CDM Northampton Stormwater System Assessment and Plan 2012-05 Vol 2 Appendices

7/31/2019 CDM Northampton Stormwater System Assessment and Plan 2012-05 Vol 2 Appendices

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8. There is concern about the main sluice gate operator located inside the station, that is used to cut off the gravity flow draining into the River, whether it is reliable in electric mode. It works in manual mode,but would be very time-consuming to operate manually.

9. Similarly, there is concern there may be electrical problems with the other main sluice gate operator,


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y y p g plocated outside the station, that diverts from to the main pump wet well.

10. Heat for the building is now provided by gas unit heaters fueled with natural gas. The original boiler,located in the basement is no longer used.

11. The major issue at the station is that everything is manually operated, and must be monitoredcontinuously when operating and/or when expecting that operation may need to commence.

Additionally, during times of high river elevation, even when there is no storm run-off, the station mustbe manned around the clock to allow monitoring of the drainage inlet to the station, and occasionaloperation of the electric motor driven pump to pump down the inlet bay. During daytime, the operatormay be dispatched from the WWTP, but at times the WWTP is not manned, an operator must be present(paid on overtime) at the Main Station. At the time of my visit, the Connecticut River is running high,because of winter run-off farther north, requiring occasional operation of the electric motor driven pump.The dilema is that the cost to automate will be very high, because anything to be automated must bereplaced with new equipment. The trade-off is to choose the better option, whether to automate toreduce required manpower, but spend money on new equipment, pay personnel to manually operate theexisting old equipment.

12. There do not appear to be issues regarding the capacity of the station, although John noted that hehas observed the station to be in operation with all pumps running.

13. The engines and the right angle drives appear to have some lubricating oil leaks, some of which arecontrolled by absorbant sheets.

The West St. Pumping Station is located near the Mill River adjacent to the crossing of West St., on theprotected side of the flood wall. The pumping station draws from a storm water collection system, andpumps over the flood wall to discharge into the Mill River. The storm water collection system appears toserve a limited area inside the flood wall, that is a low point for collection of storm run-off.


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Appendix B

Drainage Analysis


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Summary Tables

Appendix B Drainage Analysis

Table B.1Bridge Street/Meadows Area Drainage AnalysisExisting Conditions Drainage Analysis Summary

Hydrologic Element LocationDrainage

Area(acres)

Tc CNPeak Rate of Runoff (cfs)

2-Yr 10-Yr 25-Yr 50-Yr 100-Yr

2 Lincoln Ave. 26.9 20 84 32.7 55.1 72.9 88.3 108.71 Bridge St. 17.7 20 70 9.1 20.6 30.7 39.9 52.6


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Junction-A 44.6 41.9 75.7 103.6 128.2 161.3Reach-1 39.3 71.3 97.8 121.1 152.5FG2 Fairgrounds Site 10.9 20 80 10.9 19.6 26.7 32.9 41.2FG5 Fairgrounds Site 3.4 25 74 2.2 4.4 6.3 7.9 10.2E-Pond2 21.5 2.2 3.8 4.5 5 5.5FG3 Fairgrounds Site 13.5 20 73 8.8 18.2 26.2 33.5 43.4E-Pump 0.4 0.4 0.4 0.4 0.4E-CP1 9.7 20.8 30 37.7 48.13 Old Ferry Rd. 5.2 15 66 2 5.1 8.1 10.9 14.8Junction-B 50.9 96 132.9 165.3 209.1Reach-2 47 88.1 122 152.5 193.64 Fair St. 10.4 15 85 14.4 24 31.6 38.1 46.8Junction-C 54.8 102.2 141.2 175.4 221.6Reach-3 36.2 67.2 92.9 115.8 146.86 38.7 25 66 12.9 33.4 52.1 69.3 93.4FG1 Fairgrounds Site 20.7 20 72 12.5 26.6 38.8 49.8 64.9FG6 Fairgrounds Site 0.7 15 79 0.7 1.3 1.8 2.3 2.8E-Pond1 24.8 0.7 2.9 11 22.4 39.2FG4 7.5 70 3.9 8.7 13 16.9 22.2E-CP2 32.3 3.9 8.7 15.2 30.8 53.75 Pomeroy Terrace 25.0 30 80 21.3 38.5 52.6 64.9 81.5Wetland 9.6 32.1 107.7 183.1 277.5Reach-4 9.6 31.3 102.3 172.8 265.17 Eastern Ave. 10.0 15 82 12 20.9 28.1 34.4 42.8Junction-E 12.8 32.8 105.5 177.5 273.2Reach-5 10.3 30.8 91.6 152.5 237.28 Valley St. 19.4 30 69 8 18.3 27.5 36.1 48


Table B.1 (Contd)Bridge Street/Meadows Area Drainage AnalysisExisting Conditions Drainage Analysis Summary


Area(acres)


2-Yr 10-Yr 25-Yr 50-Yr 100-Yr

Junction-E2 18.4 36.7 96.3 160 249.29 William St. 11.1 15 83 14.1 24.1 32.2 39.3 48.6


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10 Henry St. 9.7 15 74 7.2 14.7 21.2 26.9 34.8Junction-F 35.6 68.6 101.8 167.8 260.5Reach-6 35.4 67.9 101.6 167.6 260.311 2.4 15 70 1.3 3 4.4 5.8 7.6G-Mill River 36.6 70.4 102.1 168.3 261.413 Industrial Dr. 82.9 25 84 92.6 155.3 206.4 250.6 309.512 Marshall St. 34.8 30 82 32.9 57.5 77.3 94.6 117.742-inch Pipe 117.7 125.5 212.8 282.6 343.0 423.4

Flood Storage RoutingE-Pond1 (Inflow) 13.2 27.9 40.5 51.9 67.6E-Pond1 (Outflow) 24.8 0.7 2.9 11.0 22.4 39.2Maximum Stage (ft.) 116.5 117.0 117.1 117.2 117.3Spillway Elevation (ft.) 117.0 117.0 117.0 117.0 117.0E-Pond2 (Inflow) 13.0 23.9 32.8 40.7 51.4E-Pond2 (Outflow) 21.5 2.2 3.8 4.5 5.1 5.5Maximum Stage (ft.) 117.4 118.2 118.7 119.1 119.5Spillway Elevation (ft.) 119.5 119.5 119.5 119.5 119.5Wetland(Inflow) 57.3 112.9 165.2 221.7 300.6Wetland(Outflow) 9.6 32.1 107.7 183.1 277.5Maximum Stage (ft.) 115.6 116.5 116.6 116.6 116.7

Spillway Elevation (ft.) 116.5 116.5 116.5 116.5 116.5


Table B.2Elm Street Brook Area/Florence Area Drainage Analysis

Existing Conditions Drainage Analysis Summary


Area(acres)


2-Yr 10-Yr 25-Yr 50-Yr 100-Yr

A Bridge Rd. 27.1 15 72 17.5 37.5 55 70.8 92.5Junction-1 54.8 27.9 63.4 95.5 124.7 165.1


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B Strawberry Hill Rd. 27.7 15 67 11.8 29 45.3 60.3 81.4Junction-2 73.0 32.4 74.2 112.2 146.9 195C 18.2 15 66 7.1 18 28.5 38.2 51.8Junction-3 113.9 59.3 124.5 181 232.6 304.1D 6.8 15 77 6.2 11.8 16.5 20.6 26.2E 3.1 15 74 2.3 4.8 6.9 8.7 11.3F Straw Avenue 31.0 25 78 25.5 47.2 65.1 80.9 102.5Detention Basin 1 (Inflow) 59.3 124.5 181 232.6 304.1Detention Basin 1 (Outflow) 113.9 27 51.8 55.4 59 64.9Maximum Stage (ft) 186.9 188.1 188.2 188.4 188.5Spillway Elevation (ft) 187.5 187.5 187.5 187.5 187.5Junction-4 157.8 29.4 65.2 80.5 98.7 120.4G 20.7 15 72 13.4 28.7 42.1 54.2 70.8H 17.0 15 62 4.1 13 21.5 29.9 41.9I 6.3 15 61 1.3 4.5 7.5 10.5 14.9Junction-5 180.5 33.8 83 115.2 149.6 192.8J 14.6 15 66 5.7 14.5 22.9 30.7 41.6Detention Basin 2 (Inflow) 5.7 14.5 22.9 30.7 41.6Detention Basin 2 (Outflow) 14.6 3.3 6 7.8 9.2 10.8Maximum Stage (ft) 180.9 181.9 182.9 183.8 185.1Spillway Elevation (ft) 186 186 186 186 186

K 8.1 15 60 1.5 5.4 9.2 13 18.5Junction-6 208.6 34.6 89 128.9 171.6 229.3L 28.1 20 54 1.5 9.4 19.1 29.2 44.6Junction-7 241.6 42.0 108.7 165 222.3 295.5M Depot Avenue 23.0 25 64 6.2 17.5 28.1 37.9 51.9O 10.0 15 68 4.7 11.2 17.2 22.7 30.4


Table B.2 (Contd)Elm Street Brook Area/Florence Area Drainage Analysis



Area(acres)


2-Yr 10-Yr 25-Yr 50-Yr 100-Yr

Junction-8 257.9 47.2 118.0 183.7 247.7 333.3P 16.3 15 73 11.3 23.7 34.4 44.1 57.3

J i 9 49 3 38 74 1 104 8 132 8 170 9


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Junction-9 49.3 38 74.1 104.8 132.8 170.9Junction-10 307.3 74.7 171.5 262.7 349.6 471.6Q Locust St. 26.4 15 76 22.5 43.9 61.9 77.9 99.7N North Main St. 23.0 20 74 16 32.3 46.3 58.7 75.7Junction-11 374.3 89.3 209.3 320.8 425.7 573.1S South Main St. 49.4 15 65 17.5 46.1 73.7 99.6 136.2R 17.6 15 61 3.7 12.6 21 29.5 41.7Junction-12 459.1 106.9 254.2 390.6 518.1 697.6Junction-13 478.1 93.2 221.7 340 450.5 607.2Junction-14 509.5 97.6 230.2 353.3 467.3 626.8Junction-15 535.0 101.7 237.8 364.1 481.8 646.4X North Elm St. 17.0 15 73 11.8 24.7 35.8 45.8 59.5Y 8.5 15 74 6.3 13 18.6 23.7 30.6W Hospital Rd. 31.4 15 70 17.5 39.2 58.8 76.6 101.3V Elm St. 19.0 15 73 13.2 27.6 40.1 51.3 66.7U South Main St. 68.4 25 67 25.1 62.5 96.2 127.2 170.3T 16.4 15 60 3 10.9 18.6 26.2 37.448-36-in Diversion 535.0 73.8 157.4 239.2 315.7 423.736-in pipe Junction 4.4 29.0 82.5 127.9 169.6 227CC Federal St. 76.5 15 73 53.0 111.2 161.4 206.6 268.3Z Milton St. 23.2 20 74 16.1 32.6 46.7 59.2 76.4DD Elm St. 4.4 20 82 4.8 8.4 11.2 13.7 17Junction-16 549.2 76.7 161.1 243.2 320.3 429.2

AA 48-inch Pipe 14.3 15 84 18.9 32 42.4 51.4 63.4Junction-17 565.2 76.6 156.7 235 308.5 412.1EE 16.0 15 68 7.6 17.9 27.5 36.4 48.7Junction-18 585.1 80.3 162.4 242.7 317.6 423.1





Area(acres)


