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HomeMy WebLinkAbout1993-12-07 Supplemental Info Def PRD Subdiv Plan DEF SUB CHRISTIANSEN !, INC. PROFESSIONAL. ENGINEERS AND LAND SURVEYORS 160 SUMMER STREET HAVERHII_L, MASSACHUSC.TTS 01830 (508) 373.0310 FAX; (508) 372-3960 SUPPLEMENTAL INFORMA.TIOM -FOR` D E141 NI TI V 1P. R. D. SUBDIVISION PLAN pllS'TMA TREP LOCATl_- its RECORU OWNER WHI T BIRCH CJ 7 CO NS 1 R. INC. & APPLICANT J80 ESSEX ST.N!.A WRENCE tdA. DA T E: 813/93 i 1 i SUPPLEMENTAL INFORMATION FOR THE i DEFINITIVE P.R.D. SUBDIVISION PLAN OF CHRISTMAS TREE ESTATES Index Section I Soil Analysis Section TZ Hydrologic Analysis Section TZT Erosion and Sedimentation Control I SECTION I SOILS ANALYSIS i i SECTION I SOILS ANALYSIS The Soil Conservation Service Survey of Essex County, Northern Part, shows the following soil types found on site: CbB - Canton very stony fine sandy loam, 3 to 8 percent slopes CbD - Canton very stony fine sandy loam, 15 to 25 percent slopes HWE - Hinkley and Windsor loamy sands, steep. MC - Medisaprists, deep; nearly level, very poorly drained deposits of organic material Pe Pipestone loamy sand, nearly level Figure 1: Soil Conservation Service Soils Map shows the boundaries. of the soil types on and around the project site_. CoD Se CbD ' Sr Y MC StC SuB C bB Y 6� SrA RIB SuB m �6Q P c E i - SITE mc c � h ; bC- h RI Su HfC CoC e C rC Ga HWE CoB FIGURE � � SOILS MAP `JCALE ��= 500 SECTION II HYDROLOGIC ANALYSIS 0 I SECTION II HYDROLOGIC ANALYSIS A hydrologic analysis has been performed to determine what impact the development will have on the drainage conditions of the surrounding area. When a site is developed, the characteristics of the land often change in such a way as to increase the amount of stormwater runoff that leaves the site. This analysis will determine the extent of the additional runoff that the development will produce, and also provide a solution that will keep post -� development runoff rates comparable to existing runoff rates. The hydrologic analysis performed for this site consists of the Soil Conservation Service method of determining runoff values and a' computer model that uses a rainfall intensity pattern for an S.C.S. Type II Storm and a unit hydrograph to develop runoff rates. Calculations were performed to compare existing and post development runoff rates from storms of 2 and 100 year recurrence frequencies. As shown on Figure 2: Drainage Area Plan, the area that contributes runoff to the project site consists of the 12 acre project site and 6 acres of additional property that lies to the west of South Bradford Street. This watershed area drains generally from the top of the hill to the west o the site to the large wetland area that lies to the east of the site. Existing and post-devel.opment' runoff rates were calculated to determine the peak rates along the eastern I (downhill) border of the project site. Under existing conditions, the peak rates of offsite runoff during the 2 year and 100 year storm events would be 13 .4 cfs and 50.6 cfs, respectively. Under post-development conditions, if no runoff control was provided, the peak rates of offsite runoff during the 2 year and 100 year storm events would be 14 .4 cfs and 52 . 