The controversial project on the Marbar River threatens ecosystems, heritage sites, and water security across southern Iran.
The ongoing construction of the Mandegan Dam on the Marbar River in Semirom County has triggered widespread protests from environmental activists, local communities, and experts. The project, part of an inter-basin water transfer plan from the Karun River headwaters to the Zayandeh Rud basin, has been launched without proper environmental permits. Critics warn that it poses a grave threat to the Dena Protected Area and downstream rivers such as the Khersan and Karun.
A Dam Without Due Process
Supporters of the project argue that it will provide drinking, agricultural, and industrial water to Isfahan province and help manage local flooding. Yet environmental specialists say the promised benefits pale in comparison to the damage it could inflict on ecosystems, biodiversity, and water resources across southern Iran.
The controversy deepened after the Ministry of Energy bypassed earlier research and design phases, rushing directly into dam construction. Critics describe this as “putting regulatory institutions against the deed.”
The Marbar River, originating from the Semirom Plateau in the Dena Mountains, stretches nearly 50 kilometers before joining the Khersan and ultimately the Karun. Experts caution that any disruption to its flow will have cascading effects on southern provinces already struggling with water scarcity.
Environmental Risks and Irreversible Damage
The Mandegan Dam is designed not only to block the river but also to transfer 280 million cubic meters of water annually via pumping networks. Experts warn this diversion will desiccate parts of the Khersan and Karun, destroy habitats, and destabilize the region’s water balance.
Environmental activists argue that the dam’s true purpose is not drinking water supply—as officials claim—but to sustain Isfahan’s heavy industries, especially steel and other high-consumption sectors. They stress that cheaper, less destructive solutions exist for meeting household water needs.
The Dena Protected Area, a UNESCO-recognized biosphere reserve and one of Iran’s most critical ecological zones, is now under serious threat. Scientists fear the dam could trigger land subsidence, reduced vegetation, species migration, and even local climate change. Some studies suggest the Marbar River’s ecosystem could collapse entirely, erasing it from Iran’s natural geography.
Public Outcry and Institutional Weakness
Protests have spread across Khuzestan, Kohgiluyeh and Boyer-Ahmad provinces. Activists accuse the Environmental Protection Organization of inaction despite repeated warnings about the dam’s illegality. On May 14, Deputy Director Hamid Zohrabi formally requested that construction be halted until permits were secured, but the project has pressed ahead.
At a September 27 meeting in Kohgiluyeh and Boyer-Ahmad, environmental officials faced sharp criticism from activists, who questioned why no legal complaint had been filed against those pushing the dam forward. The confrontation highlighted the growing sense of mistrust between local communities and national institutions.
Threats to Cultural Heritage
Beyond environmental risks, archaeologists warn that the Semirom and Dena regions—home to dozens of historical sites spanning from the Paleolithic era to modern times—are in jeopardy. Preliminary surveys have identified at least 66 sites, including settlements from the Bakun-Lapui and Banesh periods as well as Islamic-era remains. Many could be permanently submerged once the dam reservoir is filled.
Mohammad Hossein Taheri, an archaeology professor, has cautioned that unexcavated sites may also be lost forever, erasing irreplaceable chapters of Iran’s cultural heritage.
Rising Social Tensions
Opposition to the Mandegan project has grown from professional circles to grassroots movements. In December 2024, students in Yasuj protested outside the governor’s office, warning that “implementing the Mandegan project will mean the destruction of the Dena region.” Today, social media platforms reflect growing polarization, with sharp disputes between residents of Khuzestan and Kohgiluyeh—who fear losing water security—and supporters in Isfahan.
Experts say this tension is the direct result of decades of top-down water transfer policies prioritizing industrial consumption over sustainable management. Past experiences, such as the Gotvand Dam, serve as grim reminders of projects that failed to deliver on promises while inflicting irreversible ecological damage.
Another Link in a Cycle of Mismanagement
Despite overwhelming evidence of ecological, cultural, and social risks, construction continues—driven by political pressure and industrial demand. Activists warn that the Mandegan Dam could become another costly mistake in Iran’s long history of unsustainable water projects, one that threatens not only local communities but the ecological balance of the entire south.
Unless halted, Mandegan risks joining the list of disastrous development schemes that have traded short-term industrial gain for the long-term destruction of Iran’s natural and historical heritage.
