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

the requested flow was not provided. Furthermore, high runoff in 1995 that extended relatively

high flows into early October 1995 and high spring flows in 1996 hampered data collections at the

lowest experimental flows. The actual flows when data were collected were 339,424, and 552

cfs. Because the experimental flows did not encompass the entire range of flows that we wanted

to consider, we modeled the habitat change-discharge relation, using the data from the

experimental flows as calibration, that would have occurred between 1 and 600 cfs.

Gaged flows for the White River were taken from USGS gaging stations near Rangely,

Colorado (Boise Creek) and near Bonanza, Utah (Watson).

Habitat Models

Hydraulic model. Changes in depth and velocity were simulated using the channel

conveyance module RHABSIM (version 2.0; Payne 1995). The channel conveyance module used

Manning's equation and three sets of calibration velocity measurements obtained at the

experimental flows to calculate a channel roughness coefficient (n) for each channel segment.

Water surface elevations (wsl) were calculated for each cross section using logllog regression

estimated from measured wsl and discharge at the three experimental flows. Hydraulic

parameters were simulated for flows of 1, 10,20,40,60,80, 100, 150,200,250,300,400, 500,

and 600 cfs. The hydraulic parameter of most interest was wetted perimeter, defined as the

distance across the streambed in contact with the water.

Physical habitat model. The cross sections in each habitat cluster divided the stream reach

into a number of rectangular cells. Each cell was considered to have a unique combination of

habitat type, depth, velocity, and substrate at any particular discharge. Cells near the edge of the

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