(Yicai Global) Aug. 19 -- The Three Gorges Reservoir will release the largest flood since its construction in the next few days to discharge pent up heavy rainfall in the Yangtze River’s upper reaches, the Ministry of Water Resources advised today.

The flood’s peak flow into the Three Gorges Reservoir will be about 74,000 cubic meters per second between Aug. 19 and Aug. 20 in the largest flood in the Yangtze River basin since 1981, the ministry said in the flood forecast on its website.

Torrential rains have swollen 51 Yangtze tributaries above warning levels, with 29 topping guaranteed water heights and nine hitting records, the ministry added.

The Cuntan Hydrological Station near Chongqing on the upper stretches of the reservoir will see a peak water level of about 189.3 meters around this evening, about 5.8 meters above the guaranteed water level, and a peak flow of 74,000 cubic meters per second, despite the full impoundment of upstream reservoirs, the ministry projected.

Inflow into the Three Gorges lake will top 50,000 cubic meters per second for five days, it added.

The ministry has arranged for upstream reservoirs to take in 3.5 billion cubic meters and, from Aug. 17, has gradually expanded the Three Gorges Reservoir’s discharge, which reached 48,000 cubic meters per second yesterday afternoon, to lower the pressure, the ministry said.

The Three Gorges was completed and started to store water in 2006. It is the largest reservoir in China, whose main functions are flood control and power generation. Total installed capacity of the Three Gorges Hydropower Station reached 22.5 million kilowatts in 2012 to make it the world’s largest power station.

Editor: Ben Armour