6 cfs, respectively. Since these figures represent increases of 1 .0 cfs during a 2 year storm and 2 .0 cfs during a 100 year storm, runoff mitigatiori measures, in this case, the construction of a detention area, is required. The 2.6 acres of land that will contribute runoff to the detention area is shown as drainage area 1A in Figure 2 . This area includes all of the land that will contribute runoff to the proposed drainage system, as- well as portions of Lots land 2 which will drain into the detention area by overland flow. Under proposed conditions, the peak rates of runoff that will enter into the detention area during a 2 year and 100 year storm would be 3 .0 cfs and 10 .6 cfs, respectively. The mitigating effects of the detention area would result in peak rates of runoff equal. to 1.4 cfs and 5 . 8 cfs flowing out of the detention area during a 2 year abd 100 year storm. The outflow from the detention area, when combined with the runoff from the remainder of the overall drainage area, results in peak offsite flow rates of 13.2 cfs and 49 .0 cfs during a 2 year and 100 year storm. The following table 1 summarizes the results of the analysis: PEAK RATES OF OFFSITE RUNOFF Existing conditions Proposed Conditions 2 year storm 13 .4 cfs 13 .2 cfs 100 year- storm 50. 6 cfs 49 .0 cfs As the table indicates, the peak rates of offsite runoff will be slightly less under post-development conditions than they are under existing conditions. The following information has been included to support the results of this analysis: i i - Figure 2: Drainage Area Plan - Runoff calculation work sheets for overall drainage area and drainage Area 1A -- Hydrographs for 2 year storm: Overall drainage area and drainage area IA - Detention Area Data for the 2 year storm: inflow/outflow rates and stage/storage data - Hydrographs for 100 year storm: Overall drainage area and drainage area 1A - Detention Area data for 100 year storm: Inflow/outflow 3 rates and stage/storage data r � ,._ , 7bao AMINA-6E 1.A ° 1 • �1 � G FIGURE 2 D 41u>4GF- ARC PLAN `r= 500 ` i Worksheet 2: Runoff curve number and runoff � ate D Project { `fj.I� Y . Location Checked Date Circle one: Present Developed �- 1 . Runoff curve number (CN) Soil name Cover description Area Product and CN 1/ of hydrologic (cover type, treatment, and « �� CN x area e1 7 group hydrologic condition; r; + + C acres c�F N 7 percent impervious; mi unconnected/connected impervious co CO ❑ (appendix A) area ratio) w w P K PC- ,1 w006SIMCNvm-i --FNER- 73 6, 4- 46-71 Z C CIO61 Gb 0 '4 w000s -F/VfZ 60 4 r S Z70r 0 wc�vns — �aor� Zs J� l Z7,S Pe ,Mc ..�,� wy��IQ►�n 90 . 