PROJ00515

• Contract/PO #: FS0019X
• Contractor Name: Turkey Creek Snowball Creek Project CWRPDA 1985
• Contract Type: Loan
• Water District: 0
• County: Archuleta
• Loan Projects - Doc Type: Feasibility Study

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EXECUTIVE SUMMARY

This feasibility study was authorized in two parts by the Colorado Water
Resources and Power Development Authority in December, 1984, to examine
potential water supplies for the Town of Pagosa Springs. The reconnaissance
study examined two dam sites, one on Turkey Creek and one on Snowball Creek with
the feasibility study focusing on the selected site. A vicinity map is shown on
Figure E.S.-l. Figure E.S.-2 shows the Snowball Creek and Turkey Creek
reservoir sites.

Based on information collected during the reconnaissance portion of this
investigation it was recommended that the Snowball Creek dam site be the
preferred alternative.

Once the site was selected and prior to the geotechnical investigation the
topography for the dam site, reservoir basin, canal and pipeline route was
obtained from aerial photogrammetry. The geotechnical program was comprised of
drilling four holes along the proposed dam axis and excavating test pits
in potential borrow areas. The information obtained from the geologic and
geotechnical investigation revealed the following: adequate embankment materials
exist for dam construction; the dam foundation is suitable for a dam of the size
proposed; the seismic risk is judged to be low at the proposed site; and no
critical geologic or geotechnical conditions were identified that would preclude
construction of a dam and creation of a reservoir at the site.

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Four potential participants expressed interest in the results of this phase
of the study, but they were unwilling or unable to commit to being a sponsor at
this time. For the purposes of this study, only the water demands of Pagosa
Springs and Archuleta Water Company were considered in sizing the reservoir.
Their combined annual water supply needs in the year 2020 were estimated to be
2,691 acre-feet based on a projected population of 9,440.

Conservative assumptions were used in the operations study to determine the
size of the reservoir. The historic period used for the study, 1960 through
1980, was selected because it represents a period of below average runoff

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