State leaders discuss ideas to restor [The people running Nevada want to drain Powell to fill Mead]

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Waterbaby

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http://www.lasvegasnow.com/news/sta...-to-restore-lake-meads-water-levels/715294780

State leaders discuss ideas to restore Lake Mead's water levels
By: Paul Joncich


Posted: May 16, 2017 09:36 PM PDT

LAS VEGAS - Members of the State Senate were in Carson City Tuesday talking about restoring the water levels at Lake Mead.

One of the ideas pitches was to drain Lake Powell and decommission the Glen Canyon Dam. If Lake Powell is removed to get rid of the Glen Canyon Dam billions of gallons of water, could avoid evaporation, which would fortify the river downstream, and restore Lake Mead.

But the idea is controversial.

"Today climate change is making the west hotter and dryer with less water to store and more quickly evaporating the water that is stored," said Ellen More, Progressive Leadership Alliance of Nevada. "In fact, more than 160 billion gallons of water evaporates from Lake Powell's surface annually, with another 120 billion gallons leaking out from the bottom."

"I have to tell you that you can't regulate our water supply," said according to Danny Thompson, Laborers Local 872. "If you want to force Southern Nevada to look for water elsewhere, do away with the Glen Canyon Dam, not to mention the over 4,217 gigawatts of power that is clean power that is produced by this dam every year- you'd have to replace that as well."

Others lining up in opposition included the Howard Hughes Corporation, the Las Vegas Metro Chamber of Commerce and Boulder City.

However, the idea is a long way from happening. Tuesday's discussion was only about ordering a study of alternative management practices, which included draining the lake and destroying Glen Canyon Dam.
 

Desert Mountain Angler

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Such a waste of time and money.....

Why would the Upper Basin states ever agree to drain the lake since they rely on its water source? How much of NV actually relies on the CO rivershed?

As the West gets drier, even more reason to have a reservoir to control water usage. 160 billion gallons evaporated, 120 billion gallons 'lost' out the bottom? So 280 billion gallons of the total water source of 4,179,093,780,491

SO.....7% evaporation AND loss rate. Sounds pretty reasonable to me.

Politicians and activist must think people are stupid; just because someone says 280 BILLION we should get nervous? They should be more get nervous about this number: $19 TRILLION??
 

Dungee Fishing

Well-Known Member
Desert mountain hit it right on the head. Journalism and especially politics is now almost solely based on trigger words, what trigger words or statements will get the most response even if deviod of full facts. The fact remains that whether you like it or not (or more likely the case aware or not) Powell is needed by MILLIONS of people to survive in their current state.
 

Endurance

Well-Known Member
scouse, do you have a cite for that figure? I would love to have that ready for any discussions I have with those who favor taking away from Powell to fill Mead.
 

VanillaIceCream

Well-Known Member
I was told by "someone" that Mead has less evaporation for its water volume - its not so spread out as compared to LP.

It's a deeper bucket.

I really don't know....
 

Tiff Mapel

Well-Known Member
Actually, your "someone" has it wrong. Mead evaporates more water since it is much hotter. And, Mead is more spread out in large open bays. Powell is narrower with shaded canyons. Powell evaporates 2 to 3%, while Mead evaporates 5 to 6%.

And, let's not forget that the GCI commissioned their own "study" to come to the conclusion that Powell leaks 120 million gallons out the bottom. In reality, there is no definitive data on that number.

Welcome back, Len.
 

Jimbo

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Is it only 120 million gallons per year? That does not seem like it would even fill Al Gores swimming pools.
 

Waterbaby

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I was told by "someone" that Mead has less evaporation for its water volume - its not so spread out as compared to LP.

It's a deeper bucket.

I really don't know....

Not sure why anyone would say that. It is a spread out lake and gets about 5 months more of very hot weather than Lake Powell.. also, what those environmentalists always ignore is Lake Powell gives back. The rocks absorb water and then when the lake draws down give back with seeps and falls. When the lake is full or near full they found the wells on the Navajo Reservation filled and when the lake drops their wells drop. This water is not lost as Glen Canyon Institute, which has been trying to drain this lake for 30-years would have people believe, it is much more efficiently stored than in Lake Mead. There is also the pesky little fact that if the environmentalists had their way and we only had one lake this drought would have been an huge disaster for the rest of the SW like it was in Northern California due to their resistence to upgrade their dam infrastructure [environmentalists again]..... we need both dams and both lakes and -- Glen Canyon Dam is the dividing line between Upper Colorado and Lower Colorado. At this point a good rule of thumb is if it comes from Glen Canyon Institute or people they feed their info to, ignore it, because it is all aimed at one thing, to brainwash people to think Lake Powell is bad and wastes "their" precious water.

