PROJ00137

• Contract/PO #: C153467
• Contractor Name: Greeley, City of
• Contract Type: Loan
• Water District: 0
• County: Weld
• Bill Number: XB 99-999
• Loan Projects - Doc Type: Feasibility Study

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CHAPTER V: PLAN OF DEVELOPMENT

1.0 SITE INSPECTIONS

1.1 General

Twin lakes Dam and Reservoir were inspected on several occasions during the
study by various members of the MKE staff. The first inspection was a site
reconnai ssance made on June 10, 1986. At that time a Phase I Inspecti on
Checklist was filled out, similar to the inspection form used by the State
Engi neer' s Offi ce. The reservoi r is presently under a zero storage
restriction from the State Engineer's Office and was drained at the time of
the inspection, except for the two permanent natural pools at elevations 9283
and 9277. The reservoi r remai ned empty duri ng all subsequent i nspecti ons.
This report is included in Appendix A. The dam was inspected again during the
bore hole and test pit phase of the geotechnical investigation between August
21 and August 27, 1986. Finally, the dam was inspected on September 22, 1986,
when additional soil samples were obtained.

1. 2 Dam

1.2.1 Description

Twin Lakes Dam is an earth embankment with a maximum height of about 35 feet
and a crest length of 220 feet at elevation 9300. The dam was constructed
around the turn of the century, of sand and gravel deri ved from weathered
bedrock, and appears to be founded on sound gneiss and pegmatite of
Precambrian age. Releases from the reservoir are controlled by an outlet
works that di scharges into an unnamed creek downstream of the dam. The
spillway is located in a low saddle in the northwest corner of the reservoir.
Periodic maintenance has been performed on the dam and spillway but there is
no record of any major modifications. Figure V.l represents the existing dam
in plan and section.

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