PROJ00350

• Contract/PO #: C153574
• Contractor Name: Longmont, City of
• Contract Type: Loan
• Water District: 5
• County: Boulder
• Bill Number: SB 88-30
• Loan Projects - Doc Type: Contract Documents

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EXHIBIT A

engmeers . planners . surveyors

September 24, 1987

Mr. Ken Huson
City of Lon9mont
1100 South Sherman
Longmont, CO B0501

RE: Revised proposal to determine preliminary
design improvements to McCall Lake

Dear Ken:

Rocky Mountain Consultants, Inc. (RMC) is pleased to present this revised
proposal to determine preliminary design improvements to McCall Lake and asso-
ciated cost estimates for preliminary design alternatives. Results of this
study will be summarized in a report that can.be submitted to the Colorado Water
Conservation Board (CWCB) for potential funding of lake repairs. The summary
report will be written according to the CWCB "Guidelines for Preparation of
Feasibility Reports" and will address all of the requirements therein or as
modified by CWCB staff. Specific improvements to McCall Lake contemplated by
the City of Longmont as we understand them are:

1) Flatten unstable banks and provide riprap protection,
2) Design new outlet works with a control gate,
3) Extend the outlet pipe to the Oligarchy Ditch or to
St. Vrain Creek, or make improvements.to the Longmont
Supply. Ditch to divert water to the Oligarchy,
4) Examine the feasibility of raising the existing spillway, and
5) Replace the existing spillway with a more permanent~nonerodible
structure.

McCall Lake is a Class II - Moderate Hazard dam as determined by the State
Engineer's Office (SED). The potential exists for significant property damge to
improved property in the event of failure of a Class II dam while the lake is at
the high water line, but no loss of life is expected. The SED requires the
spillway pass the probable maximum flood (PMf) for a Class II dam. McCall Lake
is under the jurisdiction of the SED and there is currently no gage height
restriction for the lake.

The following scope of services are proposed to conduct a feasibility study
for McCall Lake repairs.

EXHIBIT A
(Feasibility Contract)

<y Mountain Consultants, Inc.
Induslnal CirCle. Suile A Lonomen;. Colorado 80501
s also in Denver. BOLlloer.: and Es!~~!ark. CC

303-i/2.5282
Melro ltne: 6c5-€283

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