Stormwater & Drainage Calculators
Estimate design storm runoff with the Rational Method (Q = C·i·A) and size drainage collection and conveyance infrastructure.
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Stormwater Runoff (Rational Method) Calculator
Estimate peak stormwater runoff with the Rational Method (Q = C·i·A) for drainage design and storm sewer sizing.
Q = 2.78 × C × i × A (L/s, A in ha, i in mm/h)