Lower Washita - Water Resources Board - State of Oklahoma

The Canadian River aquifer consists of clay
and silt downgrading to fine- to coarsegrained
sand with lenses of basal gravel.
Formation thickness ranges from 20 to 40 feet
in the alluvium with a maximum of 50 feet in
the terrace deposits. Yields in the alluvium
range between 100 and 400 gpm and between
50 and 100 gpm in the terrace. The water is
a very hard calcium bicarbonate type with
TDS concentrations of approximately 1,000
mg/L. However, the water is generally suitable
for most municipal and industrial uses. The
aquifer underlies a small portion of Basin 15.
The Gerty Sand alluvial aquifer consists of
gravel, sand, silt, clay, and volcanic ash. The
saturated thickness varies from 5 to 75 feet,
averaging 28 feet. Depth to water ranges from
10 to 110 feet. Typical well yields vary from
100 to 450 gpm with some wells yielding as
much as 850 gpm. Water quality is fair to good
and moderately hard with TDS values usually
less than 1,000 mg/L. This aquifer underlies
portions of Basin 14.
The Washita River alluvial aquifer consists of
silt and clays downgrading into fine to coarse
sand. Wells in this aquifer yield from 200 to
500 gpm, while formation deposits average
70 feet in thickness. The water is hard to very
hard and generally of a calcium magnesium
bicarbonate type. TDS values are usually
less than 1,000 mg/L. This aquifer underlies
portions of Basins 14, 15, and 16.
The Red River alluvial aquifer, underlying
southern portions of basins 21, 22, and
23, consists of clay, sandy clay, sand, and
gravel. Located in Jefferson, Love, and Bryan
Counties, the aquifer supplies water for
Municipal and Industrial, Crop Irrigation,
and domestic purposes. The average saturated
thickness is estimated to be around 20-30 feet;
however, little data are available concerning
the aquifer and its potential as a major source
of groundwater.
delineated minor alluvial
aquifers. Minor Minor
bedrock aquifers may have
a significant amount of
water in storage and high
recharge rates, but generally
low yields of less than 50
gpm per well. Groundwater
from minor aquifers is an
important source of water
for domestic and stock
water use for individuals in
outlying areas not served
by rural water systems, but
may have insufficient yields
for large-volume users.
Groundwater Resources
Lower Washita Region
Minor bedrock aquifers in the region
include the El Reno, Marietta, Texoma, and
Woodbine bedrock aquifers; there are no
The major bedrock aquifers in the Lower Washita Region are the Antlers, Arbuckle-Simpson, and Rush
Springs. Major alluvial aquifers in the region are the Canadian River, Gerty Sand, Red River, and Washita
River. Major bedrock aquifers are defined as those that have an average water well yield of at least 50
gpm; major alluvial aquifers are those that yield, on average, at least 150 gpm.
10 Lower Washita Regional Report Oklahoma Comprehensive Water Plan