: Agricultural expansion along the Batinah plain during the last few decades has been associated with the use of high rate discharge pumps and consequently, over pumping of groundwater has caused saline water intrusion into the coastal aquifers of the region. The rapid and significant development in the study area has resulted in an increase in water demand. Excessive pumping has resulted in a decline of ground water levels which lead to the migration of saline/fresh ground water interface inland. This has led to increase in ground water pollution by salinisation, both in the immediate vicinity of the coastal wells and further inland, causing more farmlands near the coast to be lost. If this trend continues without constraint then agriculture area would decline with perhaps large loss of use of agriculture lands. MWR installed a dam in the study area to promote ground water recharge in the wadi channels. This study is done to observe the effect of this dam on ground water recharge and quality and the extent of saline water intrusion. For this study, 38 ground water samples from the study area were collected and analysed. Chemical data is presented by using two graphical methods (Stiff and Piper diagrams). The present ground water quality is also compared with the ground water quality before, during, and after dam construction and impoundment. Two geophysical profiles were conducted by using Time Domain Electromagnetic Method (TDEM) to determine the interface between fresh water and saline water in the aquifer. Hydrological data such as ground water level of some monitoring boreholes and rainfall data were collected from many sources and analysed. The study shows that dam installation in the study area has resulted in an increase in recharge of ground water into the alluvial aquifer in the vicinity of the dam. The ground water quality in the vicinity of the dam has slightly improved. Near the coast ground water quality has deteriorated because of the excessive pumping. Saline water intrusion exists over a distance of about 4 km from the coast line. Also, saline/ fresh water boundary migration downgradient of the dam in the main wadi channel has not advanced inland as much as in surrounding areas

: Agricultural expansion along the Batinah plain during the last few decades has been associated with the use of high rate discharge pumps and consequently, over pumping of groundwater has caused saline water intrusion into the coastal aquifers of the region. The rapid and significant development in...