PROJ00147

• Contract/PO #: C153637
• Contractor Name: North Poudre Irrigation Company
• Contract Type: Loan
• Water District: 3
• County: Larimer
• Bill Number: SB 92-87
• Loan Projects - Doc Type: Feasibility Study

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Reservoir No. 6 has deficiencies primarily associated with the outlet works. The
main deficiencies are as listed beiow.

RESERVOIR NO. 6

1. Deteriorated masonry outlet conduit and operator.
2. Seepage around the outlet at the toe of the main dam.
3. Deteriorated masonry gateweil structure.
4. Locaily oversteep downstream face slope in the area of the outlet.
6. No energy dissipation structure.

The generai overail condition of the embankments and their foundations Is good
with no serious problems. The dam embankment was rehabilitated in 1980 and
the slopes, slope protection, and spillway require no additional repair.

Two main alternatives were considered for the repair and rehabilitation of the
Reservoir No. 6 dam. Considering the problems noted above, the two alternatives
were developed to provide a range of choices and solutions to the problems
noted. Cost estimates were prepared for each alternative utilizing ail existing
Information and the information developed for this report. The principal features
of each alternative and their costs are summarized as foilows.

RESERVOIR NO.6 - ALTERNATIVES
CONSTRUCTION COST ESTIMATE

Alternative

Description

Estimated Cost

1.

Line the existing masonry outlet with a 30" HDPE
pipe, line or repair the masonry gateweil, replace
the gate and operator, extend the outlet 100 feet
with a 36" RCP, construct an outlet structure with
an energy dlsslpator, flatten the downstream slope
at the outlet, and instail 360' of toe drain.

$ 111,688

2.

Breach the dam to remove the outlet and replace
with a new 36" RCP, construct an Intake structure
an outlet structure with an energy dlsslpator,
new gate and operator, toe drains, and flatten
the downstream slope at the outlet.

$ 208,212

III.