Four Corner - Texas Water Development Board

SITE OVERVIEWS
Detailed maps of each area are presented on Plates 2 and 3.
Four Comers Area
The Four Comers area is bounded by the State Highway 6 on the east, a line roughly parallel to
McKaskle Road on the south, FM 1464 on the west, and the proposed Bissonnet Road right of
way on the north. The area is bisected by Old Richmond-Boss Gaston Roads in an east to west
direction, and by Old Richmond-Gaines Roads in a north-south direction. The total study area is
about 3. 7 square miles. Roads within the area are generally two lane asphaltic concrete with
roadside ditches. Little commercial development is present. The Sprint Landfill is located near
the center of the site (Plate 2).
Cummings Road Area
The three subdivisions in the Cummings Road area are all located immediately north of the
Brazos River along stretches of Cummings Road, east ofFM 723. Roads in the Tinsley Estates,
Rio Brazos and C.J. Dickerson Subdivisions consist of two-lane asphalt roadways with roadside
ditches.
Geologic Setting
GEOLOGIC DATA REVIEW
A review of the Bureau of Economic Geology 1982 Geologic Atlas of Texas, Houston Sheet,
indicates that the uppermost geologic formation underlying the study areas is the Pleistocene
Beaumont Formation and Quaternary alluvial deposits associated with the Brazos River (Plate 4).
The Beaumont Formation (Qb, Plate 4) sediments consist primarily of clays, silts and sands
which were deposited in fluvial (river derived) and deltaic environments during the Pleistocene
Epoch by the ancestor of the present day Brazos River. The environments of deposition for
sediments of the Beaumont Formation are variable across the area. Distributary channels, levees,
point bars, and back marsh deposits are common in the Beaumont Formation.
The Quaternary alluvial deposits (Qal, Plate 4) of the Brazos River were deposited in a broad
floodplain ranging in width from two to five miles in Fort Bend County. The current course of
the river is located in the southern part of the floodplain and Oyster Creek, located in the
northern part, represents an abandoned course of the river. Sediments are primary sands and
gravels associated with channels, and clays associated with interchannel area.
In the Four Comers area the contact of the Beaumont Formation and Quaternary alluvium
roughly coincides with Red Gully. North and east of the gully, the area is located within the
Beaumont Formation. South and west of the gully, the soils are associated with the Quaternary
alluvial deposits of the Brazos River (Plates 4 and 6.1 ). In general the southern and western part
of the Four Corners area is likely to contain more sand deposits associated with the alluvial
formations, whereas the northern and eastern part is likely to be underlain by more clay deposits.
In the Cummings Road area the soils are entirely located within the Quaternary alluvial deposits
of the Brazos River. The Brazos River in this area takes a broad left bend and the subdivision is
located on the side of the river where point bar deposits have developed in the recent geologic
past. On the south side of the river, where Rosenberg is located, a cut bank is present and no
recent point bar deposits are present. Point bar deposits consist of crescent shaped sand bodies
2