PROJ00370

• Contract/PO #: FS0031X
• Contractor Name: Yampa Project DNR 1972
• Contract Type: Miscellaneous
• Water District: 0
• County: Moffat
• Loan Projects - Doc Type: Feasibility Study

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CONCLtlS ~ONS

We do not foresee any problem in Increasing the
height of the high water level from 6342 feet to
6375 feet. The bank at the reservoir should be
Impervious. and allow a minimal loss of water.

Further Investigation of subsoil conditions along
the dam axis will be necessary. The design of the
dam including the location of the spillway and
outlet structure may have to be revised.

GENERAL

Elkhead Dam and Reservoir is located at the basin between the Elkhead

Mountain on the north and the Will lams Fork Mountain on the south. The

basin is drained by the Vampa River.

The initial feasibil ity study of Elkhead Dam and Reservoir was made

by Engineering Consultants, Inc. in August, 1968. A 55 foot high dam

Was .proposed with high water level at elevation 6342 feet and a total

reservoir capacity of 5250 acre feet.

In October, 1971, in cooperation withEngineering Consultants, Inc..

we drilled 5 test holes along the dam axis to depth 20 feet. We also

investigated 2 sources of borrow area Immediately to the north of the dam

site. Detailed laboratory testing was made on the borrow materials and

the undisturbed samples taken along the dam axis. Laboratory testing

included classification tests, triaxial shear tests, direct shear tests

and consolidation tests.

We understand that it is now desired to increase the height of the

dam to 80 feet with new crest elevation at 6375 feet and high water level

at elevation 6367 feet.

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This will Increase the total capacity of the

reservoir to 13,420 acre feet. The attached figure indicates the high

water line. The increased reservoir capacity will be used for an emergency

supply source for the proposed Colorado Ute power plant.