2-Yr 10-Yr 25-Yr 50-Yr 100-Yr

BB Washington St. 19.8 15 86 28.8 47.3 61.9 74.4 91.1Junction-19 27.5 27.2 82.2 126.3 167 223

D t ti P d 3 (I fl ) 27 2 82 2 126 3 167 223


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Detention Pond 3 (Inflow) 27.2 82.2 126.3 167 223Detention Pond 3 (Outflow) 27.5 26.9 75.7 104.3 150.2 210Maximum Stage (ft) 148.2 150.3 152.4 154.0 154.8Spillway Elevation (ft) 153.55 153.55 153.55 153.55 153.55Sink-1 689.1 123.6 261 376.8 485.6 664.3


Table B.3King Street/Market Street/Downtown Area Watershed Drainage Analysis


Hydrologic Element LocationDrainage Area

Tc CN2-year 10-year 25-year 50-year 100-year

(cfs) (ac-ft) (cfs) (ac-ft) (cfs) (ac-ft) (cfs) (ac-ft) (cfs)(mi 2) (ac)

KS-E 0.0302 19.3 19 95 46.8 5.0 56.7 6.1 70.4 4.8 82.1 9.1 97.7

KS-F 0.0278 17.8 15 83 31.8 3.0 41.6 3.9 55.4 3.5 67.4 6.4 83.4

J-1 King Street @ Church 0 0580 37 1 78 3 8 0 978 10 0 125 2 4 2 148 7 15 4 180 0


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J-1 King Street @ ChurchStreet 0.0580 37.1 78.3 8.0 97.8 10.0 125.2 4.2 148.7 15.4 180.0

KS-G 0.0394 25.2 15 87 52.5 4.9 66.6 6.3 86.5 3.9 103.6 9.9 126.2

King 36" 0.0580 37.1 73.3 8.0 91.6 10.0 117.2 4.2 139.2 15.4 168.4

J-2 King Street @ Finn Street 0.0973 62.3 100.4 12.9 125.6 16.3 161.1 4.1 191.5 25.4 232.0

King 48" 0.0973 62.3 98.9 12.9 123.9 16.3 158.8 4.1 188.8 25.4 228.8

KS-I 0.0249 16.0 15 92 38.8 3.7 47.8 4.6 60.2 4.5 70.9 7.0 84.9

J-3 0.1223 78.3 114.3 16.6 142.9 20.9 182.9 4.2 217.3 32.4 263.0

Div. at North St King Street @ NorthStreet 0.1223 78.3 114.3 16.6 142.9 20.9 182.9 4.2 183.1 31.3 183.1

King 48"/54" 0.1223 78.3 112.8 16.6 141.2 20.9 181.0 4.2 183.1 31.3 183.1

KS-J 0.0258 16.5 15 89 36.7 3.5 46.0 4.4 59.0 4.1 70.2 6.8 84.9

KS-K 0.0324 20.7 15 88 44.6 4.2 56.3 5.3 72.6 4.0 86.6 8.4 105.2

KS-L 0.0425 27.2 15 85 52.7 4.9 67.9 6.4 89.2 3.7 107.7 10.2 132.2

KS-M 0.0070 4.5 15 84 8.4 0.8 10.9 1.0 14.4 3.6 17.5 1.7 21.5

J-8 Trumbull @ State Street 0.0820 52.4 105.7 9.9 135.0 12.7 176.2 3.8 211.8 20.2 258.9

Trumbull 24" 0.0820 52.4 103.8 9.9 132.6 12.7 173.0 3.8 207.8 20.2 253.8

J-7 King Street @ TrumbullRoad 0.2300 147.2 184.0 29.9 234.0 38.0 304.1 4.0 364.3 58.4 443.9

King 54" 0.2300 147.2 183.2 29.9 232.8 38.0 302.4 4.0 362.4 58.4 441.4

KS-Q 0.0386 24.7 15 94 63.1 6.2 76.9 7.6 95.9 4.7 112.2 11.3 133.7

J-9 0.2686 171.9 229.7 36.1 289.7 45.6 373.8 4.1 446.0 69.7 541.7

King 54"/66" 0.2686 171.9 225.1 36.1 283.8 45.6 366.1 4.1 436.8 69.7 529.8

KS-R 0.0230 14.7 15 96 39.1 3.9 47.2 4.8 58.4 4.9 67.9 7.0 80.6

J-10 0.2916 186.6 243.0 40.0 305.4 50.4 392.8 4.2 467.9 76.8 567.1

Div. at Main St King Street @ Strong Ave 0.2916 186.6 232.8 39.6 235.4 47.7 285.2 3.8 285.2 68.3 285.2

King 60"/66" 0.2916 186.6 218.0 39.6 229.4 47.7 282.5 3.8 285.2 68.3 285.2

KS-T 0.0164 10.5 15 97 28.4 2.9 34.1 3.5 42.0 5.0 48.8 5.1 57.8


Table B.3 (Contd)King Street/Market Street/Downtown Area Watershed Drainage Analysis



Tc CN2-year 10-year 25-year 50-year 100-year

(cfs) (ac-ft) (cfs) (ac-ft) (cfs) (ac-ft) (cfs) (ac-ft) (cfs)(mi 2) (ac)

J-12 King Street @ PleasantStreet 0.3079 197.1 221.9 42.5 234.9 51.2 289.1 3.9 292.9 73.4 296.8

King Street Old Mill River 0.3079 197.1 221.9 42.5 234.9 51.2 289.1 3.9 292.9 73.4 296.8

S A 0 0119 6 1 9 19 9 2 0 2 1 2 30 0 8 3 0 3 6 1 6


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KS-U Hampton Avenue 0.0119 7.6 15 95 19.9 2.0 24.1 2.4 30.0 4.8 35.0 3.6 41.6

Old Mill River 0.0119 7.6 19.9 2.0 24.1 2.4 30.0 4.8 35.0 3.6 41.6

KS-A Culvert @ Bikeway 0.0707 45.2 34 78 47.1 6.1 64.1 8.3 88.8 3.0 110.5 14.2 139.9

Brook Rail Trail 0.0707 45.2 45.4 6.1 61.8 8.3 85.5 3.0 106.4 14.2 134.7

KS-B 0.0293 18.7 27 75 18.7 2.2 26.2 3.1 37.2 2.8 47.0 5.4 60.4

J-4 Culvert @ WoodmontRoad 0.0999 63.9 53.3 8.4 72.5 11.3 100.6 3.0 125.3 19.6 158.7

Brook Woodmont Rd 0.0999 63.9 52.9 8.4 72.1 11.3 99.9 3.0 124.5 19.6 157.7

KS-D 0.0233 14.9 31 92 27.8 3.5 34.3 4.3 43.3 4.5 50.9 6.6 61.0

KS-C 0.0145 9.3 15 83 16.6 1.5 21.7 2.0 29.0 3.5 35.2 3.3 43.6

J-5Old Market Street @Highland Avenue 0.1377 88.1 66.5 13.4 89.0 17.7 121.5 3.3 150.2 29.5 188.8

Market 48" 0.1377 88.1 66.0 13.4 88.3 17.7 120.7 3.3 149.1 29.5 187.4

KS-H 0.0097 6.2 15 89 13.8 1.3 17.3 1.6 22.2 4.1 26.4 2.6 31.9

J-6 Old Market Street @North Street 0.1474 94.4 68.9 14.7 90.8 19.3 123.6 3.3 182.1 33.1 264.6

Market 44"/48" 0.1474 94.4 68.0 14.7 89.9 19.3 122.5 3.3 174.8 33.1 255.6

KS-O 0.0480 30.7 19 89 63.5 6.4 79.6 8.1 102.1 4.1 121.3 12.7 146.7

KS-P 0.0065 4.2 20 90 8.7 0.9 10.9 1.1 13.9 4.2 16.5 1.8 19.8

KS-N Market Street @ WalnutStreet 0.0357 22.8 26 82 32.1 3.7 42.3 4.8 56.8 3.4 69.5 8.0 86.4

Market 18"/21" 0.0357 22.8 29.7 3.7 39.2 4.8 52.6 3.4 64.3 8.0 80.0

J-11Old Market Street @Bridge Street 0.2376 152.1 137.1 26.2 193.5 36.1 263.0 4.0 371.2 64.0 543.3

Market 72" 0.2376 152.1 120.5 26.2 189.3 36.1 260.9 4.0 367.1 64.0 534.9

KS-S 0.0370 23.7 16 89 51.7 5.0 64.8 6.3 83.2 4.1 98.8 9.8 119.5

J-13 Old Market Street @Hancock Street 0.2746 175.8 133.3 31.1 199.2 42.4 272.2 4.0 387.0 73.8 558.2

Market 82" 0.2746 175.8 128.6 31.1 198.0 42.4 271.2 4.0 384.6 73.8 553.7




Hydrologic Element Location Drainage Area Tc CN2-year 10-year 25-year 50-year 100-year

(cfs) (ac-ft) (cfs) (ac-ft) (cfs) (ac-ft) (cfs) (ac-ft) (cfs)

KS-W 0.0151 9.7 15 90 22.2 2.1 27.7 2.6 35.3 4.2 41.8 4.1 50.4

KS-V 0.0049 3.1 15 96 8.4 0.8 10.1 1.0 12.5 4.9 14.5 1.5 17.2

J-14 Old Market Street @Holyoke Street 0.2947 188.6 133.6 34.1 202.7 46.0 276.6 4.0 392.7 79.4 563.1

M k t 60" 0 2947 188 6 130 5 34 1 202 2 46 0 275 7 4 0 390 2 79 4 558 5


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Market 60" 0.2947 188.6 130.5 34.1 202.2 46.0 275.7 4.0 390.2 79.4 558.5

KS-X 0.0058 3.7 15 85 7.1 0.7 9.2 0.9 12.1 3.7 14.6 1.4 17.9

J-15 Old Market Street @Hockanum Road 0.3004 192.3 131.5 34.7 203.3 46.9 277.0 4.0 392.0 80.8 560.6

Market Street Old MillRiver 0.3004 192.3 131.5 34.7 203.3 46.9 277.0 4.0 392.0 80.8 560.6


Table B.4Austin Circle/Ryan Road Area Drainage AnalysisExisting Conditions Drainage Analysis Summary


Tc CN2-year 10-year 25-year 100-year

(mi 2) (ac) (cfs) (cfs) (cfs) (cfs)RR-A1 Gregory Lane 0.0455 29.1 34 56 5.3 10.6 20.2 44.1Gregory Ln DB 0.0455 29.1 2.1 2.9 3.2 3.8Detention Basin (Inflow) 5.3 10.6 20.2 44.1Detention Basin (Ouflow) 2.1 2.9 3.2 3.8


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( )Maximum Stage (ft) 282.7 283.6 285.1 288.0Peak Storage (acre-ft) 0.3 0.5 1.3 3.2Top of Basin (ft) 288.0 288.0 288.0 288.0RR-A2 Matthew Lane 0.0248 15.9 16 50 1.2 3.3 8.4 23.1Matthew Dr DB 0.0703 45.0 2.3 3.3 4.1 5.6Detention Basin (Inflow) 2.6 5.0 9.9 24.6Detention Basin (Ouflow) 2.3 3.3 4.1 5.6Maximum Stage (ft) 280.2 280.9 281.7 283.7Peak Storage (acre-ft) 0.2 0.3 0.6 1.3Top of Basin (ft) 284.0 284.0 284.0 284.0Matthew Drive Route 0.0703 45.0 2.3 3.3 4.1 10.8RR-A3-1 0.0377 24.1 45 59 5.6 10.2 18.0 36.6RR Elem School 0.0377 24.1 5.6 10.2 18.0 36.5RR-B Penscal Drive Area 0.0100 6.4 15 63 3.5 5.8 9.5 17.8J-1 Outlet at Elementary School 0.1179 75.4 7.0 13.5 24.5 48.1Ryan Road Channel 1 Btw School and Brierwood Dr. 0.1179 75.4 7.0 13.4 24.1 47.4RR-D Brierwood Drive/Austin Circle Area 0.0378 24.2 19 60 8.9 16.1 27.9 55.8J-4 Brierwood Drive Culvert 0.1557 99.6 11.6 20.2 34.9 70.5Ryan Road Channel 2 Btw Brierwood and Acrebrook Dr. 0.1557 99.6 11.5 20.1 34.8 70.3RR-G Acrebrook Drive Area 0.0332 21.2 15 71 21.0 30.6 45.1 76.4

