29 Sept 2025
The nation faces severe water stress, predominantly due to agricultural consumption, climate change, and depleted groundwater reserves, rather than domestic use. While desalination is a known technology, its high cost, energy demands, environmental impact, and inefficiency make it suboptimal for Iran's vast needs, suggesting wastewater treatment and agricultural reform as more sustainable paths.
Iran experiences significant water stress, evidenced by frequent water cuts, primarily due to high overall consumption, climate change leading to low rainfall in a dry and warm country, and the severe depletion of groundwater resources.
Approximately 90% of Iran's water resources are consumed by agriculture, 7-8% by industry, and only 3-4% by domestic households, despite significant pressure on citizens for household water conservation.
Desalination plants, or water sweetening devices, are widely used in GCC countries, employing methods like Reverse Osmosis (RO) and thermal distillation, both of which have specific advantages and disadvantages.
RO works by filtering pressurized water through a fine membrane, allowing only water molecules to pass, separating salt and other impurities; the resulting distilled water requires remineralization for potability and can be enhanced with bioreactors for sludge treatment.
Thermal desalination involves multi-stage distillation of seawater, similar to boiling and condensing, which is common in the Middle East but is energy-intensive, typically requiring fossil fuels and causing environmental pollution unless waste heat is efficiently reused.
Nuclear desalination uses a small nuclear reactor to generate heat for water purification and electricity, offering high production capacity and stability, but it faces challenges related to reactor construction, security, political risks, and the complex management of nuclear waste.
Desalination is considered an inefficient method for Iran, converting only 30-43% of input water into fresh water, while the remaining concentrated brine requires careful return to the sea to prevent ecological damage; it also demands significant electricity (45-50 TWh for 90 million people) and necessitates plant proximity to the sea, limiting its applicability.
Improperly designed or operated desalination plants can devastate local ecosystems, reduce dissolved oxygen in water, harm marine life and corals, and release chemical pollutants like chlorine, further exacerbating the environmental damage from increased brine concentration.
Iran has poor wastewater management; however, the Membrane Bioreactor (MBR) method, exemplified by developments at Mobarakeh Steel and Kashan Steel, is a cost-effective solution that uses a membrane with specialized bacteria to purify wastewater into potable water, allowing for multiple reuse cycles.
A major contributor to Iran's water crisis is the cultivation of water-intensive crops like rice in provinces such as Isfahan and watermelon in Yazd, which are unsuitable for their arid climates, diverting water from natural sources like Urmia Lake and exacerbating regional water scarcity.
Effective water management requires the strict segregation of urban, agricultural, and industrial water uses, a reform of agricultural practices to match regional climates, and significant investment in robust wastewater treatment systems as the most logical and sustainable long-term solutions.
Over the past decade, the average static water level in Iran's wells has drastically dropped from 6 meters to 90 meters, indicating severe depletion of groundwater aquifers and a near-empty state of underground water reserves.
The country's primary water challenge is not household consumption, but the vast agricultural water use and the mismanagement of resources, especially the cultivation of water-intensive crops in arid regions.
| Key Aspect | Description | Relevance/Impact |
|---|---|---|
| Water Consumption Distribution | Agriculture consumes ~90% of water resources, industry 7-8%, and households only 3-4%. | Overemphasis on household conservation diverts attention from the primary drivers of water scarcity. |
| Desalination Inefficiency | Desalination technologies convert a maximum of 30-43% of input seawater into fresh water, with the remainder being highly concentrated brine. | High energy consumption, significant waste, and potential ecological damage from brine disposal. |
| Wastewater Treatment (MBR) | The Membrane Bioreactor (MBR) method purifies wastewater into potable water cost-effectively, allowing for multiple reuse cycles (up to 17 times). | Offers a highly sustainable, affordable, and local solution for increasing potable water supply without large energy demands. |
| Groundwater Depletion Crisis | The average static water level in wells has drastically decreased from 6 meters to 90 meters over the last decade. | Indicates severe and critical depletion of underground water reserves, threatening long-term water security. |
| Agricultural Mismanagement | Cultivation of water-intensive crops (e.g., rice, watermelon) in arid, unsuitable regions is widespread, diverting significant water resources. | Directly exacerbates regional water stress and contributes to the desiccation of natural lakes. |
| Misplaced Investment Priorities | The cost to fill Latyan Dam (75 million m³) with desalinated water (~$35-40 million) is less than the cost of building a single luxury villa in areas like Lavasan. | Reveals a severe misalignment of national investment priorities, favoring luxury over critical infrastructure. |
