Case Study: Abu Mansour & Al-Bilad Dams (Libya, 2023)

The Abu Mansour and Al-Bilad Dams near Derna, Libya failed on September 11th, 2023, following a rainstorm with an estimated annual probability of less than 0.1% that dumped 14 inches of rain onto the region. The resulting flash flood in the Wadi Derna riverbed overtopped both dams with several feet of water, resulting in a mammoth flood wave that killed roughly 12,000 people. Maintenance issues in both dams had been noted for decades prior to the disaster, and their spillways were undersized. However, political instability kept necessary repairs and retrofits from being made. Imprudent development practices compounded these problems. The wake of the failures has offered little hope of meaningful long-term solutions, especially given Libya’s ongoing political tumult.