The story of the sinking capitals

Nik Kowsar: Old Persia was once the land of hydrogeologists who were able to drain a limited amount of groundwater without depleting the aquifers. Many consider the Persian civilization, the Kariz Civilization. Qanator Kariz is a system for transferring water from an aquifer to the surface through a gently sloped tunnel. Qanat is known to be one of the most sustainable means of transporting water in arid zones, as it limits evaporation.

After World War II and the commencement of Truman’s Point 4 Plan, many Iranians were introduced to deep well drilling machines and powerful diesel and electric water pumps. In 1963, the late Shah’s land reforms gave many peasants a chance to own land, and through the loans provided by the banks, these new landowners were able to dig wells and purchase water pumps. “The access to various types of water pumps has enabled the farmers to extract groundwater individually. Having access to the pumps, each farmer extracts as much water as he wishes” (Seyed Akbar Mirikhoozani, 1993). Lack of supervision and failure to enforce laws and regulations gradually dried up aquifers in several farming regions. Before the 1979 Islamic Revolution, there were almost 80,000wells dug, mostly in farmlands and near cities. Aquifers have been the main source of water for farming, industry, and towns. Though the Shah was enamored with building mega-dams after admiring the Hoover Dam and the Tennessee Valley Authority’s achievements, he was also curious about Israeli technologies used to save as much water as possible and avoid wasteful policies and plans. Obtaining digging permits was getting harder for farmers and many Qanats were still active and providing water for everyone. After 1979 and the rule of the Islamists, Ayatollah Khomeini and his pupils encouraged farmers to produce grains without any regard for the water consumed in the process. Many farmers dug wells and exploited the groundwater resources beyond the equilibrium yield of the aquifer.(film)

Before the mid-1980s, there was a balance between drafting and recharge in many plains of the country but since then, over-drafting has killed numerous aquifers and many farmlands and adjacent cities are subsiding. In spring 2001, I wrote two op-eds criticizing the government for their water policies and for building too many dams without understanding the consequences. The president summoned me to his office three days after his re-election to provide me the opportunity to explain my points. I told him that his administration’s concerted efforts toward dam building and water transfer blatantly disrespected Iran’s aquifers and ignored the warning signs that will have a very negative impact on the country in the next few decades. Rather than listen to my points, the only thing his government took seriously from my talking points was censoring me.* Isfahan: A city and its heritage are sinking In 1998, a major and long-lasting drought started and because of overconsumption and also decreasing rain and snow, rivers such as Zayandeh-Rud shrunk. Zayandeh Rud, which originates from Zard Kuh (Yellow mountain) in the Zagros mountain range, is the most important and strategic river in the central Iranian plateau (Gohari et al, 2013). People settled near this river and the city of Isfahan was born thousands of years ago during the Bronze age because of its proximity to the Zayanedh Rud. In the past, the usual flow was over 1.4 billion cubic meters (BCM), and out of that 1.4 million cubic meters (MCUM), 650 MCUM was from tributaries and groundwater and the rest was and has been transferred from the Karun basin. The Zayandeh Rud river ends in the Gav Khuni marshes.

There are some facts to consider: - During the last 2 decades, we have faced both a decrease in rainfall and a decrease in snowfall. - The average inflow of water to Zayandeh-Rud Dam has decreased by 25% in the last 12 years. Zayandeh Rud has had an average of about 1.100 billion cubic meters of water in the last 10 years.

- In the last 50 years, the area under cultivation in the Zayandeh-Rud catchment has tripled in size, from 66,000 hectares to 208,000 hectares. - Consumption of drinking water and sanitation has increased from 60 MCUM to 400 million cubic meters (including Isfahan and other cities and townships including Yazd and Kashan). - Industries draw about 70 MCUM of water from the river and use the rest from wastewater treatment.

- The defined consumption for the Zayandeh River is about 1.5 BCM, while the river has an average of only 1.100 BCM of water.

