Stormwater Detention Calculation Spreadsheet
Stormwater detention calculation is crucial for managing urban runoff and preventing flooding. This calculator helps estimate the volume of stormwater detention needed for a given catchment area, rainfall intensity, and duration.
How to Use This Calculator
- Enter the rainfall intensity in inches per hour.
- Enter the duration of the rainfall event in minutes.
- Enter the catchment area in acres.
- Click the “Calculate” button.
Formula & Methodology
The calculation uses the formula:
Volume (acre-feet) = Rainfall Intensity (in/hr) * Duration (hr) * Catchment Area (acres) * 10.2941
Where 10.2941 is the conversion factor from inches to acre-feet.
Real-World Examples
Data & Statistics
| Return Period (years) | Intensity (in/hr) | Duration (min) |
|---|---|---|
| 2 | 1.5 | 60 |
| 10 | 2.5 | 90 |
| 100 | 4.0 | 150 |
Expert Tips
- Consider using a safety factor to account for uncertainties in the calculation.
- Regularly maintain and inspect detention facilities to ensure they function properly.
Interactive FAQ
What is the difference between detention and retention?
Detention controls the rate of water release, while retention stores water for later use, such as irrigation.