# Flooding the Grand Canyon **URL:** \ **Category:** Factual Questions\ **Created:** [November 22, 2004, 6:54pm UTC](https://boards.straightdope.com/t/flooding-the-grand-canyon/276150 "2004-11-22T18:54:56Z")\ **Posts on this page:** 14\ **Page:** 1
**Author:** ![HeyHomie](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/heyhomie/32/207_2.png) [@HeyHomie](https://boards.straightdope.com/u/HeyHomie)\ **Post date:** [November 22, 2004, 6:54pm UTC](https://boards.straightdope.com/t/flooding-the-grand-canyon/276150/1 "2004-11-22T18:54:56Z")
Apparently [the Grand Canyon has been flooded](http://news.yahoo.com/news?tmpl=story&u=/ap/20041122/ap_on_re_us/grand_canyon_flooding_12). 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? ---
**Author:** ![lieu](https://avatars.discourse-cdn.com/v4/letter/l/c2a13f/32.png) [@lieu](https://boards.straightdope.com/u/lieu)\ **Post date:** [November 22, 2004, 7:11pm UTC](https://boards.straightdope.com/t/flooding-the-grand-canyon/276150/2 "2004-11-22T19:11:36Z")
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. ---
**Author:** ![Electronerd](https://avatars.discourse-cdn.com/v4/letter/e/8e8cbc/32.png) [@Electronerd](https://boards.straightdope.com/u/Electronerd)\ **Post date:** [November 22, 2004, 7:23pm UTC](https://boards.straightdope.com/t/flooding-the-grand-canyon/276150/3 "2004-11-22T19:23:27Z")
> [@Linked News Story](#): > > The release should reach a peak early Monday morning, when 41,000 cubic feet of water — enough to fill more than 11 tractor-trailers — will be moving through the dam every second. 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. ---
**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\ **Post date:** [November 22, 2004, 7:35pm UTC](https://boards.straightdope.com/t/flooding-the-grand-canyon/276150/4 "2004-11-22T19:35:08Z")
The volume of the Grand canyon is [52 billion cubic yards](http://www.earthsky.com/shows/showsmore.php?t=20040220). The volume of lake Powell is [23 million acre feet](http://outside.away.com/outside/magazine/0299/9902dam.html). 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. ---
**Author:** ![friedo](https://avatars.discourse-cdn.com/v4/letter/f/8edcca/32.png) [@friedo](https://boards.straightdope.com/u/friedo)\ **Post date:** [November 22, 2004, 9:11pm UTC](https://boards.straightdope.com/t/flooding-the-grand-canyon/276150/5 "2004-11-22T21:11:07Z")
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. ---
**Author:** ![moriah](https://avatars.discourse-cdn.com/v4/letter/m/b2d939/32.png) [@moriah](https://boards.straightdope.com/u/moriah)\ **Post date:** [November 22, 2004, 10:16pm UTC](https://boards.straightdope.com/t/flooding-the-grand-canyon/276150/6 "2004-11-22T22:16:28Z")
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. ---
**Author:** ![kniz](https://avatars.discourse-cdn.com/v4/letter/k/c37758/32.png) [@kniz](https://boards.straightdope.com/u/kniz)\ **Post date:** [November 23, 2004, 3:04am UTC](https://boards.straightdope.com/t/flooding-the-grand-canyon/276150/7 "2004-11-23T03:04:17Z")
**PBS** recently ran this show, [**NATURE: The Colorado River.**](http://www.pbs.org/wnet/nature/grandcanyon/river.html) 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] ---
**Author:** ![Kegg](https://avatars.discourse-cdn.com/v4/letter/k/9e8a1a/32.png) [@Kegg](https://boards.straightdope.com/u/Kegg)\ **Post date:** [November 23, 2004, 10:39am UTC](https://boards.straightdope.com/t/flooding-the-grand-canyon/276150/8 "2004-11-23T10:39:30Z")
Not sure, but isn’t “the dam” down river from the Grand Canyon?? * * * Spelling and grammer subject to change without notice. ---
