` y;�`t �\ '`i i , 1.r -y i S J\ \.ii 1 ` ;• y i >,-'w '1 �. c: \.`` ' f �• „`S. , I t „�;��1�1�14.r:'�4�.4N�at.s]t�.�1!I'a..al_L�.r�-.Ju°rst�l,��.k.il:4b 41.�,.,.x..rr.. .._. t.n+ 2, Watershed area "A" is indicated as being slightly larger under proposed Conditions than under existing conditions. Subarea plans indicate that tlli.s area would be reduced 01 Ixtents cinder proposed conditions. Watershed area "B" is indicated as flowing to the north and discharging into subarea ;`D" oil the Existing Watershed Map (EWM). Based oil contours indicated on the EWM and coni'mied by field inspection, this subarea drains to a low area along the property lisle. If this low lying, area floods, excess runoff would flow to the north across the existing driveway Lind into the existing nand. Singe this low area straddles the Property line. it should be analyzed to determine if the proposed read will impact die. abutter to (he south of the site. The existing and proposed flow path used to determine the t.inle of concentration (rc) in this subarea is not consistent with the c ontourw, The model used ("or existbig conditions assumes that runoff frwn this area flows to the upstream end of the 10" CMP next to the existing shed. This is inconsistent with the contours and flow paths indicated on the EWNL 4. The length of the flow path for subarea "E" on the EWM is longer than the length in the caluultrtions, A longer Tc under existing C011ditio111; will result in a lclvArer existing conditions peak rate of runoff, 5. No information has been provided to indicate how stage-discharge values have been calculated. A cross section indicating the width and elevations of existing overflow areas Lit the 10"' culvert e-Ind the exititiiig pond outflow shouid be provided. The formula and coefficients used to develop weir, culvetl. and orifice discharge values should be provided in the calculations. Since this information has not been provided we Ciiililot Co111111ent' oil they calculation results, G, Filter fabtic slloetlel be required for the sctbdrilin and not be optional as indicatedon the. plan, 7, Storni sewer calculations do include calculations of velocity as required by the ` Re. gkilations, OegulProposed storril, draiats have as little as otie and one foul'feet oCc;over. The ations �. roquire two and one half feet of cover. f 9. 1 detail of the retaining wall in the: proposed detention basin should be provided. 10. The detention basin should have an unierg,ency overflow spillway sized to bass a 100 year Storal bA ffie event that tlV. outlet Structure or i#ilea pipe to the structure is bIockcd. 11. A detail o die construction of the detemion basin dike should be provided. 1 1. IN l 1. 1J, ��I �'•it 1' / 1 �,t 1�•l , '•ti '1f t- N l ; .. �, ;� � •. r .�•l �- ,f '�h - r •� P !` ,:� 't tl':� t r;; tihl �P+_�+ \7 •1 . 1 '1 5 `,i•7;t - + /• ?ttC.��J.{d'..su..�_Prv�A:�-IklA�1JdS.11 17, The design of the dike should include an access route to and along the top for a maintenance ve.htale to access the outlet sti•llC ire. We appreciate the OPPOrtunity to assist the Plaiming Board on this pr(ject and grope that this; il)ro nation is -SW311ci.ent For your needs, It is anticipated that some or the issues raised in this correspondence may be addressed by the Applicant providing, copies of Support data.used in the development of the catculations• We would be pleased to meet ,,%4(h the Commission or the design engineer to discuss this project at your convenience, If you have any questions please do not hesitate to contact us, Very truiy yours, COLER& COLANTONIQ, INC. i fohn C, chessia. P,E. I r P l 1( k �I I�l 3' h �I s� 1=f r 4.