610 540.0 / Use only one CN source per line. Totals = total product _1W,7 M � —lb Use CN = �Zr� CN (weighted) total area 1&0 2. Runoff Storm 111 Storm #2 Storm .13 Frequency . . . . . . . . . . . . . . . yr Z /nU Rainfall, P (24-hour) . . . . . . . . . . . . . . . . . . in Runoff, Q . . . . . . . . . . . . . . in 0181 3r3 (Use P and CN with table 2-1 , fig. 2-1 , or eqs. 2--3 and 2-4.) Longest Flow Path _ZOdO ft , Avg . Slope Tc ZS. Z min . No . of - Time Increments 4 Area Contributing/ Inc . L�, � ac Worksheet 2: Runoff curve number and runoff Project ST Date By ��{�{ Location 4, (`( Checked Date Circle one: Present Develo��ed OVA"(,(- OfeA �1G6 /o/L 4 1 . Runoff curve number (CN) Soil name Cover description 1/ Area Product and CN -- of hydrologic (cover type, treatment, and F—, CN x area group hydrologic condition; ❑ages (]mi percent impervious;unconnected/connected impervious co ono ❑(appendix A) area ratio) E is P. b6fc 67iZ Pe- M c b 6,o Sgv, 0 cbr>, cbD �D 2,v rw,a J" l loUlaS-- CN(+2 62. cbn,l CO .��« 1Mp i2U�U�S 98 015 �9,0 HWl� _ A, Wows_ GOoU / Use only one CN source per line. Totals = � �� 13Z�i7 total product73+-76 Use CN CN (weighted) = total area I610 2. Runoff storm #1 Storm #2 Storm #3 Yr 2. 100 Frequency . . . . . . . . . . . . . . . . . . Rainfall, P (24--hour) . . . . . . . . . . . . . . . . . . in 3+ GA Runoff Q in d+��p �j :S� (Use� P and CN with table 2-1 , fig. 2--1, or eqs. 2-3 and 2-4.) Longest Flow Path ZOOU ft . Avg . Slope `],.S % Tc Z4{ 3 min . too. of Time Inc're€rents 4- Area Contributing/ Tnc . 4,S ac Worksheet 2: Runoff curve number and runoff Project SCSI{M L�I'w " By �3,� Date Z Location Checked Date r Circlo one: Present Developed ( RAWA60 SY�r-PM WRTElZS��4� 1 . Runoff curve number: (CN) Soil name Cover description Area Product CN i/ of and CN x area hydro Logic (cover type, treatment, and �ii r, group cv N /1res hydrologic condition; percent impervious; m unconnected/connected impervious ❑ co man ` (appendix A) area ratio) [- P. PGE.� Pbti Gb if D Lnwvlmf-,meow 4 2-7 , G��3 /�}� ...�rr �'P,OAbWA I 1/0POZY10q q� of 3 Gtj �+- C g i () �� ii li3N ►4t2ir{� �3 laoWnr /#*400�J � s s w� � 61 O Z- 13 8 1/ Totals = Dz�1 + Use only one CN source per line. total Product - 1g4,1 - �4�G Use CN �S�b CN (weighted) = total area z 1f1 2. Runoff Storm !11 Storm U2 Storm #3 Frequency yr ®Q Rainfall, P (24-hour) . . . . . . . . . . . . . . . . . . in 6. Runoff, q . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . in � i � Z .6Z (Use P and CN with table 2--1, fig. 2-1, or eqs. 2--3 and 2-4.) Longest Flow Path J.J0 ft . . Avg . Slope. 7. Tc &7 mina No . of Time Increments Area Con-tributing/ Inc . �, 3 ac CLIENT -- SOUTH BRADFORD STREET DATE -- 7/ 15/93 CONDITION -- EXISTING CONDITIONS - OVERALL DRAINAGE AREA FILE NAME - SBE2 PERIOD STORM :' YE AR(3 TIME. FLOW. TIM& FLOW. E...Et_3URS CF-S HOURS GFS i 9 . W80 7 6ri 8 3 1 13. 37 9. 1 . 27 12. 1 12. 56 I 9. 2 . 45 12. 