Al-Kabeer River Coastal Plain faces very important economic activities which lead to growing water demands. This research aims to define the relationship between rainfall and subterranean-water levels. In the mountainous area fissured marl and limestone with high permeability spread. However, on the coastal plateau deposits with moderate to low permeability values spread, and water levels quickly respond to rainfall and irrigation water, which makes it get easily polluted and affected by climatic factors. Analyses and discussions of field data have led to the fact that subterranean-water levels are to do with many natural and artificial interrelated parameters. And in some cases, they can be adversely oriented, and difficult to isolate and monitor separately, and become very difficult to derive mathematical formula for describing the relationship between just two parameters (subterranean-water percentages and rainfall levels)