C150295 Feasibility Study

• Contract/PO #: CT2015-038
• Contract/PO #: C150295
• Contractor Name: Dillon, Town of
• Contract Type: Loan
• Water District: 0
• County: Summit
• Loan Projects - Doc Type: Feasibility Study

Town of Dillon
Loan Application Additional Information
The e~sting Yeservoir has a surface area of about 9 acres and is impounded by two
embankments about 5 to 7 feet high in a saddle on an east-west trending ridge. Water is
supplied by the Dillon Ditch via a divexsion from Salt Lick Gulch, located approxunately 1
mile north of the reservoir. The ditch flow is conveyed under Intexstate 70 (I-70) in an
inverted siphon. Salt Lick Gulch is tributary to the Blue Rivex. Cuxrently, flows are diverted
to ODR and retuxned to Salt Lick Gulch approximately 0.9 miles downstream of the
diversion via an oudet channel and culvert under I-70. Summit County Government and the
Towns of Dillon and Silverthorne have identified the need for additional water supplies to
meet future water demands within their service areas (CJPCO Upper Colorado River Basin
Study 1998). Each entity requires the increased water storage capacity and water supply
securiry. The purpose of this project is to provide additional watex storage capacity and
water supply security to meet e~sting and future domestic watex supply needs. Addirionally,
the Town of Dillon's current water supply from Straight Creek is susceptible to
contamination from several sources, including potential wildfire due to massive pine beede
kill and potential contamination fYOm hazardous material spills on I-70 in the watershed,
requiring an identified need to find an altexnative water supply. This project will impxove
the utility of Old Dillon Reservoir as an alternative water supply for the Town of Dillon.
The Town of Dillon and Suirunit County initiated studies on the feasibility of enlarging Old
Dillon Reservoir in 1995. In 2004 the County and Dillon solicited the assistance of the
Colorado River Water Conservation District to make the enlaxgement a reality. The Town
of Silverthorne was invited to parricipate in the enlargement by Suminit Counry. The thxee
entities entered into an IGA to formalize the.
The project includes seven elements:
1) enlarging the existing reservoir from 62 acre-feet (AF~ to 286 acre-feet;
2) restoring the outlet fxom ODR to the south to the Blue River (now Dillon Reservoix);
3) rehabilitation and modification of Dillon Ditch and its headgate on Salt Lick Gulch to
serve the enlarged reservoir;
4) rehabilitating the oudet to Salt Lick Gulch;
5) temporary road access improvements;
6) burying overhead power and cable lines
7) wetlands creation
Attachment for question B.8
Preliminar~ Sco~ing Document Old Dillon Reservoir Ex~ansion" com~leted by SAIC and
TZA in November 1995; Enlargement of Old Dillon Reservoir Engineering Feasibilitv
Study" com~leted by GEI Consultants, Inc. in ~une 1998; Evaluarion of Old Dillon
Reservoir First Enlargement" com~leted by the Coloxado R.iveY Water Conservation District
~CRWCD) in Decembex 2005 (copies of these docutnents are attachments to the loan
feasibiliry study.)
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