Four Corner - Texas Water Development Board

Four Comers Area
Thirteen investigations containing 72 borings were reviewed for this sub-area. The terminal
depths of the borings ranged from 5 to 50 feet below ground surface. The soils encountered were
mostly firm to very stiff clay, sandy clay, and silty clay surface stratums which ranged in
thickness from 4 to 25 feet. The plasticity index of the cohesive soils ranged from about 10 to
70. The cohesive soils were generally underlain by very loose to medium dense sands and silts.
Most of the very sandy and silty soils with plasticity indices less than 7 occurred to the south of
the sub-area where surface strata occasionally consisted of sands and silts. Calcareous and
ferrous nodules were usually scattered throughout the depth of exploration for most of the
borings in and near the sub-area. Surface layers of fill material ranging from about 2 to 4 feet in
thickness occurred fairly often on the boring logs. In one case, the fill material extended to about
10 feet below ground surface. Groundwater was recorded at levels ranging from 8 to 15 feet
below ground surface. However, several borings with depths up to 20 feet were dry.
Cummings Road Area
Four investigations with a total of 19 borings were reviewed for this sub-area. The terminal
depths of the borings ranged from 4 to 80 feet below ground surface. The soils encountered were
generally alternating strata of sandy and silty clays with sands and silts. Surface layers ranging
from about 2 to 8 feet in thickness were made up of either clays or sands. Loose to medium
dense silt, sand, and silty sand occurred from about 2 to 15 feet below ground surface. The
consistency of the cohesive soils ranged from firm to very stiff. The plasticity index of the
cohesive soils ranged from 8 to 53. Surface layers of fill material occurredwith depths ranging
from 4 to 10 feet below ground surface. Ferrous and calcareous nodules were scattered
throughout the depth of exploration for borings in the area. Groundwater levels ranged from 31
to 35 feet below ground surface in borings located just south of the Cummings Road area on the
southern side of the Brazos River. Borings north of the Brazos River were dry or no
groundwater information was available. Note that near the Cummings Road area the geology
changes from the Beaumont Formation on the south side of the Brazos River to Quaternary
alluvium on the north side.
SITE RECONNAISSANCE
A site reconnaissance of the area was performed on October 10 and 15, 1998 on foot and by
automobile. Streets and surrounding land were observed for land use. In addition, the
reconnaissance included a check for evidence, such as broken pavement, of subsidence, heaving
soils, and faulting such as broken pavement.
Four Comers Area
Most of the land in this sub-area appeared as large tracts of generally wooded land. The next
most predominant use of land occurred as residential use. Most of the residential developments
were rural developments with approximately one-acre lots. However, at least one modem urban
development with closely-spaced homes was observed along the south side ofBissonnet between
Richmond-Gaines Rd. and State Highway 6. Several of the rural lots were vacant or used for
horse grazing and gardening. Most of the commercial and industrial land use occurred along
State Highway 6 near Bissonnet and intermittently along FM 1464 between Bissonnet and Pecan.
Kingsbridge Elementary School was observed on the north side of Bissonnet west of State
Highway 6 and Hodges Bend Middle School was observed along the north side of Bissonnet just
east ofFM 1464. Most of the streets in this sub-area were asphalt pavements drained by roadside
ditches and lined with overhead power lines. Other utilities such as telephone and cable appear
to carried by overhead and buried lines. At least one gravel road, Oleta Lane, was observed and
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