Basalt Aquifer System (West)

The Yarmouk Basin constitutes the western section of the Basalt Aquifer Complex. It extends between the Jebel al Arab Mountain, the Hauran Plateau and the south-eastern foothills of Mount Hermon. In the south-west, the Basalt Aquifer stretches into the Golan Heights to Lake Tiberias.

Groundwater flow is generally directed from topographically higher catchments to the major discharge zone around Wadi Hreer-Mzeirib in the Yarmouk Basin, while the western part of the Golan Heights drains towards Lake Tiberias. Groundwater discharge in the Yarmouk Basin appears to be largely maintained by present-day recharge over wide catchment areas, with travel periods of several thousands of years. The main aquifer system in the basin comprises permeable layers in Neogene-Quaternary basalts and the underlying sedimentary rocks (Paleogene and/or Upper Cretaceous formations, depending on the lithostratigraphy of the sequence), which are hydraulically connected with the basalts.

Groundwater and surface water are closely interlinked in this region and the Basalt Aquifer constitutes an important source of water for the Yarmouk River and the Jordan Basin as a whole. Large-scale expansion of groundwater abstraction in some parts of the Yarmouk Basin is likely to have affected natural flow and discharge patterns within a larger radius and may have contributed to the hydrological decline of the Yarmouk River. This has long been a point of conflict between Jordanian and Syrian authorities.