WSP04803

• File Number: 8221.110.A
• Description: Juniper-Cross Mountain Project
• State: CO
• Basin: Yampa/White
• Date: 10/1/1980
• Title: Summary Report: Juniper-Cross Mountain
• Water Supply Pro - Doc Type: Project Overview

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use of non-glare insulators as well as for a design that minimizes
the possibility of electrocution to large predatory birds such as
eagles. Special siting, grading and drainage measures have been de-
signed throughout to minimize impact and the .potential for ero-
sion and degradation. Many of the scenic overlook points and
trails have been designed to highlight the finer and more attrac-
tive features in the project area.
WATER. The Yampa River of Western Colorado has been and
will continue to be a life-giving thread to the people, plants and
animals in its 7,200 square-mile basin. The Yampa, third largest
river in Colorado has two reservoirs and 120 diversion works on
its mainstem. An additional 45 reservoirs are located on tribu-
taries of the Yampa and the largest single owner of reservoir
storage in the basin is the Colorado Division of Wildlife. The
Yampa ranges in elevation from 12,000 feet near its headwaters
in the mountains where most of the flow originates from snow-
melt to 5,000 feet about 25 miles below Cross Mountain Dam
where the Yampa joins and becomes the Green River. Typically,
while one million acre-feet annually flows in the Yampa, only
10 inches of precipitation falls at the lower elevations, such as
the project area.
Like most water storage projects, juniper-Cross Mountajn will
smooth out both peak and low flows spreading water availability
and power production more evenly for better use. The following
figures give a comparison of average monthly flows on the Yampa
below the confluence of the Snake River using an average of three
possible operating modes for juniper-Cross. The figures presume
all other tributaries remain the same.
Without With
Juniper-Cross juniper-Cross Change
May 8,020 5,051 -37%
June 7,246 4,234 -42%
july 1,688 2,120 +26%
August 415 1,326 +320%
The increase continues through most of the year, essentially
spreading high spring run-off flows across 12 months instead of
two. Water is the determining factor both in the growth of
Western Colorado and more importantly J how it grows. Estimates
for the population related, directly and indirectly, to a one
million barrel a day oil shale industry is 115,000. That .sized
industry is likely by the year 2000. In comparison, that figure
represents the entire population of Northwest Colorado in the
1970 census. Total water consumption in Western Colorado is
projected to increase by 500,000 acre-feet by the year 2000 for
all uses ranging from energy development to enhancement of
the environment.
The River District has reserved the right to release water in
time of need while paying for any related power losses. Location
of Juniper-Cross and control of its releases and water supply by
the River District, an agency governed by representatives from 15
Western Colorado counties, provides the opportunity to alleviate
short supplies throughout Western Colorado. In time of short
supply, Juniper-Cross can be operated to satisfy senior decree-
holders downstream by exchange, so that upstream users, Steam-
boat Springs and Hayden as examples, can meet their needs. In
the event of a call on the river by the lower basin states against
Colorado under the Colorado River Compact, releases from
Juniper-Cross can be used to satisfy that call, enabling users along
every stream in Western Colorado to continue, rather than
suspend, water use.
ENVIRONMENT. Total cost of environmental mitigation
features of the Juniper-Cross Mountain Project as proposed
exceeds $3 million. The figure includes an additional $1 million
for multi-level outlet works in Juniper Dam to warm water
temperatures for fish, the planting and care Glf 5,000 trees at a
cost of $136,750 for wildlife habitat enhancement and funds
allocated for mitigation but unspecified as to programs pending
.further consultation with state and federal fish and wildlife
agencies Just as the project's size promises major benefits to
man in terms of a large amount of water storage, a major power
production plant and one of the greatest recreation facilities in
the region, it has just as large an impact on wildlife in that it

inundates some 22,000 acres of habitat. Some terrestrial wildlife
populations are expected to diminish due to displacement by the
project and the inability to find similar, unoccupied habitat.
However, mitigation measures are expected to make up some of
the losses and the project has the potential for serving other,
different wildlife populations. As an example, up to 40 bald
eagles have been observed in the project area. Because bald eagles
reiy on open water for hunting and much of the reservoirs will
freeze pver, trees will be planted and perches constructed along
the seven-river-mile-stretch between the two reservoirs. This area
shouid become an excellent hunting and roosting area for eagles.
The project may infringe some on the greater sandhill crane,
though the actual significance of that impact is as yet undeter-
mined; the project may also allow for the establishment of a
Canadian goose population. As stated, specific mitigation mea-
sures are contingent on further consultations with U. S. Fish and
Wildlife. Within the constraints of $1.2 million budgeted for
terrestrial enhancement and mitigation, the River District has
suggested the following possibilities:
Construction of shallow, artifical ponds and marshes along
the reservoir edges where mudflats could occur due to reservoir
level fluctuations. The ponds would be fed both by the reservoir
and channeled river flow depending on the reservoir level. These
ponds and marshes, would significantly enhance habitat for
aquatics, birds, amphibians and waterfowl.
_ Extensive planting of willow, cottonwood, Russian olive and
box elder in various sizes. In addition, palatable plant species may
be planted for wildlife feeding. The trees would be artifically
watered for five years and fenced initially to insure successful
establishment. As an alternative to the plants, supplemental
feedings could be conducted in severe winters.
_ Construction of artificial perches and cottonwoods not only
along the nine-river-mile stretch between the two reservoirs but
for up to 10 miles downstream of Cross Mountain Dam.
Water quality generally is expected to improve as a result of
the project. Air pollution during construction will be mitigated
and noise pollution is considered a non-factor. All phases of
construction are designed to keep earth, plant and wildlife
disturbance to a minimum: Many, smaller mitigating features
have been included in the project, such as fencing off a patch of
one plant listed as threatened. Sole source of air, noise or water
pollution after completion of the project will be that generated
by recreation users.
Listed Fishes
Of the the 33 reported fish species in the Yampa River around
the project area, 21 have been introduced and 12 are native. Of
the 12, four are listed by state or federal agencies as threatened
or endangered. Fish authorities have stated that Colorado Squaw-
fish are not reproducing in the project area and will die out
whether the project is constructed or not. The two fishes of
primary consideration by government officials are the squawfish
and humpback chub and the area of possible impact is down-
stream of the project rather than in the project area itself. The
net effect downstream of the project on these species should be
positive for several reasons. First, the project will warm water
temperatures downstream thereby enhancing the spawning of
both. Second, since the amount of habitat available to aquatic
organisms is dependent on the area submerged, the increase in
low flows from Cross Mountain Dam will make more aquatic
habitat available. Fluctuations as a result of Cross Mountain Dam
releases will be 2.5 feet at the confluence with the Little Snake
River and one foot at the confluence with the Green River.
However, besides the two positive effects, peak power releases
from both Flaming Gorge on the Green River and Cross Mountain
on the Yampa can have either an additive or averaging effect
from that confluence downstream. Depending on the timing and
magnitude of releases from both projects, from the confluence
down, this can result in either a beneficial or adverse impact on
the reproduction of the listed species. The River District has'
proposed a computer modeling study to determine how com-
bined releases from both projects would affect the Green below
the confluence with the Yampa.