Situated 50 km east of Algiers, the Beni Amrane Dam supplies the Algerian capital with drinking water.
Brought into service in 1988, this gravity dam, operated by the Algerian national dams agency (ANBT), faced a major problem of silting which, in 2003, had reduced the reservoir capacity from 11.6 million m³ to 5 million m³.
Since then, the dam level has been raised by installing straight-crested fusegates on the sill of the spillway.
Made of reinforced concrete, each fusegate weighs 510 tonnes.
The extra 7.1 million m³ improve the quality of the water by increasing the sedimentation time for silt particles prior to pumping.
The perilous access to the spillway sill represented a real technical challenge. A strict planning schedule was also put in place in order to ensure maximum storage of the spring rains.
Despite a violent earth tremor on May 21, 2003 (6.1 on the Richter scale), the project was completed in a record 16 weeks.