Hydrologic Engineering Center

Free
Software to optimize reservoir operations for planners, operators, and managers
Free
HEC-SSP is an integrated system of software, designed for interactive use
Free
Simulates and monitors the work of dendritic watershed systems
Free
Performs steady and unsteady flow calculations
Free
HEC-ResSim is a program used to model reservoir operations
Free
Manages and imports GIS data to and from HMS