PROJ00259

• Contract/PO #: C153424
• Contractor Name: Colorado River Water Conservation District
• Water District: 0
• Bill Number: XB 99-999
• Loan Projects - Doc Type: Feasibility Study

I

I

The proj ect area experiences a range of
Average precipitation varies from 11 inches near
more than 30 inches at the higher elevations.
averages 157 days but may exceed 190 days.

climatic conditions.
the Colorado River to
The growing season

I
I

The population of the study area was estimated by the Bureau of
Census in 1977 to be 6,210. The area is primarily dependent upon
agriculture, but tourism, skiing and hunting are additional economic
resources. Nearby mineral resources including coal and oil shale also
influence the local economy.

I
I

Irrigated lands are primarily used for the production of hay and
pasture for livestock. The remaining crops are small grains and
fruits. The primary sources of water for irrigation in the project
area are West Divide Creek, East Divide Creek, Mamm Creek and Dry
Hollow Creek, all of which flow north to the Colorado River. Several
adjacent basins were also included in the scope of the study
including: Thompson Creek and Yank Creek located to the southeast,
Owens Creek and Buzzard Creek to the south and Beaver Creek to the
West.

I
I

C. Hydrology and Water Rights

I

1. Colorado River Basin

I
I

The Colorado River, which flows along the northern edge of
the project area, has a drainage area of about 7000 square miles
upstream of Rifle, Colorado. The average annual flow is approximately
2.5 million acre-feet at the stream gage located near Cameo, Colorado,
40 miles downstream of Rifle. Peak stream flows occur during the
spring snowmelt period. By late Summer and continuing through the
f all and winter the flow in the river is relatively low. There is
regulation by eight major reservoirs and a depletion of the natural
flow by many transbasin diversions.

I
I

In addition to the natural influences of precipitation and
runoff the flow of the river is also affected by the administration of
Colorado's water rights system. The large upstream senior water
rights which have the greatest influence are the Colorado Big Thompson
project, Denver trans-basin diversions, the Fryingpan-Arkansas project
and the Homestake project. The major downstream water rights are the
Shoshone Hydroelectric Power Plant near Glenwood Springs and the group
of water rights above Grand Junction known as the Cameo call.

I
I
I

In a typical year the Shoshone Plant places calls on the river
during the winter months preventing junior upstream reservoirs from

I

1-2

I
I