Bwanje Valley dam

Bwanje Valley dam
Context & Issues

The Malawi Ministry of Irrigation and Water Development appointed Artelia to supervise the works on the rockfill dam designed for irrigating the Bwanje Valley, the project being funded by the European Union.

The dam will be 40 metres high and approximately 150 m long with a storage capacity of 5.6 million m³ (Stage I). The design takes into account future possibilities for raising the dam, on the existing embankment. Stage II of construction would thus permit expansion of Bwanje Dam and would require raising the dam to a height of 59 m with a resulting storage capacity of 31.5 million m³.

Project characteristics
  • Total storage capacity: 5,640,000 m3
  • Net capacity: 4,550,000 m3 
  • Surface area of the reservoir at maximum capacity: 72.2 ha
  • Maximum height: 40.1 m
  • Maximum depth: 34.1 m
  • Approximate volume: 180,000 m3
  • Crest length: 150 m
  • Crest width: 6.0 m
  • Slope of the upstream face: 1V:2.0H
  • Slope of the downstream face: 1V:1.7H