J-5 Acrebrook Drive Culvert 0.1888 120.9 25.1 40.3 64.9 121.5 Acrebrook Drive 0.1888 120.9 25.1 40.3 64.9 121.5


Table B.5Bridge Street/Meadows Area Drainage AnalysisFuture Conditions Drainage Analysis Summary


Area(acres)

Tc(min) CNPeak Rate of Runoff (cfs)

2-Yr 10-Yr 25-Yr 50-Yr 100-Yr

2 Lincoln Ave. 0.0 20 86 35.8 58.5 76.4 91.8 112.21 Bridge St. 0.0 20 71 9.9 21.7 32 41.3 54.1

Junction-A 0.0 45.7 80.2 108.4 133.1 166.3


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Reach-1 0.0 43 75.6 102.4 125.8 157.33 Old Ferry Rd. 0.0 15 67 2.2 5.5 8.5 11.3 15.3Junction-B 0.0 45 80.3 109.4 135 169.4Reach-2 0.0 41.5 73.6 100.1 123.4 154.94 Fair St. 0.0 15 86 15.1 24.7 32.3 38.9 47.6Junction-C 0.0 49.7 87.7 118.9 146.3 183.3Reach-3 0.0 32.9 58 79 97.4 122.2FGP1 Fairgrounds Site 0.0 15 78 34.6 64.8 90 112.1 142FGP7 Fairgrounds Site 0.0 25 74 2.2 4.4 6.3 7.9 10.2Ppond2 0.0 4.4 10.8 13.7 15.5 17.9

SWTC2 0.0 4.4 10.8 13.7 15.5 17.9FGP3 Fairgrounds Site 0.0 15 79 8.4 15.5 21.3 26.5 33.4FGP8 Fairgrounds Site 0.0 15 79 0.7 1.3 1.8 2.3 2.8Ppond4 0.0 1.8 4.8 8.1 10.9 13.1SWCT1 0.0 1.8 4.8 8.1 10.9 13.1FGP2 Fairgrounds Site 0.0 15 82 5.8 10.2 13.7 16.8 20.9Ppond1 0.0 1.4 3.5 5.6 7.4 9.9FGP6 Fairgrounds Site 0.0 15 95 2.1 3 3.8 4.4 5.2SWTC3 0.0 2.5 4.8 7.5 9.7 12.8FGP5 Fairgrounds Site 0.0 15 80 0.6 1.1 1.5 1.9 2.4Ppond3 0.0 7.6 19.4 28.3 35.3 42.7FGP4 Fairgrounds Site 0.0 20 76 1.3 2.5 3.4 4.3 5.5FGP9 0.0 15 87 0.7 1.1 1.4 1.7 2.1P-CP2 0.0 7.9 20.3 30.4 38.2 476 0.0 25 66 12.9 33.4 52.1 69.3 93.45 Pomeroy Terrace 0.0 30 81 22.5 39.9 54.2 66.6 83.1


Table B.5 (Contd)Bridge Street/Meadows Area Drainage AnalysisFuture Conditions Drainage Analysis Summary


Area(acres)


2-Yr 10-Yr 25-Yr 50-Yr 100-Yr

Wetland 0.0 10.4 41.3 110.2 174.2 253.2Reach-4 0.0 10.4 40 104.5 165.6 242.1

7 Eastern Ave. 0.0 15 83 12.6 21.6 28.9 35.2 43.6J ti E 0 0 13 2 41 7 107 7 170 4 250 3


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Junction-E 0.0 13.2 41.7 107.7 170.4 250.3Reach-5 0.0 10.9 38.5 94 147.9 220.18 Valley St. 0.0 30 70 8.7 19.3 28.7 37.4 49.4Junction-E2 0.0 19.3 40.8 98.7 155.1 232.39 William St. 0.0 15 85 15.5 25.8 33.9 41 50.310 Herny St. 0.0 15 75 7.7 15.4 21.9 27.7 35.7Junction-F 0.0 38.2 72 104.4 162.8 243.1Reach-6 0.0 37.9 71.1 104.1 162.6 242.611 0.0 15 70 1.3 3 4.4 5.8 7.6G-Mill River 0.0 39.1 73.6 104.6 163.3 243.7

13 Industrial Dr. 0.0 25 85 96.9 160.4 211.7 256 314.812 Marshall St. 0.0 30 83 34.6 59.5 79.5 96.8 119.942-inch Pipe 0.0 131.5 219.6 289.7 350.1 430.5

Flood Storage RoutingP-Pond1 (Inflow) 5.8 10.2 13.7 16.8 20.9P-Pond1 (Outflow) 0.0 1.4 3.5 5.6 7.4 9.9Maximum Stage (ft.) 112.3 112.7 113.0 113.3 113.6Pond Surface Elevation (ft.) 115.0 115.0 115.0 115.0 115.0P-Pond2 (Inflow) 36.2 68.4 95.2 118.9 150.8P-Pond2 (Outflow) 0.0 4.4 10.8 13.7 15.5 17.9Maximum Stage (ft.) 114.1 115.1 116.0 119.6 119.9Pond Surface Elevation (ft.) 119.0 119.0 119.0 119.0 119.0P-Pond3 (Inflow) 7.7 19.7 28.7 35.7 43.0P-Pond3 (Outflow) 0.0 7.6 19.4 28.3 35.3 42.7Maximum Stage (ft.) 113.2 113.4 113.6 113.7 113.8


Table B.5 (Contd)Bridge Street/Meadows Area Drainage AnalysisFuture Conditions Drainage Analysis Summary


Area(acres)


2-Yr 10-Yr 25-Yr 50-Yr 100-Yr

Pond Surface Elevation (ft.) 114.0 114.0 114.0 114.0 114.0Spillway Elevation (ft.) 112.85 112.85 112.85 112.85 112.85

P-Pond4 (Inflow) 9.1 16.8 23.2 28.7 36.2P Pond4 (Outflow) 0 0 1 8 4 8 8 1 10 9 13 1


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P-Pond4 (Outflow) 0.0 1.8 4.8 8.1 10.9 13.1Maximum Stage (ft.) 112.7 113.3 113.8 114.2 114.8Spillway Elevation (ft.) 117.0 117.0 117.0 117.0 117.0Wetland (Inflow) 54.8 119.9 173.5 218.9 280.6Wetland (Outflow) 180.6 10.4 41.3 110.2 174.2 253.2Maximum Stage (ft.) 115.7 116.5 116.6 116.6 116.7Spillway Elevation (ft.) 116.5 116.5 116.5 116.5 116.5


Table B.6Elm Street Brook Area/Florence Area Drainage Analysis

Future Conditions Drainage Analysis Summary


Area(acres)


2-Yr 10-Yr 25-Yr 50-Yr 100-Yr

G 0.0 15 73 14.4 30.1 43.8 56.0 72.7 A Bridge Rd. 0.0 15 73 18.8 39.4 57.1 73.1 95.0

Reach-A 0.0 17.8 36.2 52.2 66.9 87.0B Strawberry Hill Rd 0 0 15 68 12 2 29 9 46 6 62 0 83 3


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B Strawberry Hill Rd. 0.0 15 68 12.2 29.9 46.6 62.0 83.3Reach-B 0.0 12.0 30.2 46.6 61.5 82.2Junction-1 0.0 29.5 66.1 98.7 128.4 169.3Reach-C 0.0 28.1 61.7 91.6 119.3 157.6C 0.0 15 66 7.1 18.0 28.5 38.2 51.8Junction-2 0.0 33.9 76.7 115.3 150.4 198.9Reach-D 0.0 32.6 72.9 109.7 143.4 190.0D 0.0 15 77 6.2 11.8 16.5 20.6 26.2E 0.0 15 75 2.3 4.8 6.9 8.7 11.3F Straw Avenue 0.0 25 79 27.0 49.0 67.1 83.0 104.8

Junction-3 0.0 62.1 128.4 185.6 237.7 309.7Detention Basin 1 0.0 30.9 52.1 55.8 59.3 65.6Reach-E 0.0 30.2 52.0 55.7 59.3 65.6Junction-4 0.0 33.6 65.9 82.4 101.6 122.5Reach-G 0.0 32.7 64.1 79.3 96.7 116.2H 0.0 15 67 7.4 17.9 27.9 37.1 50.0Reach-F 0.0 7.1 17.6 27.3 36.2 48.6I 0.0 15 62 1.5 4.8 8.0 11.1 15.5Junction-21 0.0 8.6 22.4 35.2 47.0 63.6Reach-Z 0.0 8.2 20.8 32.7 43.9 59.4J 0.0 15 67 6.3 15.4 24.0 31.9 43.0

Detention Basin 2 0.0 3.5 6.2 8.0 9.4 10.9Reach-H 0.0 3.5 6.2 8.0 9.4 10.9K 0.0 15 60 1.5 5.4 9.2 13.0 18.5Junction-5 0.0 39.1 89.8 125.3 159.5 200.3Reach-I 0.0 38.7 88.3 122.8 155.2 195.3





Area(acres)


2-Yr 10-Yr 25-Yr 50-Yr 100-Yr

L 0.0 20 54 1.5 9.4 19.1 29.2 44.6Junction-6 0.0 39.7 95.6 138.4 181.2 233.4

Reach-J 0.0 39.7 94.9 138.9 180.9 234.7M Depot Avenue 0.0 25 66 7.7 19.8 30.9 41.1 55.4


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M Depot Avenue 0.0 25 66 7.7 19.8 30.9 41.1 55.4Reach-K 0.0 7.2 18.3 28.6 38.2 51.8O 0.0 15 68 4.7 11.2 17.2 22.7 30.4Junction-7 0.0 47.5 117.3 176.8 234.3 306.3Reach-L 0.0 47.4 116.5 176.9 231.4 305.1P 0.0 15 80 17.6 31.8 43.5 53.6 67.3Junction-8 0.0 55.6 129.4 198.6 262.8 346.2Q Locust St. 0.0 15 76 22.5 43.9 61.9 77.9 99.7N North Main St. 0.0 20 78 20.5 38.2 52.8 65.6 83.0Junction-9 0.0 42.5 80.0 111.4 139.8 178.4

Junction-10 0.0 86.2 186.3 279.2 367.8 487.3Reach-M 0.0 84.6 182.1 272.7 356.3 470.6S South Main St. 0.0 15 65 17.5 46.1 73.7 99.6 136.2R 0.0 15 61 3.7 12.6 21.0 29.5 41.7Junction-11 0.0 101.4 224.4 337.6 444.2 590.5Reach-N 0.0 96.0 213.2 321.1 421.4 558.1U South Main St. 0.0 25 68 27.7 66.1 100.5 131.9 175.6T 0.0 15 60 3.0 10.9 18.6 26.2 37.4Junction-12 0.0 120.0 271.6 410.0 539.3 718.0Reach-O 0.0 101.4 230.8 349.2 458.1 610.4V Elm St. 0.0 15 73 13.2 27.6 40.1 51.3 66.7

