ISMAR6 Proceedings 30 EXPLORING THE POTENTIAL OF MANAGED AQUIFER RECHARGE TO MITIGATE WATER SCARCITY IN THE LOWER JORDAN RIVER BASIN WITHIN AN IWRM APPROACH Leif Wolf 1 , Heike Werz 1 , Heinz Hoetzl 1 , Marwan Ghanem 2 1 Department of Applied Geology, University of Karlsruhe, Kaisterstr. 12, 76128 Karlsruhe, Germany. (wolf@agk.uka.de) 2 Palestine Hydrological Group, P.O. Box 323, Ramallah ABSTRACT ABSTRACT ABSTRACT ABSTRACT The Lower Jordan River Valley is a place of extreme water scarcity and constitutes an overexploited closed river basin. No surface runoff currently leaves the area and the water level of the Dead Sea, as the final sink, has already dropped by more than 20 m over the past fifty years as a result. This demonstrates, that even apart from water quality considerations, total inflows into the system do not match outflows, resulting in a continuous depletion of the available storage, i.e. all available water is already utilised. The only means of providing additional volumes of water to the area are water imports or reduction of evaporation from open water bodies or reduction of evapotranspiration from irrigated agriculture. Wastewater reuse and desalinisation would increase the amount of water fit for human demand but not affect the water balance in total. Increasing the amount of managed aquifer recharge (MAR) would be beneficial to the water availability of the region by reducing evaporation. In this background setting, the research initiative SMART (Sustainable Management of Available Resources with Innovative Technologies) has now been launched to include all available water resources of the Lower Jordan River, namely ground water, waste water, saline water, and flood water into an integrated management concept. This paper briefly explores the application of MAR technologies to the region and the barriers toward their implementation. Currently MAR technologies which aim at direct infiltration of water into the underground are not, or only at a very limited scale, implemented in the Lower Jordan River Valley. Dams and reservoirs which have been installed at the outlet of major wadis provide additional groundwater recharge but are characterised by high evaporation losses and progressive silting. Harvesting of rainwater in man-made subsurface structures (e.g. cisterns) is common in rural settings of both Palestine and Jordan. Soil aquifer treatment (SAT) concepts are successfully implied in Israel, although not in the Jordan River Basin. A significant contribution to groundwater recharge is provided through irrigation schemes with either freshwater or recycled water. Considering the prevailing aquifer characteristics (limestone and alluvial aquifers with sufficient hydraulic conductivity), MAR is considered feasible. Strong episodic rainfall runoff, especially from urban areas in the highlands, would be available to feed the MAR schemes. However, given the steep topography, often the karstic aquifers would not provide appropriate long term storage but discharge the water soon afterwards. A common concern is the quality of urban surface runoff which may require source control measures in the catchment. Due to rapid groundwater flow velocities and short residence time of contaminants in the aquifer system, karstic aquifers are particularly vulnerable to contamination. Careful site selection must take place to maximize the probability of success. At this point, major targets for managed aquifer recharge schemes could be the alluvial fan aquifers as well the carbonate aquifers in the western part of the study area. In conclusion, a series of detailed investigations on MAR applicability in the region is needed for future planning. Besides the screening for suitable aquifers, it is