Disi water use for irrigation - a false decision and its consequences

Abstract

Disi water has been utilized during the last 2.5 decades in irrigation purposes in a very dry country, very short of water resources and where the groundwater in Disi represents the only strategic water reserve. After 25 years of exploitation, groundwater levels dropped by around 25m signalizing aquifer emptying. Disi aquifer receives an average water replenishment of 50 million cubic meters per year (MCM/y), but this amount is lost as natural outflow. Therefore, groundwater extraction is quasi a mining process. During the last 25 years, about 2 billion m3 of groundwater were exploited from Disi for irrigation purposes with a value of around US$ 2 billion. The only input from Jordan in these irrigation projects has been water. The environmental consequences of groundwater extractions in Disi are: dropping water levels, mobilization of some salty water bodies in geologic units connected vertically with Disi aquifer such as Khureim Formation and irrigation return flow waters with their high salt contents, biocides, and fertilizers concentrations. In the meantime, it has been recognized that Jordan's drinking water needs in the coming few decades can only be satisfied by utilizing Disi groundwater. But Disi aquifer cannot supply the water amounts for both drinking and irrigation. Recently, the government decided not to renew the licenses for Disi irrigation projects which is a very sound decision to protect the national water resources. It represents a reversal of a former decision which was based on a wrong policy built on false and distorted information. Overpumping of non-renewable groundwater sources causes depletion of resources and mobilization of connected saline groundwater. Pumping of saline groundwater underlying fresh groundwater aquifers allows the fresh groundwater to flow into the emptied saline water regimes becoming salinized there.