Vertical Walls-What are the Implications?

Many water surface profile software programs prior to HEC-RAS had a quirky rule against having perfect vertical sides.  In other words, you could not have two or more elevations at the same stationing.  A perfect example of this is a rectangular flume.  The workaround for the older software was to define the tops of the […]

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The Measuring Tool

I don’t think you’ll find this anywhere in the manuals, but HEC-RAS has a very convenient tool for measuring lengths and slopes in the Geometry window and just about any graphical plot.  It only works in the geometry window if your RAS model is georeferenced, as it measures distances based on coordinates.  However, in the […]

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Stabilizing a Dynamic Unsteady HEC-RAS Model

One of the most frustrating aspects of unsteady HEC-RAS modeling can be the model stabilization process. You know, you’ve gone to great lengths collecting the best survey/topo data and solid hydrology. Then you’ve painstakingly spent hours…possibly days entered all of that data only to find that once you press the “Compute” button, the model crashes. […]

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Downstream Boundaries

I just received this question about downstream boundaries in HEC-RAS, and thought it would make a nice post here on RASModel.com. “…regarding the boundary condition, if I use critical depth instead of normal depth will it be unacceptable?  When choosing the normal depth I need to enter a slope, can i use just one slope […]

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