Although Iran’s national average rainfall in the current water year (September 23, 2025 to September 22, 2026) has been roughly double that of the previous year, this does not mean water conditions have improved across all regions. Several areas, including the central and southern Alborz belt, are still facing acute shortages.
Iran is currently going through its sixth consecutive year of drought, a prolonged period that has taken a heavy toll on both surface and groundwater resources across the country.
In terms of timing, this autumn was completely dry and ranked as the driest in 57 years. Although several months remain until the end of the water year in late September, a crucial period for replenishing water resources has already been lost. As a result, aquifers have not been properly recharged and reservoir levels have dropped to very low levels.
According to official statistics, the country’s average rainfall in the current water year (from September 23 to February 7) stands at about 121 millimeters, which is close to the long-term norm. In the same period last year, national rainfall was nearly half that amount, at around 60 millimeters.
However, Jamal Mohammadvali Samani, a professor of water management and engineering, said in an interview with Donya-e Eqtesad that these rains have not been enough to make up for the severe autumn deficit. He also stressed that rainfall has been distributed very unevenly across the country.
For instance, precipitation in some western provinces has been above normal, while conditions in parts of the south have been relatively acceptable. But in provinces such as Khuzestan and Kermanshah in the west and southwest, rainfall has remained below average. This uneven distribution, he said, has created additional challenges for water management.
Mohammad Hobbevatan, an expert in water governance and resource management, echoed this point, saying the national average does not reflect the reality of water stress in all provinces, including several densely populated ones, and cannot serve as the sole basis for policymaking.
“Water management is fundamentally a local issue, and it is not possible to assess the situation in all provinces based on a single national rainfall average,” he said.
According to Hobbevatan, the core of the crisis lies in the central and southern Alborz belt, where population density is high and reliance on both surface and groundwater resources is significant.
Samani also confirmed that provinces such as Tehran, Alborz, Qom, Qazvin, Hamedan, and even Arak within that belt are facing unfavorable rainfall conditions, with precipitation showing a clear decline compared with long-term averages.
Serious Warning
In Tehran, data from the Energy Ministry show that rainfall between September 23 and February 7 fell by 14% compared with the same period last year and by about 50% compared with the 57-year average.
According to Samani, this situation is a serious warning for the drinking water supply of the multi-million-strong capital.
He said consecutive droughts in recent years have weakened aquifers and sharply reduced dam reserves, with the five main reservoirs supplying Tehran reaching critically low levels. Recent winter rainfall has not been enough to replenish them, and any improvement will depend on substantial snowfall and rain in the coming months.
He added that although dam storage and mountain snowpack are usually assessed only at the end of the water year, the current outlook is not encouraging.
Samani explained that aquifers and reservoirs are already depleted, and near-normal rainfall alone cannot quickly make up for the accumulated deficit.
Criticizing national water management, he said policymakers appear to assume that all precipitation can be used, while scientific principles require that at least 40% of renewable water be preserved to sustain natural cycles.
“In Iran, especially in water-scarce megacities, not only is all rainfall consumed, but additional pressure is also placed on groundwater. This approach poses a serious long-term threat to the sustainability of the country’s water resources,” he said.
This year, however, only limited measures have been taken to manage water resources in Tehran. One has been the transfer of water from the Taleghan Dam to the capital, which is widely seen as a temporary and unsustainable solution. At the same time, since the summer, authorities have reduced water pressure or cut supply during nighttime hours—though without a publicly announced schedule—and this policy has continued into mid-winter.
Meanwhile, Tehran’s city council has announced extensive plans and budget allocations to expand wastewater reuse, water recycling, smart irrigation for green spaces, and the use of water-saving equipment in public places and offices. Still, it remains unclear how quickly and effectively these projects will be implemented.
“For the next water year, stricter scenarios must be considered from now, given the likelihood of further pressure reductions, a sharp decline in reservoir storage, and a continued weather warming.”