2 10 W".. 9. 4 . 63 12. 4 2. 87 9. 5 . 63•�r- 12. 5 . 0 6 9. 6 . 6-,3 12. 6 1 . 6 A,. V. ( . 63 12. 7 1 . 62 ',.. 9. 8 . 63 12. 8 1 . 62 9. 9 . 63 12. 9 1 . 6 10 . 63 13 10. 1 . 72 13. 1 1 . 44 10. 2 . 72 13. 2 1 . 2 :) 10. 3 . 81 1.3. i . 99 10. 4 . 81 .13.4 .01 10. 5 . 81 . 91 10. 6 . 81 13. 6 . 81 10. 7 . 01 13. 7 . 01 10. 8 . 81 13. 9 . 01 10. 9. . 81 03 9 . 81 11 . 81 14 u81. 11 . 1 . 99 14. 1 . 72 11 . 2 1 . 26 14.2 �54 1. 1 . 3 1 . 44 14. 3 . 45 11 . 4 1 . 62 14.4 .36 11 . 5 1 . 79 14. 5 . 36 11 . 6 2. 42 14r6 . 36 11. 7 4. 04 1.4. 7 . 36 1. 1 . 8 6. 1 14. 8 F3 > 11 . 9 10. 32 14. 9 . 36 DIRECT RUNOFF - . 89 INCHES AREA IEEE ACRES FOR TIME SEGMENT 1. = 4. 5 AREA IN ACRES FOR TIME SEGMENT 2 = 4. `:t AREA IN ACRES FOR TIME SEGMENT 3 = 4. 5 AREA IN ACRES FOR TIME SEGMENT 4 = 4. '5 PR#0 C;LIF.NT - SOUTH BRADFORD STREET' DATE 7/15/93 9 _ OVERALL DRAINAGE AREA CONDI'i"ION -- PROPOSED CONDIT'IGN FILE NAME - S BP2 V-)ERTOD STirRI'l - 2 YEARS TIME, FLOW T I ME, FLOW. kiOURS CFS HOURS CF6 9 . 08711712 1.2 14. 4 ' ', 1. . '_��' 1 •'. 1. 13. 55 9. '_ T4S 11 . 2 11 . 81. 9r3 , S8 12. 3 6. 97 9. 4 . 68 12. 4 3A � 68 i.: . 2. 23 9„ h < 6£9 12."w 1r74 0 7 68 1'2. 7 1 . 74 , 9„8 . 68 1' . 8 1 .7�i 9,9 . 68 12. 9 1 . 74 t� G6S 13 1 �7.4 1 , 1 . 77 13. 1 1 . 55 10. 2 =77 13.2 1 . 36 10. 3. . 07 13. 3 1 . 06 10. 4 . 07 13. 4 . 91 10. 5 . 97 13. 5 . 37 18. 6 .07 13. 6 87 #.,C1, 7 . 97 13. 7 . 87 _ 1.0. 8 .87 13.E .67 10. 9 . 87. 13. 9 . 87 1. 1 n87 14 . B7. 11. 1 1 . 06 14. 1 . 77' 11 . 2 1 . 36 14. 2 .58 11 . 3 1 . 55 14. 3 . 48 11 . 4 1 . 74. 14. 4 .39 11. 5 1 . 94 14. 5 . 39 11 . 6 2. 61 1.4.6 .39 11 . 7 4. 36 14. 7 . 39 6. 50 14.8 .39 11 . 9 1. 1 . 13 14. 9 . 39 DIRECT RU 0 17:F - 96 INCHES r'a ?Er'� 3.N ACRES FOR TIME SEGMENT 1 = 4. 5 AREA IN ACRES F O R TIME SEGMENT 2 = 4.5 AREA IN ACRES FOR TIME SEGMENT 3 = 4. 5 AREA, IN ACRES FOR TIME SEGMENT 4 = 4.5. � i CLIENT - SOUTH BRADF0HD STREET DATE - CONDITION - PROPOSED CONDITIONS - DRAINAGE AREA 1A ) FILE NAME - SB1A-2 PERIOD STORM - 2 YEARS TIME, FLOW TIE, FLOW, . H0UUB C F S HOURS CFG 9 ^ 026740116 12 2, 98 i ^ 1 1 75 9. 1 . 1 12 ~ 9. 2 . 1 12. 2 . 62 12. 3 . 41 9. 4 . 1 12. 4 . 31 12. 5 . 31 ! 6 9^ ~ ~ . 9. 7 12 7 31 � . 1 .8 �1 . 9. 8 . 1 12^ ' 9.9 . 1 12.9 . 31 � 13 . 31 � 10 . 1 . 1 1 0 1 1��^ | � . 1 ^ �1 � 13 2 1' 10. 2 . 1 . ~ . 10. 3 1 10. 4 . 1 13. 4 ^ 10 5 ^ 1 13. � . 1 l ~ . . 16 | 10. 6 . 1 13 . 17 10. 7 . 1 13. 7 10. 9 . 1 13. 8 . 1 � 1 � 1 1390. 9 . 1 . . 1 � . 1 14 . 1 11 ^ 1 . 21 14, 1 ..11 . 2 31 14. 2 � 1 ` 11 . 3 .31 14. 3 . 11 . 4 . 31 14. 4 . 1 ! . 31 14. 5 ^ 11 . 6 51 14. 6 . 1 . 7 1 � 11 . 7 1 . 03 14 . � 11 . 8 1 . 44 14. 8 , 1 | 11 . 9 2. 37 . 14^ 9 ^ 1 ! � DIRECT RUNOFF - 1 . 