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SW drought

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  • mike@usinter.net
    As you all know, I think the ecology of the Gulf of California has, along with higher CO2 for gas exchange, caused the drought in the Southwest. Interesting
    Message 1 of 1 , Nov 20, 2004
      As you all know, I think the ecology of the Gulf of California has,
      along with higher CO2 for gas exchange, caused the drought in the
      Southwest. Interesting article in this regard. But keep in mind that
      presently no water flows into the Gulf itself--flows are used by the
      Mexicans as well:


      Wave coming down the Colorado

      Fri Nov 19, 6:20 AM ET Top Stories - USATODAY.com

      By Patrick O'Driscoll, USA TODAY

      The federal government will unleash a torrent of reservoir water down
      the Colorado River starting Sunday in an experiment to rebuild
      beaches that provide habitat for endangered wildlife and campsites
      for thousands of Grand Canyon tourists.

      The Interior Department will open giant valves in Glen Canyon Dam in
      Arizona to begin what the agency calls "a high flow test study." At
      the peak of the test, the dam will release enough water to fill
      370,000 bathtubs each minute for 60 straight hours.

      The five-day "flush," ending Thanksgiving night, should push
      downstream almost a million tons of sediment that washed into the
      Colorado from a side canyon this fall after weeks of storms.

      If the experiment works, that sediment will rebuild sandbars critical
      to rare fish, birds and snails that inhabit the canyon. Those
      creatures became imperiled after the dam and Lake Powell reservoir
      were built in 1963, abruptly stopping the flow of more than 90% of
      the river's sand and sediment.

      If the experiment fails, critics, such as the Sierra Club (news - web
      sites), will continue to press for other measures. Among them:
      tearing down the dam or hauling sediment from above Glen Canyon Dam
      by truck or pipeline to spots downstream, including Grand Canyon
      National Park.

      Removing the dam, an idea suggested decades ago by environmental
      activists and a few scientists, gained renewed attention after a
      similar water-release experiment in 1996 failed. That attempt did
      rebuild more than 50 beaches and sandbars. But within months, river
      erosion melted them away again.

      Bennett Raley, assistant Interior secretary for water and science,
      says he is optimistic this experiment will help develop strategies
      less radical than tearing down the dam to aid the canyon's ecology
      and recreation. He says removing the dam is an idea that won't float.

      "Glen Canyon Dam is there. It's not going anywhere," Raley
      says. "Periodic discussion about tearing it down or draining (Lake
      Powell) are fun for those that engage in that rhetoric, but that's
      not the real world."

      The sandy deposits blocked by the dam and reservoir are vital because
      they create a habitat for the humpback chub, an oversized minnow
      whose numbers have shrunk to 2,000 fish. The sediment also anchors
      plants that shelter an endangered bird, the Southwestern willow

      In addition, beaches created by the deposits are campsites for tens
      of thousands of people who raft the Colorado each year on trips
      through the Grand Canyon.

      Federal laws protect the rare species and require the National Park
      Service to preserve places like the Grand Canyon for future
      generations. But the dam and reservoir also have become essential to
      human life in the West by providing hydroelectric power and a
      critical supply of water.

      As the Interior Department tries to balance the needs of people and
      the canyon's ecology, biologists are skeptical of the water-release

      "It is not a long-term solution, it is a Band-Aid," says river
      scientist Dave Wegner of Durango, Colo., who headed the team that
      managed the 1996 release. "It will move sediment around, but the
      (erosion) process will continue."

      Wegner, a board member of the Glen Canyon Institute, a conservation
      advocacy group, now favors building fewer dams and removing others.
      He isn't advocating that Glen Canyon Dam be torn down, but he thinks
      dredging sediment from above it and moving it
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