Groundwater extraction from the plains in and around Tehran Province is 10 times faster than the rate at which water tables can replenish themselves, a water resources management expert said.
“Pumping groundwater at a faster rate than it can be recharged could have a worsening impact on the environment and the people using the water, some of which are lowering the water tables and reducing water streams and rivers, leading to land subsidence, seismic activities, vegetation degradation, food security implications and deterioration of water quality,” Dariush Mokhtari also told ISNA.
Water resources in the sprawling capital are already under tremendous pressure and adding to the number of subscribers in the mega city is a recipe for disaster, he added.
Tehran accounts for a massive 17% or 1 billion cubic meters of the total potable water consumed in Iran per year, which amounts to 7 bcm.
The official said there are 2.7 million water subscribers in the city and increasing the number will lead to catastrophic consequences, as subsurface and surface sources cannot take additional pressure and most of them are on the verge of collapse.
Of the total consumption in Tehran (3 million cubic meters), 70% are pumped from Taleqan, Latyan, Mamlou, Karaj and Lar dams, and the rest is extracted from underground aquifers.
The most severe consequence of excessive groundwater pumping is that the water table, below which the ground is saturated with water, can be lowered. For water to be withdrawn from the ground, water must be pumped from a well that reaches below the water table. If groundwater levels decline too much, then the well owner might have to deepen the well, drill a new well, or attempt to increase the pump use.
The main cause of land subsidence is a loss of support below ground. Simply put, sometimes when water is taken out of the soil, the soil layer collapses, compacts and drops. This depends on a number of factors, such as the type of soil and rock below the surface. Land subsidence is most often caused by human activities, mainly from the removal of subsurface water.
Per capita water use in the province has surpassed 300 liters per day.
The unsustainable pattern should reduce by at least 100 liters as it has already taken a heavy toll on some plains, including Varamin, that are sinking by about 0.5 to 1 millimeter every day.
Raising Water Tariffs
Mokhtari believes that raising water tariffs will not necessarily lead to lower consumption, but can help if applied in tandem with other management measures.
“Higher tariffs will result in filling the pockets of water organizations. These companies will use the additional income to improve their financial posture. They will not spend it on plans and programs to encourage people to consume water judiciously.”
The government has raised water tariffs by 7% each year since 2019, but the uptrend in consumption has not stopped.
Most experts say one of the factors contributing to unusually high water consumption and waste is that the precious commodity is sold at very low prices to farmers, households and industries.
It costs the government 50,000 rials (15 cents) to deliver 1 cubic meter of water to consumers, whereas consumers only pay 20% of the total cost (10,000 rilas or 3 cents), which explains why they take the precious resource for granted.
The Energy Ministry says higher tariffs are necessary to compensate a part of distribution costs and encourage subscribers to consume less.
However, experts, such as Mokhtari, believe that promoting awareness about water scarcity and the impending problems can play a more effective role in containing the decades-old water crisis that has emerged as a serious source of concern in many rich and poor countries.
Located in one of the world's most water-stressed regions, Iran is saddled with excessive consumption plus high levels of water loss because of aging infrastructure and outdated farming practices.
Desertification, population growth, climate change, illegal water wells, wasteful farming, building water-intensive industries in arid regions, injudicious use of water in households and mismanagement of underground water resources are known to have made a bad situation worse.
An increasing number of voices are being heard against the government’s old and questionable agriculture policies, with many saying that growing many crops and fruits inside the country is simply not affordable.
However, some analysts insist Iran's water reserves are adequate to meet the needs of its 80 million people, but years of mismanagement and excessive consumption have made things difficult.
The presence of 400,000 illegal water wells has become a major problem for water authorities struggling to curb the high extraction and consumption rates, especially in agricultural regions.
