Mass emigration, low precipitation and illegal water withdrawal from depleting underground water resources have contributed dangerously to water shortages in Alborz Province, head of the provincial water company said.
“Not long ago (1990s) underground water was available at the depth of 15 meters. Now wells have to be dug at least 300 meters to reach water,” Davoud Najafian was quoted as saying IRNA.
The pattern of relocation to the province (population 3 million and counting) from many dry regions has dramatically increased water demand.
It also has created new challenges for utilities and urban managers struggling to handle the influx.
An estimated 941 million cubic meters of water is consumed here annually, of which 60 mcm is provided by rivers and the balance comes from underground resources and wells.
Najafian added that households, industries and the agro sector on average use about 277 mcm, 40 mcm and 624 mcm of water every year, respectively.
Iran's annual water consumption is near 100 billion cubic meters.
Alborz Province, 50km northwest of Tehran, covers an area of 5,800 square km, of which 700 sq km is farmland. It has more than 3,500 industrial units most of which produce water-intensive products like food and textile.
The textile industry is dependent on water in almost all steps of manufacturing. Dyes, specialty chemicals, and finishing chemicals used to produce clothing are all applied to fabrics in water baths.
“Most industrial towns are tapping into the dwindling underground water tables, as a result of which aquifer levels drop 90 centimeters a year.”
Referring to the other ills, he said there are 11,000 unauthorized wells in the area through which 90 mcm of water is extracted per annum.
According to provincial authorities, the region’s groundwater balance is negative – this means the rate of water withdrawal is over and above recharge.
Prolonged drought and rising temperatures in Iran plus the plight of global warming, have led to a decline in replenishing groundwater resources.
The depleting pattern has had a negative impact on the plains causing ground subsidence in some regions and exposing many others to land subsidence.
“Despite the good rainfall (480 millimeters) since the beginning of the current water year (Sept 2019), aquifers are drying up at alarming rates,” the water official warned.
Long-term precipitation in the province has declined by a massive 32%, plunging from 400 milliliters in 1960s to 270 mm at present.
Efficient Management
Techniques such as aquifer management and watershed management have proven, he noted, to be effective in alleviating the water crisis.
“Watershed and aquifer management projects worth $4 million have been carried out in Alborz Province over the last two years.”
These projects plus artificial recharge of aquifers (with floodwaters from Kordan River) have helped add 85 mcm to underground water tables in Fardis, Svojbolagh and Karaj counties in the last two years.
Watershed management is a term used to describe the process of implementing land use practices and water management practices to protect and improve the quality of the water and other natural resources within a watershed.
It seeks to sustain and enhance functions that affect the plant, animal, and human communities within the watershed boundary.
Precipitation in Iran's six main catchment areas has decreased by 6% since September. According to a recent report by the Iran Water Management Company, 301 millimeters of rain fell over the last 250 days, down 6% compared to the same period in 2018.
Iran is divided into six primary and 31 secondary catchment areas. The Persian Gulf and Sea of Oman basin in the south have had the highest rainfall at 440 mm so far, but still 14% lower than the year.
The Caspian Sea in the north received 410 mm of rainfall in the period (250 days). Urmia Lake in the northwest with 336 mm experienced a 27% decline in the period compared to 2018. Karakum basin in the northeast had 274 mm of rain, down 27% compared to the previous year.
Two basins received more rain. Over 225 mm of rainfall was registered in the Central Plateau in Markazi Province, 8% higher compared to last year. The least amount of rain fell in the Hamoun Wetlands in the east reaching 146 mm, but was up 46% compared to 2018.
