Water supplies dangerously low in major city in Iran

Key Concepts

• Day Zero: A critical point where water supply runs out.
• Karaj Dam: A major water source for Tehran, currently at 8% capacity.
• Water Deficit: A significant shortfall in available water resources.
• Aquifers: Underground layers of permeable rock, sediment, and soil that hold and transmit groundwater.
• Water Bankruptcy: A state of severe depletion of water resources due to mismanagement.
• Climate Change: Long-term shifts in temperatures and weather patterns.
• Population Growth & Consumption: The increase in the number of people and their water usage.
• Water Rationing: The controlled distribution of water during shortages.

Tehran's Looming Water Crisis

Tehran, Iran's capital, is facing an imminent water crisis, with reservoirs supplying its 15 million residents critically low. The Karaj Dam, responsible for a quarter of the city's drinking water, is only 8% full. This dire situation has prompted the president to warn of potential evacuations and the implementation of water rationing in some areas.

Causes of the Water Shortage

The crisis is attributed to a confluence of factors:

• Drought Conditions: The period from September to November has been the driest in 50 years, with rainfall 89% below the long-term average, according to the National Weather Forecasting Center. This has resulted in a severe water deficit across a vast area, depicted in red on maps.
• Climate Change: While a contributing factor, climate change alone does not fully explain the crisis. Prolonged periods of low rainfall and high temperatures over several years have exacerbated the situation.
• Population Growth and Increased Consumption: Tehran's population has nearly doubled since 1979, from 4.9 million to 9.7 million. Concurrently, water consumption has quadrupled, rising from 346 million cubic meters in 1976 to 1.2 billion cubic meters currently. This surge is linked to increased wealth, leading to the adoption of appliances like washing machines and dishwashers.
• Over-reliance on Aquifers and Competition with Agriculture: To supplement dwindling reservoir supplies, Tehran has increasingly relied on underground aquifers, which now provide 30-60% of its tap water. This has created direct competition with farmers who draw water for irrigation. Aquifer levels are declining by 101 million cubic meters annually around Tehran.
• Chronic Mismanagement: The former deputy head of Iran's environment department described the situation as "water bankruptcy," attributing it to decades of mismanagement, lack of foresight, and an over-reliance on infrastructure and engineering projects in a water-scarce country.

Government Responses and Mitigation Measures

• Water Pressure Reduction: The government is considering reducing water pressure to zero during nighttime hours when residents are asleep to prevent waste. This measure, while aimed at conservation, could inconvenience the public.
• Public Awareness and Action: Citizens are being urged to install water storage tanks to ensure a personal supply.
• Blame Allocation: Government ministers have cited climate change, water leaks, and the 12-day war with Israel as reasons for the shortage.

Global Context and Vulnerability

Tehran is not alone in facing water scarcity. Other cities are also vulnerable:

• Cape Town, South Africa: Narrowly avoided a "Day Zero" scenario eight years prior through city-wide water-saving efforts.
• London, UK: Despite its reputation for rain, London is also at risk due to supply not keeping pace with population growth and demand.

Conclusion

The water crisis in Tehran is a complex issue stemming from a combination of severe drought, exacerbated by climate change, rapid population growth, increased water consumption, over-extraction of groundwater, and decades of mismanagement. The situation highlights the fragility of water supplies in urban centers globally when faced with environmental challenges and unsustainable resource management. As Thomas Moore of Sky News noted, "droughts that are being made more likely and more severe by climate change can expose the fragility of water supply."