USACE CWMS - Colorado River Watershed (SWF)

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)

The Colorado River flows northwest to southeast, beginning approximately near Lamesa, TX and emptying into the Gulf of Mexico near Bay City, TX. The river begins at an approximate elevation of 3,300 ft. While the perennial portion of the river is entirely located within Texas, its drainage basin of approximately 42,000 square miles does encompass part of eastern New Mexico. Precipitation within the Colorado River basin varies from west to east. The western portion of the basin receives 14-16 inches of precipitation, on average, each year. As one travels east, average annual precipitation exceeds 40 inches. The basin, particularly in the southeast, can experience extremely intense precipitation events capable of producing staggering rainfall totals. These systems range from intense thunderstorms to hurricanes.
Many reservoirs were constructed in the Colorado River Basin, and they are managed for water supply, irrigation, flood control, recreation, and other uses. Several entities assist with water management operations including: U.S. Army Corps of Engineers (USACE), U.S. Bureau of Reclamation (USBR), Upper Colorado River Authority (UCRA), Lower Colorado River Authority (LCRA), and Colorado River Municipal Water District (CRMWD). Reservoirs in the basin with USACE regulatory authority include: Hords Creek Dam within the Pecan Bayou basin, O.C. Fisher Dam and Twin Buttes Dam (Section 7) within the Concho River basin, and Mansfield Dam (Section 7) on the mainstem Colorado River.