02 INCHES � . � AREA IN ACRES F0R TIME SEGMENT 1 AREA IN ACRES FOR TIME SEGMENT 2 . � ' � ` - � ' PROJECT - SOUTH BRADFORD STREET DATE 8/:3/93 �I DETENTION AREA STORK PER1CID '_ YEARS .h IST LEVEL POND AREA -SF 3000 mAX DEPTH -FI 1 214D LEVEL POND AREA-SF 3500 MAX DEPTH -FT 1 , 3RD LEVEL POND AREA -SF 4000 PIPE DIAMETER 1 - FTPE LENGTH 20 SLOPE 5E-0, HANNING COEFFICIENT .013 ENTRANCE COEFFICIENT (10 : COEFFICIENT OP DISCHARGE (C); .79 ANSWER FILE NAME-. SPPOIdD-2 INPUT FILE NAME: SEIA-2 INFLOW INFLOW OUTFLOW OUTFLOW REVISED ACCU•1 ij -- VALUE ACCUll TIME O-VALUE CU FT CFS CU FT MIN CFS 1 01 0 6 0 1 .01 ID 12 1 Sri 01 .07 18 I 90 •01 .43 ,y 1 I26 p1 1.43 1 � 30 62 .01 4.18 1 36 1 162 .01 0.27 42 1 98 234 .02 14.31 48 1 270 .03 23.49 54 1 306 .03 33.8b 1 60 34"2 .04 47.06 66 1 378 .04 63.1 72 1 414 .05 80.(3 78 1 450 .05 . 100.17 84 1 486 07 123.06 90 •1 522 .07 149.46 96 '1 558 08 177.81 102 •1 59k 08 208.12 108 1 630 .06 238.43 1€4 .1 666 .08 268.73 . 120 •1 .08 299.04 126 .21 702 1 331.42 132 757.8 .4 .11 368.04 851 136 .31 851 .16 '416.23 144 •31 963 . 17 476.33 150 .31 1074.6 544.21 156 .31 11136.2 25 625.77 162 .51 1333.8 .35 733.77 1.@3 B95.85 168. 1.44 205055.6 .55 174 274 2.37 1.4 qi 1158.99 180 1.20 1553.94 3704.4 2.90 186 1,37 2031.'5B 192 1.75 4555.13 1.30 2527.44 4982.4 190 6L 5167.8 1,31 3011.55 204 .41 5297.4 1.15 3453.9E1 210 .31 5409 .95 3831.97 216 .31 5520.6 .0 4146.34 222 .31 56322 .68 4413.3 31 4635.53 234 •31 2 5743..8 .55 240 31 5855.4 .51 4826.94 246 31 5967.00001 46 5001.SR 6060.60001 .39 5153.23 �. 252 21 6116.4 .33 5282.49 256 ' 1 6152.4 .3 5396.18 264 •1 ,25 5494.93 6188.4 276 1 b2 ,2 5576.49 24.4 27 1 . 19 5646.95 282 l 6260.4 17 5712.16 29 ' 1 63b296.44 . 17 5774.70 6368..4 24' 1 . 16 5834.89 300 1 6kp4.4 .15 5889.96 306 •1 ,1_r 5937.81 312 .1 6440.4 5980.9�+ 6476.4 •12 3113 I 6512.4 .12 6024.07 324 1 6548.4 ,11 6065.03 330 .1 11 6103.81 6584.4 342 1 6620.4 . 11 6142.58 3 •1 6656. e .11 6101.36 1 4 6692.4 6220.14 348 11 354 l 6728.4 !I 6258.92 360 1 - REV I SED POND POND CHANNE1_ TIME STORAGEDE DEPTH VELOCITY MIN CU FT C T FPS 6 1 0 0 12 1 0 0 is 53.93 • 02 0 24 89.58 . 03 0 30 124.58 04 0 36 1.57.83 . 05 ] 42 189.73 . 06 0 4a 219.7 .08 83 54 246.52 . 09 1. 02 60 272. 15 . 09 1 .02 66 2?4. 94 . 1 . 98 721 314.91 . 11 .913 78 333. 2 . 12 1, 06 84 349. 83 . 12 1 .06 90 362.94 113 1. 17 96 372.511 . 13 102 300. 19 . 14 1 . 105 385.89 . 14 1. 2 114 391 .57 . 14 1.2 120 397-20 ' 14 1.2 1.26 402 96 . 14 1 . 2 132 426.39 . 15 1 .35 1.30 483.36 . 17 1 .36 144 546.77 . 2 1 • 43 150 598.20 .22 1. 42 156 641.99 .24 1.47 162 708.03 . 26 1 . 54 168 877.23 .33 1 .62 174 1159.75 . 44 1.7 180 15 02.41 .62 1 .78 166 2150.46 .85 1.8 192 2524.22 1 1 .74 1.90 2454.96 . 98 1.77 204 2156.25 .88 1c81 210 1843.42 .76 1 .8 216 1577.0-3 .65 1 .79 222 1374.26 , 56 1.77 228 1218.9 . 5 1 .73 234 1108.27 .44 1 . 7 240 1029. 46 . 41 1 .69 246 965.42 .38 1.68 252 907.37 .35 1 .66 258 833.91 .32 1 . 59 264 756.22 .29 1 .59 270 693.47 .26 1,54 276 647.91 . 24 1 .47 282 613.45 .23 1 . 4B 288 5134.24 .22 1 .42 294 557.62 . 21 1. 42 300 533.51 .2 1 .43 306 514. 44 . 19 1 . 44 312 502.59 . 18 1 .36 310 495. 46 . 18 1 .36 324 480.33 . 18 1 .36 330 483.37 . 