Towns including Derna were hit by the floods earlier this month and it has since emerged experts repeatedly called for immediate maintenance to the two structures meant to protect the city but successive governments in the chaos-stricken North African nation did not react.
Writing last year in an academic journal, civil engineering professor Abdelwanees Ashoor said: “In the event of a big flood, the consequences will be disastrous for the residents of the valley and the city”.
The dams were originally built in the 1970s from clay, rocks and earth and could hold up to 24 million cubic metres of water.
“Both dams had not been maintained for many years, despite repeated floods that struck the city in the past,” said Saleh Emhanna, a geological researcher with the University of Ajdabia in Libya.
“They were dilapidated.”
Both dams broke on September 11 letting loose a wall of water that swept large swaths of the coastal city into the sea.
More than 11,300 people were reported killed and over 10,000 remained missing a week after the disaster, according to the Libyan Red Crescent and the United Nations.
The country has since divided between rival administrations: one in the west backed by an array of lawless armed groups and militias, and the second in the east allied with the self-styled Libyan National Army, which is commanded by powerful Gen. Khalifa Hifter.
The dams suffered major damage in a strong storm that hit the region in 1986, and more than a decade later a study commissioned by the government revealed cracks and fissures in their structures, Libya‘s general prosecutor al-Sediq al-Sour said.
He said: “I reassure citizens that whoever made mistakes or negligence, prosecutors will certainly take firm measures, file a criminal case against him and send him to trial.”
A report by a state-run audit agency in 2021 said the two dams had not been maintained despite the allocation of more than $2 million for that purpose in 2012 and 2013.