Apparently the Grand Canyon has been flooded.
I’m unclear on the definition of “flooded.” Does that mean that there is, in fact, no longer (however temporarily) a Grand Canyon and instead a giant lake? Or does that mean that the Colorado river is a few inches (feet, yards, whatever) higher than it normally is in the GC?
Can someone please link some pictures of the pre-flood and post-flood Grand Canyon so I can get some sort of a visual on what’s happening?
I think “flooded” in this situation is meant to infer that temporary flood conditions, normally absent due to the presence of the dam, have been artificially recreated by opening the lower gates and allowing much of the sediment that’s fallen out of suspension to be released, along with a mechanism to redistribute them downstream in a fashion similar to historic, pre-dam days.
I’m not sure to what degree this would elevate the water level in the canyon (appreciable, I’m sure) but being a free flowing river no lake is going to have been created.
While this may seem like a lot of water, that’s not going to be nearly enough to fill the Grand Canyon. Add to the fact that it is a continuous flow–everything that flows in will flow out the other side–and you can confidently infer that the “flooding” refers to the Colorado River’s water level and not to the canyon itself being completely flooded.
The volume of the Grand canyon is 52 billion cubic yards.
The volume of lake Powell is 23 million acre feet.
23 million acre feet equals 43.56 billion cubic yards, so there’s not enough water in lake Powell to completely flood the Grand canyon.
The radio said this morning that some areas downstream of the dam can expect to see water levels five to ten feet higher than usual, for a couple days.
When I’ve seen the Grand Canyon in person, flying overhead, or on TV, there is usually some pretty wide dry banks on either side of the river flowing through the canyon (though, I imagine there might be parts with no dry bank in particularly narrow areas). When I hear that the canyon is flooded, I presume that they mean that the dry banks are flooded (underwater by a few inches to a few feet), not that the whole canyon is flooded.
Peace.
PBS recently ran this show, NATURE: The Colorado River.
During that program they told how the damming of the river had damaged the rivers ability to form sand bars, shoals, etc. These are important to animals, fish and plants. The program mentioned that “flooding” had been tried, but that the sand bars, etc. formed, soon disappeared. Soon after I watched that program, I heard on the news that it is being done again. :dubious: [sup]There is nothing new under the sun.[/sup]
Not sure, but isn’t “the dam” down river from the Grand Canyon??
Spelling and grammer subject to change without notice.
There are a whole bunch of dams on the Colorado River. Here’s a map. Lake Mead is behind the Hoover Dam, and Lake Powel is behind the Glen Canyon Dam. The Glen Canyon is the one that’s spewing copious amounts of water, directly downriver into Grand Canyon National Park.
Can you do the math please??
My quick calc came up with 11.1 billion cubic yards. But I must admit conversions are not my strong point. I just can’t envision any lake even coming close to filling up the GC even to the halfway point.
Google says that the lake falls short by about 14.9 billion cubic yards.
We were both wrong. Thanks.
The idea I understand is to recreate the natural cycle of a honking wall of water coming down every couple of years. This will flush out a bunch of sand and stuff and will let the river change its course.
I say ‘Cowabunga!’ lets get the surf boards!
The Colorado River naturally has more silt than most rivers due to the type of soil it passes thru. Before dams were built, sand bars and beaches were naturally developed. Now the silt settles to the bottom of the man-made lakes. This flooding is to rid the lake(s) of the silt and allow it to build new sand bars and beaches.
USA Today article
