COORDINATED RESERVOIR OPERATIONS
The Coordinated Reservoir Operations Study
is a component of the Recovery Implementation Program for Endangered Fish Species in the
Upper Colorado River Basin (Recovery Program). The purpose of this study effort is to
identify operational flexibility in existing water storage reservoirs (both
private) that could be used to enhance peak flows in the 15-mile reach of the Colorado
River to benefit endangered fish species and their habitat without reducing a project's
yields or affecting a project's water rights. The study team identified some operational
flexibility in individual facilities that could be used to enhance spring peak flows
during water years in which near average runoff conditions exist. In water years with
significantly above average runoff conditions, the potential for peak flow enhancement is
diminished due to flood concerns and the relatively minor contribution peaking operations
would have on total flows on a percentage basis. Conversely, in water years with below
average runoff conditions there is little, if any, flexibility in modifying reservoir
operations to enhance peak flows without affecting reservoir yields. It was further
recognized by the study team that while individual facilities possess only limited ability
to enhance spring peak flows by themselves, coordination of releases and/or filling
patterns of multiple reservoirs may result in spring peak flow enhancement that may be
beneficial to endangered fish species and their habitat without adversely affecting
The Division of Water Resources is cooperating with
the Colorado Department of Natural Resources in development and implementation of the Colorado River Decision Support System
Model. The model is being used to quantify future river flows for the Colorado River
Programmatic Biological Opinion and the Yampa River Management Plan.
The Service sees great potential in the
model to enable biologists and water managers to assess flow conditions in sensitive
habitat areas, aid in the evaluation of flow impacts of alternative water management
scenarios, and recommend conservation measures for water projects.
INSTALLATION AND MAINTENANCE
Personnel continue to work with the U.S.
Geological Survey, Bureau of Reclamation, and the
Colorado Division of
Wildlife to maintain the current gage at the head of the 15-mile reach; and two gages
located near Deerlodge Park on the Yampa River.
During 1998 funds were made
available in cooperation with U.S. Geological Survey and the Bureau of
Reclamation to upgrade the satellite link and
install a water temperature probe at the Jensen Gage on the Green River.
Colorado River Basin - River Temperature Data
The overall goal of the Recovery Program's Channel
Monitoring Program is support the efforts of the Recovery Program in
developing flow recommendations, restoring flooded bottomlands, and monitoring channel
morphology conditions. Each year, one or two important river reaches are selected for
baseline or follow-up surveys based on annual program guidance and priorities.
The goal of
1998 was to establish a new channel monitoring site in the lower one mile of the Yampa
River in an area known as Echo Park. The site that was monitored is the only known
razorback spawning bar on the Yampa River and is an important habitat site where no
geomorphology work has been undertaken.
With the assistance of a Bureau of
Reclamation survey crew, river cross sections were established and a
topography map of the Echo Park spawning bar was developed. This physical data will be
used to develop information on timing, sediment load, bed material, sand inundation,
cobble incipient motion, and flow hydraulics. The 1998 work at the Echo Park spawning bar
will benefit the Recovery Program in that it will serve as a baseline to identify
historical trends and then compare with the Jensen spawning bar to help describe the
function and dynamics of a spawning bar. The Echo Park work will also add to the database
that the Recovery Program is developing on status and trend as related to changes in river
channel morphology and riparian habitat. The cross sections established will also be
monitored periodically as a part of an ongoing channel monitoring program.
DELIVERY OF LATE
The year 1998 was an average to moderately
low runoff year. Flows in the 15-Mile Reach and the Yampa River were monitored on a daily
basis and weekly conference calls with water management agencies were held to coordinate
releases from Ruedi, Green Mountain and Wolford Reservoirs. Flows in the 15-mile Reach
remained above Service recommendations most of the summer with flow support from Wolford,
Ruedi and Green Mountain Reservoirs. In the final analysis, 11,500, 20,800 and 31,728 acre
feet of water were used from Wolford, Ruedi and Green Mountain Reservoirs,
respectively. Yampa River flows were monitored closely and dropped relatively low by the end of summer
but did not drop below Service flow targets of 150 cfs in August, 110 cfs in September and
115 cfs in October. Water was released from Steamboat Lake under the
"take or pay" lease
with the Colorado Division of Parks.
Personnel work with willing sellers to gather
information on water rights, develop scopes of work for water rights
consultant supervision, contract administration and review of the consultant's work.