Iran’s shrinking water reserves threaten crisis

Iran’s key reservoirs are reaching dangerously low levels as years of declining rainfall and heavy reliance on hydropower take their toll, a senior water official warned.

Isa Bozorgzadeh, spokesman for Iran’s water industry, said on Tuesday that the usable capacity of Karaj Dam near Tehran has dropped to nearly half, much of it rendered useless due to sediment buildup.

“Lar Dam has practically dried up, and Latian, Taleqan, and Mamloo reservoirs are facing a 46% decrease in rainfall compared to the average and 25% compared to last year,” he told ILNA news agency.

Water shortages have triggered growing concerns in recent weeks, particularly in Tehran and Isfahan provinces, where officials have raised the possibility of rationing.

Bozorgzadeh cautioned that Tehran is consuming 50 million cubic meters of surface water each month while the combined reserves of the capital’s five main dams—including dead storage and sediment—amount to just 60 million cubic meters.

“Conditions have deteriorated to the point where even a motorcyclist could drive through the reservoirs,” he said.

Eastern Tehran’s water and wastewater company reported that Latian and Mamloo dams are each only 12% full, while Lar is down to just 1%. Karaj, a historically stable reservoir, has shrunk to 7% capacity.

Iran’s water supply depends largely on rainfall, snowmelt, and underground aquifers, but decades of over-extraction have left groundwater tables severely depleted. The sharp decline in precipitation—down more than 40% in Tehran province relative to long-term averages—has compounded the problem.

Beyond Tehran, Bozorgzadeh identified Hormozgan, Sistan and Baluchestan, Khuzestan, Kohgiluyeh and Boyer-Ahmad, and Bushehr as regions struggling with a 50% drop in rainfall.

Government spokeswoman Fatemeh Mohajerani acknowledged the severity of the situation, saying, “A nationwide decrease in average rainfall this year has led to shortfalls as high as 75% in some provinces.”

Iran’s energy ministry reports show that despite lower rainfall, hydropower generation increased by 24% in the fiscal year beginning March 2023, amid the country's energy crisis, reaching 17 terawatt-hours and maintaining that level into the current year.

Dalga Khatinoglu, an oil and gas analyst, suggested the government’s decision to sustain hydroelectric output was a factor in the current crisis.

“Iran failed to achieve its planned growth in thermal and renewable energy, leaving it dependent on hydropower,” he told Iran International. “Over the past two years, the country commissioned just 4 gigawatts of new plants—about 30% of its target—with 90% being gas-fired. The rest came from renewables.”

Hydropower reliance, combined with a persistent drought, has accelerated reservoir depletion, leaving little room for recovery even if precipitation levels were to improve.

Meanwhile, Iranian media has begun to raise alarms about broader implications. Etemad newspaper warned that 2025 could mark a turning point in the country’s water and energy crisis, predicting that shortages could become more severe than any previously experienced. Some hydrologists have cautioned that Iran has used up nearly 1,000 years' worth of groundwater reserves in just three decades.