Managed Aquifer Recharge (MAR) in areas used for agricultural purposes: the Rye Island pilot study

For a long-term retention of water in aquifers and its subsequent use in drier or heavier demand periods, the Managed Aquifer Recharge (MAR) techniques are studied and implemented in 4 pilot areas of the DEEPWATER-CE project. In Slovakia, the pilot study is situated in the Rye Island. A calibrated MODFLOW model is used for a prediction of groundwater level changes caused by the Recharge Dam MAR. Results of the simulations showed that the increased groundwater level caused by the realization and operation of three proposed weirs affects the volume of water infiltrated to the aquifer but does not cause the flooding of the adjacent area.

An Investigation of Excessive Seepage from the Al-Fulaij Recharge Dam, Oman

The Al-Fulaij recharge dam is located on the Al Batinah coast in Oman and was constructed in 1992. The dam is about 3.3 km long and 7.7 m high with a storage capacity of 3.7 million cubic meters of water. It is an earthfill dam with silty, sandy gravel fill in the embankment. Excessive seepage of between 5,000–12,500 m3/day was observed during floods in 1993, and several sinkholes were noticed close to the upstream toe. Remedial work consisting of an upstream blanket and a cutoff trench wall was performed in 2000. However, these remedial measures failed and almost the same seepage was noticed again during the impoundment. This paper investigates possible causes of the seepage using a finite element model. The input data for the model were collected from site investigations and field records during the construction and monitoring of the dam. The study reveals that the most probable cause of the excessive seepage is the presence of a permeable soil layer underneath the dam due to the dissolution of the gypsum material.