PROJ00026

• Contract/PO #: C153412
• Contractor Name: Louisville, City of
• Contract Type: Loan
• Water District: 6
• County: Boulder
• Bill Number: HB 83-1102
• Loan Projects - Doc Type: Feasibility Study

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PROJECT SUMMARY

The City of Louisville currently relies on Louisville Reservoir for its
winter water supply. The capacity of Louisville Reservoir is 171 acre-feet
although it holds a storage decree for 290 acre-feet. The useable capacity of
Louisville Reservoir is approximately 130 acre-feet. Therefore, during winter
operation, the total winter supply available to the City of Louisville is a
maximum of 420 acre-feet which includes 130 acre-feet of carryover storage
in Louisville Reservoir plus the 290 acre-feet storage decree. By the winter
of 1984-1985, demands by the City of Louisville will have exceeded its winter
water supply.
In response to the demand for storage, the City inititated studies on
four potential reservoir sites which included: (1) expansion of Louisville
Reservoir; (2) expansion of Harper Lake; (3) construction of an on-stream reservoir
on South Boulder Creek near Eldora Springs, Colorado, and (4) construction of
a storage facility at the gravel pit site located west of 80th Street, adjacent
to Harper Lake. This report evaluates seven alternate reservoir configurations
at the four sites including one alternate for the Louisville Reservoir expansion,
one alternate for the gravel pit, four alternates for the Harper Lake site and
one alternate for the Eldorado Springs site. A summary of the seven alternatives
is shown on the attached table on page ix.
Harper Lake Alternate II is recommended as the most feasible alternative
of the various sites examined. The recommended Harper Lake Reservoir would
provide a total storage capacity of 715 acre-feet with a usable capacity of 615
acre-feet, assuming maintenance of a 100 acre-foot recreational pool. Features
of the project would include: (1) construction of a zoned earthfilled embank-
ment ranging in height from less than one foot to a maximum of 14 feet with a
total embankment volume of 164,000 cubic yards, (2) excavation of 941,000 cubic

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