Subjectivist wrote:It amazes me how incompetent members here believe engineers in China are.
In objective terms any large hydro dam project has a ton of studies that deal with flood control. As for the fact that releasing water faster flood land downstream well yeah, what did you think would be the result? The point is a low energy flood is survivable while allowing a dam failure to avoid low scale flooding would be catastrophic.
The Three Gorges Dam is not just a water retention dam, it is one of the largest hydroelectric generation projects on the planet. Losing the dam would force China to restart dozens of coal power plants to make up the loss in generation. Building flood diversion system into any large dam is a standard procedure. In addition to the generator sets every big dam has 'flood gates' that divert flow when the pool gets too full.
Also Three Gorges is a gravity dam, which means even if it does get overtopped the main lump of the structure will still be in the canyon where it was poured and will prevent the pool from draining more than part way to the historic river level before the dam way built.
As is shown here the reservoir has been maxed out before with the gate system keeping things under control.
Outcast_Searcher wrote:In objective terms any large hydro dam project has a ton of studies that deal with flood control.
Outcast_Searcher wrote:
.... allowing a dam failure to avoid low scale flooding would be catastrophic.
Three Gorges Dam waters drop from peak, but flood risk persists
CHONGQING -- The water level at China's Three Gorges Dam has dropped from its record peak over the weekend, although the risk of flooding lingers as heavy rains continue.
The water receded to 165 meters Monday after reaching 167.65 meters Saturday, the highest since the hydroelectric dam opened in 2003, Xinhua News Agency reported.
But the water line remains far above the 145-meter limit set to control flooding during the summer and fall rainy season.
Authorities remain vigilant as heavy rains are expected to persist upstream on the Yangtze River through Wednesday. Floodwaters have inundated parts of Sichuan Province, the metropolis of Chongqing and other areas upstream from the dam.
The floods have affected almost 4 million people and caused nearly 20 billion yuan ($2.89 billion) in direct damage, with crops and commercial buildings among the hardest hit.
Water levels have fallen in upstream cities, and floodwaters continue to recede from roads and other affected areas. In Chongqing, a commercial development that was flooded has partially reopened, according to local media.
Alfred Tennyson wrote:We are not now that strength which in old days
Moved earth and heaven, that which we are, we are;
One equal temper of heroic hearts,
Made weak by time and fate, but strong in will
To strive, to seek, to find, and not to yield.
Plantagenet wrote:
China is by no means immune from dam failures and similar catastrophes..... One of the worse dam failure floods in history occurred in 1975 when the Banqiao dam in China collapsed, causing as many as 240,000 casualties downstream.
Banqiao_Dam_failure
dissident wrote:The current hysteria about this dam is politically motivated BS. But what happens in the long term is another issue. A 10,000 year flood is not such a safe outlier in the era of global warming. Much like those "unlikely" floods on the Mississippi. So any real risk from this dam comes down to what the engineers estimated for the catchment water loading. Current engineering estimates are likely to be inadequate for situations arising even before 2060.
yellowcanoe wrote: I highly doubt the sluice gates on the Three Gorges dam were operating at full capacity since the dam was built to handle a 10,000 year flood.
jedrider wrote:I suspect that the Chinese engineers used historical data to figure out how to control flooding.
Outcast_Searcher wrote:jedrider wrote:I suspect that the Chinese engineers used historical data to figure out how to control flooding.
It's fairly safe to bet that when the Three Gorges Dam was designed and started, the Chinese engineers didn't BEGIN to know what we know today about global warming (just like 99.9% of the rest of the world). It's also highly likely that those engineers don't manage day to day (or season to season) decisions on flood management.
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