PEAK flood by rational FORMULA is given by \({Q_P} = \frac{1}{{36}}K{P_c}A\)Where, K = Co-efficient of run off; PC = INTENSITY (cm/hr); A = area in hectare\({Q_p} = \frac{1}{{36}} \times 0.5 \times 80 \times 3.6 = 4.00\frac{{{m^3}}}{{sec}}\)