Estimating design floods for small earth dams in Malawi

Small earth dams are a common device for water harvesting and storage throughout the rural areas of Malawi and the rest of southern Africa. As a source of water during dry periods, they are a vital resource for many rural communities. Estimates of flood magnitudes and associated return periods are required for the safe design of dams. This paper summarizes guidelines for deciding the return period of design floods and for estimating their magnitude at ungauged sites by statistical techniques. These guidelines are available to those involved in the design and rehabilitation of small earth dams in Malawi and elsewhere in southern Africa.