Grand Ethiopian Renaissance Dam Project

The Challenge

Following a detailed dam safety assessment and six decades of successful operation, rehabilitation measures have become necessary. These are to be combined with an expansion of the basin by an additional 10 million m³. As part of the in-depth assessment, the hydrological design parameters were also re-evaluated. As a result, for example, the design flood increased from 410 m³/s to 888 m³/s – more than doubling.

The Solution

A secondary embankment (secondary dam) divides the reservoir into two functional storage zones: Flood Protection Zone 1, located on the downstream side of the secondary embankment, and Flood Protection Zone 2, located upstream of it. Flooding of the second zone occurs automatically through a designed notch in the secondary embankment, requiring no operator intervention.

The Impact

Supporting safe construction progress and compliance for a strategic renewable asset delivering ~15,500 GWh/year.