HEC-2, named HEC-RAS, (River Analysis System) was released by the Corps in 1995. The later versions of HEC-RAS have the added capability to solve time dependent flows (unsteady). There are computational differences between HEC-2 and HEC-RAS so that they compute slightly different water surface elevations for the same input data. HEC-RAS PROCEDURES FOR HEC-2 MODELERS CHAPTER 1: INTRODUCTION The U.S. Army Corps of Engineers (USACE) Hydrologic Engineering Center's River Analysis System (HEC-RAS) supersedes its HEC-2 program, widely used in the HEC-RAS Hydraulics HEC-RAS is a one-dimensional steady flow hydraulic model designed to aid hydraulic engineers in channel flow analysis and floodplain determination. The results of the model can be applied in floodplain management and flood insurance studies. HEC RAS: DESIGN NOTE 1 VER. 1.0 S TEP 10; Draw a box around the polylines as shown in the following image and press [Enter]. All of these cross sections are now sample lines for the streams centerline alignment. Everything is now completed in order to export to a HEC RAS file. This feature is not available right now. Please try again later. HEC-RAS integrated with AutoCAD, MicroStation and ArcGIS, supports latest HEC-RAS 5 engine. Try GeoHECRAS and save 50% of your time. The HEC-RAS manual published by the Army Corps of Engineers is also available at this site. The installation instructions are given on the Internet. ILLUSTRATIVE EXAMPLES In this section there are four illustrative examples: HEC-RAS: 10 Steps These 10 steps can be used with simple culvert and bridge analyses. This approach will help you get familiar with HEC-RAS and ready for more complex projects. To download HEC-RAS, go to the US Army Corps of Engineers web site. (Search HEC-RAS). Before using HEC-RAS for your project, you will need to collect the HEC-RAS 5.0 now has a user interface that includes the RAS Mapper, which is used for 2D modeling. It is also possible to see the results in an