Abstract

Egypt is considered an arid country and dependsmainly on the Nile River and groundwater reservoirs to supplywater for drinking and various uses. The northwestern coastalzone is one of the regions that rely heavily on groundwater andrainwater for drinking and irrigation. As a result of changes inclimate and the rise in sea level, the increase in seawaterintrusion is growing. Furthermore, groundwater exploitationand increased pumping of some wells installed in this area havea negative impact on the amount of water in the region’ssubterranean reservoirs. One of the approaches suggested formanaging freshwater lenses floating on top of seawater fromsaltwater intrusion in this region is to recharge the aquiferlenses with fresh water. This can be done either by injectionwells or by use of groundwater mounds, i.e., infiltrationtrenches. Due to the expected higher cost operation of injectionwells, it is interesting to study the recharge of freshwater lensesthrough the use of groundwater mounds. Studies have beencarried out in the past on the Sidi Kirayr area in terms ofrecording the water table levels and the amount of rainfallbefore and after the rainy season. However, we propose usingan environmentally sustainable economic solution to rechargethe underground reservoirs through the use of rainwaterinstead of letting it run off into the sea. In this respect, aninfiltration trench is designed to recharge the aquifer in the SidiKirayr area. Two design types for the trench are proposed, withthe geometrical calculations of the appropriate dimensions. Thetrenches are suggested north and south of the asphalt road inthe area of Sidi Kirayr, providing that the trenches can berecharged by rainfall or surplus water when being availablefrom other sources.