There are 58,000 unauthorized wells in the central plateau of Iran, from which 1.8 billion cubic meters of water are extracted annually, which is a significant figure considering the low rainfall and severe water shortage in the region, said the deputy for protection and social affairs of the central and eastern plateau watershed at Iran Water Resource Management.
Referring to land subsidence as one of the harmful consequences of excessive and illegal water extraction, Abdollah Fazeli Farsani said land subsidence has now affected most of the country's plains and is also damaging the infrastructure in some regions, IRNA reported.
The official pointed to Isfahan Province, located in central Iran, where the sharp decline in underground water resources and land subsidence have become a serious threat to historical structures and cultural heritage.
Land subsidence is defined as a gradual or sudden sinking of the earth's surface owing to subsurface movement of earth materials.
Although reversing land subsidence is almost impossible, slowing its progress is doable and a number of measures have been taken in this regard in the past few years, but their progress is very slow.
Close to 2.5 million residents of Isfahan Province are being unsettled by the gradual or sudden sinking of the ground.
Rapidly declining water resources have compelled water officials in the arid province to increase the number of plains from which water withdrawal is banned to 30. There are totally 35 plains in the region.
Plains in Borkhar and Mahyar counties, which extend over 4,000 square kilometers, are in imminent danger, as all aquifers in the areas have already been emptied.
Based on estimates by organizations like the International Association of Hydrological Sciences, if a piece of land sinks 4 millimeters a year, it is in critical conditions and the residents of the region are in danger.
The land is sinking by about 40 centimeters in Borkhar and Mahyar plains annually, which is 100 times higher than the global standards.
The problem has evolved over a long time and cannot be addressed overnight, but short-term measures are expected to help improve present conditions and prevent the expansion of land subsidence.
Disorganized urbanization, old and obsolete farming practices and the presence of water-intensive industries are adding pressure on Isfahan’s rapidly dwindling water reserves.
Unauthorized Wells
There are 338,000 unauthorized wells in the country and the total annual water extraction from these wells is about 6.5 billion cubic meters, which is more than three times the current volume of Urmia Lake, Farsani said.
Over 7,000 unauthorized wells have been sealed since 2005, which helped save 215 million cubic meters of water a year in the dry central region. The drop in groundwater levels is estimated to average 1-1.5 meters a year, but the annual subsidence rate in some plains of Isfahan ranges from 20-40 cm.
In Iran, the population has more than doubled in the past 50 years, while groundwater pumping remains unregulated. The country’s cities are now among the fastest-sinking urban centers in the world, plummeting by up to 25 cm each year.
Isfahan Province has been suffering from drought for years. It is facing more serious problems this year due to the decline in last year’s precipitation that has resulted in a further reduction of surface water and groundwater.
A recent report by the Iran Meteorological Organization said 80% of the region are affected by drought and the situation will get worse before it gets better.
In the not-too-distant past, the Zayandehroud river had regular and significant water flow, but is almost dry for more than eight months to the detriment of farmers largely dependent on the river for their livelihood.
Once the pride of the region, Zayandehroud originates in the mountains of Chaharmahal-Bakhtiari Province and flows eastward toward Isfahan before ending up in the famous Gavkhouni Wetland.
