TEHRAN — Iran is headed for a water shortage of epic proportions, and little is being done to reverse a decades-long trend that has reduced the country’s water supply to crisis levels.
Changes in the global climate, a century of rampant development, and heavy subsidies on water and other utilities are all contributing to a situation that is likely to get much worse.
‘‘Our water usage is twice the world standard, and considering the situation in our country, we have to reduce this level,’’ Massoumeh Ebtekar, a vice president and the head of Iran’s Department of Environment, said in a recent speech.
Iranians use 250 liters of water per day, on average. They use much less water than Americans, who lead the world at nearly 400 liters per day, but Iran and other dry Middle Eastern countries do not enjoy the abundance of fresh water the Americas and Europe have. Accurate data for Iraq and Afghanistan are not available, but other Persian Gulf countries, including Saudi Arabia and the United Arab Emirates, consume water at levels similar to Iran, although their populations are much smaller.
With Iran’s annual precipitation at a third of the global average, overconsumption has ravaged water resources. A 2013 study by the World Resources Institute ranked Iran as the world’s 24th most water-stressed nation, putting it at extremely high risk of future water scarcity.
Iran has several large desalination projects — it even plans to sell water to neighboring countries — but converted saltwater is seen as a solution only for areas close to the country’s two main saltwater sources, the Caspian Sea and the Persian Gulf. The transportation costs of moving water to the remotest regions of Iran are too high.
Throughout Iran, landscapes are being transformed as scientists warn that the already arid country runs the risk of becoming a vast desert. Urmia, a salt lake in Iran’s northwest, once the largest in the Middle East, has been depleted to just 5 percent of its former volume over two decades. The Zayandeh river is mostly a dry bed. It has been diverted and dammed to help irrigate farms.
Disappearing lakes and rivers are the symptoms, but the root causes are less visible, stemming from the techniques and habits of a more traditional and less mechanized era.
‘‘In less than 50 years, we’ve used all but 30 percent of our groundwater supply, which took a million years to gather, and it’s getting worse and worse due to unsustainable development,’’ said Nasser Karami, an Iranian physical climatologist who is currently an associate professor at the University of Bergen in Norway.
Iran’s population has more than doubled since the 1979 revolution and has grown eightfold since 1900.
After six years of below-average rainfall, few Iranian authorities acknowledge the seriousness of the problem, instead offering quick-fix solutions. But in recent days, Karaj, a sprawling suburb of Tehran with 1.6 million inhabitants, implemented rationing. Other major cities seem certain to follow suit.
Environmental experts say that any solution will need to extend beyond conservation to include a long-term strategy to reverse the damage done to groundwater supplies.