Calculate required detention storage volume using the Modified Rational Method, Baker Method, FAA Method, and simplified approaches. Professional stormwater management tool for civil engineers.
Modified Rational Method: Calculate storage from peak flows using triangular hydrograph approximation. Best for preliminary sizing.
Quick Methods: Estimate storage using simplified formulas (Baker, FAA, or Simplified). Useful for screening-level analysis.
Detention storage volume is the amount of stormwater that must be temporarily held in a detention basin to reduce peak discharge rates to allowable levels.
The Modified Rational Method calculates storage as:
Where:
| Method | Best For | Accuracy |
|---|---|---|
| Modified Rational | Preliminary sizing | Good for small watersheds |
| Baker Method | Quick estimates | Approximate |
| FAA Method | Airport drainage | Conservative |
| Simplified | Screening analysis | Order of magnitude |
For final design, use level pool routing with detailed stage-storage-discharge relationships.
Educational Purpose: The calculations provided by DrainageCalculators.com are for informational and educational purposes only. While we strive for accuracy, these tools do not substitute for professional engineering judgment or designs stamped by a licensed Professional Engineer (PE) where required by law.
Professional Certification: Users are solely responsible for verifying all calculations, confirming compliance with local codes and regulations, and determining the appropriateness of any methodology for their specific application. Critical infrastructure and public safety projects require review and certification by a licensed Professional Engineer.
Limitation of Liability: DrainageCalculators.com, its owners, operators, and contributors assume no liability for damages or losses arising from the use of these calculators. By using this tool, you acknowledge that you have read, understood, and agreed to these terms.
This disclaimer applies to the Storage Volume Calculator calculator and all associated calculations.
PE Stamp Required: Many jurisdictions require drainage designs to be reviewed and stamped by a licensed Professional Engineer. Check your local requirements before using these calculations for construction or permit applications.