The article from Bulletin of the Atomic Scientists describes a deepening water crisis in Tehran that could lead to a “Day Zero,” a moment when taps run dry. During the summer of 2025, the region was hit by a severe heat wave, with temperatures nearing 50 °C. That extreme heat followed several years of below-average rainfall, pushing reservoir levels supplying the city to record lows. By early November, the reservoir behind Amir Kabir Dam, one of Tehran’s main water sources, dwindled to roughly 8% of capacity.
The shortage has already disrupted urban life. Rivers and wetlands have dried up, hydropower generation has fallen, and water supply systems are under heavy strain. Some districts face water pressure cuts or intermittent supply. Local authorities have imposed strict conservation measures.
The article also notes that Tehran’s crisis is not just about this summer’s heat. Over the past five years, rainfall during the wet season (December–April) has remained persistently below the long-term average. The 2024–25 rainy season was particularly dry, meaning reservoirs never refilled before the 2025 summer heat hit.
Some officials have warned that if conditions don’t improve soon, the city, home to tens of millions, might become uninhabitable. In fact, evacuation of parts of the city has been floated as a last-resort option.
Ultimately, the article argues that Tehran’s plight reflects a broader failure of water management. Population growth, excessive water use, dependence on dam reservoirs, and now accelerating climate stress combine to create a dangerous situation. Without swift action, such as better water governance, conservation, and adaptation measures, Tehran’s “Day Zero” may no longer be a distant warning, but an imminent reality.