Author: Fanack Water Editorial Team
Iran’s Water Crisis Part 3: Transboundary Tensions and Regional Water Politics
Iran’s water crisis now extends far beyond its borders. With major rivers shared across volatile frontiers and rising competition for dwindling flows, regional hydropolitics have become a defining issue. This third article in our series explores how cross-border development—especially recent dam projects in Afghanistan and neighboring countries—threatens Iran’s fragile water balance.
Shared Waters, Shared Tensions
Iran depends heavily on transboundary rivers like the Helmand, Harirud, and Aras. Upstream withdrawals, combined with regional drought, have badly reduced the inflows Iran once relied on. The 1973 Helmand River Treaty nominally guarantees Iran an annual flow of 820 million cubic meters, but implementation has rarely lived up to this standard. In the past two years, intensified dam construction and recurring drought have almost dried out the Hamoun wetlands—once Iran’s third-largest lake system. These wetlands were the lifeline for communities in Sistan–Baluchestan province, now facing soaring unemployment, dust storms, and forced migration (Wikipedia, Stratheia).
The Taliban leadership in Kabul insists it respects Iran’s water rights, but projects launched since 2021 tell another story. They aim to secure Afghanistan’s irrigation, energy, and food independence—largely by expanding dam networks along shared rivers. Iranian officials have repeatedly accused the Taliban of using water as “a political weapon,” while Afghan leaders describe Tehran’s opposition as an infringement on national sovereignty (Iran International).
The New Flashpoint: The Pashdan Dam
In August 2025, Afghanistan inaugurated the Pashdan Dam, one of its largest infrastructure projects since the Taliban return to power. Located in Herat province on the Harirud River—just 70 kilometers from Iran’s Taybad region—the $117 million dam stores around 54 million cubic meters of water, irrigates some 13,000 hectares of farmland, and generates 2 megawatts of electricity (Ariana News, Shafaq News).
For Afghanistan, the project symbolizes economic progress and “self-reliance in resource management.” But for Iran, it’s a looming threat. Experts warn that the Pashdan Dam will severely reduce flow into the Harirud Basin—water upon which northeastern provinces like Khorasan Razavi depend. Mashhad, Iran’s second-most populous city, could face serious water shortages if inflows decline further (8 AM Media, Blue Community Network).
Tehran responded cautiously at first, calling for “transparent hydro-diplomacy.” Yet domestic pressure has intensified. Iranian newspapers accused the government of failing to defend water rights, while environmental experts warn that depletion of the Harirud could become “the next Helmand crisis.” Tensions reflect a deeper mistrust: Iran perceives Afghanistan’s dam-building surge as the continuation of a pattern—prioritizing upstream demands at the expense of downstream security.
The Wider Regional Picture
Iran’s water stress extends beyond the Afghan border. To the northwest, construction and diversion projects on the Aras River in Turkey and Azerbaijan are reducing flows into Iran’s East Azerbaijan and Ardabil provinces. Farmers in these regions report shrinking yields and rising soil salinity. Meanwhile, joint operations at the Doosti Dam on the Harirud with Turkmenistan are increasingly strained by drought conditions and reduced river inflow (Fanack Water).
Except for the Helmand Treaty, Iran has no robust legal frameworks governing its shared rivers. Unlike Europe or Southeast Asia—where international river commissions set clear rules—the Middle East remains dominated by bilateral politics and ad hoc negotiations. This vacuum worsens during climate shocks: floods, droughts, or dam operations cascade without warning, leaving downstream communities vulnerable.
Building Bridges, Not Dams
Regional experts are calling for a reset in water diplomacy. Iran’s Ministry of Energy and UNESCO’s Regional Centre on Urban Water Management have begun a satellite-based drought monitoring system that could provide neutral data to all riparian states. Iran’s water scholars also advocate a new Helmand River Authority—modeled loosely on the Mekong River Commission—to depoliticize management and boost transparency (IntelliNews).
Afghanistan, however, views such regional initiatives warily. Taliban officials say water agreements will be “based on mutual respect,” but have shown little interest in reactivating the 1973 treaty mechanisms. With the Kamal Khan Dam already restricting Helmand River flows, and Pashdan Dam now in operation, Tehran faces a growing reality: its eastern waters are no longer secure.
Water and Geopolitics Collide
For Iran, the stakes are existential. Its eastern provinces rely on transboundary flows for drinking water, agriculture, and power production. Without diplomatic breakthroughs, communities in Khorasan and Sistan may face even deeper shortages, forcing migration westward. Iran’s own dam expansion plans offer little relief if upstream countries retain control of the headwaters.
Water, more than oil or politics, now defines Iran’s vulnerability. Regional negotiation—anchored in science, trust, and equitable sharing—may be the only way to turn this cycle of scarcity into cooperation.