PROJ00223

• Contract/PO #: C153723
• Contractor Name: Orchard Mesa Irrigation District
• Contract Type: Loan
• Water District: 0
• County: Mesa
• Bill Number: HB 95-1155
• Loan Projects - Doc Type: Feasibility Study

program. As a first step, they require that an alternatives analysis
incorporate both structural and non-structural elements. Two structural
alternatives will be considered for evaluation in this report:

Alternative A-I - Replace the existing ditch system with a pipeline to carry
the irrigation water. The pipeline will generally flow under pressure,
although it could flow under open channel flow.

Alternative A-2 - Replace the existing ditch system with a reinforced
concrete-lined ditch system. This system will obviously flow under open
channel flow and will use headgates for diversion of flows to water users
(as does the existing system).

The only non-structural alternative that is applicable to this project is as
follows:

Alternative B-1 - This is a no-action alternative, which basically states that
the existing Mutual Mesa Lateral ditch system will not be improved and
will be operated in its present manner.

2.

Factors Used for Evaluation

The comparative analysis in this section will be based primarily on factors
suggested for use in studies funded by CWCB; however, in considering
these factors, it must be remembered that NRCS is also funding a portion
of the project, and their evaluation criteria must be considered. The main
criteria of concern to NRCS is salinity control, i.e., reduction of seepage
water into the Mancos shale. Other criteria of concern (primarily to
aMID) are lowered maintenance requirements and cost, reducing safety
hazards and potential liability of an open ditch, probable water savings, and
easier control of water dispersed to water users.

CWCB suggests consideration of 6 factors for evaluation of alternatives.
These are as follows:

a. PrQject Output. The expected output of each alternative under
investigation should be described. For irrigation projects, the yield
of the project would be expressed in terms of acre feet of water
supplied to the service area on an annual basis. For projects which
involve rehabilitation of existing facilities, the yield would be
expressed in incremental difference in water supply with and without
the project. In this case, there will be a water savings due to a
reduction in seepage and evaporation. The water input to the head
of the Mutual Mesa Ditch may be reduced as a result.

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