ABSTRACT
The Omaruru Delta (OMDEL) aquifer system of western Namibia consists of four paleochannels filled with alluvial sand and conglomerate contributing groundwater to coastal settlements. Only one is considered for supplying potable water. After various investigations it was concluded that low recharge rates are due to a deposit of a very fine layer of silt-rich clay material on the surface of the riverbed impeding water penetration. The OMDEL artificial recharge project was proposed to infiltrate clean water in a controlled manner using infiltration basins. After two good rainy seasons (1997 & 2000) the OMDEL artificial recharge facility was evaluated to quantify artificial recharge and to identify difficulties. A numerical model (TRI-WACO) was compiled to improve the understanding of the aquifer behavior. Conclusions drawn from this project resulted in improved artificial recharge processes, reduced environmental impact and optimized the utilization of the most valuable commodity in an arid country, water.
