The steady flow rate Q can be found for a gravity well by using the Dupuit formula:

Q =[1.36K(H ²-h ²)]/log(D/d)

where
Q =flow, gal/day (liter/day)

K= hydraulic conductivity, ft/day (m/day), under
1:1 hydraulic gradient

H= total depth of water from bottom of well to free-water surface before pumping, ft (m)

h= H minus drawdown, ft (m)

D= diameter of circle of influence, ft (m)

d =diameter of well, ft (m)

The steady flow, gal/day (liter/day), from an artesian well is given by

Q=[2.73Kt(H -h)]/log(D/d)

where
t = thickness of confined aquifer, ft (m).