ZB 22 13 2023 03 Drainage Statement

14 Hydrograph Report Hydraflow Hydrographs by Intelisolve v9.1 Wednesday, Apr 5, 2023 Hyd. No. 5 Proposed Site (Impervious) Hydrograph type = SCS Runoff Peak discharge = 3.577 cfs Storm frequency = 10 yrs Time to peak = 725 min Time interval = 1 min Hyd. volume = 13,204 cuft Drainage area = 0.730 ac Curve number = 98 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = USER Time of conc. (Tc) = 4.00 min Total precip. = 5.22 in Distribution = Custom Storm duration = NOAA Atlas 14 Type-D.cds Shape factor = 484 Proposed Site (Impervious) Q (cfs) Q (cfs) Hyd. No. 5 -- 10 Year 4.00 4.00 3.00 3.00 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. 5

15 Hydrograph Report Hydraflow Hydrographs by Intelisolve v9.1 Wednesday, Apr 5, 2023 Hyd. No. 6 Proposed Site (Pervious) Hydrograph type = SCS Runoff Peak discharge = 0.973 cfs Storm frequency = 10 yrs Time to peak = 726 min Time interval = 1 min Hyd. volume = 3,054 cuft Drainage area = 0.320 ac Curve number = 75 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = USER Time of conc. (Tc) = 4.00 min Total precip. = 5.22 in Distribution = Custom Storm duration = NOAA Atlas 14 Type-D.cds Shape factor = 484 Proposed Site (Pervious) Q (cfs) Q (cfs) Hyd. No. 6 -- 10 Year 1.00 1.00 0.90 0.90 0.80 0.80 0.70 0.70 0.60 0.60 0.50 0.50 0.40 0.40 0.30 0.30 0.20

0.40 0.30 0.30 0.20 0.20 0.10 0.10 0.00 0.00 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 Time (min) Hyd No. 6

16 Hydrograph Report Hydraflow Hydrographs by Intelisolve v9.1 Wednesday, Apr 5, 2023 Hyd. No. 7 Proposed Total Hydrograph type = Combine Peak discharge = 4.538 cfs Storm frequency = 10 yrs Time to peak = 725 min Time interval = 1 min Hyd. volume = 16,258 cuft Inflow hyds. = 5, 6 Contrib. drain. area = 1.050 ac Proposed Total Q (cfs) Q (cfs) Hyd. No. 7 -- 10 Year 5.00 5.00 4.00 4.00 3.00 3.00 2.00 2.00 1.00 1.00 0.00 0.00 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 Time (min) Hyd No. 7 Hyd No. 5 Hyd No. 6

17 Hydrograph Summary Report Hydraflow Hydrographs by Intelisolve v9.1 Hyd. Hydrograph Peak Time Time to Hyd. Inflow Maximum Total Hydrograph No. type flow interval peak volume hyd(s) elevation strge used description (origin) (cfs) (min) (min) (cuft) (ft) (cuft) 1 SCS Runoff 6.851 1 725 25,674 ---- ------ ------ Existing Site (Impervious) 2 SCS Runoff 1.215 1 726 3,839 ---- ------ ------ Existing Site (Pervious) 3 Combine 8.056 1 725 29,513 1, 2 ------ ------ Existing Total 5 SCS Runoff 5.953 1 725 22,312 ---- ------ ------ Proposed Site (Impervious) 6 SCS Runoff 2.048 1 726 6,553 ---- ------ ------ Proposed Site (Pervious) 7 Combine 7.991 1 725 28,864 5, 6 ------ ------ Proposed Total 2023-04-03 2, 10, 100 yr.gpw Return Period: 100 Year Wednesday, Apr 5, 2023

18 Hydrograph Report Hydraflow Hydrographs by Intelisolve v9.1 Wednesday, Apr 5, 2023 Hyd. No. 1 Existing Site (Impervious) Hydrograph type = SCS Runoff Peak discharge = 6.851 cfs Storm frequency = 100 yrs Time to peak = 725 min Time interval = 1 min Hyd. volume = 25,674 cuft Drainage area = 0.840 ac Curve number = 98 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = USER Time of conc. (Tc) = 4.00 min Total precip. = 8.66 in Distribution = Custom Storm duration = NOAA Atlas 14 Type-D.cds Shape factor = 484 Existing Site (Impervious) Q (cfs) Q (cfs) Hyd. No. 1 -- 100 Year 7.00 7.00 6.00 6.00 5.00 5.00 4.00 4.00 3.00 3.00 2.00 2.00 1.00 1.00 0.00 0.00

1.00 0.00 0.00 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 Time (min) Hyd No. 1

19 Hydrograph Report Hydraflow Hydrographs by Intelisolve v9.1 Wednesday, Apr 5, 2023 Hyd. No. 2 Existing Site (Pervious) Hydrograph type = SCS Runoff Peak discharge = 1.215 cfs Storm frequency = 100 yrs Time to peak = 726 min Time interval = 1 min Hyd. volume = 3,839 cuft Drainage area = 0.210 ac Curve number = 70 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = USER Time of conc. (Tc) = 4.00 min Total precip. = 8.66 in Distribution = Custom Storm duration = NOAA Atlas 14 Type-D.cds Shape factor = 484 Existing Site (Pervious) Q (cfs) Q (cfs) Hyd. No. 2 -- 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. 2

20 Hydrograph Report Hydraflow Hydrographs by Intelisolve v9.1 Wednesday, Apr 5, 2023 Hyd. No. 3 Existing Total Hydrograph type = Combine Peak discharge = 8.056 cfs Storm frequency = 100 yrs Time to peak = 725 min Time interval = 1 min Hyd. volume = 29,513 cuft Inflow hyds. = 1, 2 Contrib. drain. area = 1.050 ac Existing Total Q (cfs) Q (cfs) Hyd. No. 3 -- 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 1560 Time (min) Hyd No. 3 Hyd No. 1 Hyd No. 2

21 Hydrograph Report Hydraflow Hydrographs by Intelisolve v9.1 Wednesday, Apr 5, 2023 Hyd. No. 5 Proposed Site (Impervious) Hydrograph type = SCS Runoff Peak discharge = 5.953 cfs Storm frequency = 100 yrs Time to peak = 725 min Time interval = 1 min Hyd. volume = 22,312 cuft Drainage area = 0.730 ac Curve number = 98 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = USER Time of conc. (Tc) = 4.00 min Total precip. = 8.66 in Distribution = Custom Storm duration = NOAA Atlas 14 Type-D.cds Shape factor = 484 Proposed Site (Impervious) Q (cfs) Q (cfs) Hyd. No. 5 -- 100 Year 6.00 6.00 5.00 5.00 4.00 4.00 3.00 3.00 2.00 2.00 1.00 1.00 0.00 0.00 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560