On 30 August, five of Israel's six large coastal desalination plants stood still. The trigger was a microalgae bloom, believed to have originated in the Nile Delta and favoured by seawater above 30 °C. Mekorot called it an "extremely rare event". Supply continued from the Sea of Galilee, wells and reserves. According to CNN, desalination provides at least 65 % of the country's drinking water.
As of 5 October, Ashdod was running at 66 %, Sorek B at 60 % and Palmachim at 85 %. According to an analysis by Calcalist, the state is spending around NIS 45 million (USD 15 million) on replacement membranes. No abnormal membrane damage has been observed so far.
This time the threat did not come from outside but from the sea itself. A plant is only as secure as its intake, and a country with this share needs fallback routes planned in advance.