Plans to build large dams have been removed from the Energy Ministry agenda, the head of Iran Water and Power Resources Development Company said.
"Except for pump-back hydroelectric and cascade dams, no new dam projects have been undertaken over the past seven years and there are no plans to this effect in the foreseeable future as there is no water or rainfall to store," Behrouz Moradi was quoted as saying by ILNA.
Pump-back hydroelectric dams, like Siah Bisheh in Mazandaran Province and Seimareh in Ilam Province, do not need much water. Moreover, no water is wasted as it always circulates between two reservoirs. Japan and the US produce 30,000 megawatts and 25,000 MW via this system respectively.
A flexible, dynamic, efficient and green way to store and deliver large quantities of electricity, pumped-storage hydro plants store and generate energy by moving water between two reservoirs at different elevations. During times of low electricity demand, such as at night or weekends, excess energy is used to pump water to an upper reservoir. The turbine acts as a pump, moving water back uphill. During periods of high electricity demand, the stored water is released through turbines.
Referring to the Gotvand and Karun II dams in Khuzestan Province, he said they are cascade dams, which means unlike other dams in which water collects behind the dam, the cascade types just channel the water. Moreover, they can help generate a large amount of power compared to other kinds of dams namely embankment or arch dams.
"The capacity of hydroelectricity plants was 9,300 MW in 2016 when water behind dams amounted to 4 billion cubic meters," he said, adding that the installed capacity decreased to 4.5 gigawatts in 2017 when the volume of water declined to 2.3 bcm.
The water official said large dams can wipe out species, flood huge areas of wetlands, forests and farmlands and displace large numbers of people.
Persistent Decline
Iran has 172 dams but due to years of drought and steep decline in rainfall, the water now in dams is estimated at around 19.8 billion cubic meters or 40% of overall capacity and 19% less than last year.
Precipitation in the last water year (Sept. 23, 2017-Sept. 22, 2018) decreased by 21% compared to a year before and as a result the volume of water inflow into dams fell by 31%.
Iran is facing the worst drought in half a century and large parts of the country will soon face severe water deficits as the water crisis worsens.
Expansion of industries, population growth, mismanagement, waste…have far outpaced the amount of rainfall and the development of water technologies, leading to desiccation of wetlands and rivers.
Established in 1989, the IWPCO's main responsibility is to actualize a considerable part of the hydropower potential and develop facilities for preserving and transferring water.
