Overview

HEC-RAS (River Analysis System) is the hydraulic modeling software package used to compute water surface profiles based on inflows from the HEC-HMS and HEC-ResSim models. HEC-RAS is primarily used to generate inundation outputs, including polygons and depth grids, that can be used as inputs to the HEC-FIA model or displayed on an inundation map.  

Accomplishments

HEC-RAS 6.4.1 was released in the third quarter of FY23 and included many new features and bug fixes, a few of which are listed below.

  • 1D Unsteady Flow Encroachments - 1D unsteady flow encroachment analysis provides capability for the five traditional methods of analysis as well as integrating Encroachment Regions for limiting the water surface in the floodplain fringe.
  • 2D Unsteady Flow Encroachments - The tools and methods in HEC-RAS allow the user to create Encroachment Regions, which are applied as a Terrain Modification (fills the floodplain fringe, thereby allowing the reuse of the same 2D mesh for a Base geometry and the Encroached run).
  • Flow Optimization - Flow Hydrograph Optimization in HEC-RAS is an automated tool that allows the user to specify a Reference Location for the model to monitor either Stage or Flow and perform adjustments to the inflow hydrographs to hit a Target Value specified by the user.
  • HEC-RAS Mapper Render Mode Improvements - An additional interpolation scheme is available in 6.4. A simple sloping method using 2D cell corners for interpolation has been re-introduced.
  • Composite Land Classification - A new feature for land classification values allows Manning's n-values to be spatially composited over each cell rather than a single point value at the center.
  • Reference Area Query - Users can add a "Reference Polygon" to HEC-RAS Mapper (like a reference line or point) and aggregate or average results for all the cells in that area.

In addition to development in the HEC-RAS version 6 line, much progress has been made on version 7 in the areas of mesh development tools, terrain creation and rendering, and running simulations using a new computation engine.

Field Support and Technology Transfer

  • HEC-RAS Version 7 Demonstration Webinar
  • HEC-RAS Monthly Working Sessions on Microsoft Teams
  • Advanced 1D/2D Modeling with HEC-RAS PROSPECT Course
  • Steady Flow with HEC-RAS PROSPECT Course
  • HEC-RAS 1D Fundamentals Course (Tulsa District)
  • HEC-RAS 2D Modeling Course (New Orleans District)
  • HEC-RAS 2D Modeling Course (St. Paul District)
  • HEC-RAS 2D Modeling Course (Huntington District)
  • HEC-RAS 2D Sediment Course (St. Louis District)