Lake Powell Water Level

[Jim]

It HAS been a very wet year for the Upper Colorado River watershed. Lake Powell is rising, and while the surface area will expand and rise rates will decrease, it is still coming up. According to the lake website, Lake Powell hasn't been this full since June of 2002!
http://lakepowell.water-data.com/

I wonder how how it will get? Will it approach a full pool in 2011? This winter has probably been close to 1984 when the dam was nearly over topped from the massive wet winter and late spring precipitation. We're well below the 1984 lake level, though. Most upper reservoirs are also looking good. Now, Lake Mead is still really low, so things aren't perfect, but it is impressive to see lake Powell get this high.

Anyone in Page have recent photos of the lake behind the dam? Within the last day or two.

[RedRoxx44]

Dare I mention another book I like---"Cadillac Desert" Marc Reisner ( spelling?).

[PaleoRob]

How about the large percentage of it lost to evaporation in the lakes? Just sayin...

San Diego also drinks Colorado River water. City of 2 million or so.

It is not a terribly large percentage lost to evaporation. Powell has the most evaporation, due to its large surface area. It is between 1-3%, depending on lake level. Currently, at ~70% storage (18.2 Maf), 2% of the lake evaporates into the atmosphere a year. That would break down to 364,000 acre feet of evaporation per year. Considering we are releasing downstream between 8.23-13 Maf this year, that is pretty much a drop in the bucket. If we look across the Colorado basin the total maximum storage is pretty close to 61,759,250 acre-feet. That is 1,235,185 acre-feet of evaporation. It is a lot of water, but compared to the amount of water stored it is literally a "drop in the bucket".

[azbackpackr]

Dare I mention another book I like---"Cadillac Desert" Marc Reisner ( spelling?).

Ah, yes. Also, "Chinatown," starring Jack Nicholson, Faye Dunaway, etc.

[Jim]

Lake Powell is now the highest it has been since May 7, 2002. Lake Mead, for some stupid reason, reports their within 2" of this level as yesterday, instead of the more logical to know last time before yesterday or this week. Mead is at 1101.63 feet, if anyone knows the last time it was that high before this month, it would be nice to know.

[Cultjam]

Dare I mention another book I like---"Cadillac Desert" Marc Reisner ( spelling?).

Ah, yes. Also, "Chinatown," starring Jack Nicholson, Faye Dunaway, etc.

Reisner also wrote "Game Wars" about the devastation of American wildlife due to poor game management and poaching. Great books.

[Jim]

Powell is now the highest since April 27, 2002, and Mead updated their site as well. Mead is now the highest since March 21,2010.

Seems like the book discussion could be done in a book thread.

[big_load]

Mead is now the highest since March 21,2010

This isn't too impressive, but perhaps it is more a function of management practices than watershed inputs.

[Jim]

Mead is now the highest since March 21,2010

This isn't too impressive, but perhaps it is more a function of management practices than watershed inputs.

I mentioned that becuase in my previous post about Mead, I note that for some reason they mention the previous within 2" of this level as the day before, which is fairly useless. They switched to a more relevant date.

[big_load]

I mentioned that becuase in my previous post about Mead, I note that for some reason they mention the previous within 2" of this level as the day before, which is fairly useless. They switched to a more relevant date.

It started me thinking, though. Is Mead's level generally more protected by withdrawing from Powell in dry years?

[Jim]

Probably. In March of 2008, they did a "flood" release from Powell. The stated purpose was to mimic a natural flood as happened pre-dams. Being, cold, clear and free of silt, all it did was do a little re-shaping of the canyon bottom, and that disappeared by summer's end from the constant flow level that never dropped to a summer low level. I do not think they really did it to mimic a flood, I think it was to bolster Lake Mead's levels. The Secretary of the Interior can give the order, and pretty much tell you what ever he wants to for his reason. With Mead at less than 50% for a good long while and nearly a decade, with lake levels approaching rationing levels, and with Vegas building lower intake pipes to water the lawn, I think it was for less than environmental reasons. Despite what people might think of my position, I would favor a long term release from Powell to raise Mead, but Powell is really more about electricity, or so I've been seeing.

[RickVincent]

Can't believe any hiker or nature lover is happy about Lake Foul being full again.

Water is a basic survival requirement. I think the needs of the communities who rely on our reservoirs are more important than my desire to go on nature hikes. Its a necessary sacrifice.

[Tough_Boots]

Water is a basic survival requirement.

