HEC-RAS is designed to perform one-dimensional hydraulic calculations for a full network of natural and constructed channels. HEC-RAS has been developed for the U.S. Army Corps of Engineers. It is also available for download and use by individuals outside of the Corps of Engineers without charge. Download learning tutorial on HEC-RAS from following Link:
Other Basic and Advance Tutorial on HEC-RAS is available to download on HEC-RAS Tutorial Page.
HEC-RAS Software can be downloaded from HEC-RAS website.