Test wells used in the study,
Surface-Geophysical Characterization of Ground-Water Systems of
the Caloosahatchee River Basin, Southern Florida, 2001, WRIR 01-4084
figure 1 |
Abstract: |
The Caloosahatchee River Basin, located in southwestern Florida, includes
about 1,200 square miles of land. The Caloosahatchee River receives
water from Lake Okeechobee, runoff from the watershed, and seepage
from the underlying ground-water systems; the river loses water through
drainage to the Gulf of Mexico and withdrawals for public-water supply
and agricultural and natural needs. Water-use demands in the Caloosahatchee
River Basin have increased dramatically, and the Caloosahatchee could
be further stressed if river water is used to accommodate restoration
of the Everglades. Water managers and planners need to know how much
water will be used within the river basin and how much water is contributed
by Lake Okeechobee, runoff, and ground water. In this study, marine
seismic-reflection and ground-penetrating radar techniques were used
as a means to evaluate the potential for flow between the river and
ground-water systems. Seven test coreholes were drilled to calibrate
lithostratigraphic units, their stratal geometries, and estimated
hydraulic conductivities to surface-geophysical profiles. A continuous
marine seismic-reflection survey was conducted over the entire length
of the Caloosahatchee River and extending into San Carlos Bay. Lithostratigraphic
units that intersect the river bottom and their characteristic stratal
geometries were identified. Results show that subhorizontal reflections
assigned to the Tamiami Formation intersect the river bottom between
Moore Haven and about 9 miles westward. Oblique and sigmoidal progradational
reflections assigned to the upper Peace River Formation probably
crop out at the floor of the river in the Ortona area between the
western side of Lake Hicpochee and La Belle. These reflections image
a regional-scale progradational deltaic depositional system containing
quartz sands with low to moderate estimated hydraulic conductivities.
In an approximate 6-mile length of the river between La Belle and
Franklin Lock, deeper karstic collapse structures are postulated.
These structures influence the geometries of parallel reflections
that intersect the river channel. Here, reflections assigned to the
Buckingham Limestone Member of the Tamiami Formation (a confining
unit) and reflections assigned to the clastic zone of the sandstone
aquifer likely crop out at the river bottom. Beneath these shallow
reflections, relatively higher amplitude parallel reflections of the
carbonate zone of the sandstone aquifer are well displayed in the
seismic-reflection profiles. In San Carlos Bay, oblique progradational
reflections assigned to the upper Peace River Formation are shown
beneath the bay. Almost everywhere beneath the river, a diffuse ground-water
flow system is in contact with the channel bottom. Ground-penetrating
radar profiles of an area about 2 miles north of the depositional
axis of the deltaic depositional system in the Ortona area show that
progradational clinoforms imaged on seismic reflection profiles in
the Caloosahatchee River are present within about 17 feet of the ground
surface. Ground-penetrating radar profiles show southward dipping,
oblique progradational reflections assigned to the upper Peace River
Formation that are terminated at their tops by a toplapping or erosional
discontinuity. These clinoformal reflections image clean quartz sand
that is probably characterized by moderate hydraulic conductivity.
This sand could be mapped using ground-penetrating radar methods. |
Metadata: |
caloo2001well_point |
Shapefile: |
caloo2001well_point [ZIP 10 KB] |
Online Report: |
WRIR 01-4084 |
Browse Graphic: |
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