Monday, May 28, 2012

Sediment floods approved from Glen Canyon dam

The US Dept. of Interior plans to release controlled floods from Glen Canyon dam on a more regular basis, to try to rebuild beaches and sandbars, and return the Colorado River to a more natural state.  The releases are supposed to occur when conditions are right on the Paria River coming from Utah, and on the Little Colorado on the Arizona side to maximize sediment transport.     Without the sediment, the cold waters during tests reportedly did more harm than good on native fish.  [Right, controlled flood from the Glen Canyon dam.  Credit, USGS]

Proponents cheered the move as helpful to the humpback chub but questions rose almost immediately, including one about the wisdom of spring flushes, on the basis that previous flood tests in the spring benefited non-native fish that eat the native population.   Energy managers warned that release of large volumes of river water cost energy consumers $3-4 million each time, and could complicate legal requirements of water delivery from the upper Colorado River basin to the lower.

1 comment:

  1. Gregory9:38 PM

    I think that these flushes of sediment should not be allowed. These sediments contain tens of thousands of pounds of uranium, way more than would ever be contributed by uranium mining outside the GCNP. Flushing these uranium bearing sediments into and through Colorado River the would endanger the drinking water of millions of people who rely on these water for irrigation, drinking, and industrial uses.

    The EIS for the Northern Arizona Withdrawal proved that this was true! That is why Mr. Salazar did the withdrawal!

    How can the DOI even think about doing these flushes on a regular basis.