Reservoirs of the dams supplying water to Tehran are currently at their lowest level in a century.
Iranian authorities have urged people to limit water consumption as the country grapples with severe shortages during an ongoing heatwave.
The national meteorological service said Iran is experiencing its hottest week of the year so far with temperatures exceeding 50 degrees Celsius (122 Fahrenheit) in some areas.
Government spokesperson Fatemeh Mohajerani announced in a post on X on Sunday that Tehran province would observe a public holiday on Wednesday because of the ongoing heatwave.
“In light of the continued extreme heat and the necessity of conserving water and electricity, Wednesday … has been declared a holiday in Tehran province,” she wrote.
Temperatures in Tehran reached 40C (104F) on Sunday with a further rise to 41C (106F) forecast for Monday, according to meteorological reports.
Impact of climate change
Water scarcity is a major issue in Iran, particularly in arid provinces in the country’s south, with shortages blamed on mismanagement and overexploitation of underground resources, as well as the growing impact of climate change.
Tehran city council chair Mehdi Chamran urged people to “conserve water to avoid drops in supplies”, according to the ISNA news agency.
Authorities across Iran have issued similar appeals in recent days, asking residents in several provinces to limit water usage.
Tehran’s provincial water management company called for usage to be reduced by “at least 20 percent” to help ease the shortages.
In a statement, it said “the reservoirs of the dams supplying water to Tehran are currently at their lowest level in a century”, following years of steady decline in rainfall.
Javan, a conservative newspaper, reported on Saturday that authorities reduced water supplies in parts of the capital in a bid to mitigate the crisis, resulting in “water outages lasting between 12 and 18 hours” in some areas.
Energy Minister Abbas Aliabadi apologised on Sunday for reduced water supplies, saying the move comes “to better manage resources”.