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  Experimental Flood Flow Set For Next Spring
  BQR ~ fall 1995

t seems like we have danced to this tune before and it looks like this coming March it might actually happen. What we are talking about is the controlled flood release from Glen Canyon Dam to support the research and monitoring called for in the Grand Canyon Protection Act and the Glen Canyon Dam Environmental Impact Statement. The need for this flood is well documented in the scientific research that has been conducted through the Glen Canyon Environmental Studies and is specifically necessary to maintain the dynamic nature of the ecosystem supported by the Colorado River through the Grand Canyon.
The flood flow research is currently scheduled to be initiated on March 26, 1996. The timing is as follows:
Why are we doing this flow now? Good question. Primarily we are doing it because we have the water in Lake Powell, the sediment in the bottom of the channel, and the momentum from the previous GCES work. By doing it in early April we can avoid impacting nesting birds, avoid flushing young humpback chubs downstream, prior to the seeds from Tamarisk being dispersed, after trout spawning in the Lees Ferry reach, available light for aerial photography, and prior to the heavy recreation season. No time is perfect—however this period meets the majority of the needs and avoids most of the impacts. There will be considerable research and photography going on during the test, so be forewarned, this will not be a quiet time in the Canyon.

We are setting up the technical elements of the studies in early November and if anyone is interested we will be publishing a study plan prior to the event. Call us at GCES, 520/556-7363 if you have any questions.

Dave Wegner

March 26
Initiate at 8,000 cfs and hold steady for 4 days
March 31
Ramp up at a rate of 2,500 cfs/hr for 16 hours to 45,000 cfs
April 1
Hold steady at 45,000 cfs (+/- 1,000 cfs/day) for 7 days
April 8
Ramp down at a rate of 1,500 cfs/hr for 25 hours to 8,000 cfs; hold at 8,000 for through April 12
April 13 (approximately):
Return to interim flow April levels


big horn sheep