WSP11463

• File Number: 8200.760
• Description: Yampa General Publications - Correspondence - Reports
• State: CO
• Basin: Statewide
• Date: 7/20/1999
• Author: Ayres Associates
• Title: Yampa River Issues 1999 - Water Management Requirements for the Yampa River Basin - Draft Synthesis Report
• Water Supply Pro - Doc Type: Report/Study

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Impacts related to water depletions and recovery actions in the Green River will be addressed
in separate consultations for Flaming Gorge Dam on the Green River and Duchesne River, a
tributary to the Green, On the Gunnison River, consultation on the Aspinall Unit, in part, will
address these issues, Similar processes are contemplated for the Yampa, White and Dolores
rivers, as well.

In July of 1999, the CRWCD, CWCS, USFWS, USSR agreed that a PSO process, similar to
that of the 15-mile reach PSO, should be followed for the Yampa River.

7. ISSUES AND DIRECTION

The Yampa Management Team believes most of the relevant technical data have been
collected or are readily available (e,g" USGS stream flow records), However, several issues
need to be resolved before additional hydrologic analyses are carried out. The issues include:

. PSO Structure and Scope
On what federal action would a PSO be based (e,g" implementation of a water
management plan for the Yampa River, as an element of the RIPRAP)?
What are the geographical limits of the PSO? Following the example of the 15-mile reach
PSO which ends at the Gunnison River confluence, the Yampa Management Team
suggests that the geographic scope of the Yampa PSO extend from the headwaters of the
Yampa River and its tributaries to its confluence with the Green River,
Will the PSO protect all existing and foreseeable future human water depletions?
Which events or conditions (e,g" popUlation criteria) will trigger reinitiation of the PSO?
Who would sign the recovery agreement: all water users?
Should the PSO consider factors unrelated to instream flow (e,g" incidental take due to
entrainment in diversions, non-native fish control)?

. Administration of the River
There has seldom been a call on the Yampa River requiring the river to be administered,
Moreover, many water users in the Yampa River Sasin do not wish to be administered,
However, some potential alternatives to augment instream flow for the endangered fish
may require administration of the river, Furthermore, the CROSS hydrologic model for the
Yampa River assumes administration of water rights in priority based on water need and
availability, Although no model perfectly replicates actual river conditions, the Yampa
Management Team believes the CROSS model is the best available and provides a means
by which to evaluate alternatives quickly and economically.

. Year Flow Recommendations
Instream flow requirements for fish have been determined for mid summer through early
fall. The Yampa Management Team feels that flow requirements also must be identified
for spring and winter periods, especially if these flows will be used to augment low flows in
summer and fall. The USFWS currently is evaluating past flow recommendations to
determine if they are appropriate or should be modified.

. Role of the Aquatic Management Plan
This plan deals with stocking of non-native fish in reservoirs and streams, Should this plan
be tied into the PSO?

Draft 07/28/99

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Ayres Associates