“Water stored in five dams near the sprawling capital was 962 mcm last September. Now it has declined by 10% or 865 mcm,” IRNA quoted Mohammad Shahriari as saying.
Giving some numbers on water behind each dam, he said Taleqan, Latyan, Mamlou, Amirkabir and Lar dams hold 318 mcm, 68 mcm, 195 mcm, 149 mcm and 135 mcm, respectively.
Inflow of water shows a 15% decrease year-on-year, he warned.
An estimated 2.2 billion cubic meters of water flowed into the five dams since September 2019. In 2019 the volume was 2.6 bcm.
Since the start of the water year, average rainfall in the province has reached 462 millimeters – up 20% compared to the corresponding period last year.
Despite the average rise, water in dams is plummeting as the coronavirus spreads forcing households to consume more water for improving hygiene.
Following outbreak of Covid-19 and the need to observe personal hygiene safety measures, water consumption has soared because of regular washing of hands and cleaning possessions and the environment. The pattern is universal and is causing anxiety among water managers.
Unprecedented Consumption
“Daily water consumption in Tehran surpassed 3.6 million cubic meters in August that was unprecedented in the history of the mega city.” Consumption has risen by a massive 20%, or 600,000 cubic meters, per day since March when it was 3 mcm/d.
Shahriari said the weatherman has forecast below normal precipitation in autumn and because 30% of the water in Tehran is extracted from underground resources, not using water intelligently will profoundly affect the supply chain. Moreover, it will exacerbate land subsidence in the plains.
The earth sinks in some plains in Tehran Province by about 0.5 millimeter every day, and conditions are grave in Shahriar and Varamin counties in southwest and south Tehran, he said.
“An annual 310 mm of land subsidence is reported in Tehran Province. Over 1.5 bcm of water is extracted from the ground in the capital every year,” he warned.
In related news, IRNA quoted Mohammadreza Bakhtiari, managing director of Tehran Province Water and Wastewater Company, as saying that 3.8 mcm of water can be transferred from dams around the city to water treatment facilities on a daily basis.
“All water treatment plants are operating at full capacity.”
Bakhtiari said there is no way pathogen (coronavirus or any other virus) that can contaminate the water supply and distribution chain as chlorine levels (at least 4 milligrams per liter) are high enough to destroy the viruses.
“Covid-19 virus has not been and will never be detected in drinking water” as current drinking water disinfection practices provide the means to control most pathogenic bacteria and viruses contributing to for waterborne diseases, he said.
According Energy Ministry data, the average Iranian uses 250 liters of water a day, while per capita water consumption in metropolises such as Tehran may exceed 300 liters.
Tehran accounts for less than 1.1% of the country’s land area, but accounts for 20% of the population and 45% of the industrial base. This means high and rising water consumption and that regular appeals for judicious consumption has fallen on deaf ears.
In the past 24 hours, at least 2,000 were diagnosed with the deadly infection, taking the country’s caseload to 400,000. Overnight deaths stood at 128 on Sunday, pushing the national toll to pass the 23,000 mark.