Groundwater flow in the Galma River Basin of Nigeria was modelled by modifying the partial differential equation governing flow in an unconfined aquifer. Simulation was carried out for up to 20 years. There is a direct correlation of 0.799 between simulated and observed hydraulic heads. The ground surface, the water table surface and the underlying Basement rock surface were found to be non-parallel to one another, and are non-horizontal. COMSOL Multiphysics code was applied for graphical simulation of the flow.