Junction-13 0.0 104.5 237.1 357.9 469.7 626.3Reach-O1 0.0 104.6 236.1 357.7 470.1 624.5W Hospital Rd. 0.0 15 70 17.5 39.2 58.8 76.6 101.3Junction-14 0.0 109.1 245.6 371.0 486.7 645.7Reach-P 0.0 108.8 245.4 369.4 485.9 646.7

Appendix B

Drainage Analysis




Area(acres)


2-Yr 10-Yr 25-Yr 50-Yr 100-Yr

X North Elm St. 0.0 15 73 11.8 24.7 35.8 45.8 59.5Reach-Q 0.0 12.0 24.6 35.4 45.0 58.2

Y 0.0 15 74 6.3 13.0 18.6 23.7 30.6Junction-15 0.0 113.2 253.2 381.6 500.9 665.6


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48-36-in Diversion 0.0 79.6 167.3 250.5 328.1 436.0Reach-S 0.0 78.8 165.9 247.6 324.0 431.1

AA 48-inch Pipe 0.0 15 84 18.9 32.0 42.4 51.4 63.4Junction-16 0.0 82.0 170.9 254.4 332.5 441.5Reach-T 0.0 79.3 162.9 241.4 314.5 416.9EE 0.0 15 68 7.6 17.9 27.5 36.4 48.7Junction-17 0.0 80.8 165.8 245.5 319.9 423.8BB Washington St. 0.0 15 87 30.1 48.7 63.3 75.8 92.4Junction-18 0.0 84.6 171.6 253.1 329.1 434.8

CC Federal St. 0.0 15 74 57.0 116.5 167.5 213.1 275.3Z Milton St. 0.0 20 74 16.1 32.6 46.7 59.2 76.4DD Elm St. 0.0 20 84 5.3 8.9 11.8 14.3 17.636-in pipe Junction 0.0 34.8 88.0 134.1 176.4 233.9Reach-R 0.0 30.7 81.4 123.9 162.6 215.9Junction-19 0.0 33.7 87.3 132.0 173.2 229.3Detention Pond 3 0.0 33.2 78.9 107.8 156.5 216.6Sink-1 689.0 128.7 270.2 387.1 506.5 683.3Detention Basin 1 (Inflow) 62.1 128.4 185.6 237.7 309.7Detention Basin 1 (Outflow) 113.9 30.9 52.1 55.8 59.3 65.6Maximum Stage (ft) 187.1 188.1 188.2 188.4 188.6Spillway Elevation (ft) 187.5 187.5 187.5 187.5 187.5Detention Basin 2 (Inflow) 6.3 15.4 24 31.9 43Detention Basin 2 (Outflow) 14.6 3.5 6.2 8.0 9.4 10.9Maximum Stage (ft) 181.0 182.0 183.0 184.0 185.2Spillway Elevation (ft) 186.0 186.0 186.0 186.0 186.0

Appendix B

Drainage Analysis




Area(acres)


2-Yr 10-Yr 25-Yr 50-Yr 100-Yr

Detention Pond 3 (Inflow) 33.7 87.3 132 173.2 229.3Detention Pond 3 (Outflow) 27.5 33.2 78.9 107.8 156.5 216.6

Maximum Stage (ft) 148.4 150.5 152.7 154.1 154.9Spillway Elevation (ft) 153.55 153.55 153.55 153.55 153.55


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Appendix B

Drainage Analysis

Table B.7King Street/Market Street/Downtown Area Watershed Drainage Analysis




(mi 2) (ac) (cfs) (cfs) (cfs) (cfs)KS-E 0.0302 19.3 19 95 46.8 56.7 70.4 97.7KS-F 0.0278 17.8 15 83 34.4 44.3 58.2 86.3J-1 King Street @ Church Street 0.0580 37.1 80.8 100.5 127.9 182.8

KS-G 0.0394 25.2 15 87 52.5 66.6 86.5 126.2King 36" 0.0580 37.1 75.7 94.0 119.7 171.0


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gJ-2 King Street @ Finn Street 0.0973 62.3 102.8 128.2 163.7 234.7King 48" 0.0973 62.3 101.2 126.4 161.4 231.4KS-I 0.0249 16.0 15 92 38.8 47.8 60.2 84.9J-3 0.1223 78.3 116.7 145.4 185.5 265.6Div. at North St King Street @ North Street 0.1223 78.3 116.7 145.4 183.1 183.1King 48"/54" 0.1223 78.3 115.0 143.5 182.5 183.1KS-J 0.0258 16.5 15 89 36.7 46.0 59.0 84.9KS-K 0.0324 20.7 15 88 44.6 56.3 72.6 105.2KS-L 0.0425 27.2 15 85 56.6 71.9 93.4 136.3KS-M 0.0070 4.5 15 84 9.1 11.6 15.1 22.2J-8 Trumbull @ State Street 0.0820 52.4 110.3 139.8 181.2 263.7Trumbull 24" 0.0820 52.4 108.3 137.3 177.8 258.5J-7 King Street @ Trumbull Road 0.2300 147.2 188.9 239.2 309.4 449.1King 54" 0.2300 147.2 188.0 237.8 307.7 446.6KS-Q 0.0386 24.7 15 94 63.1 76.9 95.9 133.7J-9 0.2686 171.9 234.7 295.0 379.3 547.1King 54"/66" 0.2686 171.9 229.9 288.9 371.4 535.0KS-R 0.0230 14.7 15 96 39.1 47.2 58.4 80.6J-10 0.2916 186.6 247.8 310.5 398.1 572.3Div. at Main St King Street @ Strong Ave 0.2916 186.6 234.2 239.0 285.2 285.2King 60"/66" 0.2916 186.6 217.5 232.7 283.2 285.2KS-T 0.0164 10.5 15 97 28.4 34.1 42.0 57.8J-12 King Street @ Pleasant Street 0.3079 197.1 221.2 238.2 289.8 297.0King Street Old Mill River 0.3079 197.1 221.2 238.2 289.8 297.0KS-U Hampton Avenue 0.0119 7.6 15 95 19.9 24.1 30.0 41.6

Appendix B

Drainage Analysis





(mi 2) (ac) (cfs) (cfs) (cfs) (cfs)Old Mill River 0.0119 7.6 19.9 24.1 30.0 41.6KS-A Culvert @ Bikeway 0.0707 45.2 34 78 51.7 69.1 94.3 146.0Brook Rail Trail 0.0707 45.2 49.8 66.6 90.8 140.5

KS-B 0.0293 18.7 27 75 19.7 27.3 38.5 61.9J-4 Culvert @ Woodmont Road 0.0999 63.9 58.0 77.8 106.4 165.0


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@Brook Woodmont Rd 0.0999 63.9 57.7 77.3 105.7 164.0KS-D 0.0233 14.9 31 92 27.8 34.3 43.3 61.0KS-C 0.0145 9.3 15 83 18.0 23.2 30.4 45.1J-5 Old Market Street @ Highland Avenue 0.1377 88.1 71.4 94.4 127.5 195.3Market 48" 0.1377 88.1 70.9 93.7 126.6 193.8KS-H 0.0097 6.2 15 89 15.1 18.6 23.4 33.0J-6 Old Market Street @ North Street 0.1474 94.4 72.8 96.1 129.6 272.0Market 44"/48" 0.1474 94.4 72.2 95.3 128.4 262.8KS-O 0.0480 30.7 19 89 69.4 85.4 107.7 151.8KS-P 0.0065 4.2 20 90 8.7 10.9 13.9 19.8KS-N Market Street @ Walnut Street 0.0357 22.8 26 82 32.1 42.3 56.8 86.4Market 18"/21" 0.0357 22.8 29.7 39.2 52.6 80.0J-11 Old Market Street @ Bridge Street 0.2376 152.1 144.3 199.2 269.9 554.9Market 72" 0.2376 152.1 135.5 195.8 267.6 546.3KS-S 0.0370 23.7 16 89 56.5 69.6 87.7 123.6J-13 Old Market Street @ Hancock Street 0.2746 175.8 149.1 206.1 281.4 570.1Market 82" 0.2746 175.8 144.2 205.0 279.6 565.5KS-W 0.0151 9.7 15 90 24.8 30.2 37.6 52.5KS-V 0.0049 3.1 15 96 8.4 10.1 12.5 17.2J-14 Old Market Street @ Holyoke Street 0.2947 188.6 149.4 210.3 287.4 575.3Market 60" 0.2947 188.6 145.9 209.7 286.1 570.4KS-X 0.0058 3.7 15 85 8.2 10.3 13.2 19.0J-15 Old Market Street @ Hockanum Road 0.3004 192.3 147.0 211.0 287.8 572.6Market Street Old Mill River 0.3004 192.3 147.0 211.0 287.8 572.6


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Bridge Street/Meadows Area Drainage Analysis


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2 Y 10 Y 25 Y 50 Y 100 YPeak Rate of Runoff (cfs)

H d l i El L iDrainage Area

( ) T CN

Existing Conditions

Williams Street Brook Drainage AnalysisNorthampton, MA

Drainage Analysis SummaryApril 2011

Table 1


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2-Yr 10-Yr 25-Yr 50-Yr 100-Yr2 Lincoln Ave. 26.9 20 84 32.7 55.1 72.9 88.3 108.71 Bridge St. 17.7 20 70 9.1 20.6 30.7 39.9 52.6

Junction-A 44.6 41.9 75.7 103.6 128.2 161.3Reach-1 39.3 71.3 97.8 121.1 152.5

FG2 Fairgrounds Site 10.9 20 80 10.9 19.6 26.7 32.9 41.2FG5 Fairgrounds Site 3.4 25 74 2.2 4.4 6.3 7.9 10.2

E-Pond2 21.5 2.2 3.8 4.5 5 5.5FG3 Fairgrounds Site 13.5 20 73 8.8 18.2 26.2 33.5 43.4

E-Pump 0.4 0.4 0.4 0.4 0.4E-CP1 9.7 20.8 30 37.7 48.1

3 Old Ferry Rd. 5.2 15 66 2 5.1 8.1 10.9 14.8Junction-B 50.9 96 132.9 165.3 209.1Reach-2 47 88.1 122 152.5 193.6

4 Fair St. 10.4 15 85 14.4 24 31.6 38.1 46.8Junction-C 54.8 102.2 141.2 175.4 221.6

Reach-3 36.2 67.2 92.9 115.8 146.86 38.7 25 66 12.9 33.4 52.1 69.3 93.4

FG1 Fairgrounds Site 20.7 20 72 12.5 26.6 38.8 49.8 64.9FG6 Fairgrounds Site 0.7 15 79 0.7 1.3 1.8 2.3 2.8

E-Pond1 24.8 0.7 2.9 11 22.4 39.2FG4 7.5 70 3.9 8.7 13 16.9 22.2

E-CP2 32.3 3.9 8.7 15.2 30.8 53.75 Pomeroy Terrace 25.0 30 80 21.3 38.5 52.6 64.9 81.5

Wetland 9.6 32.1 107.7 183.1 277.5Reach-4 9.6 31.3 102.3 172.8 265.1

7 Eastern Ave. 10.0 15 82 12 20.9 28.1 34.4 42.8Junction-E 12.8 32.8 105.5 177.5 273.2Reach-5 10.3 30.8 91.6 152.5 237.2

8 Valley St. 19.4 30 69 8 18.3 27.5 36.1 48Junction-E2 18.4 36.7 96.3 160 249.2

9 William St 11 1 15 83 14 1 24 1 32 2 39 3 48 6

Hydrologic Element Location (acres) Tc CN

March 2011


Drainage Characteristics

Table 2


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Total Area Area Impervious

(acres) (sq. mi.) (acres)

1 17.7 0.0277 2.3 13% 70 20 122 26.9 0.0420 12.4 46% 84 20 123 5.2 0.0081 0.7 14% 66 15 94 10.3 0.0162 5.3 51% 85 15 95 25.0 0.0391 9.6 38% 80 30 186 38.7 0.0605 2.7 7% 66 25 157 10.0 0.0156 4.4 45% 82 15 98 19.4 0.0303 3.3 17% 69 30 18

9 11.1 0.0174 6.3 56% 83 15 910 9.7 0.0151 3.4 35% 74 15 911 2.3 0.0037 0.1 6% 70 15 912 34.7 0.0543 11.7 34% 82 30 1813 82.9 0.1296 45.1 54% 84 25 15

FG1 20.7 0.0324 2.9 14% 72 20 12FG2 10.9 0.0171 3.6 33% 80 20 12

FG3 13 5 0 0211 3 2 24% 73 20 12

Existing Conditions

Watershed%Imp.

