PROJ00044

• Contract/PO #: FS0011X
• Contractor Name: Cotton Creek Water Company
• Contract Type: Loan
• Water District: 0
• County: Moffat
• Loan Projects - Doc Type: Feasibility Study

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Alternatives Evaluated

A range of alternatives were considered including 1) don't
the project, 2) line the Cotton Creek Ditch with concrete,
install a pressure pipeline, 4) install a non-pressurized
pipeline, and 5) repair the Cotton Creek Ditch and retrench
a minimum amount of labor.

build
3 )

with

A subjective evaluation of the alternatives follows:

1. Don't build the project:

The route along the natural channel of Cotton Creek would
continue to be utilized, and will work in high water years.
However, during low water years the seepage loss will take
most of the water and pivots will have to be abandoned due
to lack of water. This alternative is feasible, but not
considered desirable by the project sponsor.

2. Concrete lined ditch:

Construct a new concrete lined ditch along the alignment of
the Cotton Creek Ditch (old Airline Ditch). The new ditch
would be small, with a 1211 bottom width and a 2411 maximum
height. The ditch drops approximately 720 feet in 2.5
miles. Because of the steep slope (s=0.054) design problems
would arise in dealing with the high velocity of water in
the ditch and the potential for scouring of the concrete
with sand and rocks traveling at high speeds. Other issues
of animal crossings, trail head traffic, and liability
issues would also need to be dealt with. Although the cost
for this alternative is relatively low, the design issues
are significant. This alternative is feasible, but is not
considered the preferred alternative.

3. Install a pressure pipeline;

Install a pipeline along the alignment of the Cotton Creek
Ditch (old Airline Ditch). This would eliminate the problem
with animal crossings and trail head traffic. However, with
operation as a closed system, design problems would arise
with static pressure, and with dynamic pressure associated
with operation of a downstream control valve. Pipe strength
would need to be increased significantly, leading to
increased cost. Repair and maintenance could be a problem
with a pipeline system.

A pressure pipeline could provide opportunities, such as the
generation of electricity with a small hydroelectric plant.
However, this alternative is not considered feasible by the
project sponsor, because of the higher up-front costs.

Feasibility of Rehabilitation of the
Cotton Creek Airline Ditch
March 1997

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