One and a Half Meters Decrease in Groundwater Levels in Tehran

An official from the Water Organization in Tehran province has stated that the level of groundwater resources in the province has decreased by one and a half meters due to excessive exploitation over the past year. In an interview with Mohammad Reza Fatemi, a water resources expert and faculty member in Tehran, we first asked him about the subsidence of Tehran's plains: Mohammad Reza Fatemi: The city of Tehran is located on a slope, in a cone of the Alborz mountains that leads towards the plain, ultimately reaching the Varamin plain where the elevation decreases and the land becomes flat. Most of the water that enters the city of Tehran and its groundwater resources extends towards the plain, where we have resources and wells that are being exploited. It can be said that over the past twenty years, especially in Tehran, groundwater has been used for green spaces in residential areas, large complexes, and also in southern Tehran for agriculture. A one and a half meter decrease in water has occurred just this year. This decrease has started several years ago, and it can be said that groundwater levels have decreased by about 20 to 30 meters. The groundwater level is decreasing at an annual rate of half to one meter. Rainfall has decreased somewhat in recent years, and the recharge of groundwater from the heights of Tehran and the mountains has diminished, and for this reason, the amount of extraction has decreased compared to the replacement, leading to a decline in groundwater. You think if this trend of consumption and lack of rainfall continues in Tehran province, how many more years will the groundwater resources last? With this trend, I can say that in 30 to 50 years, the water level will be below 100 meters, and its quality will also significantly decrease. The second point is that a portion of Tehran's drinking water is currently supplied from these aquifers. We also have six dams around Tehran that supply drinking water. If consumption is managed, we can reverse this trend indefinitely and establish a balance between consumption and production so that water remains sustainable. In the current situation, I can say that in 30 to 50 years, we should no longer rely on groundwater. Moreover, as the amount of water decreases, its purification decreases, and its pollution will increase to such an extent that it will no longer be usable for drinking or agriculture. Mr. Nozari-Pour in the Ministry of Energy also mentioned attracting foreign investments regarding the sale of treated wastewater. What impact can this treated wastewater have on the subsidence of the plains? As I mentioned, the water of Tehran, specifically southern Tehran, namely the Varamin plain and adjacent plains, is currently used for agriculture. Secondly, the sewage of Tehran is treated in several treatment plants, such as the southern treatment plant, and its output is used for two purposes. One is for recharging groundwater, which undergoes initial purification, and a significant amount of its pollutants is removed, resulting in relatively clean water being returned to the ground, which is important. The second is the water that directly goes to agriculture from this treatment plant. This work is currently being done and does not require attracting foreign investors. Perhaps for development projects that want to establish treatment plants like the western treatment plant... the municipality is currently constructing the western treatment plant in Tehran to supply sewage or treated wastewater for agricultural irrigation. They may be able to significantly reduce extraction from groundwater in this way. It can be said that 30 to 40 percent can be saved, and this alone will delay the decline of groundwater levels.