17 1 . 36 336 480.59 . 17 J ,36 342 477. B2 . 17 1.36 348 475.04 . 17 1 .36 35 4 472.26 . 17 1 . 36 360 469. 48 . 17 1 .36 4 PR4-4:O CL I EN-I" SC)UTH BRADF ORD STREET DATE - 7/15/93 CONDITION - EXISTING CONDITIONS OVERALL_ DRAINAGE AREA FILE NAME SBE 100 I-.,ER IOD STORM - 100 YEARS T I ME, €=I-(JW 5 T I M I:--. FL...O OW. Hi�IJIRS CFS HOURS CFS 9 . 305917=•9 12 50� 63 -.. 1. 1 . 02 12. 1. 4 7. c.,"t 9. .2 1 . 7 1.2. 2 41 . 46, 9. 3 2,. o4 12. 3 2/1-. 4.7 9. 4 <_.« R 12,4 10. 8.'Y 9. 6 2. 38 12. 6 6. 1 9. ! 2. 33 12. 7 6. 12 9. 8 2. 38 12. 8 6. 1 9. 9 2. 38 12. 9 6. 12 10 2. 38 13 6. 12 10. 1 L. 72 13. 1 5. 44 10. 2 2. 72 13.2_ 4. 7 e:) 10. 3 3. 06 13. 3 3. 74 10. 4 3. 06 13. 4 3. 056 10. 5 3, 06 13. 5 3. 06 10. 6 � 06 13. 6 5. Q;3 10. 7 3. 06 13. 7 3. 06 10. 8 3. 06 13. 8 3. 06 10. 9 .3. 06 13. 9 3. 06 11 3. 06 14 3. 06 11 . 1 3. 74 14. 1 2. 72 11 . 2 4. 76 14. 2 11 . 3 5. 44 14. 3 1 . 7 11 . 4 6. 12 14. 4 1 . 36 11. 5 6. 8 14. 5 1 . 36 11 . 6 9. 17 14. 6 1 . 36 1. 1 . 7 15. 29 14. 7 1 . 36 11 . 8 23. 11 14. 8 1 ..36 9 39. 08 14. 9 1 . 3E 11 . DIRECT RUNOFF 3-57 INCHES AREA IN ACRES FOR TIME SEGMENT 1 = 4. `a AREA IN ACRES FOR TIME SEGMENT 2 = 4, 15 AREA IN ACRES F(--)R TIME SEGMENT 3 = 4. 5 AREA IN ACRES FOR TIME SEGMENT 4 = 5+. 5 PR#m CLIENT -- SOUTH BRADFORD STREET DATE - 7/ 15/93 CONDITION PROPOSED CONDITIOWS OVERALL DRAINAGE:. AREA FILE NAME - Sl'P100 I'ERl0l) STORM - 100 YEARS TIMES FLOW,, TIME. Fl.wOW HOURS CFS HOURS CF'S 9 . 31761 45 12 5�'. 5 D 9. 1 1 . 06 12. 1 49. 41 9. 2 1 . 76 12. 2 43. 05 9. 3 2. 12 12. 3 25. �� 1 01r4 2. 47 1.2. 4 11. . =:4;' 9. 5 2. 47 1*22. 5 8. 12 9. 6 2. 1 7 12. 6 6. 35 9. 7 2. 47 12. 7 6. 35 9. 8 2. 47 12. 8 6. 315 9. 9 - .-1+7 12. 9 6. 35 10 2. 47 13 6. 3'-- 1.0. 1 2. 82 13 1. 5. 6 10. 2 2. E32 13. 2 4. 9/t- 1�. 3 3. 18 13. 3 3. 88 10. 4 3. 18 13. 4 3. 10 10. 5 3. 18 13. 5 3. 1.8 1& 6 3. 18 13. 6 3. 16 10. 7 3. 18 13.7 3. 19 18. 8 3. 18 13. 8 3. ie 10. 9 3. 18 13. 9 3. 18 11 - 3. 18 14 3. 18 1. 1 . 1 3. 89 14. 1 2. 82 11 . 2 4. 94 14. 2 2. 12 1. 1 . 3 5. 65 14. 7) 1 . 76 • 11 . 4 6. 35 14. 4 1 . 4:1 ' 11A5 7. 06 14. 5 1 . 41 11 . 6 9. 53 14.6 1 . 41. 11. 7 15. 88 14. 7 1 . 41 11 . 8 24 14.8 1 . 41 1. 1 . 9 40- 58 14. 9 1 . 41 DIRECT RUNOFF - 3. 5 INCHES AREA , I N ACRES FOR TIME SEGMENT 1 - 4. 5 AREA IN ACRES FOR TIME SEGMENT 2 = 4. `.a AREA IN ACRES FOR TIME SEGMENT 3 = 4. 5 AREA IN ACRES FOR TIME SEGMENT 4 = 4. 5 � . � i � � PR#0 CLIENT - SOUTH DRADF0RD STREET i DATE - 8/3/93 � C0NDITI0N - PROPOSED CONDITIONS - DRAINAGE AREA 1A FILE NAME - SB1A-100 PERIOD STORM - 100 YEARS ' � TIME, FL0W, TIME, Ft 0W" HOURS CFS HOURS CFS 9 . 0949011Y6 12 10. 59 9. 1 . 37 12. 1 6. 21 9. 2 . 37 12. 2 2. 19 9.3 . 37 t2. 3 1 . 46 � 9. 4 . 37 12. 4 1 . 1 � 9.5 . 37 12. 5 1 . 1 9. 6 . 37 12. 6 1 . 1 9.7 . 37 12. 7 1 . 1 | / 9. 8 . 37 12. 8 1 . 1 � . 9. 9 . 37 12. 9 1 . 1 � 10 . 3 13 1 1 | 7' . | 10. 1 . 37 13. 1 . 73 / \ 10. 2 . 37 13. 2 . 37 ` 10" 3 . 37 . 13. 