PROJ02070

• Contract/PO #: C150233
• Contractor Name: Tom Hill
• Contract Type: Loan
• County: Grand
• Loan Projects - Doc Type: Feasibility Study

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SEDTIIIFIVE

Formulation of .emalivesT

No increase in storage was considered for McElroy Reservoir because it is located upstream of
Wolford Mountain Reservoir. Wolford Mountain Reservoir right is junior to McElroy Dam but
it has an appropriate date of 1981 for 119,600 ac-ft. This right controls Muddy Creek. McElroy
Reservoir is on Pass Creek, which is tributary to Muddy Creek upstream from Wolford Mountain
Reservoir. Therefore, there is no available water upstream from Wolford Mountain Reservoir for
appropriation. An enlargement of McElroy Reservoir would not yield any additional water and
therefore no increase in storage was considered. All of the storage in the McElroy Reservoir is
used every year, therefore, no decrease in storage was considered.

McElroy Reservoir was constructed with an 18-in corrugated metal pipe for an outlet works.
This 18-in pipe was able to deliver any administrative releases from the reservoir. We contacted
Bill Thompson, Water Commissioner, Water District 50 to confirm the 18-in pipe was sufficient
for releases from the reservoir. The re-design includes a 24-in steel pipe encased in concrete.
The larger diameter pipe was selected for design and maintenance reasons not administrative
releases. The larger pipe is to avoid the outlet works from pressurizing to avoid dam safety
considerations.

The existing embankment and its slopes were shown to be stable in accordance with the New
Rules and Regulations for Small, Class III dams. Therefore, no change in the slopes were
considered.

For these reason no reconstruction alternatives were considered. The dam was replaced in-kind.

A no-action or keep the breached reservoir alternative will be evaluated financially.

'URS

T:\PROJECTS\22238900_MCELROY _DAMlCWCB LOAN FEASIBILITY REPORT DRAFT.DOC\ 11-OCT -06\22238900IDEN 5-1