WeightedCN

Lag Time(Min)

Tc Min)

Existing Conditions

Area 1 Area 2 Area 3


Time of Concentration Calculation April 2011

Table 3


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Hydraulic Length 1500 ft Hydraulic Length 1500 ft Hydraulic Length 510 ftSlope 0.005 ft/ft Slope 0.007 ft/ft Slope 0.005 ft/ft*Velocity 1.3 fps *Velocity 1.5 fps *Velocity 1.3 fpsTc1 19.2 min Tc2 16.7 min Tc3 6.5 minTc Used 20.0 min Tc Used 20.0 min Tc Used 15.0 minLag Time 0.20 hr Lag Time 0.20 hr Lag Time 0.15 hr

Area 4 Area 5 Area 6Hydraulic Length 990 ft Hydraulic Length 240 ft Hydraulic Length 1740 ftSlope 0.005 ft/ft Slope 0.005 ft/ft Slope 0.005 ft/ft*Velocity 1.3 fps *Velocity 1.3 fps *Velocity 1.3 fpsTc4 12.7 min Tc5-1 3.1 min Tc6 22.3 minTc Used 15.0 min Hydraulic Length 60 ft Tc Used 25.0 minLag Time 0.15 hr Slope 0.170 ft/ft Lag Time 0.25 hr

*Velocity 7.5 fpsArea 7 Tc5-2 0.1 min Area 9

Hydraulic Length 540 ft Hydraulic Length 1950 ft Hydraulic Length 1260 ftSlope 0.009 ft/ft Slope 0.005 ft/ft Slope 0.020 ft/ft*Velocity 1.7 fps *Velocity 1.3 fps *Velocity 2.5 fpsTc7-1 5.3 min Tc5-3 25.0 min Tc9 8.4 minHydraulic Length 360 ft Total TcF 28.2 min Tc Used 15.0 minSlope 0.014 ft/ft Tc Used 30.0 min Lag Time 0.15 hr *Velocity 2.0 fps Lag Time 0.30 hr Tc7-2 3.0 minTotal Tc7 8.3 min Area 8 Area 10Tc Used 15.0 min Hydraulic Length 1440 ft Hydraulic Length 1050 ftLag Time 0.15 hr Slope 0.002 ft/ft Slope 0.005 ft/ft

*Velocity 0.8 fps *Velocity 1.3 fpsArea 11 Tc8 30 0 min Tc10 13 5 min


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2 -Yr 10 -Yr 25-Yr 50-Yr 10 0-Yr2 Lincoln Ave. 26.9 20 86 35.8 58.5 76.4 91.8 112.21 Bridge St. 17.7 20 71 9.9 21.7 32 41.3 54.1

Peak Rate of Runoff (cfs)Hydrologic Element Location

Drainage Area(acres) Tc(min) CN

Future Conditions



Table 1


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gJunction-A 44.6 45.7 80.2 108.4 133.1 166.3Reach-1 44.6 43 75.6 102.4 125.8 157.3

3 Old Ferry Rd. 5.2 15 67 2.2 5.5 8.5 11.3 15.3Junction-B 49.8 45 80.3 109.4 135 169.4Reach-2 49.8 41.5 73.6 100.1 123.4 154.9

4 Fair St. 10.4 15 86 15.1 24.7 32.3 38.9 47.6Junction-C 60.1 49.7 87.7 118.9 146.3 183.3

Reach-3 60.1 32.9 58 79 97.4 122.2FGP1 Fairgrounds Site 35.9 15 78 34.6 64.8 90 112.1 142FGP7 Fairgrounds Site 3.4 25 74 2.2 4.4 6.3 7.9 10.2

Ppond2 39.3 4.4 10.8 13.7 15.5 17.9SWTC2 39.3 4.4 10.8 13.7 15.5 17.9FGP3 Fairgrounds Site 8.3 15 79 8.4 15.5 21.3 26.5 33.4FGP8 Fairgrounds Site 0.7 15 79 0.7 1.3 1.8 2.3 2.8

Ppond4 9.0 1.8 4.8 8.1 10.9 13.1SWCT1 9.0 1.8 4.8 8.1 10.9 13.1FGP2 Fairgrounds Site 4.9 15 82 5.8 10.2 13.7 16.8 20.9

Ppond1 4.9 1.4 3.5 5.6 7.4 9.9FGP6 Fairgrounds Site 1.0 15 95 2.1 3 3.8 4.4 5.2

SWTC3 5.9 2.5 4.8 7.5 9.7 12.8FGP5 Fairgrounds Site 0.6 15 80 0.6 1.1 1.5 1.9 2.4

Ppond3 54.7 7.6 19.4 28.3 35.3 42.7

FGP4 Fairgrounds Site 1.6 20 76 1.3 2.5 3.4 4.3 5.5FGP9 0.4 15 87 0.7 1.1 1.4 1.7 2.1P-CP2 56.7 7.9 20.3 30.4 38.2 47

6 38.7 25 66 12.9 33.4 52.1 69.3 93.45 Pomeroy Terrace 25.0 30 81 22.5 39.9 54.2 66.6 83.1

Wetland 180.6 10.4 41.3 110.2 174.2 253.2Reach-4 180.6 10.4 40 104.5 165.6 242.1

7 Eastern Ave. 10.0 15 83 12.6 21.6 28.9 35.2 43.6Junction-E 190.6 13.2 41.7 107.7 170.4 250.3Reach-5 190.6 10.9 38.5 94 147.9 220.1

8 Valley St. 19.4 30 70 8.7 19.3 28.7 37.4 49.4Junction-E2 210.0 19.3 40.8 98.7 155.1 232.3

9 William St. 11.1 15 85 15.5 25.8 33.9 41 50.3

10 Herny St 9 7 15 75 7 7 15 4 21 9 27 7 35 7

March 2011



Table 2Future Conditions


144/243



1 17.7 0.0277 2.3 13% 71 20 122 26.9 0.0420 12.4 46% 86 20 123 5.2 0.0081 0.7 14% 67 15 94 10.3 0.0162 5.3 51% 86 15 95 25.0 0.0391 9.6 38% 81 30 186 38.7 0.0605 2.7 7% 66 25 157 10.0 0.0156 4.4 45% 83 15 98 19.4 0.0303 3.3 17% 70 30 189 11.1 0.0174 6.3 56% 85 15 9

10 9.7 0.0151 3.4 35% 75 15 911 2.3 0.0037 0.1 6% 70 15 912 34.7 0.0543 11.7 34% 83 30 1813 82.9 0.1296 30.7 37% 85 25 15

FGP1 35.9 0.0561 12.2 34% 78 15 9FGP2 4.9 0.0076 2.7 55% 82 15 9FGP3 8 3 0 0129 2 0 24% 79 15 9

Future Conditions

Watershed%Imp.

WeightedCN

Lag Time(Min)

Tc Min)

Future Conditions

Area 1 Area 2 Area 3H d li L th 1500 ft H d li L th 1500 ft H d li L th 510 ft



Table 3


145/243

Hydraulic Length 1500 ft Hydraulic Length 1500 ft Hydraulic Length 510 ftSlope 0.005 ft/ft Slope 0.007 ft/ft Slope 0.005 ft/ft*Velocity 1.3 fps *Velocity 1.5 fps *Velocity 1.3 fpsTc1 19.2 min Tc2 16.7 min Tc3 6.5 minTc Used 20.0 min Tc Used 20.0 min Tc Used 15.0 minLag Time 0.20 hr Lag Time 0.20 hr Lag Time 0.15 hr




*Velocity 0.8 fps *Velocity 1.3 fpsArea 11 Tc8 30 0 min Tc10 13 5 min

Future Conditions

tA tB tCHydraulic Length 480 ft Hydraulic Length 600 ft Hydraulic Length 2010 ft


Muskingum(K) Calculation April 2011

Table 4


146/243

Hydraulic Length 480 ft Hydraulic Length 600 ft Hydraulic Length 2010 ftSlope 0.005 ft/ft Slope 0.004 ft/ft Slope 0.003 ft/ft*Velocity 1.3 fps *Velocity 1.2 fps *Velocity 0.9 fpstA 6.2 min tB 8.3 min tC 39.4 mintA 0.10 hour tB 0.14 hour tC 0.7 hour

tD tE tFHydraulic Length 450 ft Hydraulic Length 1290 ft Hydraulic Length 150 ftSlope 0.005 ft/ft Slope 0.008 ft/ft Slope 0.003 ft/ft*Velocity 1.3 fps *Velocity 1.5 fps *Velocity 0.9 fpstD 5.8 min tE 14.3 min tF 2.8 mintD 0.10 hour tE 0.24 hour tF 0.05 hour


147/243

2 -Yr 1 0-Yr 25 -Yr 50 -Yr 1 00 -YrFGP1 Fairgrounds Site 35.9 15 78 34.6 64.8 90 112.1 142FGP7 Fairgrounds Site 3.4 25 74 2.2 4.4 6.3 7.9 10.2

Ppond2 39.3 4.4 10.8 13.7 15.5 17.9SWTC2 39.3 4.4 10.8 13.7 15.5 17.9

Future Conditions (Alternative 1)



Table 1




148/243

FGP3 Fairgrounds Site 8.3 15 79 8.4 15.5 21.3 26.5 33.4FGP8 Fairgrounds Site 0.7 15 79 0.7 1.3 1.8 2.3 2.8




Ppond3 54.7 7.6 19.4 28.3 35.3 42.7FGP4 Fairgrounds Site 1.6 20 76 1.3 2.5 3.4 4.3 5.5FGP9 Fairgrounds Site 0.4 15 87 0.7 1.1 1.4 1.7 2.1P-CP2 56.7 7.9 20.3 30.4 38.2 47

6 38.7 25 66 12.9 33.4 52.1 69.3 93.4FS-1 95.5 7.8 17.9 24.6 30.6 47.5

5 Pomeroy Terrace 25.0 30 81 22.5 39.9 54.2 66.6 83.11 Bridge St. 17.7 20 71 9.9 21.7 32 41.3 54.1

Junction-A 17.7 9.9 21.7 32 41.3 54.1Reach-1 17.7 9.3 20.3 30 38.8 50.9

3 Old Ferry Rd. 5.2 15 67 2.2 5.5 8.5 11.3 15.3Junction-B 22.9 11.2 25 37 48 63.1Reach-2 22.9 10.5 23.1 34.1 44.1 58.2

Junction-C 22.9 10.5 23.1 34.1 44.1 58.2Reach-3 22.9 6.5 14.5 21.7 28.3 37.4Wetland 143.4 4.9 12.4 23.6 39.8 72.7Reach-4 143.4 4.9 12.4 23.3 39.2 70.7

