The Corps Water Management System (CWMS) includes four interrelated models to assist with water management for the basin:

- GeoHMS (Geospatial Hydrologic Modeling Extension)
- ResSIM (Reservoir System Simulation)
- RAS (River Analysis System)
- FIA (Flood Impact Analysis)

Lake where it flows in a southeasterly direction to empty into the Gulf of Mexico near Freeport, Texas. The Brazos River is the 11th longest river in the United States flowing 1,280 miles. The Brazos River and its principal tributaries Clear Fork Brazos River, Aquilla Creek, Bosque River, Leon River, Lampasas River, Little River, San Gabriel River, Navasota River, and Yegua Creek flow through mostly rural and agricultural areas. The largest urban areas are Waco, Belton, Georgetown, Richmond, and Freeport. The total drainage area of the Brazos River basin is approximately 45,625 square miles. The precipitation varies from west to east and from the north to south portions of the basin. The upper Brazos from the west to the east receives 15 – 30 inches, and from the upper to lower receives 30 – 45 inches, on average, each year. The basin, particularly in the southern basin, can experience extremely intense precipitation events capable of producing staggering rainfall totals. These systems range from intense thunderstorms to hurricanes.

The climate of the Brazos watershed varies considerably from temperate to subtropical. The average annual temperature is 59°F in its upper reaches and 70° in the coastal region. Normally, the winters are mild and short, even in the upper reaches, but severe weather is not unknown. Temperatures of zero and even lower have been recorded. The average annual rainfall is 29.5 inches, ranging from sixteen in the northwest to forty-seven in the southeast. Soil types along the Brazos vary from sandy loams to deep clay. A variety of natural vegetation ranges from scattered oak mottes and bunch grasses in drier areas to conifers and hardwoods in areas where rain is plentiful. Virtually the entire area of the watershed is suitable for some form of farming or ranching activity. The most important products of the region have been cotton, cattle, and oil.

Many reservoirs were constructed in the Brazos Basin, and they are managed for flood control, water supply, recreation, and other uses. Brazos River Authority (BRA) is the primary entity that manages surface water in the Brazos Basin. BRA has water supply contracts with USACE in all nine USACE reservoirs; Lake Whitney, Aquilla Lake, Waco Lake, Proctor Lake, Belton Lake, Stillhouse Hollow Lake, Georgetown Lake Granger Lake, and Somerville Lake. Additionally BRA operated three large water supply reservoirs that have impacts on USACE Water Management Operations; Possum Kingdom Lake, Lake Granbury, and Lake Limestone.

During non-flood control operation, the USACE reservoirs are operated for water supply requests from BRA. During flood control operations, the USACE reservoirs are operated to multiple downstream USGS gages to provide a balanced system approach of the USACE flood storage and the local water supply reservoir releases. Priority is first given to the local water supply reservoir releases at the downstream USGS gage locations.

The Brazos River supports Dow Chemical, one of the largest manufacturers of chemicals and plastics in the world. Dow has senior water rights on the Brazos to 48 billion gallons of water a year. In recent drought years Dow has requested Texas Commission on Environmental Quality (TCEQ) to suspend the junior rights of farmers, municipalities, and other users upstream to ensure their water demands are met.