Dam Spillway Cavitation: What is it?

Cavitation is a danger in all spillways attached to large dams. The Three Gorges Dam, and others along the Yangtze River are the ones in question at the moment. Cavitation occurred at the Glen Canyon Dam in 1983. Repairs were made in time to deal with the snow melt of 1984, at very high cost.

The video documentary above is a record of how it was repaired, with good pictures of what cavitation (the creation of caves) actually looks like: A series of holes inside the spillway tunnel. Holes up to 25 feet wide by 40 feet deep were gouged out of heavy reinforced concrete and further into the earth by powerful flowing water. The Three Gorges Dam has the additional problem of large amounts of debris including cars, landslide rocks and rubble, corpses of humans and animals, and lots of trash, much of it metal.

The question that needs to be asked is, what are these dams really built for? Cynically speaking, it give insiders the opportunity to skim millions, if not billions of dollars in tax funding. This is called a boondoggle.

Is it for flood control? If so, it obviously doesn’t work, and in fact experience shows that dams make the effects of flooding worse, due to holding back the water until the danger of collapse forces the release of that water in dangerous outflows.

Is it for energy production? Hydroelectric works fine where a naturally occurring waterfall exists, but dams create an artificial waterfall at very high cost. It’s our money paying the cost though, so who cares, right?

Between the years 2000 and 2009 more than 200 notable dam failures happened worldwide.

Here are some relatively small dam collapses caught on video:

A U.S. government document on hydropower generation paints a rosy picture:

“At facilities called hydroelectric powerplants, hydropower is generated. Some powerplants are located on rivers, streams, and canals, but for a reliable water supply, dams are needed. Dams store water for later release for such purposes as irrigation, domestic and industrial use, and power generation. The reservoir acts much like a battery, storing water to be released as needed to generate power.”


The reality is very different from what you’ll read in that government pamphlet. Reports by real people are that dams make dry seasons drier and wet seasons wetter. A naturally occurring flood generally gives people time to bring animals and moveables to higher ground. But when flood gates are opened after a long accumulation of water, the result is a powerful flash flood that destroys everything in its path. The government doesn’t always give timely notice in Communist China. Even the dam spillway itself is destroyed in these outflows, as seen in the Glen Canyon video.

The final video above is simple enough for a five year old to understand. It quickly covers a few of the major disasters caused by dams in the last century, all of which were built against the wishes of the people who lived there, all of which resulted in thousands of deaths and much destruction. The money spent on these dams is called “government” money in the video, but of course it’s ours.

A more detailed technical report on the consequences of building dams on the Yangtze River has been available online since October 2, 2010 at https://doi.org/10.1016/j.gloplacha.2010.09.006

The report itself is highly technical and costs money to access, but the abstract is:

“Using 50 years of hydrologic and bathymetric data, we show that construction of ~ 50,000 dams throughout the Yangtze River watershed, particularly the 2003 closing of the Three Gorges Dam (TGD), has resulted in downstream channel erosion and coarsening of bottom sediment, and erosion of the Yangtze’s subaqueous delta.”

I’ve learned a great deal about Chinese cities along the Yangtze River while watching flood videos. Except for the historic areas, those cities look hideous to me. These are planned cities built over the past twenty years, to hold millions of workers in a highly concentrated city.

Besides being poorly constructed due to corruption in the building industry and government, these high rises leave people in a very vulnerable position, in part due to the dependence on elevators which aren’t working in the floods.

Even worse, I remember a couple of months ago that in Wuhan the Communist government welded shut the exits on the first few floors, trapping the people inside.

I’m imagining what those buildings have become by now. Are people dying of starvation inside? Is anyone removing dead bodies or delivering food? What has become of those residents, especially the children. Are the sewer systems working where high rises are flooded up to the third floor? Is there water? Reports on Twitter are that the tap water is poisonous. The electricity is definitely not working in some of those high rises. Imagine climbing 23 flights of stairs carrying groceries, even if you have an exit.

One thing I noticed is that all the flooded cars in China are brand new. Those are the ones on the street, but what we don’t see are the car garages flooded under the buildings.

In America at this point, if we had the same disaster, the flooded cars would mostly be a bunch of junkers way past their useful life. Many Americans have become too poor to even own a car, largely due to China’s Unrestricted Warfare waged upon us during my lifetime.

More than a few times I’ve called God’s curses upon Chinese hackers who have made my life very difficult. Still my heart breaks to see the destruction in that nation, considering that only a few of them are responsible for messing with my equipment, and many more are simply victims of Communism. The harsh reality is that it was going to be us or them, and God mandates the outcome.

www. climatecrocks.com has a good, short report on the Three Gorges Dam:

“In a rare revelation, Beijing has admitted that its 2.4-kilometer Three Gorges Dam spanning the Yangtze River in Hubei province “deformed slightly” after record flooding.”

The Three Gorges Dam Corporation is the money aspect of this dam.

“Three Gorges Corporation, a state-owned enterprise that manages the dam and the sprawling power plant underneath it…”

It’s the income from the power plants that motivates these dangerous projects.

Chongqing city has been severely flooded most recently. It’s above the Three Gorges Dam.
Only the Three Gorges Dam is marked on this map, but there are many more dams not shown here.

The floods in Chongqing make for increasing inflows higher than outflows at Three Gorges Dam. Rumors are that the deformation of Three Gorges Dam has damaged some spillway gates making it impossible to open them. If true, the result is even faster increase in water levels in the reservoir, causing fear of a collapse of the dam wall. The CCP is censoring images of the spillway, possibly to prevent people from seeing that not all of the spillways are working.

The CCP itself has been reported to suffer from infighting lately, with the military in disagreement with President Xi Jinping’s antagonistic behavior towards all the neighbors. Reports are that military leaders, being painfully aware of their own corruption, don’t want to wage war with the shoddy equipment from which they’ve skimmed so much tax revenue. This infamous skimming of contracts has enriched the Generals but left China practically defenseless in terms of functioning equipment and weapons.

This dam break was filmed in Brazil and posted today:

Please follow my Twitter feed for additional information about China. Latest reports are that people are being forced to take unknown “medicine” three times a day. Because of censorship, the translations from Chinese are difficult. The people have to write in a sort of code language, just like we in America are forced to do. We now can’t even use the letter Q without being censored. Crazy.

This is my latest Twitter handle. I get removed regularly, proud to say.

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