1D Hydraulic Analysis and Modeling
HEC-RAS is an integrated system of software that performs one-dimensional (1D) hydraulic calculations for a full network of natural and constructed channels. The system is comprised of a graphical user interface (GUI), separate hydraulic analysis components, data storage and management capabilities, & graphics and reporting facilities. Currently the steady and unsteady flow hydraulic analysis components of HEC-RAS are fully implemented for use.
HEC-RAS has been developed for the U.S. Army Corps of Engineers. However, software developed at the Hydrologic Engineering Center is made available to the public whenever appropriate. Use is not restricted and individuals outside of the Corps of Engineers may use the program without charge. HEC will not provide user assistance or support for this software to non-Corps users. See the software vendor list to locate organizations that provide the program, documentation, and support services for a fee. Downloading this software indicates full acceptance of your responsibility in the use of this program.
This model is public domain and can be downloaded for FREE using this link.
See also the Watershed Modeling System
WMS or the Surface-Water Modeling System (SMS) which both provide a high qaulity graphical user interfaces for HEC-RAS. WMS and SMS have powerful tools for extracting cross-sections from digital elevation data, defining and referencing stream reaches using digital maps, generating the HEC-RAS input file, running HEC-RAS directly within the interface and integrating the HEC-RAS results with floodplain delineation or 2D hydraulic analysis.