Ecuador Faces Anticipated Dry Season With Strategic Reservoir Below Normal and Colombian Imports Halted

The Mazar reservoir, the backbone of Ecuador’s hydroelectric system, dropped nearly 10 meters in 45 days, from 2,153.32 meters above sea level on July 26 to 2,143.72 meters by September 9, 2026. The decline accelerated sharply in early September, consuming more than 20 million cubic meters of water in just nine days and depleting approximately 20 percent of the reservoir’s 300 million cubic meter useful capacity. Mazar feeds the Paute Integral complex, comprising the Mazar, Paute-Molino, and Sopladora plants with a combined installed capacity of 1,757 MW, which supplies between 30 and 40 percent of national electricity demand. The reservoir’s critical operational threshold sits at 2,115 meters above sea level, below which generation must halt to prevent sediment damage to turbines.

Inflows to Mazar averaged just 54.4 cubic meters per second in the first eight days of September, falling as low as 43.94 cubic meters per second on September 9, well below the historical monthly average range of 75 to 106.3 cubic meters per second. The Ministry of Environment and Energy confirmed the dry season began in September 2026, one month ahead of the typical October start, and will extend through March 2027. August 2026 electricity consumption averaged 4,430 MW per hour daily, approximately 500 MW above the 3,945 MW projected by national grid operator Cenace, with September demand reaching 4,500 MW per hour.

Colombia activated its supply risk period on August 27, 2026, through Resolution 101-127, prioritizing domestic demand and restricting electricity exports. Colombian imports to Ecuador, which averaged 281.1 MW daily between September 1 and 6, collapsed to an average of 2 MW on September 9 as pricing surged from a range of $0.25 to $0.39 per kilowatt-hour in August to peaks of $0.88 per kilowatt-hour after the risk declaration took effect. Colombia’s own reservoirs stood at 78 to 79 percent of capacity, short of the 80 percent target needed before its own dry season begins in December. The interruption in Colombian supply transfers pressure directly onto Mazar at the onset of Ecuador’s most vulnerable period.

The government initially projected incorporation of 920 MW of new thermal generation during 2026, comprising 525 MW of leased capacity and 395 MW of purchased assets. The Vice Ministry of Electricity acknowledged in August that only 50 MW of leased generation would materialize in 2026. Large industrial consumers and commercial centers in Quito received direct requests to activate private generators voluntarily, three months before mandatory self-generation rules take effect, signaling immediate system stress despite official assurances that the 2024 rationing scenario, which saw outages of up to 14 hours daily for three months, will not recur.