Kh - Average horizontal hydraulic conductivity
W - Average width of the retention pond, midway between basin bottom and water level at time t
H - Initial saturated thickness of the aquifer
hc - Height of water in basin above the initial ground water table at time t
Fx - Dimensionless parameter representing physical and hydraulic characteristics of the retention basin and effective aquifer system
D - Average saturated thickness of the aquifer
T - Stage Two Volume recovery time