Iran - especially its capital, Tehran - is facing an unprecedented drought this autumn, with rainfall at record lows and reservoirs nearly empty. Officials are pleading with citizens to conserve water as the crisis deepens.

President Masoud Pezeshkian has warned that if there is not enough rainfall soon, Tehran's water supply could be rationed. But he said that even rationing might not be enough to prevent a disaster.

"If rationing doesn't work," Pezeshkian said, "we may have to evacuate Tehran."

His comments have prompted criticism in Iranian newspapers and on social media. Former Tehran mayor Gholamhossein Karbaschi called the idea "a joke" and said "evacuating Tehran makes no sense at all".

Iran's meteorological officials say no rainfall is expected over the next 10 days.

Meanwhile, the water crisis is already affecting daily life in the capital.

"I'm planning to buy water tankers to use for toilets and other necessities," a woman in Tehran told BBC Persian.

In the summer, Iranian rapper Vafa Ahmadpoor posted a video on social media showing a kitchen faucet with no running water.

"It's been four or five hours," he said. "I've bought bottled water just to be able to go to the toilet."

The manager of the Latian Dam, one of Tehran's main water sources, says it now holds less than 10% of its capacity. The nearby Karaj Dam — which supplies water to both Tehran and Alborz provinces — is in a similarly dire condition.

"I have never seen this dam so empty since I was born," an elderly local resident told Iranian state TV.

According to Mohammad-Ali Moallem, the manager of the Karaj Dam, rainfall has plummeted dramatically.

"We had a 92% decrease in rain compared to last year," he said. "We have only eight per cent water in our reservoir — and most of it is unusable and considered 'dead water.'"

The government is now pinning its hopes on late autumn rain, but forecasts are bleak. Iran's Minister of Energy, Abbas Ali Abadi, has warned the situation could soon force authorities to cut water supplies.

"Some nights we might decrease the water flow to zero," he said.

Officials have also announced plans to penalise households and businesses that consume excessive amounts of water.

Iran's energy minister Ali Abadi has said Tehran's water crisis is not only due to a lack of rainfall. He blamed water leakage caused by the capital's century-old water infrastructure and even pointed to the recent 12-day war with Israel.

During that conflict, Israel targeted the northern Tehran neighbourhood of Tajrish on 15 June. Afterwards videos showed heavy flooding in the area.

The day after the strike, the Israel Defence Forces said it had targeted Iranian military "command centres".

But the crisis extends far beyond the capital.

The head of Iran's National Centre for Climate and Drought Crisis Management, Ahmad Vazifeh, has warned that, apart from Tehran, dams in many other provinces — including West Azerbaijan, East Azerbaijan and Markazi — are also in a "worrying state", with water levels in the single-digit percentages.

In Mashhad, Iran's second-largest city, officials are sounding the alarm as well.

The Governor of Khorasan Razavi Province in north-east Iran, said the water reserves in Mashhad's dams have dropped to "less than eight percent," warning that the province faces a "mega-challenge of drought."

CEO of Mashhad's Water and Wastewater Company put the figure even lower.

"The storage level of the city's main dam is below three percent," Hossein Esmaeilian said.

"Only three percent of the combined capacity of Mashhad's four water-supplying dams — Torogh, Kardeh, Doosti, and Ardak — remains. Apart from Doosti Dam, the other three are out of operation."

Iran's water crisis has been decades in the making.

Even Iran's Supreme Leader, Ayatollah Ali Khamenei, has repeatedly acknowledged the looming threat — speaking about water shortages in his Nowruz addresses in 2011 and on other occasions in the following years.

Yet little has changed.

Today, Tehran, Karaj and Mashhad — home to more than 16 million people combined — are facing the real possibility of their taps running dry.