Recharging the Freshwater Coastal Aquifer of Sidi Kirayr Area Using Sustainable Infiltration Trenches

Abstract

Egypt is considered an arid country and depends mainly on the Nile River and groundwater reservoirs to supply water for drinking and various uses. The northwestern coastal zone is one of the regions that rely heavily on groundwater and rainwater for drinking and irrigation. As a result of changes in climate and the rise in sea level, the increase in seawater intrusion is growing. Furthermore, groundwater exploitation and increased pumping of some wells installed in this area have a negative impact on the amount of water in the region’s subterranean reservoirs. One of the approaches suggested for managing freshwater lenses floating on top of seawater from saltwater intrusion in this region is to recharge the aquifer lenses with fresh water. This can be done either by injection wells or by use of groundwater mounds, i.e., infiltration trenches. Due to the expected higher cost operation of injection wells, it is interesting to study the recharge of freshwater lenses through the use of groundwater mounds. Studies have been carried out in the past on the Sidi Kirayr area in terms of recording the water table levels and the amount of rainfall before and after the rainy season. However, we propose using an environmentally sustainable economic solution to recharge the underground reservoirs through the use of rainwater instead of letting it run off into the sea. In this respect, an infiltration trench is designed to recharge the aquifer in the Sidi Kirayr area. Two design types for the trench are proposed, with the geometrical calculations of the appropriate dimensions. The trenches are suggested north and south of the asphalt road in the area of Sidi Kirayr, providing that the trenches can be recharged by rainfall or surplus water when being available from other sources.