SIGNIFICANCE OF VERTICAL FLOW-THROUGH LOW-CONDUCTIVITY ZONES IN BROMSGROVE SANDSTONE AQUIFER

When water passes vertically through low-conductivity zones in aquifer s, significant vertical head gradients occur. The importance of such g radients is identified in a study of the Bromsgrove Sandstone Aquifer Unit. A mathematical model incorporating the low-conductivity layers h as been developed to explain the changed conditions from 1900, when th ere were extensive spring flows, to the present day, when deep borehol es intercept much of the groundwater flow. The mathematical model also helps in understanding the changing pumped drawdowns and water table elevations.