“Of the remaining volume [400 bcm], close to 250 bcm are fresh, half of which have been used and the rest is depleting rapidly and normal rainfall will not be able to replenish the diminishing ancient freshwater resource,” Zahir Heidari-Nejad was also quoted as saying by IRNA.
The term fossil water, or paleowater, refers to underground finite water reservoirs that have been geologically sealed. The water cannot be replenished and may have been locked in for thousands of years.
“For over 50 years, Iran has relied on fossil water supplies that are now dwindling rapidly,” he said.
“Population growth, frequent droughts and the effects of climate change are creating the ‘perfect storm’ for future water insecurity.”
According to the Institute for Forest and Pasture Research, groundwater levels have dwindled by two meters in recent years across 70 plains, affecting as much as 100 million hectares.
Based on statistics issued by the UN Development Program, the level of Iran’s per capita water resources is projected to plummet to as little as 816 cubic meters in 2025, down from 2,025 cubic meters in 1990.
“Annual excess abstraction from non-renewable resources has increased from 250 million cubic meters in 1981 to 10 bcm in 2019, up 3,900% over the last four decades,” Isa Kalantari, the former head of the Department of Environment, said.
He added that between 1981 and 1989, the annual over-extraction was around 250 mcm, which then rose by 750 mcm and reached 1 bcm per year between 1990 and 1997.
The trend continued and approached 4 bcm between 1998 and 2005. Over the next eight years (2006-13), the volume doubled and reached 8 bcm per annum.
Excessive Extraction
The figure has continued to rise and close to 1.5 bcm have been added to the excess extraction in the last six years and now is close to 10 bcm annually.
Research shows that over the last two decades, Iran ranked second in the world (after India) in terms of groundwater depletion, constituting 15% of global groundwater depletion for irrigation.
Demand for groundwater in Iran is dominated by agriculture, which gobbles up at least 90% of the country’s water, 52% of which are currently supplied from groundwater resources.
Regarding the amount of fossil water in the country, not more than 35 bcm of water should be extracted per year but unfortunately, “extraction has reached 51 bcm per year”, Kalantari said.
Located in one of the most arid regions in the world, Iran has an annual average precipitation rate of 252 millimeters, approximately one-third of the global average. Exacerbating the severity of water shortages, as much as 70% of precipitation are lost to evaporation.
The rapid depletion of aquifers is also a growing concern. It not only questions the government's myopic attitude toward environmental problems, but also prompts worries at national and local levels about different aspects of excessive groundwater exploitation and related social implications.
Iran has historically relied on groundwater resources for development purposes, but in recent decades it has experienced a progressive decline in water levels of aquifers.
Groundwater policies and measures to control over-extraction have largely failed to restore the groundwater balance.
This indicates that Iran’s current groundwater problems, including dwindling groundwater levels and land subsidence caused by over-extraction, will intensify as authorities have not taken the alarming situation seriously.
Inflow Into Dams
According to Firouz Qasemzadeh, the head of Data and Information Department at Iran Water Resources Management Company, water inflow into dams across Iran from the beginning of the current water year, [Sept. 22, 2021] until Jan. 15, 2022, has been as low as 5 billion cubic meters.
“The figure is 40% of the 9 bcm inflow recorded in the same period of last water year,” he added.
The official noted that currently, dams in the country hold 19 billion cubic meters of water while the figure was 27 bcm last year, showing a 30% decline year-on-year, adding that the total capacity of dams in Iran is 50 bcm and they are now less than 50% full.
Referring to the volume of water stored in some important dams, Qasemzadeh said Zayandehroud Dam in Isfahan Province, Shamil Dam in Hormozgan Province, Sefidroud Dam in Gilan Province and Kosar Dam in Kohgilouyeh-Boyerahmad Province are 13%, 15%, 25% and 77% full respectively.
Dams in Tehran Province (Taleqan, Latyan, Mamlou, Amir Kabir and Lar) and in Khuzestan Province (Karkheh and Dez) are 18% and 55% full respectively.
Northern provinces had the highest volume of rainfall during the period, with Gilan, Mazandaran and Golestan receiving 255 mm, 246 mm and 150 mm of precipitation, respectively, Mehr News Agency reported.
This is while central and southern provinces recorded very low rainfall, such that Semnan with 6.5 mm and Khorasan Razavi with 10 mm registered the lowest volume of precipitation.