The Victoria Province drought relief project. II. Borehole yield relationships

ABSTRACT Composite aquifers composed of relatively high storage, low permeability regolith overlying low storage, higher permeability fissured bedrock occur in the Basement terrain of Victoria Province. The adequacy of these aquifers for rural‐water supplies is variable and locating optimum borehole sites is difficult. The analysis of data from the Victoria Province Drought Relief Project suggests that a variety of environmental factors influence borehole yield. Despite the wide scatter of data, certain generalizations can be made using statistical techniques. The results show that for regolith aquifers specific capacity increases with rainfall, regolith thickness, and altitude, which is in turn probably related to the age of the erosion surface. In fissured bedrock aquifers the upper 20 m is crucial for the provision of an adequate yield.