Detention Pond Sizing Calculator
Calculate the necessary size for a detention pond based on hydrological parameters using our interactive tool.
Hydrologic Inputs
How to Use This Calculator
Provide the runoff coefficient, rainfall intensity, and drainage area for your project. We multiply the dimensionless runoff factor by how much rain falls over the drainage area to size the detention volume needed to hold that runoff.
Methodology
This tool mirrors the simplification used in many stormwater manuals: multiply the peak depth of runoff by the contributing area, convert hectares to square meters, and reserve a volume that can safely detain the resulting runoff.
- The runoff coefficient translates how much rain becomes runoff versus how much infiltrates or evaporates.
- Rainfall intensity is the design storm depth over one hour; adjust it to match the return period you are modeling.
- Drainage area is converted to square meters before multiplying to keep units consistent.
Full original guide (expanded)
This section preserves the legacy guidance that users relied on before the refactor.
Frequently Asked Questions
What is a detention pond?
A detention pond is a basin designed to temporarily hold stormwater runoff and release it at a controlled rate.
Why are detention ponds important?
They help prevent flooding and control the flow of stormwater into natural water bodies.
How do I calculate the size of a detention pond?
Use our calculator to input your area-specific hydrological data and get an accurate pond size.