The Wadi Derna is a river valley in Libya which leads down from the Jebel Akhdar mountains to the port city of Derna. Like many other wadis in North Africa, it is an intermittent riverbed that for much of its length contains water only when heavy rain occurs. It is long and drains a drainage basin of 575 km.
The Derna waterfalls are located in Wadi Derna about 7 km (4.3 mi) to the south of Derna.
In September 2023, against the backdrop of the civil war, torrential rainfall from Storm Daniel led to the collapse of two damsâÂÂthe Derna dam and the downstream Abu Mansour damâÂÂalong the river, causing catastrophic flooding in the city of Derna and killing least 5,923 people. It was one of the deadliest dam failures in history.