2022 10 Drainage Statement Signed

0.00 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 Time (min) Hyd No. 5

22 Hydrograph Report Hydraflow Hydrographs by Intelisolve v9.1 Monday, Oct 24, 2022 Hyd. No. 6 Proposed Site (Pervious) Hydrograph type = SCS Runoff Peak discharge = 1.839 cfs Storm frequency = 100 yrs Time to peak = 724 min Time interval = 1 min Hyd. volume = 5,490 cuft Drainage area = 0.280 ac Curve number = 76 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = USER Time of conc. (Tc) = 2.00 min Total precip. = 8.66 in Distribution = Custom Storm duration = NOAA Atlas 14 Type-D.cds Shape factor = 484 Proposed Site (Pervious) Q (cfs) Q (cfs) Hyd. No. 6 -- 100 Year 2.00 2.00 1.00 1.00 0.00 0.00 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 Time (min) Hyd No. 6

23 Hydrograph Report Hydraflow Hydrographs by Intelisolve v9.1 Monday, Oct 24, 2022 Hyd. No. 7 Proposed Total Hydrograph type = Combine Peak discharge = 8.098 cfs Storm frequency = 100 yrs Time to peak = 724 min Time interval = 1 min Hyd. volume = 27,267 cuft Inflow hyds. = 5, 6 Contrib. drain. area = 1.040 ac Proposed Total Q (cfs) Q (cfs) Hyd. No. 7 -- 100 Year 10.00 10.00 8.00 8.00 6.00 6.00 4.00 4.00 2.00 2.00 0.00 0.00 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 Time (min) Hyd No. 7 Hyd No. 5 Hyd No. 6

24 Hydraflow Rainfall Report Hydraflow Hydrographs by Intelisolve v9.1 Monday, Oct 24, 2022 Return Intensity-Duration-Frequency Equation Coefficients (FHA) Period (Yrs) B D E (N/A) 1 0.0000 0.0000 0.0000 -------- 2 69.8703 13.1000 0.8658 -------- 3 0.0000 0.0000 0.0000 -------- 5 79.2597 14.6000 0.8369 -------- 10 88.2351 15.5000 0.8279 -------- 25 102.6072 16.5000 0.8217 -------- 50 114.8193 17.2000 0.8199 -------- 100 127.1596 17.8000 0.8186 -------- File name: SampleFHA.idf Intensity = B / (Tc + D)^E Return Intensity Values (in/hr) Period (Yrs) 5 min 10 15 20 25 30 35 40 45 50 55 60 1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 2 5.69 4.61 3.89 3.38 2.99 2.69 2.44 2.24 2.07 1.93 1.81 1.70 3 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5 6.57 5.43 4.65 4.08 3.65 3.30 3.02 2.79 2.59 2.42 2.27 2.15 10 7.24 6.04 5.21 4.59 4.12 3.74 3.43 3.17 2.95 2.77 2.60 2.46 25 8.25 6.95 6.03 5.34 4.80 4.38 4.02 3.73 3.48 3.26 3.07 2.91 50 9.04 7.65 6.66 5.92 5.34 4.87 4.49 4.16 3.88 3.65 3.44

4.38 4.02 3.73 3.48 3.26 3.07 2.91 50 9.04 7.65 6.66 5.92 5.34 4.87 4.49 4.16 3.88 3.65 3.44 3.25 100 9.83 8.36 7.30 6.50 5.87 5.36 4.94 4.59 4.29 4.03 3.80 3.60 Tc = time in minutes. Values may exceed 60. Precip. file name: Essex County.pcp Rainfall Precipitation Table (in) Storm Distribution 1-yr 2-yr 3-yr 5-yr 10-yr 25-yr 50-yr 100-yr SCS 24-hour 0.00 3.44 0.00 0.00 5.22 6.44 0.00 8.66 SCS 6-Hr 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Huff-1st 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Huff-2nd 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Huff-3rd 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Huff-4th 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Huff-Indy 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Custom 1.25 3.44 0.00 0.00 5.22 6.44 0.00 8.66

MULTI-HYDROGRAPH PLOT – EXISTING AND PROPOSED SUPERIMPOSED 2 YR. 10 YR & 100 YR.

Multi-Hydrograph Plot Hydraflow Hydrographs by Intelisolve v9.1 Hyd. No. 3 Hyd. No. 7 Existing Total Proposed Total Hydrograph type = Combine Hydrograph type = Combine Peak discharge = 2.944 cfs Peak discharge = 2.89 cfs Time to peak = 12.07 hrs Time to peak = 12.07 hrs Hyd. Volume = 9,861 cuft Hyd. Volume = 9,553 cuft Existing Total and Proposed Total Q (cfs) Q (cfs) 2-yr frequency 3.00 3.00 2.00 2.00 1.00 1.00 0.00 0.00 0.0 1.8 3.7 5.5 7.3 9.2 11.0 12.8 14.7 16.5 18.3 Time (hrs) Hyd No. 3 Hyd No. 7

Multi-Hydrograph Plot Hydraflow Hydrographs by Intelisolve v9.1 Hyd. No. 3 Hyd. No. 7 Existing Total Proposed Total Hydrograph type = Combine Hydrograph type = Combine Peak discharge = 4.689 cfs Peak discharge = 4.64 cfs Time to peak = 12.07 hrs Time to peak = 12.07 hrs Hyd. Volume = 15,817 cuft Hyd. Volume = 15,477 cuft Existing Total and Proposed Total Q (cfs) Q (cfs) 10-yr frequency 5.00 5.00 4.00 4.00 3.00 3.00 2.00 2.00 1.00 1.00 0.00 0.00 0.0 1.8 3.7 5.5 7.3 9.2 11.0 12.8 14.7 16.5 18.3 Time (hrs) Hyd No. 3 Hyd No. 7

Multi-Hydrograph Plot Hydraflow Hydrographs by Intelisolve v9.1 Hyd. No. 3 Hyd. No. 7 Existing Total Proposed Total Hydrograph type = Combine Hydrograph type = Combine Peak discharge = 8.140 cfs Peak discharge = 8.10 cfs Time to peak = 12.07 hrs Time to peak = 12.07 hrs Hyd. Volume = 27,668 cuft Hyd. Volume = 27,267 cuft Existing Total and Proposed Total Q (cfs) Q (cfs) 100-yr frequency 10.00 10.00 8.00 8.00 6.00 6.00 4.00 4.00 2.00 2.00 0.00 0.00 0.0 1.8 3.7 5.5 7.3 9.2 11.0 12.8 14.7 16.5 18.3 Time (hrs) Hyd No. 3 Hyd No. 7

STORMWATER COLLECTION SYSTEM CLACULATIONS (PIPE SIZING)