WSP08362

• File Number: 8220.101.10.D
• Description: Glen Canyon Dam/Lake Powell
• State: AZ
• Basin: Colorado Mainstem
• Date: 5/25/1994
• Title: CWCB May 25-26-1994-Board Meeting - Glen Canyon Dam Operations-1995 AOP Issues- Beach/Habitat Building Flows
• Water Supply Pro - Doc Type: Board Memo

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Colorado Water Conservation Board

Department of Natural Resources

721 State Centennial Building
1313 Shennan Street
Denver, Colorado 80203
Phone [phone]
FAX [phone]

STATE OF COLORADO

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Roy Romer .
Gov~r

May 25, 1994

James S. Lochhead
Bxecnlive Director, DNR

i)ll1ies C. Lile, P .E..
Director, CWCB

Glen Canyon Dam Operations - 1995 AOP Issues
BeachlHabitat Building Flows
CWCB Meeting May 25-26, 1994

As a result of sediment transport studies conducted by the U.S. Geological Survey (USGS)
in the Grand Canyon since 1987, the -Bureau of Reclamation and the Cooperating Agencies of
the Glen Canyon Dam Environmental Impact Studies recommended in 1993 that a steady release
of 45,000 cfs for research purposes be scheduled from Glen Canyon Dam for one to two weeks
during April, 1994. .

The research flows would have tested hypothesis developed by the U.S.G.S. on sediment
transport, beachlhabitat building and the effects othigh flows on backwater, beaches, vegetation
and wildlife,

The research flows would have exceeded the Glen Canyon Dam power plant capacity of
33,200 cfs. Although the research flow releases were included in the 1994 Annual Operation
Plan for Colorado River Reservoirs, they were not implemented for a variety of reasons including
concerns expressed by the Upper Basin States that bypassing the power plant at Glen Canyon
Dam would violate the Law of the River and the Grand Canyon Protection Act of 1992,

The Draft Environmental Impact Statement (DEIS) for the operation of Glen Canyon
Dam, published in January 1994, included beachlhabitat building flows as an element common
to all restricted fluctuating flow and steady flow alternatives. However, such flows were only
recommended during years when sufficient quantities of sediment were available in the river,
The beachlhabitat building flows would be implemented as part of the adaptive management
process recommended in the DEIS and scheduled as part of the Annual Operating Plan.

In early 1994, Reclamation and the Cooperating Agencies again recommended that the
Annual OperatiIig Plan for 1995 include beach/habitat building flows during April that are in
excess of power plant capacity. The recommended flows were increased to 52,000 cfs. The
flows would be made as part of the annual 8.23 MAP release or as part of an equalization release
between Lake Mead and Lake Powell, if an equalization release is required.