Heavy rains from the beginning of the current water year in September have significantly boosted water levels in hydroelectric dams.
Dams across Iran can hold a maximum of 50 billion cubic meters of water and now 70% of them are full, IRNA reported. The rise has helped increase hydropower output by 218% compared to last year.
Hydropower stations generated close to 26,103 gigawatt hours of electricity between March and November (2019), while the figure in the same period in 2018 was 8,198 GW hours.
Of the total production (26,103 GW hours), about 1.022 GW hours was generated between November 22 and Dec. 21.
Hydroelectric plants have an installed capacity of 12,169 MW, but they usually produce less if water levels in dams fall.
Hydropower plants play a key role during power outages because they quickly reestablish supply after a blackout and support other plants (mostly thermal).
Hydropower is a renewable energy and its production is cleaner compared to other sources and constitutes approximately 12,000 MW of Iran’s total installed power generation capacity of 77,000 MW.
Regarding hydroelectric power, Iran is ranked 19th in the world and 6th in Asia. China is first in Asia and the world with 341,000 MW.
According to Energy Ministry data, there are 55 hydroelectric power stations in Iran (mostly in the Persian Gulf coastal regions) generating at least 30,000 GW hours annually.
Of the total 55 plants, 16 are located in the northern Caspian Sea catchment area, 25 in the Persian Gulf, 13 in in the Central Plateau and one in Lake Urumia’s catchment area.
Based on ministry data, 17 hydropower plants are under construction, which (when operational) will add 3,500 MW to installed capacity.
Groundwater Deficit
Despite the fact that good rains have helped increase water levels in dams and output from hydroelectric plants, the deficit in groundwater reserves has not been compensated, managing director of the office for conservation and exploitation of groundwater resources said.
“The deficit in groundwater reservoirs -- a critical resource -- has reached more than 130 billion cubic meters,” Mohammad Ali Mostafavi said.
The deficit in groundwater reservoirs has exceeded the tolerance threshold of aquifers, he added.
According to reports, every year 50 billion cubic meters of water is extracted from groundwater sources. Almost 60% of water for households and industries and 50% for farming comes from groundwater.
Surveys and studies in the plains show that the negative trend is rising across the board. The steep decline in groundwater levels is having devastating effects.
Excessive pumping harms groundwater tables and stops wells from reaching the groundwater. When groundwater is overused, lakes, streams and rivers connected to groundwater also start diminishing.
Groundwater overdraft may also lead to land subsidence as it occurs when there is loss of support below the ground. Destruction of vegetation, increasing dust storms, holes in the plains and higher salt content in groundwater are the other consequences.
