By John — Desalination News
An algae bloom drifting up from Egypt’s Nile Delta forced five of Israel’s six seawater desalination plants offline in early September, triggering the country’s most severe test yet of a water system that now depends on desalination for roughly 70-80% of its supply — and reopening a debate over how much the country should lean on the sea for its drinking water.
The Israel Water Authority first shut the Soreq A, Soreq B, Palmachim, Ashkelon and Ashdod plants over the weekend of August 29-30 after unusually high turbidity — caused by microscopic algae carried on rough seas from the Nile region — began clogging intake filters. Plants briefly reopened Monday, September 1, only to shut again Tuesday morning as conditions worsened. Only the Hadera plant, in central Israel, kept operating normally throughout.
The disruption hit hardest in the south. In the Ramat Negev region near the Egyptian border, Mekorot, Israel’s national water company, halted fresh water deliveries to farms just as growers were irrigating some 20,000 dunams (roughly 2,000 hectares) of newly planted tomatoes, cucumbers, peppers and eggplants — a crop area producing an estimated two million tons of vegetables a year. Eran Doron, head of the Ramat Negev Regional Council, warned that fields needing about 1,500 cubic meters of water an hour were receiving as little as 300-500, and that a prolonged cutoff risked wiping out the season entirely for farmers who had already taken out loans to plant it.
Energy and Infrastructure Minister Eli Cohen described the turbidity event as a “once-in-30-years phenomenon” and said by September 2 that the worst was “mostly behind” the country, as three of the five affected plants began partial restarts. Recovery proved uneven: by September 5, the Energy Ministry and Water Authority were describing the sector as “fully stable,” with Hadera back to normal output, Palmachim and Sorek B partially online and Sorek A expected to ramp up further, even as Ashkelon and Ashdod remained offline. Officials said residential and agricultural supply continued without restriction throughout, backstopped by increased pumping from the Sea of Galilee and more than 1,000 wells nationwide, and that national reservoirs were being topped up over the weekend to build redundancy heading into the following week.
Even as supply stabilized, the episode has revived a longer-running argument among Israeli water specialists about over-reliance on coastal desalination. Prof. Dror Avisar of Tel Aviv University argued desalination was “supposed to complement, not replace, natural sources,” while Clive Lipchin of the Arava Institute said decades of leaning on desalination had bred “a false confidence” in the system’s resilience to exactly the kind of environmental shock the algae bloom represented. Israel currently plans to roughly double desalination output, to 2.3 billion cubic meters a year, by 2050. Critics point to an unfinished 2025 draft masterplan that calls for rehabilitating around 400 idle groundwater wells — at an estimated cost of $1.3 billion — plus 200 more as emergency backup, alongside tiered water pricing and buy-back programs to encourage agricultural conservation, as evidence the country has under-invested in alternatives to the sea.
The episode also revived questions, so far unresolved, about whether sewage outflows from Gaza may be contributing to algae growth along the affected stretch of coastline — a link Israeli water officials have not confirmed.
For a country that built its water security strategy substantially around desalination over the past two decades, the bloom was a reminder that the technology’s main structural weakness is the sea itself: a shared, variable resource that can degrade faster than any single plant operator can control. Whether the incident produces lasting policy change — faster well rehabilitation, more storage buffers, tighter turbidity monitoring — or fades once the algae clears is now the open question hanging over Israel’s water planners.
(Source: The Times of Israel) (Source: Ynetnews) (Source: The Jerusalem Post)