PROJ00434

• Contract/PO #: C153337
• Contractor Name: Farmers Extension Ditch & Highland Lake Lateral Company
• Contract Type: Loan
• Water District: 1
• County: Weld
• Bill Number: FSA
• Loan Projects - Doc Type: Feasibility Study

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REHABILITATION ALTERNATIVES

The main purpose of this report is to investigate the different ways available
to rehabilitate the Highland Lateral and Farmers Extension Irrigation Ditch.
The goal is to alleviate the problems of scour and erosion, to make the ditch
serviceable, to eliminate the seepage problems, and to accomplish this in a manner
which is economically feasible for the shareholders of the ditch. The Soil Con-
servation Service will be doing the structural design for the ditch rehabilitation.
A preliminary Engineering Report was prepared by S.C.S. for this ditch which out-
lined what they felt should be done to improve it. They outline their recommenda-
tions for the ditch by breaking the total length of the ditch into thirteen (13)
separate reaches. We will follow their numbering of ditch reaches in our report.
It was, however, necessary to break down these reaches into smaller sections for
the purpose of defining yearly construction phases. These sections have been
described and shown on Exhibit No.3. (Page No.

The S.C.S. based their rehabilitation program strictly on the use of reinforced

concrete lining. S.C.S. recommendations also called for the replacement of ex-

isting check structures with similar units in the same locations. We believe

that this is but one alternative available. We have used their information in

our report but have not limited our study to only this type of construction.

We began our study by looking at three alternatives which we feel could be ap-
plicable for this project. These alternatives are:

1. Reshape the ditch as an earthen structure using a bentonite or
chemical sealant to seal and strengthen the ditch embankments.
All the check structures will be rebuilt in a similar location
as they, are today, but will be hydraulically designed upstream
and downstream of the ~tructure to prevent scouring, erosion
and excessive velocities. All turnouts will b~ replaced.

2. Rebuild the ditch according to the Soil Conservation Service plan;
entirely lining the ditch with unreinforced concrete. Check
structures would be built as a unit with the concrete lining.

3. Rebuild the ditch with reinforced concrete pipe of a size enough
enough to meet the needs of the farmers. Check structures can
be eliminated and outlet pipes installed in their place.

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