The POSGCD has within its boundaries formations of the Carrizo-Wilcox, Trinity, Queen City, Sparta, and Brazos River Alluvium aquifers. Following is an approximate description of the aquifers and their location within the District. Each description will also include an estimate of Projected Water Availability in acre-feet per year according to Table 4 of the 2002 State Water Planning Database.
The District is divided into groundwater management zones for the purposes of identifying the different characteristics and necessary management practices for each of the groundwater sources located there. These zones are as briefly described below:
Trinity Management Zone
This zone includes that part of the Trinity aquifer located in the northwest part of the
Brazos Alluvium Management Zone
This zone is located along the eastern boundaries of the District and is limited to the water bearing alluvial sediments of the Brazos River.
Queen City and Sparta/Jackson Management Zone
This zone includes all of the water-bearing outcrop and down-dip formations of the Queen City and Sparta/Jackson aquifers which are found in the District.
Carrizo-Wilcox/Simsboro Shallow Management Zone
This zone includes all of the water-bearing formations of the outcrop and down-dip of the Carrizo-Wilcox and Simsboro aquifers including, and north and west of, the Milano Fault Zone.
Carrizo-Wilcox/Simsboro Deep Management Zone
This zone includes all of the water-bearing formations of the outcrop and down-dip of the Carrizo-Wilcox and Simsboro aquifers located south and east of the Milano Fault Zone.