7 Eastern Ave. 10.0 15 83 12.6 21.6 28.9 35.2 43.6Junction-E 153.4 12.9 22.3 30 41.1 74.2Reach-5 153.4 10.2 17.7 23.8 39.4 68.9

8 Valley St. 19.4 30 70 8.7 19.3 28.7 37.4 49.49 William St. 11.1 15 85 15.5 25.8 33.9 41 50.3

10 Herny St. 9.7 15 75 7.7 15.4 21.9 27.7 35.7Junction-F 193.5 38 71.2 99.1 123.9 157.5Reach-6 193.5 37.6 70.3 97.7 122 154.9

11 2.4 15 70 1.3 3 4.4 5.8 7.6G-Mill River 195.9 38.8 72.8 101.3 126.6 160.9

13 Industrial Dr. 82.9 25 85 96.9 160.4 211.7 256 314.82 Lincoln Ave. 26.9 20 86 35.8 58.5 76.4 91.8 112.24 Fair St 10 4 15 86 15 1 24 7 32 3 38 9 47 6


April 2011



Table 2


149/243



1 17.7 0.0277 2.3 13% 71 20 12

2 26.9 0.0420 12.4 46% 86 20 123 5.2 0.0081 0.7 14% 67 15 94 10.3 0.0162 5.3 51% 86 15 95 25.0 0.0391 9.6 38% 81 30 186 38.7 0.0605 2.7 7% 66 25 157 10.0 0.0156 4.4 45% 83 15 98 19.4 0.0303 3.3 17% 70 30 18

9 11.1 0.0174 6.3 56% 85 15 910 9.7 0.0151 3.4 35% 75 15 911 2.3 0.0037 0.1 6% 70 15 912 34.7 0.0543 11.7 34% 83 30 1813 82.9 0.1296 45.1 54% 85 25 15

FGP1 35.9 0.0561 12.2 34% 78 15 9FGP2 4.9 0.0076 2.7 55% 82 15 9

FGP3 8 3 0 0129 2 0 24% 79 15 9

( )

Watershed%Imp.

WeightedCN

Lag Time(Min)

Tc Min)


Area 1 Area 2 Area 3Hydraulic Length 1500 ft Hydraulic Length 1500 ft Hydraulic Length 510 ft



Table 3


150/243

Slope 0.005 ft/ft Slope 0.007 ft/ft Slope 0.005 ft/ft*Velocity 1.3 fps *Velocity 1.5 fps *Velocity 1.3 fpsTc1 19.2 min Tc2 16.7 min Tc3 6.5 minTc Used 20.0 min Tc Used 20.0 min Tc Used 15.0 minLag Time 0.20 hr Lag Time 0.20 hr Lag Time 0.15 hr




*Velocity 0.8 fps *Velocity 1.3 fps

A 11 T 8 30 0 i T 10 13 5 i


151/243


152/243

2-Yr 10-Yr 25-Yr 50-Yr 100-YrFGP1 Fairgrounds Site 35.9 15 78 9.9 64.8 90 112.1 142FGP7 Fairgrounds Site 3.4 25 74 9.9 4.4 6.3 7.9 10.2

Ppond2 39.3 9.3 10.8 13.7 15.5 17.9SWTC2 39.3 2.2 10.8 13.7 15.5 17.9




Table 1




153/243

FGP3 Fairgrounds Site 8.3 15 79 11.2 15.5 21.3 26.5 33.4FGP8 Fairgrounds Site 0.7 15 79 10.5 1.3 1.8 2.3 2.8




Ppond3 54.7 0.7 19.4 28.3 35.3 42.7FGP4 Fairgrounds Site 1.6 20 76 1.8 2.5 3.4 4.3 5.5FGP9 Fairgrounds Site 0.4 15 87 1.8 1.1 1.4 1.7 2.1P-CP2 56.7 5.8 20.3 30.4 38.2 47

6 38.7 25 66 1.4 33.4 52.1 69.3 93.45 Pomeroy Terrace 25.0 30 81 2.1 39.9 54.2 66.6 83.11 Bridge St. 17.7 20 71 2.5 21.7 32 41.3 54.1

Junction-A 17.7 0.6 21.7 32 41.3 54.1Reach-1 17.7 7.6 20.3 30 38.8 50.9

3 Old Ferry Rd. 5.2 15 67 1.3 5.5 8.5 11.3 15.3Junction-B 22.9 0.7 25 37 48 63.1Reach-2 22.9 7.9 23.1 34.1 44.1 58.2

Junction-C 22.9 12.9 23.1 34.1 44.1 58.2

Reach-3 22.9 22.5 14.5 21.7 28.3 37.4Wetland 143.4 38.1 13.6 35.6 70.3 139.9Reach-4 143.4 37 13.6 34.9 67.2 130.2

7 Eastern Ave. 10.0 15 83 12.6 21.6 28.9 35.2 43.6Junction-E 153.4 44 22.6 36.8 70.8 136Reach-5 153.4 39.4 18.1 34.9 64 117.9

8 Valley St. 19.4 30 70 8.7 19.3 28.7 37.4 49.49 William St. 11.1 15 85 15.5 25.8 33.9 41 50.3

10 Henry St. 9.7 15 75 7.7 15.4 21.9 27.7 35.7Junction-F 193.5 56.2 71.4 99.5 124.6 158.9Reach-6 193.5 56 70.5 98.1 122.7 156.5

11 2.4 15 70 1.3 3 4.4 5.8 7.6G-Mill River 195.9 56.6 73 101.7 127.3 162.4

13 Industrial Dr. 82.9 25 85 96.9 160.4 211.7 256 314.8


March 2011



Table 2


154/243



1 17.7 0.0277 2.3 13% 71 20 12

2 26.9 0.0420 12.4 46% 86 20 123 5.2 0.0081 0.7 14% 67 15 94 10.3 0.0162 5.3 51% 86 15 95 25.0 0.0391 9.6 38% 81 30 186 38.7 0.0605 2.7 7% 66 25 157 10.0 0.0156 4.4 45% 83 15 98 19.4 0.0303 3.3 17% 70 30 18

9 11.1 0.0174 6.3 56% 85 15 910 9.7 0.0151 3.4 35% 75 15 911 2.3 0.0037 0.1 6% 70 15 912 34.7 0.0543 11.7 34% 83 30 1813 82.9 0.1296 45.1 54% 85 25 15

FGP1 35.9 0.0561 12.2 34% 78 15 9FGP2 4.9 0.0076 2.7 55% 82 15 9

Watershed%Imp.

WeightedCN

Lag Time(Min)

Tc Min)


Area 1 Area 2 Area 3Hydraulic Length 1500 ft Hydraulic Length 1500 ft Hydraulic Length 510 ftSlope 0 005 ft/ft Slope 0 007 ft/ft Slope 0 005 ft/ft



Table 3


155/243

Slope 0.005 ft/ft Slope 0.007 ft/ft Slope 0.005 ft/ft*Velocity 1.3 fps *Velocity 1.5 fps *Velocity 1.3 fpsTc1 19.2 min Tc2 16.7 min Tc3 6.5 minTc Used 20.0 min Tc Used 20.0 min Tc Used 15.0 minLag Time 0.20 hr Lag Time 0.20 hr Lag Time 0.15 hr



Hydraulic Length 540 ft Hydraulic Length 1950 ft Hydraulic Length 1260 ftSlope 0.009 ft/ft Slope 0.005 ft/ft Slope 0.020 ft/ft

*Velocity 1.7 fps *Velocity 1.3 fps *Velocity 2.5 fpsTc7-1 5.3 min Tc5-3 25.0 min Tc9 8.4 minHydraulic Length 360 ft Total TcF 28.2 min Tc Used 15.0 minSlope 0.014 ft/ft Tc Used 30.0 min Lag Time 0.15 hr *Velocity 2.0 fps Lag Time 0.30 hr Tc7-2 3.0 minTotal Tc7 8.3 min Area 8 Area 10Tc Used 15.0 min Hydraulic Length 1440 ft Hydraulic Length 1050 ftLag Time 0.15 hr Slope 0.002 ft/ft Slope 0.005 ft/ft



tA tB tCHydraulic Length 480 ft Hydraulic Length 600 ft Hydraulic Length 2010 ftSlope 0 005 ft/ft Slope 0 004 ft/ft Slope 0 003 ft/ft



Table 4


156/243

Slope 0.005 ft/ft Slope 0.004 ft/ft Slope 0.003 ft/ft*Velocity 1.3 fps *Velocity 1.2 fps *Velocity 0.9 fpstA 6.2 min tB 8.3 min tC 39.4 mintA 0.10 hour tB 0.14 hour tC 0.7 hour

tD tE tFHydraulic Length 450 ft Hydraulic Length 1290 ft Hydraulic Length 150 ft

Slope 0.005 ft/ft Slope 0.008 ft/ft Slope 0.003 ft/ft*Velocity 1.3 fps *Velocity 1.5 fps *Velocity 0.9 fpstD 5.8 min tE 14.3 min tF 2.8 mintD 0.10 hour tE 0.24 hour tF 0.05 hour

tG tHHydraulic Length 330 ft Hydraulic Length 2820 ftSlope 0.005 ft/ft Slope 0.005 ft/ft*Velocity 1.3 fps *Velocity 1.3 fpstD 4.2 min tD 36.2 min

tD 0.07 hour tD 0.60 hour


157/243

2-Yr 10-Yr 25-Yr 50-Yr 100-Yr2 Lincoln Ave. 26.9 20 86 35.8 58.5 76.4 91.8 112.21 Bridge St. 17.7 20 71 9.9 21.7 32 41.3 54.1

Junction-A 44.6 45.7 80.2 108.4 133.1 166.3R h 1 44 6 43 75 6 102 4 125 8 157 3




Table 1




158/243

Reach-1 44.6 43 75.6 102.4 125.8 157.33 Old Ferry Rd. 5.2 15 67 2.2 5.5 8.5 11.3 15.3

Junction-B 49.8 45 80.3 109.4 135 169.4Reach-2 49.8 41.5 73.6 100.1 123.4 154.9

4 Fair St. 10.4 15 86 15.1 24.7 32.3 38.9 47.6Junction-C 60.1 49.7 87.7 118.9 146.3 183.3

Reach-3 60.1 32.9 58 79 97.4 122.26 38.7 25 66 12.9 33.4 52.1 69.3 93.4

5 Pomeroy Terrace 25.0 30 81 22.5 39.9 54.2 66.6 83.1Wetland 123.9 7.8 14.6 61.5 120.4 195.0Reach-4 123.9 7.8 14.6 58.3 114.3 183.9

7 Eastern Ave. 10.0 15 83 12.6 21.6 28.9 35.2 43.6Junction-E 133.8 13.2 23.2 61.1 118.4 190.3

Reach-5 133.8 10.6 18.7 54.1 101.8 166.48 Valley St. 19.4 30 70 8.7 19.3 28.7 37.4 49.49 William St. 11.1 15 85 15.5 25.8 33.9 41 50.3

10 Herny St. 9.7 15 75 7.7 15.4 21.9 27.7 35.7Junction-F 174.0 38.2 72 100.4 125.7 187.5Reach-6 174.0 37.9 71.1 99 123.9 186.6

