干旱区生态环境知识资源中心

Within Israel and the West Bank and Gaza Strip (WBGS), there are 15 streams that cross the Palestinian/Israeli Green Line. All originate in watersheds located in the Palestinian Authority, or in lands that will eventually be outside Israeli jurisdiction, and then flow into Israel toward the Mediterranean Sea, flow east to the Dead Sea, or the Jordan River. These transboundary streams of Israel and Palestine are plagued by severe pollution, posing a serious health hazard to humans and devastating the natural ecosystems.

Several factors have contributed to the severity of pollution in these streams. For many years, most streams were transformed into sewage conduits collecting raw sewage or low-quality effluent all year round. The region's climate is semiarid and increasing demand for water has led to overpumping of the available groundwater, drying up of the headwaters of many streams. A range of pollutants, including nonpoint agricultural runoff, urban stormwater, and discharge from industrial sites can also be found in many streams.

In 1994, the Ministry of the Environment established the River Restoration Administration as a coordinating body for actions taken by various governmental and nongovernmental bodies to restore or at least rehabilitate damaged streams. Although stream restoration constitutes a paramount environmental priority for both parties, the lack of a clear and relevant model that identifies and quantifies the key parameters for stream restoration including water flow, nutrient concentrations, and other contaminant loadings from nonpoint and point sources on a catchment scale across the virtual borders has frustrated all previous restoration attempts. The ultimate aim of the current research is to lay the foundations for an effective river restoration strategy for Israel and the Palestinian Authority. Using a "catchment scale chemical and biological monitoring network," the total pollution loadings into two transboundary streams whose geographic boundaries cross over the Israeli/Palestinian Green Line (the Zomar/Alexander and Hebron/Besor/Gaza) are to be characterized. This will for the first time enable a more systematic and comprehensive assessment of intervention options, their affect on stream restoration, and relative cost-effectiveness.