Re the evaporation rates - Lake Mead at near full pool is approximately 7.5 feet each year

Annual Rates
The average monthly rates for the Lake Mead open-water evaporation stations were computed for 1998 and 1999. For open-water stations, the sum of the average monthly rates for 1998 was 88.9 in. (7.4 ft) and the sum for 1999 was 90.7 in. (7.6 ft; table 7). For these 2 years, the average annual Lake Mead evaporation rate was 89.8 in. (7.5 ft). Monthly evaporation rates were available for only the Sentinel Island station for January–March 1998, and those rates are used instead of an average rate.

Evaporation rates at the Sentinel Island station are generally representative of evaporation of the lake as a whole. For April 1998 through November 1999, the total evaporation at the Sentinel Island station was 161.3 in., whereas, the total of average monthly evaporation for the open-water stations was 159.9 in. The difference of 1.4 in. is less than 1 percent of the total average open-water evaporation.

The annual volume of water evaporated from Lake Mead exceeded 1.1 million acre-ft in 1998 and 1999 (table 7), which probably is higher than a long-term average annual evaporation due to higher-than-normal lake elevations and corresponding larger-than-normal surface area for the period. For example, the average surface area of Lake Mead was 125,000 acres from 1942 to 1995 and the computed average annual evaporation rate was 7.5 ft from 1997 to 1998, which would equal a long-term average annual volume of 937,500 acre-ft of evaporated water.

https://pubs.usgs.gov/sir/2006/5252/section3.html

and her is an interesting little stat the environmentalists totally ignore:

https://www.newspapers.com/newspage/119486393/

THE AVERAGE ANNUAL loss of water by evaporation from Lake Mead is 108,000 acre-feet less than it was before the creation of Lake Powell, upstream on the Colorado River, a government scientist revealed yesterday. This is the amount by which evaporation has been reduced because of colder water flowing into Lake Mead, said Horace Bab-cock of Tucson, water resources division chief of the U.S. Geological Survey.

PREVIOUS estimates of evaporation from Lake Mead were based on the assumption that the rate would be the same as it was before water was stored in Lake Powell. The saving, called a "bonus" by Babcock, was discovered in a recent study conducted by the USGS. It represents a volume of water which is almost double the capacity of Canyon Lake on the Salt River. "THE TEMPERATURE of the Lake Mead inflow," Babcock explained, "was much lower in 1965 than in previous years because the water released from Lake Powell is cooler than the water that formerly flowed in the uncontrolled Colorado River." Babcock didn't have the exact temperature records of the two lakes, but described Lake Powell as "extremely cold." TOTAL evaporation from Lake Mead from 1953 to 1964, he said, was 10,004,700 acre-feet. This is about 4',4 times the combined capacity of all seven Salt River Project reservoirs. The annual evaporation varied from a low of 704,000 acre-feet in 1965 to a high of 1,-004,000 acre-feet in 1958. The USGS official explained that the volume of evaporation from a lake varies directly with the size of the surface area. LAST YEAR, when the lake was at a comparatively low level, the evaporation was 602,600 acre-feet, compared to the 10-year average of 834,000 acre-feet "Without the effect of Lake Powell," said Babcock, "this would have amounted to about 690,000 acre-feet last year." The USGS estimates that the evaporation from Lake Powell was 300,000 acre-feet last year, with the lake filled to only one-third of its 27 million acre-feet capacity.


Per official records - AVERAGE PAN EVAPORATION (INCHES)

yearly evaporation at Boulder [Lake Mead] = 116.02
1931-2004 | 3.71 4.68 7.56 10.67 13.79 16.57 16.45 14.41 11.51 8.11 4.87 3.69 116.02

yearly evaporation at Page [Lake Powell] = 80.57
1957-2005 | 0.00 2.60 5.84 8.27 10.72 12.86 13.06 11.38 8.42 5.13 2.29 0.00 80.57
 

tt600

Well-Known Member
Sounds like the easy solution is fill Powell to the max and drain Mead to the minimum. I believe this is why they keep Flaming Gorge 80+% full at all times.
 
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