This command calculates peak flow using the rational method, Q=CIA. The program is run through the dialog shown below. Depending on your area, there are different methods for determining the Intensity of Rainfall which you will need to know for this routine. The weighted Runoff Coefficient or C-factor can be calculated by the Curve Number & Runoff routine. The peak flow value can then be used for Detention Pond Sizing or Channel Design.
Peak Flow Rational Method Report:
Rational Peak Discharge
Project: Parking By: TW Date: 11/13/95
Location: West Checked: Date:
Developed
1. Data:
Drainage area:....................A = 27.1500 Acres
Weighted Runoff Coefficient:......C = 0.400
Intensity of Rainfall:............I = 2.10 in/hr
2. Peak Discharge,.................cfs = 22.8060
Pulldown Menu Location: Watershed
Keyboard Command: peakflw3
Prerequisite: None