ZB 22 13 2023 03 Drainage Statement

6 Hydrograph Report Hydraflow Hydrographs by Intelisolve v9.1 Wednesday, Apr 5, 2023 Hyd. No. 3 Existing Total Hydrograph type = Combine Peak discharge = 2.913 cfs Storm frequency = 2 yrs Time to peak = 725 min Time interval = 1 min Hyd. volume = 10,518 cuft Inflow hyds. = 1, 2 Contrib. drain. area = 1.050 ac Existing Total Q (cfs) Q (cfs) Hyd. No. 3 -- 2 Year 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. 3 Hyd No. 1 Hyd No. 2

7 Hydrograph Report Hydraflow Hydrographs by Intelisolve v9.1 Wednesday, Apr 5, 2023 Hyd. No. 5 Proposed Site (Impervious) Hydrograph type = SCS Runoff Peak discharge = 2.343 cfs Storm frequency = 2 yrs Time to peak = 725 min Time interval = 1 min Hyd. volume = 8,497 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. = 3.44 in Distribution = Custom Storm duration = NOAA Atlas 14 Type-D.cds Shape factor = 484 Proposed Site (Impervious) Q (cfs) Q (cfs) Hyd. No. 5 -- 2 Year 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

8 Hydrograph Report Hydraflow Hydrographs by Intelisolve v9.1 Wednesday, Apr 5, 2023 Hyd. No. 6 Proposed Site (Pervious) Hydrograph type = SCS Runoff Peak discharge = 0.460 cfs Storm frequency = 2 yrs Time to peak = 726 min Time interval = 1 min Hyd. volume = 1,463 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. = 3.44 in Distribution = Custom Storm duration = NOAA Atlas 14 Type-D.cds Shape factor = 484 Proposed Site (Pervious) Q (cfs) Q (cfs) Hyd. No. 6 -- 2 Year 0.50 0.50 0.45 0.45 0.40 0.40 0.35 0.35 0.30 0.30 0.25 0.25 0.20 0.20 0.15

0.25 0.20 0.20 0.15 0.15 0.10 0.10 0.05 0.05 0.00 0.00 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 Time (min) Hyd No. 6

9 Hydrograph Report Hydraflow Hydrographs by Intelisolve v9.1 Wednesday, Apr 5, 2023 Hyd. No. 7 Proposed Total Hydrograph type = Combine Peak discharge = 2.795 cfs Storm frequency = 2 yrs Time to peak = 726 min Time interval = 1 min Hyd. volume = 9,960 cuft Inflow hyds. = 5, 6 Contrib. drain. area = 1.050 ac Proposed Total Q (cfs) Q (cfs) Hyd. No. 7 -- 2 Year 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

10 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 4.116 1 725 15,194 ---- ------ ------ Existing Site (Impervious) 2 SCS Runoff 0.533 1 726 1,678 ---- ------ ------ Existing Site (Pervious) 3 Combine 4.640 1 725 16,871 1, 2 ------ ------ Existing Total 5 SCS Runoff 3.577 1 725 13,204 ---- ------ ------ Proposed Site (Impervious) 6 SCS Runoff 0.973 1 726 3,054 ---- ------ ------ Proposed Site (Pervious) 7 Combine 4.538 1 725 16,258 5, 6 ------ ------ Proposed Total 2023-04-03 2, 10, 100 yr.gpw Return Period: 10 Year Wednesday, Apr 5, 2023

11 Hydrograph Report Hydraflow Hydrographs by Intelisolve v9.1 Wednesday, Apr 5, 2023 Hyd. No. 1 Existing Site (Impervious) Hydrograph type = SCS Runoff Peak discharge = 4.116 cfs Storm frequency = 10 yrs Time to peak = 725 min Time interval = 1 min Hyd. volume = 15,194 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. = 5.22 in Distribution = Custom Storm duration = NOAA Atlas 14 Type-D.cds Shape factor = 484 Existing Site (Impervious) Q (cfs) Q (cfs) Hyd. No. 1 -- 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. 1

12 Hydrograph Report Hydraflow Hydrographs by Intelisolve v9.1 Wednesday, Apr 5, 2023 Hyd. No. 2 Existing Site (Pervious) Hydrograph type = SCS Runoff Peak discharge = 0.533 cfs Storm frequency = 10 yrs Time to peak = 726 min Time interval = 1 min Hyd. volume = 1,678 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. = 5.22 in Distribution = Custom Storm duration = NOAA Atlas 14 Type-D.cds Shape factor = 484 Existing Site (Pervious) Q (cfs) Q (cfs) Hyd. No. 2 -- 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. 2

13 Hydrograph Report Hydraflow Hydrographs by Intelisolve v9.1 Wednesday, Apr 5, 2023 Hyd. No. 3 Existing Total Hydrograph type = Combine Peak discharge = 4.640 cfs Storm frequency = 10 yrs Time to peak = 725 min Time interval = 1 min Hyd. volume = 16,871 cuft Inflow hyds. = 1, 2 Contrib. drain. area = 1.050 ac Existing Total Q (cfs) Q (cfs) Hyd. No. 3 -- 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. 3 Hyd No. 1 Hyd No. 2