9628

• UCREFRP Catalog Number: 9628
• Author: Gloss, S. P., J. E. Lovich and T. S. Melis.
• Title: The State of the Colorado River Ecosystem in Grand Canyon - A Report of the Grand Canyon Monitoring and Research Center 1991-2004.
• USFW Year: 2005.
• USFW - Doc Type: \
• Copyright Material: NO

Influence of Glen Canyon Dam Operations on Downstream Sand Resources 23

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B.

Figure 3. Repeat photographs of Tapeats Creek at the Colorado River, Grand Canyon (RM 133.8, right shore). A. (July 1952) This view
downstream from below the mouth of Tapeats Creek shows a large sandbar with few rocks or boulders exposed. This sandbar was
frequently used for layovers during river trips in the 1950s (Kent Frost, courtesy of the photographed. B. (March 27,2003) Large rocks
and boulders are now exposed because of severe beach erosion. New sand was deposited here during the 1996 beach/habitat-building
flow but was quickly removed, This camp is no longer used, which creates a problem for river runners who want to visit Tapeats Creek
(J. Janssen, stake 2676, courtesy of the Desert Laboratory Collection of Repeat Photography). (Figure after Webb and others, 2002.)

B.

c.

April 4, 1996

June 17,2000

F.

Figure 4. Time series of repeat photographs of sandbars along the left shore of the Colorado River near RM 44.5 (Eminence Break)
illustrating deposition on the sandbar during the 1996 beach/habitat-building flow (March 26-April 2; high flow occurred between
photographs B and C) and subsequent erosion since April 1996. Images provided by Northern Arizona University, Department of
Geology in cooperation with the U,S. Geological Survey.