Ryve's formula for flood estimate in cumecs, is
If `omega` is unit weight of water, Q the discharge in cumecs, H the total head lift and `eta`, the efficiency of the pump, the H.P. of the motor is
The coefficients of permeability of soils of an unconfined aquifer and another confined aquifer were determined by pumping water from the wells and observing the effect of water table in two test wells at equal distances was found to be equal. The total height of confined aquifer H is given by
The formula for calculating the overland flow time (T_{o}) in hours for any basin, is (where L_{o} is the distance of the critical point and H is the difference in elevation)
The rational formula for calculating the discharge, is (where A is the area of basin and P_{o} is one hour rainfall)