Or some might say that populating areas with water is a basic survival requirement. Populating an area and then worrying about water is something else.

[PaleoRob]

Probably. In March of 2008, they did a "flood" release from Powell. The stated purpose was to mimic a natural flood as happened pre-dams. Being, cold, clear and free of silt, all it did was do a little re-shaping of the canyon bottom, and that disappeared by summer's end from the constant flow level that never dropped to a summer low level. I do not think they really did it to mimic a flood, I think it was to bolster Lake Mead's levels.

Um...it certainly did drop from the high release level, which means that most of the sand deposited did not erode right away. In fact, this flood was the key to moving these "experimental high flow releases" from the experimental to the functional. These floods will continue now as part of the management whenever a certain "trigger load" of sediment is reached in the Paria and LCR deltas. Otherwise, without that sediment to transport, the flood would just erode the sediment. This is one of the lessons learned between the initial high flow in the 90's and the second in 2004. Much more erosion occurred between the first and the second than between the second and third. I'm not just yaking out the side of my mouth - this is basically a summary of the research that was summarized in Southwest Hydrology in 2009.
As for any of that water being released just to raise the level of Mead - the flood was budgeted into the 8.23 maf required for the year (although in reality the target is 82.3 maf over a ten year period to allow for some fluctuations, we still shoot for 8.23 a year). So Mead didn't get any extra water from Powell that year. This year they are.

[hippiepunkpirate]

Um...it certainly did drop from the high release level, which means that most of the sand deposited did not erode right away. In fact, this flood was the key to moving these "experimental high flow releases" from the experimental to the functional. These floods will continue now as part of the management whenever a certain "trigger load" of sediment is reached in the Paria and LCR deltas. Otherwise, without that sediment to transport, the flood would just erode the sediment. This is one of the lessons learned between the initial high flow in the 90's and the second in 2004. Much more erosion occurred between the first and the second than between the second and third. I'm not just yaking out the side of my mouth - this is basically a summary of the research that was summarized in Southwest Hydrology in 2009.
As for any of that water being released just to raise the level of Mead - the flood was budgeted into the 8.23 maf required for the year (although in reality the target is 82.3 maf over a ten year period to allow for some fluctuations, we still shoot for 8.23 a year). So Mead didn't get any extra water from Powell that year. This year they are.

This information is consistent with that from a presentation I saw by the Grand Canyon National Park Hydrologist in my Geology of Arizona class at NAU.

[azbackpackr]

When doing the so-called "Diamond Down" river trip in lower Grand Canyon about a month ago, I was astonished at how high the "cliffs" of silt are as you are approaching Lake Mead. They are very unstable as well, and the skipper of a boat does well to stay away from them. The river is big and wide, so it's not difficult to travel down the middle and away from these things, which tend to calve off at the slightest provocation, at least from what I'm told, sort of like glaciers into a bay. They run for miles and miles...

I am wondering how those induced floods affect these silt banks?

[Jim]

I didn't come up with my idea on my own, I read it somewhere, possibly on a Park Service site, but maybe from an environmental group who might have an anti-Glen Canyon dam stance. What I had read was that the flood basically did nothing measurable after 6 months. If that is not true, then good. BTW, the river was high yesterday. No beaches anywhere, I heard. I though Valley power needs might be the reason.

[PaleoRob]

River will be running close to 23,000cfs for the next two months at least, due to equalization. There is more water coming in to Flaming Gorge than FG has storage capacity left, so they're dumping water (though not as much as they'd like). All that water will be coming in to us.

[PaleoRob]

Just got back from Rainbow Bridge. You can see the Bridge from the boat dock and water is almost under the Bridge - maybe needs to rise another 5-10 feet.

[azbackpackr]

More like 25,000 cfs. And of course there are beaches! Otherwise, there would be nowhere to camp below Lee's Ferry. There are probably roughly 1600 people rafting the river below Lee's Ferry right this minute, (in many different groups, of course). If there were no beaches, where would they be camping?

When I went down in May, the water was up to 23,000 already. We had no problems. The reason for them letting the water down has been well-publicized. It has to do with the big snowpack in the Rockies. That water has to go somewhere, and needless to say, they don't want to overfill Lake Powell like they did in 1983.

[hippiepunkpirate]

That water has to go somewhere, and needless to say, they don't want to overfill Lake Powell like they did in 1983.

I'm 100% in favor of overfilling to the 1983 level :STP: