Tehran's reservoirs hold just 3% of capacity excluding Taleghan dam, with rainfall 97% below long-term averages in the worst drought on record, the head of Tehran's water and sewage company said on December 5.

Mohsen Ardakani said Tehran province received no rainfall in October and November with the government previously warning that Tehran will have to be evacuated in the coming months if the situation does not change.

. The region should have received at least 75mm of rain by this point but has recorded only 3-4mm, compared with 43mm in the same period last year.

Including Taleghan dam, Tehran's reservoir levels stand at 9%. The national average is 32%.

"We are in the most difficult drought period," Ardakani said at the 21st Water Exhibition. "Drought is devastating this province."

The water chief said Tehran's maximum sustainable population is 6mn but the city currently has 12mn residents. "Any new population loading is not scientifically justified," he said.

Tehran has distributed 97mn cubic metres less water than the same period last year. Pressure reductions in the 23,000km distribution network have saved 16mn cubic metres over the past eight months.

Had the company maintained previous water pressure, the city would have faced cuts in September, Ardakani said.

The company has launched a "Cut it in Half" campaign urging high-consumption households to halve their water use. The recommended consumption level is 130 litres per person per day, which 35% of Tehran subscribers currently meet.

If all residents followed this guideline, annual drinking water consumption could fall from 1.2bn cubic metres to half that level, Ardakani said.

The second Taleghan water transfer line project will supply 150mn cubic metres annually, equivalent to 10% of Tehran's needs. However, long-term solutions require changing consumption behaviour even in wet years, the official said.

Residents have reduced consumption by 12% since the start of the Iranian year in March.

Iran's Amir Kabir Dam, commonly known as the Karaj Dam, reached its dead storage level, leaving no safe capacity for further water extraction, IntelliNews previously reported on November 19. 

Current reserves stand at around 10mn cubic metres, equal to the dam’s dead volume, meaning water cannot be withdrawn without jeopardising the structural safety of the facility.

Many of Iran’s dams are drying up and risk being rendered completely inoperative if current conditions persist. 

Recent satellite data indicate a dramatic decline in snow cover across the country's highlands, fueling concerns about intensifying water shortages already impacting Tehran and other cities, IntelliNews reported on November 17.

According to the newly released statistics, the volume of snow recorded across the country is 98.6% lower than the same period in 2024 and 99.8% below the 20‑year average — figures that experts describe as “unprecedented decline.”

Nearby, Latyan Dam, one of Tehran's primary water sources, has also fallen to approximately 9% of its capacity, marking the lowest reservoir level since its completion, the Ministry of Energy reported on November 13.

To stem the losses, Energy Minister Abbas Aliabadi warned that a Tehran household consuming 145 times the standard water consumption pattern will face disconnection in addition to fines, as authorities intensify efforts to enforce fair usage, Tasnim reported on November 12.

Iran has recorded just 3.5 millimetres of rainfall over the past 50 days, equivalent to 18% of the normal average, with 20 provinces receiving no precipitation at all, Khabaronline reported on November 13.

The previous water year marked the country's fifth consecutive dry year, accompanied by a 40% decrease in rainfall. This sharp decline in precipitation created difficult conditions for drinking water supply, agriculture, and various consumption needs, according to Hamshahri.