WSP11214

• File Number: 8200.776
• Description: Uncompahgre River General
• State: CO
• Basin: Gunnison
• Water Division: 4
• Date: 1/1/1983
• Author: West Slope Hydro Par
• Title: Before the United States of America Federal Energy Regulatory Commission - Application for License for Major Project - Uncompahgre Valley Hydroelectric Project Number 2
• Water Supply Pro - Doc Type: Report/Study

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Mas'S'! .,.

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B.Solls
Soi~ in the Uncompahgre Valley have been classified into
four primary types: 1) soils formed on and from shale of the
Mancos Formation, 2) soils formed on stream terrace de-
posits, 3) soils formed on and from sandstone of the Dakota
Formation, and 4) recent alluvial flood plain soils adjacent
to the Uncompahgre River. The first two soil types listed
above are the most important with respect to the proposed
hYdroelectric developments. Due to the semiarid climate of
the area, the soils have been formed under a sparse vegeta-

tive cover resulting in only moderate to low organic content.

These soils have not been leached to any great depths and,

therefore, retain much of the natural fertility and salinity

of the parent material. They are moderately calcareous and
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have slight to moderate profile development.

About thirty-four percent of the irrigated acreage in the
Uncompahgre Valley consists of soils formed on and from the
Mancos Formation, also known as adohe soils. The Mancos

Formation is a calcareous marine shale and is fractured and

jointed near the surface. During the weathering process,

salts in the shale are dissolved and redeposited in the

joints and bedding planes of the weathered shale. Most of

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