Increasing Success Rates of Drill Holes for Water Exploration in Uganda Using MRS

Magnetic Resonance Sounding (MRS) is a geophysical method that allows direct determination of the distribution of the mobile water content and effective porosities by surface measurements. The amplitude of the MRS signal is directly proportional to the amount of mobile water. The supply of freshwater for local villages that are relocated after the end of the civil war in Uganda is a crucial effort of development aid to prevent spreading of infectious diseases such as cholera or hepatitis. Depending on the local geology the success rate of fresh water drill holes can ranges from 50 to 80 %. The yield of such wells is in the range of 300 l/h (hand pump) and more than 9000 l/h (production well). To increase the rate of successfully drilled boreholes for fresh water supply a feasibility study on the usage of MRS has been carried out. After each sounding predictions of MRS have been directly verified by drill holes. The results from MRS measurements were confirmed to a 100%, thus, making MRS a reliable tool for assessing the presence of producible water and increasing the success rates of drill holes for fresh water even in an intricate environment, as encountered in Uganda