7344

• UCREFRP Catalog Number: 7344
• Author: Veenhuis, J. E. and D. E. Hillier.
• Title: Impact of Reservoir-Development Alternatives on Streamflow Quantity in the Yampa River Basin, Colorado and Wyoming.
• USFW Year: 1982.
• USFW - Doc Type: Lakewood, Colorado.
• Copyright Material: NO

IMPACT OF RESERVOIR-DEVELOPMENT ALTERNATIVES ON STREAMFLOW QUANTITY
IN THE YAMPA RIVER BASIN, COLORADO AND WYOMING

By Jack E. Veenhuisand Donald E. Hillier

ABSTRACT

In the Yampa River basin of Colorado and Wyoming, a total of 35 major reser-
voirs and 2 transmountain diversions has been proposed for construction to provide
additional water for increasing industrial, irrigation, and municipal uses. A
multireservoir-flow computer model was used to simulate the effects on streamflow
of five potential options, including one representing historical conditions and
four representing various degrees of reservoir and transmountain-diversion devel-
opment. Various combinations of 17 proposed reservoirs and the 2 transmountain
diversions were used in the analysis. By varying the percentages (25, 50, 75, and
100 percent) of hypothetical agricultural and transmountain diversions within each
proposed reservoir-development option studied, different degrees of water-use al-
location were simulated, thus providing results for a greater range of alterna-
tives. The results of these simulations provide water managers and planners with
some insight into how proposed surface-water developments will affect streamflow.

The proposed Vidler transmountain diversion would affect streamflow only in
the Yampa River subbasin while the proposed addition to the Hog Park transmountain
diversion would affect streamflow primarily in the Little Snake River subbasin.
Streamflow in tributaries to the Yampa River could be relatively unaffected by the
Vidler transmountain diversion although streamflow could be affected to some de-
gree in all reaches of the Yampa River downstream from the proposed diversion
site.

More uniform flow regimens throughout the year could result from some of the
proposed reservoir-development options. However, existing (1979) minimum stream-
flows would not be maintained in many instances, and for many months with the
larger percentage of water-use allocations there could be no streamflow.

INTRODUCTION

Historically, the principal use of surface water in the Yampa River basin
(fig. 1) has been for irrigation of hay meadows and wheat fields. However, in-
creased energy and economic development in the basin will result in additional use
of surface water for industrial, municipal, and recreational purposes. Because
only 54,000 acre-ft of reservoir storage (Steele and others, 1979) is currently
(1979) available in the basin, the construction of numerous reservoirs in the
basin has been proposed as a means of providing additional surface water.
Proposals include the construction of 35 major reservoirs with a total capacity of
2.18 million acre-ft, which is 41 percent greater than the mean annual outflow