Southwest - Jackson Gulch Reservoir Expansion Project_Basin Water Activity Summary

• Basin Roundtable: Southwest
• Applicant: Mancos Water Conservancy District
• Description: Jackson Gulch Reservoir Expansion Project
• Account Source: Basin
• Board Meeting Date: 7/11/2007
• Contract/PO #: 0800000000076
• WSRA - Doc Type: Water Activity Summary Sheet - CWCB Evaluation/Approval Documents

Water Supply Reserve Account – Grant and Loan Program
Water Activity Summary Sheet

Applicant: Amount Requested:
Mancos Water Conservancy District $80,000.00
Water Activity Name:
Jackson Gulch An additional $20K will be requested from
Reservoir Expansion Project the Statewide Account in September.
Water Activity Purpose:
Technical Assistance for a Feasibility Study
County: Source of Funds:
Montezuma Basin Account
Drainage Basin:
Southwest
Water Source:
Mancos River

Water Activity Summary:
The Mancos Water Conservancy District is within Montezuma County and the Mancos River Drainage
(Mancos Valley). The District serves about 15,000 acres of the Mancos Valley, including the Town of
Mancos and the surrounding rural community. The District operates the Jackson Gulch Dam and
Reservoir with almost 5 miles of inlet/outlet canals. The existing reservoir is an off stream storage
facility at 7830’ MSL with a capacity of 10,000 a-f behind a rock-faced earthen dam. District water is
used for irrigation, municipal, hydroelectric, recreation, livestock, wildlife, environmental projects,
wetlands mitigation and fire protection. The population of the District is approximately 2,350 and is
growing moderately. Land use is primarily ranching (cattle, sheep, horses) and farming (grass and
alfalfa hay). The jobs in the Mancos area include rancher/farmer, logging, construction, teacher, welder,
mechanic, administrator, local, state and federal government and commercial enterprise. The local area
has 3 water treatment facilities, the Town of Mancos, the Mesa Verde National Park and the Mancos
Rural Water Company, which together serve approximately 1200 domestic and commercial water taps.

Following the general trend of the state, the Mancos Valley is experiencing a shift in demographics.
Agricultural lands are being subdivided. Demands for new water are changing from primarily
agricultural to commercial and household purposes. The Mancos Valley is a potential bedroom
community for the Durango area held back by the lack of water to treat for domestic purposes.

The area to be studied is Jackson Gulch dam, reservoir and the borrow pit that was created with the building
of the original dam. The Bureau of Reclamation (BoR) will conduct the feasibility study as outlined in the
attached Project Management Plan:

1.
Jackson Gulch Dam. ($80,000--Basin Funds for BoR Study)
The funds will be used to prepare a feasibility level study for increasing the storage capacity
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of the reservoir, including raising the dam a total of 5’.
The study will define structural needs for the Dam and related features.
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Establish the additional water that can be stored, construction cost estimates and impacts that
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must be mitigated.

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. Construction of Lake Mancos Dam, Reservoir and Canals. Total cost is $38,000. ($20,000—State
Funds for Jackson Gulch Borrow pit study. Request before the CWCB will occur at the September 2007
meeting.) This study will:
Develop information on feasibility of a new Lake Mancos Dam in the borrow pit.
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