8211

• UCREFRP Catalog Number: 8211
• Author: U.S. Bureau of Reclamation and Fish and Wildlife Service.
• Title: Final Environmental Assessment
• USFW Year: 1997.
• USFW - Doc Type: Providing Fish Passage at the Grand Valley Irrigation Company diversion Dam on the Colorado River.
• Copyright Material: NO

Opportunities to Enhance River Flows
Ruedi Reservoir
There are existing and proposed projects which have been and will be used to enhance flows in
the 15-Mile Reach. The Biological Opinion for Ruedi Reservoir Round H Water Sales, June 15,
1987, requires 5,000 acre-feet (af) of water be made available annually as instream flows to
preserve habitat in the 15-Mile Reach. The Biological Opinion also required that through
Reoperation an additional 5,000 of to be made available on an average of at least 4-out-of-5 years
in the months of July through October. Since 1991, Reclamation has annually made an additional
10,000 of available to the Service to augment flows in the 15-Mile Reach of the Colorado River.
The additional 10,000 of is not a requirement but has been made available to the Recovery
Program since contracts do not exist for all marketable Ruedi storage at this time. As part of the
Ruedi Round II water marketing program, Reclamation has agreed to provide all remaining water
after the Round II sales (21,650 ao on an interim basis not to exceed 15 years. This would make
up to 31,650 of of Ruedi water available to the Recovery Program to use for augmentation
purposes and recovery of the endangered Colorado River fishes. Because of problems
implementing this commitment, Reclamation, the Service, and the State of Colorado are
discussing alternative proposals which could make less than 31,650 of available for endangered
fish purposes on a permanent basis rather than for 15 years. Converting the fish passage flow
requirement to acre-feet per day results in a storage need of 200 af. Therefore, Ruedi Reservoir
could supply water to the passageway for 50 days (10,000 af) to 158 days (31,600 af). There are
some operational restrictions on Ruedi Reservoir that will more than likely limit the ability to
deliver storage water; however, up to 20,000 of has been delivered to the 15-Mile Reach from
Ruedi Reservoir in the past.
Orchard Mesa Check Settlement
In addition to the storage available in Ruedi Reservoir, the recent settlement in the Orchard Mesa
Check water right case and the proposed Grand Valley Water Management improvement
program, could provide approximately 60,000 of to enhance river flows on an average annual
basis.
The ability to use stored water in Ruedi Reservoir coupled with the Orchard Mesa check
settlement and Grand Valley Water Management system improvements will increase the frequency
of providing the required fish passage structure flows. The exact increase in frequency has not
been completely resolved since many of the issues regarding the three sources have not been
resolved. However, based upon historic record and up to 90,000 of of water potentially available
to enhance flows, water supply for the passage is believed to be adequate.
Based upon Table 1 there will be adequate flows to provide 100 cfs for fish passage about 83
percent of the time during the months of April through November. Without the improvements to
permit fish passage, passage would be possible 7 percent of the time during the same period.
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