7285

• UCREFRP Catalog Number: 7285
• Author: Stewart, J. M.
• Title: Summary of Water-Resources Activities of the U.S. Geological Survey in Colorado, Fiscal Year 1987.
• USFW Year: 1987.
• USFW - Doc Type: Open-File Report 87-388,
• Copyright Material: NO

PROJECT NUMBER:

CO-81-143

PROJECT TITLE:

Upper Black Squirrel Creek Basin
Ground Water

STUDY LOCATION:

Black Squirrel Creek basin,
El Paso County, Colorado

COOPERATING AGENCY:

Cherokee Water and Sanitation
District, and City of Colorado
Springs, Department of Public
Utilities

PROJECT CHIEF AND
OFFICE:

Douglas L. Cain, Subdistrict Office, Pueblo

PROJECT DURATION:

July 1983 through September 1988

PROBLEM: The upper Black Squirrel basin is designated by the State of Colorado
as a ground-water basin and a major source of water for future supply.
Large water-level declines have occurred in the basin since 1964. Recent-
ly, additional water-supply requirements have been created by the new
Consolidation Space Operations Center east of Colorado Springs. Existing
and anticipated water-supply demands make it necessary to collect and
evaluate hydrologic data to monitor ground-water changes, and to use the
data to develop a digital (3D model).

OBJECTIVES: Establish a ground-water level monitoring program consisting of
bimonthly measurements. Evaluate changing water-quality conditions in
alluvial aquifer. Develop a 3D hydrologic model of ground-water system
to determine availability and movement of ground water.

APPROACH: Continue evaluated services program with Cherokee Water and Sanita-
tion District for bimonthly water-level measurements. Measure specific
conductance; selectively sample ground water for chemical analysis.
Perform aquifer tests. Evaluate all data and develop a digital model of
the hydrologic system.

PROGRESS: The ground-water database, GWSI, was updated to the present with
hundreds of water-l eve 1 measurements collected since 1964. Water-l eve 1
measurements were collected and processed on five continuous ground-water
level recorders through 1984. Forty-three wells were sampled for asso-
ciated chemical constituents. Areas where nitrate concentrations were
near or above the drinking-water standard were identified. A two-
dimensional ground-water model was developed and calibrated. Projections
of future water-level declines were made.

PLANS FOR FY 87: Data will be collected to better define the potentiometric
surfaces of the bedrock aqui fers and the head gradi ents between the
bedrock aquifers and the alluvial aquifer, and the applicability of
temperature-profi 1 i ng methods in est imat i ng ground-water flow wi 11 be
evaluated.

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