11 2.4 15 70 1.3 3 4.4 5.8 7.6

G-Mill River 176.4 39.1 73.6 102.6 128.5 187.613 Industrial Dr. 82.9 25 85 96.9 160.4 211.7 256 314.812 Marshall St. 34.7 30 83 34.6 59.5 79.5 96.8 119.9

42-inch Pipe 117.7 131.5 219.6 289.7 350.1 430.5FGP1 Fairgrounds Site 35.9 15 78 34.6 64.8 90 112.1 142.0FGP7 Fairgrounds Site 3.4 25 74 2.2 4.4 6.3 7.9 10.2

Ppond2 39.3 4.4 10.8 13.7 15.5 17.9SWTC2 39.3 4.4 10.8 13.7 15.5 17.9FGP3 Fairgrounds Site 8.3 15 79 8.4 15.5 21.3 26.5 33.4FGP8 Fairgrounds Site 0.7 15 79 0.7 1.3 1.8 2.3 2.8

Ppond4 9.0 1.8 4.8 8.1 10.9 13.1SWCT1 9.0 1.8 4.8 8.1 10.9 13.1


159/243


Area 1 Area 2 Area 3Hydraulic Length 1500 ft Hydraulic Length 1500 ft Hydraulic Length 510 ftSlope 0.005 ft/ft Slope 0.007 ft/ft Slope 0.005 ft/ft



Table 3


160/243

*Velocity 1.3 fps *Velocity 1.5 fps *Velocity 1.3 fpsTc1 19.2 min Tc2 16.7 min Tc3 6.5 minTc Used 20.0 min Tc Used 20.0 min Tc Used 15.0 minLag Time 0.20 hr Lag Time 0.20 hr Lag Time 0.15 hr

Area 4 Area 5 Area 6

Hydraulic Length 990 ft Hydraulic Length 240 ft Hydraulic Length 1740 ftSlope 0.005 ft/ft Slope 0.005 ft/ft Slope 0.005 ft/ft*Velocity 1.3 fps *Velocity 1.3 fps *Velocity 1.3 fpsTc4 12.7 min Tc5-1 3.1 min Tc6 22.3 minTc Used 15.0 min Hydraulic Length 60 ft Tc Used 25.0 minLag Time 0.15 hr Slope 0.170 ft/ft Lag Time 0.25 hr


Hydraulic Length 540 ft Hydraulic Length 1950 ft Hydraulic Length 1260 ftSlope 0.009 ft/ft Slope 0.005 ft/ft Slope 0.020 ft/ft

*Velocity 1.7 fps *Velocity 1.3 fps *Velocity 2.5 fpsTc7-1 5.3 min Tc5-3 25.0 min Tc9 8.4 minHydraulic Length 360 ft Total TcF 28.2 min Tc Used 15.0 minSlope 0.014 ft/ft Tc Used 30.0 min Lag Time 0.15 hr *Velocity 2.0 fps Lag Time 0.30 hr Tc7-2 3.0 minTotal Tc7 8.3 min Area 8 Area 10Tc Used 15.0 min Hydraulic Length 1440 ft Hydraulic Length 1050 ftLag Time 0.15 hr Slope 0.002 ft/ft Slope 0.005 ft/ft



tA tB tCHydraulic Length 480 ft Hydraulic Length 600 ft Hydraulic Length 2010 ftSlope 0.005 ft/ft Slope 0.004 ft/ft Slope 0.003 ft/ft



Table 4


161/243

*Velocity 1.3 fps *Velocity 1.2 fps *Velocity 0.9 fpstA 6.2 min tB 8.3 min tC 39.4 mintA 0.10 hour tB 0.14 hour tC 0.7 hour

tD tE tFHydraulic Length 450 ft Hydraulic Length 1290 ft Hydraulic Length 150 ft

Slope 0.005 ft/ft Slope 0.008 ft/ft Slope 0.003 ft/ft*Velocity 1.3 fps *Velocity 1.5 fps *Velocity 0.9 fpstD 5.8 min tE 14.3 min tF 2.8 mintD 0.10 hour tE 0.24 hour tF 0.05 hour


162/243


163/243

Future Conditions (Recommended Plan)

March 2011



Table 2


164/243



1 17.7 0.0277 2.3 13% 71 20 12

2 26.9 0.0420 12.4 46% 86 20 123 5.2 0.0081 0.7 14% 67 15 94 10.3 0.0162 5.3 51% 86 15 95 25.0 0.0391 9.6 38% 81 30 186 38.7 0.0605 2.7 7% 66 25 157 10.0 0.0156 4.4 45% 83 15 98 19.4 0.0303 3.3 17% 70 30 18

9 11.1 0.0174 6.3 56% 85 15 910 9.7 0.0151 3.4 35% 75 15 911 2.3 0.0037 0.1 6% 70 15 912 34.7 0.0543 11.7 34% 83 30 1813 82.9 0.1296 21.0 25% 82 25 15

FGP1 35.9 0.0561 12.2 34% 78 15 9FGP2 4.9 0.0076 2.7 55% 82 15 9

Watershed%Imp.

WeightedCN

Lag Time(Min)

Tc Min)


165/243


166/243


167/243


168/243


169/243


170/243

Existing Conditions

Area A Area B Area CHydraulic Length 840 ft Hydraulic Length 840 ft Hydraulic Length 300 ftSlope 0.027 ft/ft Slope 0.040 ft/ft Slope 0.033 ft/ft*Velocity 2.7 fps *Velocity 3.5 fps *Velocity 3.1 fpsTcA1 5.2 min TcB1 4.0 min TcC1 1.6 minHydraulic Length 450 ft Hydraulic Length 390 ft Hydraulic Length 810 ftSlope 0.044 ft/ft Slope 0.026 ft/ft Slope 0.031 ft/ft*Velocity 3.7 fps *Velocity 2.8 fps *Velocity 2.6 fpsTcA2 2.0 min TcB2 2.3 min TcC2 5.2 minHydraulic Length 780 ft Total TcB 6.3 min Total TcC 6.8 minSlope 0.013 ft/ft Tc Used 15.0 min Tc Used 15.0 min*Velocity 2.0 fps Lag Time 0.15 hr Lag Time 0.15 hr TcA3 6.5 minTotal TcA 13.7 minTc Used 15.0 minLag Time 0.15 hr

Area D Area E Area F

Hydraulic Length 660 ft Hydraulic Length 510 ft Hydraulic Length 510 ftSlope 0.091 ft/ft Slope 0.078 ft/ft Slope 0.078 ft/ft*Velocity 5.3 fps *Velocity 4.8 fps *Velocity 4.6 fpsTcD1 2.1 min TcD1 1.8 min TcF1 1.8 minTc Used 15.0 min Tc Used 15.0 min Hydraulic Length 2400 ftLag Time 0.15 hr Lag Time 0.15 hr Slope 0.017 ft/ft

*Velocity 2.2 fpsArea G Area H TcF2 18.2 min

Hydraulic Length 300 ft Hydraulic Length 360 ft Hydraulic Length 150 ftSlope 0.067 ft/ft Slope 0.028 ft/ft Slope 0.200 ft/ft*V l it 4 5 f *V l it 2 9 f *V l it 7 0 f

Elm Street Brook Drainage AnalysisNorthampton, MA

Time of Concentration CalculationMarch 2011


171/243

*Velocity 4.5 fps *Velocity 2.9 fps *Velocity 7.0 fpsTcG1 1.1 min TcH1 2.1 min TcF3 0.4 minHydraulic Length 870 ft Hydraulic Length 420 ft Total TcF 20.4 minSlope 0.023 ft/ft Slope 0.024 ft/ft Tc Used 25.0 min*Velocity 2.5 fps *Velocity 2.7 fps Lag Time 0.25 hr TcG2 5.8 min TcH2 2.6 minTotal TcG 6.9 min Total TcH 4.7 minTc Used 15.0 min Tc Used 15.0 minLag Time 0.15 hr Lag Time 0.15 hr

Area I Area J Area KHydraulic Length 510 ft Hydraulic Length 210 ft Hydraulic Length 200 ftSlope 0.078 ft/ft Slope 0.143 ft/ft Slope 0.167 ft/ft*Velocity 4.4 fps *Velocity 5.8 fps *Velocity 7.5 fpsTcI1 1.9 min TcJ1 0.6 min TcI1 0.4 minHydraulic Length 300 ft Hydraulic Length 570 ft Hydraulic Length 510 ftSlope 0.033 ft/ft Slope 0.018 ft/ft Slope 0.029 ft/ft*Velocity 3.3 fps *Velocity 2.4 fps *Velocity 0.9 fpsTcI2 1.5 min TcJ2 4.0 min TcI2 10.0 minTotal TcI 3.4 min Hydraulic Length 60 ft Total TcI 10.4 minTc Used 15.0 min Slope 0.330 ft/ft Tc Used 15.0 minLag Time 0.15 hr *Velocity 9.0 fps Lag Time 0.15 hr

TcJ3 0.1 minArea L Hydraulic L ength 300 f t Area N

Hydraulic Length 450 ft Slope 0.005 ft/ft Hydraulic Length 1380 ftSlope 0.044 ft/ft *Velocity 1.1 fps Slope 0.015 ft/ft*Velocity 1.2 fps TcJ4 4.5 min *Velocity 2.1 fpsTcL1 6.3 min Total TcJ 9.2 min TcN1 11.0 minHydraulic Length 360 ft Tc Used 15.0 min Hydraulic Length 1200 ftSlope 0.028 ft/ft Lag Time 0.15 hr Slope 0.049 ft/ft*Velocity 0.9 fps *Velocity 3.7 fpsTcL2 7.1 min Area M TcN2 5.4 minHydraulic Length 420 ft Hydraulic Length 2250 ft Total TcN 16.4 min

Slope 0.048 ft/ft Slope 0.009 ft/ft Tc Used 20.0 min*Velocity 1.3 fps *Velocity 1.7 fps Lag Time 0.20 hr TcL3 5.4 min TcM1 22.1 minHydraulic Length 90 ft Tc Used 25.0 min Area QSlope 0.440 ft/ft Lag Time 0.25 hr H yd rau li c L en gt h 111 0 f t*Velocity 3.5 fps Slope 0.018 ft/ftTcL4 0.4 min Area P *Velocity 2.4 fpsTotal TcL 19.1 min Hydraulic Length 1050 ft TcQ1 7.7 minTc Used 20.0 min Slope 0.038 ft/ft Hydraulic Length 720 ftLag Time 0.20 hr *Velocity 3.5 fps Slope 0.028 ft/ft

TcP1 5.0 min *Velocity 3.0 fpsArea O Tc Used 15.0 min TcQ2 4.0 min

Hydr aulic Lengt h 240 f t Lag Time 0.15 hr Total TcQ 11.7 minSlope 0.125 ft/ft Tc Used 15.0 min*Velocity 6.0 fps Area R Lag Time 0.15 hr TcO1 0.7 min Hydraulic Length 510 ftHydraulic Length 810 ft Slope 0.078 ft/ft Area SSlope 0.012 ft/ft *Velocity 4.2 fps Hydraulic Length 420 ft*Velocity 1.7 fps TcR1 2.0 min Slope 0.007 ft/ftTcO2 7.9 min Hydraulic Length 450 ft *Velocity 1.5 fpsTotal TcO 8.6 min Slope 0.022 ft/ft TcS1 4.7 min

