In areas where surface water sources are limited or seasonally variable groundwater can  complement or even provide the sole source of raw water.

However, groundwater occurrences are variable, being controlled by subsurface geology and hydrological processes. Since borehole drilling is expensive, especially when drilling to depths of 100 to 200 meters or more, it follows that risk mitigation measures be taken to avoid drilling dry holes or marginally productive water wells.

Data from various geophysical survey methods, combined with regional geologic information and data on groundwater occurrences in existing boreholes can reduce the risk of drilling unsuccessful wells. Among the commonly used geophysical survey and mapping methods are those based on acquiring electrical resistivity, induced polarization, and controlled source electromagnetic (EM) data.

What we do:

Water Pathways provides advisory support by defining survey requirements, evaluating contractor proposals, and reviewing survey data and interpretation results; then using these results, to assist in preparing a drilling proposal, selecting the drilling contractor, and monitoring operations.

In Kenya, we reviewed the hydrogeological survey report  for a proposed drill site and visited a nearby successful borehole site (500 m away) to assess groundwater potential at the proposed drilling location and recommend next steps.  In Zimbabwe, discussions with hydro-geophysical researchers at the National University of Science and Technology in Bulawayo and visits to existing borehole sites have provided a preliminary basis for planning future geophysical surveys.