where:
q = specific discharge (m³/d per m²)
K = hydraulic conductivity of aquifer (m/d)
h₂, h₁ = hydraulic heads measured along flow path (m)
L = distance between head measurements (m)
W = width of cross-sectional flow (m)
D = height of cross-sectional flow (m)

• The flow is laminar.²
• The aquifer is confined.
• The aquifer is homogeneous, isotropic and of uniform thickness.

References:

¹Darcy, H., Les fontaines publiques de la ville de Dijon; Victor Dalmont, Paris, 1856.
²Domenico, P.A., and Schwartz, F.W., Physical and Chemical Hydrogeology, second edition; John Wiley & Sons, Inc., Toronto, 1998.