9520

• UCREFRP Catalog Number: 9520
• Author: Haines, G. B., D. Irving and T. Modde.
• Title: White River Base Flow Study for Endangered Fishes, Colorado and Utah, 1995-1996.
• USFW Year: 2004.
• USFW - Doc Type: 5D,
• Copyright Material: NO

2. Compare habitat measurements from above with Colorado pikeminnow habitat use

found in previous studies (Miller et al. 1982, Chart 1987, Tyus 1991, and Irving and

Modde 1994) and habitat suitability curves given in Valdez et al. 1987.

3. Incorporate data from above to develop an interim year-round flow recommendation

for Colorado pikeminnow and guidelines for discharge fluctuations a Taylor Draw Dam.

As a basis for formulating flow recommendations, we took two approaches, protection of

Colorado pikeminnow habitat and protection of riftle habitat to maintain biological productivity.

We measured meso- (pool, run, eddy, and riftle) and microhabitat (depth, velocity, substrate, and

cover) changes at three experimental flows. However, we were unable to obtain the low flow we

needed to determine the habitat-discharge relations; as a result, we used physical habitat

simulations to assist in determining these relations.

METHODS

Study Site

The study area (Figure 1) included the White River from its confluence with the Green

River near Ouray, Utah (i.e., Green River at RM 245), to Taylor Draw Dam, near Rangely,

Colorado (RM 0.0-105).

Sampling Design

A stratified cluster sampling scheme (Scheaffer et al. 1979, Bovee 1982, Armour et al.

1983) was used to collect mesohabitat data on the White River. The river was divided into four

strata (see Figure 2 for descriptions, lengths, and locations). The first three strata corresponded

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