WSP00921

• File Number: 8220.111.I
• Description: Central Utah Participating Project
• State: UT
• Basin: Colorado Mainstem
• Date: 12/16/1975
• Author: USDOI-BOR
• Title: Final Environmental Statement Authorized Jensen Unit Central Utah Project Utah
• Water Supply Pro - Doc Type: EIS

SUMMARY

() DRAFT (X) FINAL Environmental Statement

Department of the Interior, Bureau of Reclamation, Upper Colorado Region

1. Type of action: (X) Administrative () Legislative

2. Brief description of action: Jensen Unit is a northeastern Utah
water resource project that would develop municipal and industrial
water to augment existing supplies to Vernal and nearby Ashley Valley
towns and water for irrigation in the vicinity of Jensen. It would
also provide fish and wildlife, recreation, and flood control benefits.
Tyzack Dam, Reservoir, Pumping Plant and Aqueduct, and Burns Pumping
Plant are main features of the Unit. Primary benefits and impacts
would occur in Uintah County. Construction is scheduled to begin
in FY 1976 and continue over a 9-year period.

3. Summary of environmental impacts and adverse environmental effects:
Construction and operation of the Jensen Unit would have both adverse
and beneficial environmental impacts. A loss of about 1,700 man-days
of stream fishing would be sustained in Big Brush Creek. About 520
acres of land would be inundated by Tyzack Reservoir, and the present
agricultural production and fish and wildlife habitat lost or changed.
It is anticipated the reservoir would provide about 9,500 man-days of
fishing and 40,000 recreation days annually. The Unit would permit
development of 100 additional acres of marshland in Stewart Lake
Waterfowl Management Area and enhance its overall wildlife management
program. It is expected that feed crops and livestock production
would substantially increase. Development of a high quality body of
water in Tyzack Reservoir would add to esthetic and recreational
value of the region. Since the aqueduct would be buried, the major
permanent impact on the natural environment would be scars on steep
slopes along the aqueduct alinement which would resist restoration
measures. Most dam embankment borrow areas would be inundated by
the reservoir. Unit development would provide water to help meet the
needs of anticipated population increases and industrial growth in
Ashley Valley, but associated environmental problems could occur unless
adequate land use planning and regulation were accomplished. Floods
would be reduced in Brush Creek downstream from Tyzack Dam. Salinity
of the lower Colorado River is estimated to be increased 1.6 mg/l at
Imperial Dam as a result of increased irrigation, municipal, and
industrial use by the Unit. Operation of Unit pumping plants would
consume about 13 million kilowatt-hours of electrical energy annually
which in due time is expected to be available from the Colorado River
Storage Project. About 3.4 miles of new pole-type transmission lines
would be required extending from existing lines to the pumping plants.
4. Alternatives considered:
a. Nondevelopment of water supply.
b. Partial development of water supply.
c. Alternative sources of water.
d. Alternative plans and features of the proposed plan.
e. Alternative operations of the proposed plan.
5. List of Entities from whom Comments have been re uested or received:
ee attac e 1st.
6. Date made available to CE~ and the public:
DraTt ~tatement: ~pril 2 , 1975
Fi na 1 Statement: Uecember 22, 1975