A personal computer (PC) based decision-support system (DSS) can provide real-time information for improved flood prevention and control in the Trinity River basin in Texas. It uses specialized versions of the well-known programs HEC-1 and HEC-5 for forecasting runoff and simulating reservoir operation, respectively. The DSS integrates these components with a specialized program manager. Although not yet used as designed, potential improved flood prevention and control with the DSS are demonstrated with historical storm data.