Mashhad, home to around 4 million people and Iran’s holiest city, relies on four dams for its water supply. Esmaeilian said consumption in the city had reached about “8,000 litres per second, of which about 1,000 to 1,500 litres per second is supplied from the dams”.

Authorities in Tehran warned over the weekend of possible rolling cuts to water supplies in the capital amid what officials call the worst drought in decades. The Iranian president, Masoud Pezeshkian, has cautioned that without rainfall before winter, even Tehran could face evacuation.

In the capital, five major dams supplying drinking water are at “critical” levels, with one empty and another at less than 8% of capacity, officials say.