Water Levels Near Record at Three Gorges Dam in China

How will the world’s largest dam hold up in the face of torrential floods? The Three Gorges Dam is put to the test. From the New York Times:

Surging waters in the Yangtze River tested the strength of the Three Gorges Dam early Tuesday, as some of the fastest flowing floodwaters in more than a decade slammed against the world’s largest hydroelectric project, according to official Chinese news reports.

The volume of water at Three Gorges reached nearly 70,000 cubic meters per second on Tuesday morning, 20,000 more than during floods in 1998 that killed 4,150 people. The authorities have been scrambling to evacuate towns and villages along the path of the flood. For days, residents have been trodding along muddy roads in the region, abandoning their homes with little more than spare clothing stuffed into plastic bags. Emergency workers have been piling sandbags along the banks of the Yangtze and draining reservoirs.

The river has been swollen by a week of heavy rains that swept through southwest China, following months of record drought in the region.

More on the dam’s capacity and the floods’ impact, from Wall Street Journal:

Wang Jingquan, a drought and flood prevention official at the water-resources committee, said the Three Gorges Dam was designed to withstand up to 110,000 cubic meters of water a second. He added that reservoir levels are below the maximum capacity of 175 meters high and that the dam’s electricity turbines haven’t been operating at full capacity because the area had been suffering from drought.

At least 146 people have been confirmed dead and some 40 are missing since the start of July after landslides and flooding in storm-hit regions across China. Many victims are from the hilly terrain around Chongqing, the city located upstream on the western end of the 640-kilometer-long reservoir created by the Three Gorges Dam. All told, some 124,000 homes have been destroyed, and more than 1.3 million people have been forced to relocate nationwide, officials said. Economic losses are estimated at 29.5 billion yuan, or $4.4 billion.

Shipping along one of the most important inland waterways—essential for ferrying raw materials and goods into central and western China—could be disrupted by the floods. Shipping authorities said over the weekend they could close locks on the dam if water speeds exceed 45,000 cubic meters a second.

July 20, 2010 7:13 PM
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