ANOTHER DUMP NOV. 7

Discussion in 'Lake Powell Issues' started by weeds, Oct 26, 2016.

  1. weeds

    weeds Well-Known Member

    From LPYC email.

    (BOR)
    "Pending a final Leadership Team decision memo, releases from Glen Canyon Dam would begin ramping up to full power plant capacity (approximately 21,000 cfs) on the morning of November 7th. At 9am on November 7th, bypass tubes at Glen Canyon Dam would be opened and releases should continue to increase up to full power plant and bypass capacity (approximately 36,000 cfs) by mid-day November 7th. Releases would be maintained at peak release for 4 days (96 hours) and then begin ramping back down. Releases would return to normal operations in the early morning of November 12th. The entire experiment, including ramping, is expected to last 5 days, with 4 days (96 hours) at peak release. November releases from Glen Canyon Dam prior to and after the HFE are expected to fluctuate between 6,500 cfs and 9,000 cfs."
     
  2. James Todd

    James Todd Member

    No thought to the lack of moisture all summer in the Colo. mountains. The ground is very dry so it will take a lot of water to build up the ground water sources.
     
  3. weeds

    weeds Well-Known Member

    If the dump goes as in the past...the lake should drop at least 3 feet in 3 days.
    If your parked somewhere loosen the lines a bit.
     
  4. Waterbaby

    Waterbaby Administrator Staff Member

    You beat me to it, Weeds. Just saw this pop up on my email feed....

    http://www.lakepowelllife.com/high-flow-experiment-at-glen-canyon-dam/

    High Flow Experiment at Glen Canyon Dam
    [​IMG]
    October 28
    10:58 2016

    by Josh Alexander
    [​IMG]
    Glen Canyon Dam bypass tubes during 2008 HFE.

    The Bureau of Reclamation will increase water releases from Glen Canyon Dam beginning on Monday, November 7, 2016 to support a high flow experiment (HFE) in partnership with the National Park Service, U.S. Fish and Wildlife Service and U.S. Geological Survey. This high flow experiment will include a peak magnitude release of approximately 36,000 cubic feet per second (cfs) for 96 hours to move accumulated sediment downstream to help rebuild beaches and backwater habitats. The decision to conduct this HFE was made following substantial consultation with Colorado River Basin states, American Indian tribes and involved federal and state agencies.

    Reclamation and National Park Service officials remind recreational users to use caution along the Colorado River through Glen and Grand Canyons during the entire week of November 7. Flow level information will be posted at multiple locations in both Glen Canyon National Recreation Area and Grand Canyon National Park. Note that it will take several hours following the beginning and end of the HFE for high flow waters to reach and then recede at downstream locations in the canyons.

    High flow experiments benefit the Colorado River ecosystem through Glen and Grand Canyons by moving sand in the river channel and re-depositing it in downstream reaches as sandbars and beaches. Those sandbars provide habitat for wildlife, serve as camping beaches for recreationists and supply sand needed to protect archaeological sites. High flows may also create backwater areas used by young native fishes, particularly the endangered humpback chub.

    The HFE will not change the total annual amount of water released from Lake Powell to Lake Mead. Releases later in the water year will be adjusted to compensate for the high volume released during this high flow experiment.
     
  5. Bart

    Bart Well-Known Member

    Bad management to bypass the generators and waste electrical - green - energy as the taxpayers paid for the capital and operational costs of the dam , turbines, and such..
     
  6. mtnpull

    mtnpull Well-Known Member

    They'll be dumping water pretty much my whole next visit to the lake.
     
  7. Waterbaby

    Waterbaby Administrator Staff Member

    Yes it it. But then this department of Interior keeps doing it each and every year and our energy prices keep rising.
     
  8. GregC

    GregC Well-Known Member

    I'd be interested to know what the actual volume of silt and sediment is produced. Gotta be 90% settled out by the time it reaches Bullfrog. The remainder, produced by the Escalante and San Juan, etc can't be reaching the dam. Even high volumes of water aren't enough to scour any more from in front of the dam.

    GregC
     
  9. James Todd

    James Todd Member

    According to some reports I have read in the runoff there are many railcar loads of sand comes down every day .
     
  10. weeds

    weeds Well-Known Member

    Bummer. Don't get stuck on the beach.
     
  11. Tiff Mapel

    Tiff Mapel Active Member

    I just read that Lake Mead is at 37%. I guess it's time to flush the fish again. Bummer.
     
    Waterbaby likes this.
  12. Dorado

    Dorado Well-Known Member

    Greg C
    "I'd be interested to know what the actual volume of silt and sediment is produced. Gotta be 90% settled out by the time it reaches Bullfrog. The remainder, produced by the Escalante and San Juan, etc can't be reaching the dam. Even high volumes of water aren't enough to scour any more from in front of the dam."

    You are correct that most if not all the sediment is settled out by the time it reaches the dam. The purpose of the flush it so move the sediment and sand bars in the river channel....
     
  13. Waterbaby

    Waterbaby Administrator Staff Member


    One of the books I have in my Lake Powell collection has a diagram and it does settle out before Bullfrog - If I get a chance I'll look for the book and the diagram, it was pretty interesting info. In the side canyons they found the sediment builds up, but then in low water years flash-flooding scours the sediment and sends it into deeper water. What was suggested a while back, was to find some way to send the build up in Navajo Canyon to below the dam. I guess it wasn't a viable thought as thinking seems to be as far as it ever got.
     
  14. Cliff

    Cliff Well-Known Member

    I don't think it has anything to do with the lake. It's all sand bars and sediment in the river their working on from what I hear.
     
  15. WaterMan

    WaterMan Well-Known Member

    4-07-16 3608.95 -4"
    4-08-16 3608.36 -7"
    4-09-16 3607.75 -7"
    4-10-16 3607.14 -7"
    Total= -26"
     
    Last edited: Nov 11, 2016
  16. wayne gustaveson

    wayne gustaveson Administrator Staff Member

    Yes this is not about lake sediment but sediment in the river downstream. It is hoped that the flow increase will take deep sediment from the river bottom and deposit it once more on the higher elevation where it can be used by rafters for a place to camp and eat lunch.
     
  17. GregC

    GregC Well-Known Member

    Seems to me that they could get the same effect with some temporary wing dams made from those concrete highway dividers they use during construction/lane change operations. If used during normal high flow periods, you could put the sand anywhere you wanted.

    GregC
     
    James Todd likes this.