**Author:** ![friedo](https://avatars.discourse-cdn.com/v4/letter/f/8edcca/32.png) [@friedo](https://boards.straightdope.com/u/friedo)\ **Post date:** [November 23, 2004, 12:44pm UTC](https://boards.straightdope.com/t/flooding-the-grand-canyon/276150/9 "2004-11-23T12:44:03Z")
> [@Kegg](#): > > Not sure, but isn’t “the dam” down river from the Grand Canyon?? There are a whole bunch of dams on the Colorado River. [Here’s a map](http://www.kaibab.org/misc/gc_coriv.htm). Lake Mead is behind the Hoover Dam, and Lake Powel is behind the [Glen Canyon Dam](http://www.kaibab.org/images/gcdam.gif). The Glen Canyon is the one that’s spewing copious amounts of water, directly downriver into Grand Canyon National Park. ---
**Author:** ![Uncommon\_Sense](https://avatars.discourse-cdn.com/v4/letter/u/f9ae1b/32.png) [@Uncommon\_Sense](https://boards.straightdope.com/u/Uncommon_Sense)\ **Post date:** [November 23, 2004, 1:07pm UTC](https://boards.straightdope.com/t/flooding-the-grand-canyon/276150/10 "2004-11-23T13:07:49Z")
> [@Squink](#): > > The volume of the Grand canyon is [52 billion cubic yards](http://www.earthsky.com/shows/showsmore.php?t=20040220). > The volume of lake Powell is [23 million acre feet](http://outside.away.com/outside/magazine/0299/9902dam.html). > 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. 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. ---
**Author:** ![Catalyst](https://avatars.discourse-cdn.com/v4/letter/c/e47774/32.png) [@Catalyst](https://boards.straightdope.com/u/Catalyst)\ **Post date:** [November 23, 2004, 2:51pm UTC](https://boards.straightdope.com/t/flooding-the-grand-canyon/276150/11 "2004-11-23T14:51:06Z")
> [@Uncommon Sense](#): > > 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](http://www.google.com/search?hl=en&lr=&safe=off&q=52+billion+cubic+yards+minus+23+million+acre+feet+in+cubic+yards) says that the lake falls short by about 14.9 billion cubic yards. ---
**Author:** ![Uncommon\_Sense](https://avatars.discourse-cdn.com/v4/letter/u/f9ae1b/32.png) [@Uncommon\_Sense](https://boards.straightdope.com/u/Uncommon_Sense)\ **Post date:** [November 23, 2004, 3:37pm UTC](https://boards.straightdope.com/t/flooding-the-grand-canyon/276150/12 "2004-11-23T15:37:20Z")
We were both wrong. Thanks. ---
**Author:** ![Paul\_in\_Qatar](https://avatars.discourse-cdn.com/v4/letter/p/ccd318/32.png) [@Paul\_in\_Qatar](https://boards.straightdope.com/u/Paul_in_Qatar)\ **Post date:** [November 23, 2004, 3:49pm UTC](https://boards.straightdope.com/t/flooding-the-grand-canyon/276150/13 "2004-11-23T15:49:14Z")
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! ---
**Author:** ![kniz](https://avatars.discourse-cdn.com/v4/letter/k/c37758/32.png) [@kniz](https://boards.straightdope.com/u/kniz)\ **Post date:** [November 23, 2004, 4:22pm UTC](https://boards.straightdope.com/t/flooding-the-grand-canyon/276150/14 "2004-11-23T16:22:22Z")
> [@Paul in Saudi](#): > > 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. 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**](http://www.usatoday.com/news/nation/2004-11-21-colorado-river_x.htm) > [@](#): > > **The extra water is four times what the dam releases this time of year. The goal is to push downriver 1 million tons of sand and silt that washed into the Colorado from a side canyon this fall. The aim: rebuild beaches and sandbars critical to endangered fish, birds and snails. Such critters have been at risk — and some have gone extinct — since the dam and Lake Powell reservoir were built in 1963.**