FLOOD05721

• County: Larimer
• Community: Loveland
• Stream Name: Big Thompson River
• Basin: South Platte
• Title: Replacement of Dam, Aqueduct, and Hydroelectric Plant Big Thompson Canyon, Colorado
• Date: 6/1/1977
• Prepared For: Loveland, Larimer County
• Prepared By: L.J. Green
• Floodplain - Doc Type: Educational/Technical/Reference Information

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Big Thompson".

In addition the dam will utilize a type of sand trap which will allow approxi-
mately two cubic feet per second of flow to pass through a controlled gate in
the dam. This will provide two advantages: (1) it will minimize the accumula-
tion of sand and silt behind the dam reducing the necessity of flushing the
reservoir and; (2) the two cubic feet per second of water will support fish life
in the stream between the dam and the tailrace of the power plant (Ref. 11).

The replacement of the 1000 feet of wood stave pipe will occur in the section
of the pipeline which is located south of the river. This operation will require
the uncovering of the existing wooden pipe, the removal of the pipe and the
installation of a new section of pipeline in the same location_ There is an
existing right-ofway free of trees at this location and no tree removal is antici-
pated during construction. Short term noise and emission of exhaust gases from
equipment will occur during construction. After backfilling the disturbed area
will be seeded with native ground cover and the total 1000 foot length will be
restored to its present appearance_ There will be no long term impacts from
this operation.

2.

Social Environment:

It will be necessary to closely coordinate the construction at the dam site with

the operations of the Colorado Division of Highways. It is planned to schedule

the necessary construction at the north abutment with the raising of the high-

way so that both will occur concurrently. It is possible however that some

inconvenience may be caused by temporary detours of automobile traffic during

this operation_ This will be kept to a minimum and this work will be accom-

plished during the tourist off-season.

3.

Aesthetic Environment:

The reconstruction of the dam at the same location as before will produce a

reservoir that is aesthetically pleasing as well as functionally beneficial. Before

the flood this reservoir was an attraction to both the permanent residents of

the canyon and the summer tourists. The dam itself will be visually superior

to the old dam and although its overall height is greater, the exposed structure

will be no greater than the dam it replaced_

The power plant will be smaller than the old plant and will be faced with

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