3 . 37 10. 4 . 37 13. 4 . 37 � / 10. 5 . 37 13. _5 . 37 10. 6 . 37 13.6 . 37 10. 7 . 37 13. 7 .37 � 10. 8 . 37 13.8 . 3l' | 10. 9 . 37 13. 9 . 37 � 11 . 37 14 . 37 � 11 . 1 ,73 14. 1 . 37 � ! 11 . 2 1 . 1 14.2 . 37 . 11 , 3 1 , 1 14. 3 .37 \ 11 . 4 1 . 1 14. 4 . 37 11 . 5 1. 1 14. 5 . 37 . 11 . 6 1 . 83 14.6 . 37 | . 11 . 7 3 65 14. 7 . 37 . � 11 . 8 5. 11 1 149 371 , 9 B. 4 ~ ^ i |DIRECT RUNOFF _ 3, 62 INCHES � � AREA IN ACRES F0R TIME SEGMENT 1 = 1 . 3 � AREA IN ACRES FOR TIME SEGMENT 2 = 1 . 3 ' � / ' � � / | | ' | _ | ` PROJECT - SOUTH BRADFORD STREET DATE - 0/3/93 DETENTION AREA STORM PERIOD 100 YEARS 1ST LEVEL POND AREA--SF 3000 MAX DEPTH -FT I 2ND LEVEL POND AREA SF 3500 MAX DEPTH -FT € . 3RD LEVEL POND AREA -SF 4000 PIPE DIAMETER I PIPE LENGTH 20 SLOPE 5E-03 MANNING COEFFICIENT .013 ENTRANCE .COEFFICIENT (K)t' .5 COEFFICIENT OF DISCHARGE (C): .79 ANSWER FILE NAMEt SBPOND-100 INPUT FILE' NAME: SDIA-100 ! REVI5ED INFLOW INFLOW OUTFLOW OUTFLOW TIME Q-VALUE ACCUM 0 _ VALVE ACCUM MIN CF8 CV FT CFS CU FT .01 0 12 :37 , 1 .01 0 18 37. . 199.E .02 4 . 24 .37 333 .04 16.01 30 .37': 466..2 :1 41.26 36 ::37. : 549.4 .15 84.77 42. , :37' 732.6 .17 142.37 4E .37. 865.8 .2, 210.24 54 37 99Y 25 291.8 ! 60 ..37 1132.2 .28 387.56 ! 66 .37 1265.4 .3 492.06 72 ".37 1398.6 .32 602.65 78 37 1531.E .33 719.41 :84 G37, 1665. L .33 839.28 90 37 1798.2 .33 459.15 96 !.37 1931.4 .33 1079.02 102 !.37 2064.6 .35 1201.95 106 37. 2197.8 .35 1327.94 114 .37 2331 .35 1453.93 120 37 2464.2 .37 1583.09 126 .37 2597.4 .37 1715.42 132 .73 2795.4 .4 1854.OB 138 1.1 3124.E .53 2022.26 144 1.1 3520.E .69 2241.0E 150 1. 1 3916.E .8 2508.04 156 1.1 4312.E 87 2809.1 162 1.83 4040.2 1 3146 52 168 3.65 5826.E 1.32 3563.83 174 5.11 7403.4 2.52 4254.63 180 8.4 9835.2 3.96 5420.39 186 10.59 13253.4 1 5.1E 7064.1 192 6.21 16277.4 5.77 9033.4E 190 2.19 17789.4 5.58 11075.04 204 1.46 18446.4 4.96 12972.21 210 1. 1 18907.2 4.19 14619.45 216 1.1 19303.2 3.3 15966.56 222 1. 1 19699.2 2.4 16992.56 22B 1.1 20095.2 1.55 17705.22 234 1.L 20491.2 1.36 18229.02 240 1.1 20867.2 1.32 18710.11 246 1. 1 21263.2 1.3 19100.41 252 .73 21612.6 1.23 19634.55 258 .37 21810.6 1.09 20051.29 264 .37 21943.8 .91 26411.11 270 .37 22077 .8 20710.97 276 .37; 22210.2 .69 20985.93 282 .57 22343.4 .57 21211.49 28B .37 22476.6 .53 21409.6 294 .37 22609.8 .49 21594.25 300 .37 22743 .46 21765.54 306 .57 22876.2 .42 21923.67 312 .37 23009.4 .4 22071.9E 318 .37, 23142.6 .4 22216.97 324 .37 23275.8 .39 22358.79 330 .37 23409 .39 22497.43 336 .37 23542.2 .39 22636.07 342 .37. 23675.4 .39 22774.72 348 37 23808.E .37 22910.2 35r{ 37 23941.8 .37 23042.514 i60 .37 24075 .37 23174.07 POND POND CHANNEL REVISED VELOCITY STORAGE DEPTH I MIN CU FT FT FPS fa 1 @ @ 1 1 @ 0 1.a 195.0 .07 . 83 :?�+ 316.99 . 1 1 .98 1.35 30 424. 94 . 15 1 .44 36 514.6�3 . 19 FL t 590.23 . 22 1 . 42 48 655.56 .24 1 .471 .54 54 707.2 .26 60 744.6ti .28 1 .56 rS 6 773.34 .29 1.59 72 795.95 .3 1 .61 78 81 r_.39 .31 1 . 