Mapping Groundwater in Regolith and Fractured Bedrock Using Ground Geophysics: A case study from Malawi
From 1999 through 2000, Paul Bauman and Richard Kellett planned and supervised a geophysical water exploration program in the Mangochi District of Malawi. At the time, the program was highly innovative and even, many geophysicists said at the time, quite technically daring (i.e. foolhardy). Before our program, the success rate for water well drilling was less than 25% (that is, fewer than one in four wells found water). Based on the geophysical results from our program, 207 water wells were drilled, 192 were successful, and 15 were dry-a 93% success rate. In the context of the Mangochi project, a successful water well was defined as providing a yield of at least 0.2 liters per second (l/sec), servicing no more than 250 persons, being no further than 500 m from a serviced person, and being up gradient from any likely contaminant source such as pit latrines or cemeteries. No well was to service more than one village. Given these constraints, our 93% success rate is even more impressive as at some villages, we simply did not find promising drilling targets, but we were nevertheless required to provide our best possible water well location for each village.
Richard Kellett and Paul Bauman published “Mapping Groundwater in Regolith and Fractured Bedrock Using Ground Geophysics: A Case Study form Malawi,” in the February 2004 issue (Vol. 29, No. 02) of the Canadian Society of Exploration Geophysists (CSEG) publication the Recorder. The paper was recognized by the CSEG as the “Best Recorder Paper 2004.” Nevertheless, and unfortunately for donors and tens of millions of needy beneficiaries in Sub-Saharan Africa, water witching, 1-D resistivity, air photo and satellite interpretation, or simply guessing continue to be the most common methods of siting community water wells.