9596

• UCREFRP Catalog Number: 9596
• Author: Ayers Associates.
• Title: Yampa River Basin Research Final Synthesis Report.
• USFW Year: 1999.
• USFW - Doc Type: Fort Collins, CO.
• Copyright Material: NO

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5.2. Instream Flow Rights or Targets

The Phase I Study represented a Juniper Canyon instream flow right based on the contemplated
draft of the Juniper Project water rights. This instream flow right was assumed to have a 1954
priority, and was thus able to call out existing and future in-basin demands operating under rights
junior to 1954. Subordination of the Juniper rights was not represented in this particular scenario;
however, enlarged reservoirs were assumed to fill ahead of the instream flow right under portions
of the Juniper priority "peeled off' for that purpose.

The Phase" and O&M studies assumed no instream flow water right. In-basin demands were
assumed to operate in priority and to deplete the river without regard to effects on instream flows.
Reservoir releases were then made to augment instream flows at the Maybell gage so as to
bring those flows up to various target flow levels.

The flow operations simulated in the Phase II and O&M studies revealed occurrences of Maybell
flow below the relevant target and indicate that the natural flow and storage were inadequate to
meet the targeted instream flow levels. Tables 8 through 12 in the appendix show the
corresponding monthly storage releases for instream flow from the augmentation pool in the
enlarged Elkhead Reservoir.

In 1995, the CWCB filed two instream flow water rights applications: one for a baseflow right as
summarized in Table 3 and another for a "recovery flow" right. The recovery right included all the
available flow remaining in the river less a "carve-out" of 52,000 af for future development. The
carve-out could be increased by 72,000 af (124,000 af total), if it is determined that the people of
Colorado are being deprived of the beneficial use of water allocated to them under compact by
the smaller carve-out and that the natural environment of the endangered fishes will be
preserved with the larger carve-out.

The rights were withdrawn in 1999 due to public opposition and a lack of support from other
government agencies. The state may file a new application for instream flow water rights in the
future, if the RIP determines these rights are necessary to preserve the natural environment for
the endangered species to a reasonable degree.

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