Title: Peak Stormwater Runoff Calculation with the Rational Method
Contributor: Harlan Bengtson Ph.D., P.E. , Former Dean of Engineering, Southern Illinois University Edwardsville
Published Date: August/2014
Content Type: Spreadsheet
This set of worksheets facilitates the calculation of peak stormwater runoff rate, allowing comparison of several alternatives for calculating the watershed time of concentration, a key parameter in the overall calculation.
There are worksheets for calculating the following:
1. Watershed time of concentration based on user input information about the watershed.
2. Peak stormwater runoff rate using a design storm intensity calculated from user input rainfall intensity vs. duration data.
3. Peak stormwater runoff rate using a design storm intensity calculated with user input values for Steel Equation constants.
Equations used: Kirpich Equation, Kerby-Hathaway Equation, SCS Lag Equation, Manning Equation, Manning Kinematic Equation, Rational Method Equation, Steel's Formula.