| Given: | |||
|---|---|---|---|
| Area = | 50 | ac. | total watershed area in acres draining to pond |
| IC = | 20 | ac. | new impervious area in acres (40%) |
| Watershed peak discharge and runoff volume: | |||
| Event | Pre-development | Post-development | Unit |
| Q1-yr 24-hr | 6.7 | 53.5 | cfs |
| Q2-yr 24-hr | 11.6 | 69.0 | cfs |
| Q10-yr 24-hr | 36.7 | 131.9 | cfs |
| Q100-yr 24-hr | 81.8 | 222.0 | cfs |
| V1-yr 24-hr | 0.3 | 3.9 | ac-ft |
| V2-yr 24-hr | 0.6 | 4.9 | ac-ft |
| V10-yr 24-hr | 3.1 | 8.9 | ac-ft |
| V100-yr 24-hr | 7.5 | 14.7 | ac-ft |