Kempthorne said in a statement that the plan directs river management "to protect and conserve its water supplies for current and future generations." For the 2008 water year that began last October, the plan calls for a release of 8.23 million acre-feet of water from Lake Powell through the Glen Canyon Dam. If there's enough water Sept. 30 in Lake Powell, which after a good snow season is supposed to rise by 50 feet, additional water will be released from the dam to equalize amounts in Powell and Lake Mead.

BOR spokesman Kip White said Friday that the operating plan isn't expected to impact any results of the recent high-flow experiment.

"Clearly there is evidence of sediment on beaches," White said. "There's a lot that can happen with that sediment."

White referred to some of the lighter sediment scoured from under the Colorado in the 2004 experiment that just blew away over time and how the 1996 flow didn't work well because it went on for too long.

"I think it's going to take some time to evaluate the whole thing," White said about this month's experiment. "We're working on a living, breathing thing here. We're kind of optimistic it will have a positive effect on the Grand Canyon."

Monitoring of the recent flood's effects by scientists from around the world and by the U.S. Geological Survey will continue in the coming months, with data being compared to results of the previous two experiments. Groups such as the National Parks Conservation Association have already called for more high-flow releases to keep the momentum nature intended going despite the dam's presence.

However, the BOR isn't planning on another high-flow release like the one earlier this month until 2012, and even then it's not certain there will be one. Still, the BOR will at least consider doing another high-flow release sooner. Hahn said discussions along those lines are expected to begin in May and that her role will be to bring forward the science involved in deciding whether to create more man-made floods.

For those talks Hahn has photographic evidence.

She has pictures of one riverside camp site taken in 1996 after the release that year, showing a "nice" buildup of beach. A photo taken in 2006 of the same area depicted mostly rock and very little sand. Just a few days ago, she had her camera at the ready to show the beach was back.

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E-mail: sspeckman@desnews.com