Isfahan, once the capital of Persia, is now a sinking city. This jewel of central Iran has experienced many droughts through history, but its water managers prior to the last century used its resources wisely and sustainably through the ages to save it for the very generations that are witnessing its destruction. After World War II, the government’s water managers decided to transfer water from one of the Karun river basin’s tributaries, the Kuhrang river, to Zayandeh Rud, and later in the 1960s, built a major dam to store water and regulate the river. This excessive amount of water was seen as a sign of wealth at the time. The area primarily used for agriculture in the Zayandeh Rud basin expanded, resulting in many farmers beginning to cultivate rice and wheat. The government inaugurated Iran’s first steel plant in the arid central Iranian plateau, only relying on the flow of Zayandeh Rud that was receiving a constant doping shot from Karun. After the 1979 Islamic Revolution, a second steel plant that was initially supposed to be built near the Persian Gulf was established near Isfahan, stealing more water from the basin. After the drought struck in the late 1990s, farmers who did not want to change the routine began digging more wells and extracting greater amounts of water, creating an imbalance between the aquifer and the river and resulting in signs of land subsidence.

Farmers in Isfahan have withdrawn almost half of the initial 7 BCM of water from the aquifer through 3,600 active wells in the town itself and 5,421 wells in the Isfahan-Borkhar plain. It is believed that under today’s regime of over-extraction, the aquifer will die in 9-15 years.

Reza Eslami, the head of Iran’s Geologic Survey in the Isfahan province says that the continuation of this situation and the exploitation of groundwater will damage more than 6,000 historical structures, including old mosques and bridges in the city of Isfahan. In the last decade, residents of several housing projects and new towns have been forced to leave their homes, due to safety concerns after major cracks appeared in the buildings and the land subsided beneath them. Many fissures have appeared around the city and even reached the tarmac of the airport.(photo-film)

The North-South railway crosses over some of these fissures and experts have warned the local and national officials of the risks. The bedrock beneath the Isfahan aquifer is not very deep. Subsidence varies from a few millimeters near the mountains to 18 centimeters per year in the middle of the Isfahan-Borkhar plain. If at one time the limited rain and Zayandeh Rud could make up for the aquifer’s shortcomings, the drying of the river for most of the year would not give any hope of feeding the dying aquifer.

Tehran is sinking

In 2019, Mahdi Motagh and Mahmud Haghshenas published a paper indicating that using Interferometric Synthetic Aperture Radar (InSAR) time series analysis of Tehran using different SAR data between 2003 and 2017 there were three distinct subsidence features in Tehran with rates exceeding 25 centimeters per year (cm/yr) in the western Tehran Plain, approximately 5 cm/yr in the immediate vicinity of Tehran International Airport, and 22 cm/yr in the Varamin Plain to the southeast of Tehran. Tehran is a megacity located south of the Tochal mountains with inadequate infrastructure built over a major alluvial fan. For thousands of years, smaller towns and villages, including Rey, relied on a number of streams and Qanats. When the Qajar dynasty chose this part of the country as the capital in the 1800s, many moved to the new center of the Persian civilization.

The radical development of the city started after the downfall of the Qajars, and the new king had high hopes to turn Tehran into a modern capital. Between the 1960s and 1980s, various land developers and housebuilders began building settlements and suburbs without considering the soil resistance of alluvial fans and qanats. After the Iran-Iraq war, many skyscrapers appeared all around the city, after warnings made to the municipal government by a few people regarding the city’s vulnerability to major faults. Seismologists are now awaiting the return of a large earthquake, and according to estimates, the death toll from this earthquake may exceed 100,000 people.

Although civil engineers were concerned about the buildings' resistance to sudden shocks of earthquakes, they paid no attention to land subsidence, which has now turned into a silent earthquake. Cracks have appeared in many townhouses and condominiums in southern parts of Iran as well as the suburbs of Tehran, and sinkholes have emerged in various parts of the country. Parts of Tehran are sinking with a record of 25 cm/yr, close to what we have seen in Corcoran, California. To add insult to injury, cracked buildings and weakened structures caused by subsidence will have very little resistance to the large-scale earthquake that awaits them, and this will significantly increase Tehran's risk of destruction.

Gary Sick, one of the members of the national security council under Presidents Ford, Carter, and Reagan and an expert on Iran’s politics, once told me that the effect of a major earthquake is beyond a coup d'état against the Islamic Republic. I believe his statement to be true, especially because the regime has not treated water, the planet’s most precious gift, with care.

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