9400

• UCREFRP Catalog Number: 9400
• Author: U.S. Bureau of Reclamation.
• Title: Annual Operating Plan For Colorado River Reservoirs.
• USFW Year: 1995.
• USFW - Doc Type: \
• Copyright Material: NO

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Table 3. Glen Canyon Dam interim flow restrictions
Parameter (m3/s) (cfs) conditions
Maximum flow (3) 566.4 20,000
Minimum flow 141.6 5,000 nighttime
226.6 8,000 7:00 am to
7:00 pm
Ramp rates
ascending 70.8 2,500 per hour
descending 42.5 1,500 per hour
Daily fluctuations (") 141.6 / 226.6 5,000 / 8,000
Based on a request from the cooperating agencies of the GCDEIS, one week of high steady
flows for research purposes is scheduled from Glen Canyon Dam in April 1995. However,
resolution of legal issues, National Environmental Policy Act (NEPA) compliance,
Endangered Species Act requirements, and other consultations are prerequisite to this
research release. The total research release (which in part exceeds the capacity of the Glen
Canyon Dam powerplant) would occur during a period of 21 days and would require the
release of approximately 1.2 MAF during the month of April. This research release is
designed to facilitate the study of the effects of high releases on sediment transport,
backwaters, and beaches.
Representative monthly releases from Glen Canyon Dam in 1995 are shown in Tables 4(a)
and 4(b) for the most probable inflow scenario, in which the minimum objective release of
10,153 MCM (8.230 MAF) is required.
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(3) to be evaluated and potentially increased as necessary and in years when delivery to the
Lower Basin exceeds 10,150 MCM (8.23 MAF)
(4) daily fluctuations limit of 141.6 m3/s (5,000 cfs) for months with release volumes less
than 740 MCM (.600 MAF), 169.9 m3/s (6,000 cfs) for monthly release volumes of 740
to 987 MCM (.600 to .800 MAF) and 226.6 m3/s (8,000 cfs) for monthly volumes over
990 MCM (.800 MAF)
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