Investigations of Groundwater Resources in Central Jordan

Abstract

Oil shale deposits in Jordan may considerably contribute to the country's fuel consumption for the next three decades. A basic problem is the high water demand of a processing plant which - in case of arid Jordan - almost entirely has to depend on groundwater resources. Down faulting of the Dead Sea rift valley has created a complex hydraulic system with considerable head differences and flow directions in the different aquifers of Central Jordan. Its two major extended aquifers include the Lower Cretaceous/Cambrian sandstone aquifer of more than 1000 m in thickness and a 250–300 m thick Upper Cretaceous limestone aquifer. These aquifers are separated by a 400 m thick aquitard. Based on recent investigations, a two dimensional numerical model covering an area of approximately 2000 km 2 was developed. The water balance derived from steady state calibration of aquifers showed that the quantities of recoverable groundwater from the upper aquifer have been widely overestimated in the past. Recharge to this aquifer is largely lost by seepage into the lower aquifer as well as by drainage into the Dead Sea through major fault lines and wadi channels. Present water abstraction for drinking water and industrial purposes already exceeds recharge. The future demand has to be extracted from the aquifer's storage (groundwater mining). Groundwater abstraction from the deep aquifer is technically feasible but economically constrained (deep drilling, excessively high pumping lifts).