WSP11664

• File Number: 8220.128.J
• Description: Silt Project
• State: CO
• Basin: Colorado Mainstem
• Water Division: 5
• Date: 8/1/1961
• Title: Report of the Reappraisal of Direct Agricultural Benefits and Project Impacts - Silt Project-Colorado - Part 1 of 2
• Water Supply Pro - Doc Type: Report/Study

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General Description

The Silt project is located in southeastern Garfield County, Colorado.
Elevation of project lands varies from 5,500 to 6,300 feet. The climate
is semi -arid. Average annual prec ipi tation approximates 11 inches. The
average frost-free period varies from 128 to 141 days. Project lands are
all privately owned and are located on Harvey and Davie Mesas and in Dry
Elk Valley. Agriculture is the basic industry of the project area, with
livestock production being the principal type of fanning. Mining, rail-
roading and recreation also are a part of the local economy.

Proposed Project Development

The Silt project will furnish supplemental irrigation water for 4,479
acres of land presently irrigated wiU '~nly a partial water supply and
2,118 acres of non-irrigated land. In addition, 244 acres of Bureau of
Reclamation class 4 land and 226 acres of class 6W presently irrigated
land will continue to receive their present water supplies.

The project plan proposes the construction of the Rifle Gap Dam and Reser-
voir on Rifle Creek and the Silt Pumping Plant located on the Colorado
River. The reservoir will have an initial capacity of 12,650 acre-feet,
including 9,500 acre-feet of active capacity for irrigation and 3,150 acre-
feet inactive capacity for s8diment, fish and wildlife. In addition to
the dam and pumping plant, several canals and laterals, plus interceptor
and outlet drains, will also be constructed as part of the project. The
existing Harvey Gap Reservoir will continue to deliver water for use on
lands on Harvey Mesa. The increase in water suppl ies provided by the
project will be 5,030 acre-feet for presently irrigated lands and 6,700
acre-feet for new lands, a tot~ of 11,730 acre-feet, at the point of
diversion.

Evaluation of Direct Agricultural Benefits

Evaluation Areas

For purposes of the analysis, project lands were grouped into eight evalu-
ation areas. The soils, climate and water supply within each evaluation
area reflect similar crop adaptations, productivity, land and irrigation
development and production costs. Estimates of fann incomes and direct
agrIcultural benefits were developed for each area and for the project as
a whole. These areas have been designated as A, B, C, D, E, F, G and H.
Lands in evaluation areas A and B are geographically located on Harvey
Mesa, lands in C and D are located on Davie Mesa and lands in E, F, G and
H in Dry Elk Valley.

Evaluation Area A comprises 2,835 acres of presently irrigated land and
383 acres of new land. Soils are deep, medium to fine textured and have
slopes ranging from 0-6 percent. Most of the project soils having saline,
alkali and high water table problems are included in this evaluation area.

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