Flows for the Orange County rational method are calculated from the following equation:
Q = 0.90(I - Fm)A
where:
Q - peak flow (ft3/s or m3/s)
I - rainfall intensity (in/hr, mm/hr)
Fm- maximum loss rate, where Fm = ap * Fp
A - catchment area (acres)
This equation is very similar to the traditional Rational Method equation. The term I - Fm is often referred to as the effective precipitation.
Related Topics:
Losses