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Iran is carrying out cloud-seeding operations in a bid to increase rainfall as the country endures its worst water crisis in six decades.

Energy minister Abbas Aliabadi said on Tuesday the country had begun a fresh round of operations to inject crystals into clouds using planes, drones and ground-based machinery, a technique that is growing in popularity thanks to climate change.

Iran has also begun developing drones tailored specifically to cloud seeding.

“Operations on suitable precipitation systems have begun in the current water year,” Aliabadi said, referring to the period from early October to late September.

He said that in the previous water year, starting in October 2024, Iran had carried out 37 flights, 61 drone missions and about 2,000 hours of ground operations in a drive to modify the weather across the country, which has an arid and semi-arid climate.

A flight on Monday aimed to trigger rain in the northwestern provinces of East Azarbaijan, West Azarbaijan and Kurdistan. Similar flights were conducted in the northeastern province of Khorasan Razavi at the weekend. 

Mohsen Ardakani, head of Tehran’s water and wastewater company, said this week: “We are going through the sixth year of drought for the first time in six decades.” The country’s reservoirs were just 32 per cent full, and only 9 per cent full in the capital Tehran, he said.

Mohammad-Mehdi Javadianzadeh, head of the Organisation for the Development of New Atmospheric Water Technologies, said last week that drones tailored to cloud seeding were in development.

“Cloud seeding in Iran, when carried out under [the] right weather conditions, can boost rainfall by 15 to 20 per cent,” he said.

Technicians have also used ground-based generators and flares on high-elevation sites to release seeding materials.

As water shortages worsen, several lakes and rivers in Iran have dried up, while land subsidence rates have soared, partly because of the overuse of water from underground reservoirs.

President Masoud Pezeshkian has warned that the water crisis could ultimately lead to the evacuation of the capital. To sustain the city’s water flow, the government was forced to accelerate a project to transfer water via pipeline from the Taleghan dam, 140km north-west of Tehran, this summer. 

The Islamic republic is now turning to water from the Gulf and the Sea of Oman to address shortages in central regions largely covered by deserts.

On Saturday, Pezeshkian inaugurated the first phase of a project to transfer water from the Gulf via pipeline to major steel plants and refineries in the historic city of Isfahan, a key industrial hub.

“Thanks to round-the-clock efforts on this national mega-project, water from the Persian Gulf has now reached the central plateau and Isfahan,” Pezeshkian said at the inauguration ceremony. “This will reduce industries’ dependence on underground water resources.”

He said future industrial projects must be located near the sea to ensure sustainability.

Mohammad Fazeli, a pro-reform social activist, argued that such projects came with significant environmental consequences and were not a lasting solution.

Cloud seeding has grown in popularity as climate change intensifies drought conditions. According to the World Meteorological Organization, the UN’s weather and climate service, cloud seeding and other forms of weather modification are relatively common, with active programmes in at least 50 countries.

The technique uses chemical salts that include silver or potassium iodide, which are injected into clouds so water vapour can condense more easily.

Western US states have long used it to bolster water supplies by enhancing winter snowpack, while countries such as the United Arab Emirates have used it to address drought.

But the WMO has warned that the success of such programmes “is often difficult to establish with sufficient confidence” and warned of “considerable risks” as well as economic benefits.

Additional reporting by Attracta Mooney in London