59 84 825.72 .32 1 .59 Vo 8 39.@5 .32 1 . 59 96 8521.3B .32 1 .59 102 862.65 .33 1 .62 108 869.86 .33 1.14 877.@7 .33 1 .62 120 8s31 . 11 .34 1 .6 126 881 .98 .34 1.64 13'2 941.32 .36 1.63 138 1102.54 .42 1.69 1 .73 144 1279=72 .5 1. 77 150 1408.76 .56 156 1583.7 .6 1 .7 162 1693. 68 .68 1.79 168 226'2:.77 .89 1 .8 1.74 3148.77 1.24 3.21 IE30 4414.81 1. 74 5.04 186 6169.3 2.33 6.6 2.68 7.35 1R2: 7243.92 �,5b 7. 1. 198 6714.36 2 204 5474. 17 2.2.2 6.32 10 42:87.75 1.84 5.33 �tib 3336.64 1.48 4.2 222 2706.64 1,21 3.06 '.. 28 2389.99 1.03 1 ,97 ;234. 2262. 18 .93 1.8 240 2177.OV .89 1 8 246 2102.79 .86 252 1970.05 .81 1 .81 250 1759.31 .73 1.8 264 1532 69 .63 1 .7B 270 135B.03 ,56 1 . 77 276 1224.27 19 1 .73 1131.91 .45 1. 71 2132 1 .69 2'88 1067 . 42 2q4 1f�15.55 . 4 f .67 300 977.46 .3 1 .,68 ;306 952.53 .37 1 . 65 312 937.42' . 36 1 .63 318 6-1 925.63 -3C 1 . 324 917. 01 .35 1 .66 330 91 1.57 .35 1 .66 336 906. 13 .35 1 .66 342 9@QJ.65 .35 1.66 3ti 8 398. 4 34 1 .6Et. .34 1. 64 354 899. .f� 1 .64 360 900. 13 .34 SECTION III EROSION AND SEDIMENTATION CONTROL SECTION III j EROSION AND SEDIMENTATION CONTROL Erosion and sedimentation will be controlled in the following manner: As soon as the roadway right-of-way is cleared of trees and all of the stumps are removed, a row of staked hale bales will be placed at the bottom of the slope along the roadway. This form of erosion control is illustrated in Figure 3 : Sedimentation Control Detail. Crushed stone will be placed at the entrance of the roadway over the full width of the cleared area for a distance of 5.0 feet to a depth of 4 inches to provide erosion control for the uphill grade into the project. When the drainage structures are installed in the roadway, the frames and grates will be mortared and set to finish'. grade immediately. On many projects, the manholes and catch basins are left low and uncovered after installation, and act as collectors of sediment from runoff. By setting the frames and grates to. finish grade they will be higher than the surrounding roadway until it is paved. This will prevent water and sediment from entering the drainage system before the roadway is paved. Hay bales will be placed around the catch basin inlets after the roadway is paved, and will remain in place until the shoulders and side slopes are stabilized with sufficient vegetation to prevent erosion. All slopes in construction areas throughout the site will be seeded and mulched (or hydroseeded) as soon as construction in the area is completed. V41?IE5 LlalT OF VARIES ( �� IMRIES`` GR,4DI1(G i� VARIES lit t� EA'ISTING GfRQU/YD v LIMIT OF t� f�ia GRADING 67,4KE5 EACH ` BALE 5EDWENTA TION CONTROL DET,41L NOT TO -SCA L E NOTE: HAY BALE5 TO BE PLACED AND STAKED BEFORE WORK i IS TO BEGIN ,4ND REV,41N UNTIL SLOPES ARE STABILIZED WI TK LOAM AND SEED. ALL SCLT.4TION TRAPPED BY HAY BALES /5 TO BE REMOVED. FIGURE 3 SEDIMENTATION CONTROL DETAIL