Existing Conditions

tA tB tCHydraulic Length 540 ft Hydraulic Length 240 ft Hydraulic Length 810 ftSlope 0.005 ft/ft Slope 0.005 ft/ft Slope 0.025 ft/ft*Velocity 1.5 fps *Velocity 1.5 fps *Velocity 2.7 fpstA 6.0 min tB 2.7 min tC 5.0 mintA 0.10 hour tB 0.04 hour tC 0.1 hour

tD tE tF


Muskingum(K) CalculationMarch 2011


172/243

Hydraulic Length 300 ft Hydraulic Length 450 ft Hydraulic Length 900 ftSlope 0.025 ft/ft Slope 0.011 ft/ft Slope 0.067 ft/ft*Velocity 2.7 fps *Velocity 1.6 fps *Velocity 4.5 fpstD1 1.9 min tE 4.7 min tF 3.3 minHydraulic Length 280 ft tE 0.08 hour tF 0.06 hourSlope 0.005 ft/ft*Velocity 1.2 fps tItD2 3.9 min Hydraulic Length 420 ftTotal tD 5.7 min Slope 0.012 ft/fttD 0.10 hour *Velocity 1.5 fps

tI1 4.7 mintG tH Hydraulic Length 90 ft

Hydraulic Length 480 ft Hydraulic Length 450 ft Slope 0.600 ft/ftSlope 0.005 ft/ft Slope 0.033 ft/ft *Velocity 12.0 fps*Velocity 1.3 fps *Velocity 3.2 fps tI2 0.1 mintG 6.2 min tH 2.3 min Total tD 4.8 mintG 0.10 hour tH 0.04 hour tD 0.08 hour

tJ tK tLHydraulic Length 300 ft Hydraulic Length 1200 ft Hydraulic Length 360 ftSlope 0.100 ft/ft Slope 0.033 ft/ft Slope 0.028 ft/ft*Velocity 5.0 fps *Velocity 2.6 fps *Velocity 2.5 fpstJ 1.0 min tK 7.7 min tL 2.4 mintJ 0.02 hour tK 0.13 hour tL 0.04 hour


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Total Area Area Impervious(acres) (sq mi ) (acres)

March 2011



Table 2

Watershed%Imp.

WeightedCN

Lag Time(Min)

Tc


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A 27.0 0.0423 6.6 0.24 73 15 9B 27.7 0.0433 3.7 0.13 68 15 9

C 18.1 0.0284 1.8 0.10 66 15 9D 6.8 0.0106 1.1 0.16 77 15 9E 3.1 0.0049 1.1 0.35 75 15 9F 30.9 0.0484 8.6 0.28 79 25 15G 20.7 0.0324 6.3 0.30 73 15 9H 17.0 0.0265 2.0 0.12 67 15 9I 6.3 0.0098 0.6 0.09 62 15 9

J 14.6 0.0228 3.6 0.25 67 15 9K 8.1 0.0127 0.4 0.05 60 15 9L 28.1 0.0439 4.9 0.17 54 20 12M 23.0 0.0359 9.0 0.39 66 25 15N 23.0 0.0359 13.6 0.59 78 20 12O 10.0 0.0156 2.2 0.22 68 15 9P 16.3 0.0255 8.3 0.51 80 15 9

Watershed ( )


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Future Conditions (Alternative 3)Area A Area B Area C

Hydraulic Length 840 ft Hydraulic Length 840 ft Hydraulic Length 300 ftSlope 0.027 ft/ft Slope 0.040 ft/ft Slope 0.033 ft/ft*Velocity 2.7 fps *Velocity 3.5 fps *Velocity 3.1 fpsTcA1 5.2 min TcB1 4.0 min TcC1 1.6 minHydraulic Length 450 ft Hydraulic Length 390 ft Hydraulic Length 810 ftSlope 0.044 ft/ft Slope 0.026 ft/ft Slope 0.031 ft/ft*Velocity 3.7 fps *Velocity 2.8 fps *Velocity 2.6 fpsTcA2 2.0 min TcB2 2.3 min TcC2 5.2 minHydraulic Length 780 ft Total TcB 6.3 min Total TcC 6.8 minSlope 0.013 ft/ft Tc Used 15.0 min Tc Used 15.0 min*Velocity 2.0 fps Lag Time 0.15 hr Lag Time 0.15 hr TcA3 6.5 minTotal TcA 13.7 minTc Used 15.0 minLag Time 0.15 hr

Area D Area E Area FHydraulic Length 660 ft Hydraulic Length 510 ft Hydraulic Length 510 ft

Slope 0.091 ft/ft Slope 0.078 ft/ft Slope 0.078 ft/ft*Velocity 5.3 fps *Velocity 4.8 fps *Velocity 4.6 fpsTcD1 2.1 min TcD1 1.8 min TcF1 1.8 minTc Used 15.0 min Tc Used 15.0 min Hydraulic Length 2400 ftLag Time 0.15 hr Lag Time 0.15 hr Slope 0.017 ft/ft

*Velocity 2.2 fpsArea G Area H TcF2 18.2 min

Hydraulic Length 300 ft Hydraulic Length 360 ft Hydraulic Length 150 ftSlope 0.067 ft/ft Slope 0.028 ft/ft Slope 0.200 ft/ft*Velocity 4.5 fps *Velocity 2.9 fps *Velocity 7.0 fpsTcG1 1.1 min TcH1 2.1 min TcF3 0.4 minHydraulic Length 870 ft Hydraulic Length 420 ft Total TcF 20.4 minSlope 0.023 ft/ft Slope 0.024 ft/ft Tc Used 25.0 min*Velocity 2.5 fps *Velocity 2.7 fps Lag Time 0.25 hr


Time of Concentration CalculationMarch 2011


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TcG2 5.8 min TcH2 2.6 minTotal TcG 6.9 min Total TcH 4.7 minTc Used 15.0 min Tc Used 15.0 minLag Time 0.15 hr Lag Time 0.15 hr

Area I Area J Area KHydraulic Length 510 ft Hydraulic Length 210 ft Hydraulic Length 200 ftSlope 0.078 ft/ft Slope 0.143 ft/ft Slope 0.167 ft/ft*Velocity 4.4 fps *Velocity 5.8 fps *Velocity 7.5 fpsTcI1 1.9 min TcJ1 0.6 min TcI1 0.4 minHydraulic Length 300 ft Hydraulic Length 570 ft Hydraulic Length 510 ftSlope 0.033 ft/ft Slope 0.018 ft/ft Slope 0.029 ft/ft*Velocity 3.3 fps *Velocity 2.4 fps *Velocity 0.9 fpsTcI2 1.5 min TcJ2 4.0 min TcI2 10.0 minTotal TcI 3.4 min Hydraulic Length 60 ft Total TcI 10.4 minTc Used 15.0 min Slope 0.330 ft/ft Tc Used 15.0 minLag Time 0.15 hr *Velocity 9.0 fps Lag Time 0.15 hr

TcJ3 0.1 minArea L Hydraulic L ength 300 f t Area N

Hydraulic Length 450 ft Slope 0.005 ft/ft Hydraulic Length 1380 ftSlope 0.044 ft/ft *Velocity 1.1 fps Slope 0.015 ft/ft*Velocity 1.2 fps TcJ4 4.5 min *Velocity 2.1 fpsTcL1 6.3 min Total TcJ 9.2 min TcN1 11.0 minHydraulic Length 360 ft Tc Used 15.0 min Hydraulic Length 1200 ftSlope 0.028 ft/ft Lag Time 0.15 hr Slope 0.049 ft/ft*Velocity 0.9 fps *Velocity 3.7 fpsTcL2 7.1 min Area M TcN2 5.4 minHydraulic Length 420 ft Hydraulic Length 2250 ft Total TcN 16.4 minSlope 0.048 ft/ft Slope 0.009 ft/ft Tc Used 20.0 min

*Velocity 1.3 fps *Velocity 1.7 fps Lag Time 0.20 hr TcL3 5.4 min TcM1 22.1 minHydraulic Length 90 ft Tc Used 25.0 min Area QSlope 0.440 ft/ft Lag Time 0.25 hr H yd rau li c L en gt h 111 0 f t*Velocity 3.5 fps Slope 0.018 ft/ftTcL4 0.4 min Area P *Velocity 2.4 fpsTotal TcL 19.1 min Hydraulic Length 1050 ft TcQ1 7.7 minTc Used 20.0 min Slope 0.038 ft/ft Hydraulic Length 720 ftLag Time 0.20 hr *Velocity 3.5 fps Slope 0.028 ft/ft

TcP1 5.0 min *Velocity 3.0 fpsArea O Tc Used 15.0 min TcQ2 4.0 min

Hydr aulic Lengt h 240 f t Lag Time 0.15 hr Total TcQ 11.7 minSlope 0.125 ft/ft Tc Used 15.0 min*Velocity 6.0 fps Area R Lag Time 0.15 hr TcO1 0.7 min Hydraulic Length 510 ftHydraulic Length 810 ft Slope 0.078 ft/ft Area SSlope 0.012 ft/ft *Velocity 4.2 fps Hydraulic Length 420 ft*Velocity 1.7 fps TcR1 2.0 min Slope 0.007 ft/ftTcO2 7.9 min Hydraulic Length 450 ft *Velocity 1.5 fpsTotal TcO 8.6 min Slope 0.022 ft/ft TcS1 4.7 min


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3

Proposed Conditions

2-year 10-year 25-year 100-yearDrainage Area

Hydrologic Element Location (mi 2) (ac) Tc CN (cfs) (cfs) (cfs) (cfs)

KS-E 0.0302 19.3 19 95 46.8 56.7 70.4 97.7KS-F 0.0278 17.8 15 83 34.4 44.3 58.2 86.3J-1 King Street @ Church Street 0.0580 37.1 80.8 100.5 127.9 182.8KS-G 0.0394 25.2 15 87 52.5 66.6 86.5 126.2King 36" 0.0580 37.1 75.7 94.0 119.7 171.0J-2 King Street @ Finn Street 0.0973 62.3 102.8 128.2 163.7 234.7King 48" 0.0973 62.3 101.2 126.4 161.4 231.4KS-I 0.0249 16.0 15 92 38.8 47.8 60.2 84.9J-3 0.1223 78.3 116.7 145.4 185.5 265.6

King Street Watershed Drainage AnalysisNorthampton, MA

Drainage Analysis SummaryMay 2011


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Div. at North St King Street @ North Street 0.1223 78.3 116.7 145.4 183.1 183.1King 48"/54" 0.1223 78.3 115.0 143.5 182.5 183.1KS-J 0.0258 16.5 15 89 36.7 46.0 59.0 84.9KS-K 0.0324 20.7 15 88 44.6 56.3 72.6 105.2KS-L 0.0425 27.2 15 85 56.6 71.9 93.4 136.3KS-M 0.0070 4.5 15 84 9.1 11.6 15.1 22.2J-8 Trumbull @ State Street 0.0820 52.4 110.3 139.8 181.2 263.7Trumbull 24" 0.0820 52.4 108.3 137.3 177.8 258.5J-7 King Street @ Trumbull Road 0.2300 147.2 188.9 239.2 309.4 449.1King 54" 0.2300 147.2 188.0 237.8 307.7 446.6KS-Q 0.0386 24.7 15 94 63.1 76.9 95.9 133.7J-9 0.2686 171.9 234.7 295.0 379.3 547.1King 54"/66" 0.2686 171.9 229.9 288.9 371.4 535.0KS-R 0.0230 14.7 15 96 39.1 47.2 58.4

Documents

CDM Northampton Stormwater System Assessment and Plan 2012-05 Vol 2 Appendices