WSP12002

• File Number: 8509
• Description: San Luis Valley
• State: CO
• Basin: Rio Grande
• Water Division: 3
• Date: 8/10/1987
• Title: San Luis Valley Confined Aquifer Study ‎(Phase I)‎ Final Report
• Water Supply Pro - Doc Type: Report/Study

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INTRODUCTION
The report contained herein presents the documentation, findings, and
recommendations concerning Phase I of the San Luis Valley Confined Aquifer
Study. The primary aim of Phase I is to develop the information necessary to
assess the feasibility of developing ground water from the confined aquifer
system which underlies the San Luis Valley of south-central Colorado in the
depth range of about 1000 feet to 6000 feet below ground surface (Figure S.l).
In this summary, we present the Phase I results for the confined aquifer
system below about 3000 feet (termed the deep confined aquifer), as well as
for the confined aquifer system from about 1000 feet to 3000 feet (termed the
shallow confined aquifer).

Included under the original Plan of Study for Phase I were analyses
designed to assess whether sufficient quantities of ground water exist in the
shallow and deep confined aquifers of the Valley, of acceptable water quality,
and at sufficient potentiometric (artesian) pressure to make development of
this resource economically feasible. These questions have been answered by
the investigations discussed in this report. The Phase I study is believed to
be the first extensive hydrogeologic evaluation to have specifically addressed
the feasibility of ground water development of the deep confined aquifer of
the Valley.

Also included under the original Plan of Study were analyses and
investigations necessary to address the institutional issues of concern in
developing a ground water supply from the deep confined aquifer system of the
Valley. Early in the Phase I work, it was concluded that these studies should
focus first on the physical and economic feasibility of ground water
development, and should set aside the question of institutional issues until
more hydrogeologic and hydrochemical data could be assembled for the deep
confined aquifer. This led to the decision to concentrate initially on the
confined aquifer system which lies below a depth of 3000 feet, where it was
envisioned that institutional issues might be of less concern.

The geographical scope of the Phase I studies includes the entire San
Luis Valley, and all of the drainage area of the Rio Grande in Colorado. Even

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