WSP07117

• File Number: 8276.130
• Description: Grand Valley Unit-Colorado River Basin Salinity Control Project
• State: CO
• Basin: Colorado Mainstem
• Water Division: 5
• Date: 11/1/1990
• Title: Final Environmental Assessment: Price and Stubb Ditch Improvements - Grand Valley Unit
• Water Supply Pro - Doc Type: EIS

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CHAPTER II

DESCRIPTION OF ALTERNATIVES

safety ladders would be installed immediately upstream of siphons and
flumes when the size and location of the structures create a safety hazard.
The need for other safety features would be determined during
preconstruct ion studies. Handrails would be constructed on the operating
platforms of the check structures.

Ooeration, Maintenance, Reolacement and Enerav

With development of the recommended plan, changes would occur in the
operation, maintenance, and replacement (OM&R) of the canals. An estimate
was prepared for expenses that would have occurred in the thorough and
timely O&M of the systems without construction of the plan. The change in
OM&R costs is considered to be the difference in the estimated OM&R costs
with and without construction of the recommended plan. The estimated
annual OM&R cost also includes an annual charge for replacing features with
an expected life of' less than 100 years, such as canal lining and canal
structures.

Section 202 (2) of Public Law 93-320, which authorized the Grand Valley
Unit, stipulates that, "Prior to initiation of construction of the Grand
Valley Unit, the Secretary shall enter into contracts through which the
agencies owning, operating, and maintaining the water distribution systems
in the Grand Valley, singly or in concert, will assume all obligations
relating to the continued operation and maintenance of the Unit's
facilities to the end that the maximum reduction of salinity inflow to the
Colorado River will be achieved." Consequently, Colorado state law has
been modified to allow an existing irrigation district to enter into such
an O&M contract with the United States after authorization by vote of the
district water users. The modified Colorado law also provides for
assessing and levying taxes against district lands to meet the O&M and
current expenses of the districts. Both boards of directors can act on
behalf of their constituents.

The MCrD and PID have contracted with the United States for the O&M of all
Reclamation constructed salinity features within their service areas.
These agreements were executed with both irrigation districts on March 6,
1990, and cover all salinity improvements within their districts.

Water Riahts

The proposed ch~nges to the ditches would reduce seepage from the ditches
and consequently, more water should remain in the irrigation systems than
has historically. This water is commonly called "salvaged" or "saved"
water and is estimated at 1,615 acre-feet per year. The districts have
agreed not to use this saved water in a manner which would materially
increase the salinity contribution to the Colorado River. Beyond that
requirement, Colorado State water law would determine the destiny of the
salvaged water. It is anticipated that if the districts can continue to
show beneficial use of all diverted water, no change in water rights would
occur. Since both districts are essentially land locked, the likelihood of
increasing their service areas is small.

Studies conducted by Reclamation have indicated that the supply of water to
both ditches is significantly less than other ditches in the valley based
upon design standards. Therefore, it is reasonable to assume that their
peak diversion rate will not decrease and beneficial use of the Districts'
full water rights will be maintained.

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