 The rainfall incidence in the Beqaa Valley, which widely varies spatially and temporally, is an annual average of in the mountainous region of the upper valley to a low of in the south in the coastal region.However, the average annual rainfall is in the catchment area of about at the reservoir carted at the dam.According to water balance studies carried out for the Litani River, the total inflow of the river at the reservoir location has been assessed as per year, of which 60% is accounted towards aquifer recharge and evapotranspiration.