2D Stage Boundary Conditions

[Anonymous]

I have done multiple tests within HEC-RAS 5.0.3 and one thing is consistent.

Stage BC’s do not work.

If the outfall of your hydraulic model needs to utilize a BC line that acts as the final outlet; do not use a stage BC line.

You can test this with any surface by just drawing a small 2D mesh with any number of cells, adding and input hydrograph at the top of the grid and a stage BC line at the downstream end. This stage can be tested for multiple elevations but none will work.

Visually it will seem like nothing is fairly wrong; but check your mass balance and you will immediately see a great discrepancy.

[dlhaggie]

I have noticed the same issue. I am trying to connect sections of 1D/2D RAS model for a large river with stage hydrographs at the downstream end and flow hydrographs at the upstream end. The 2D stage boundaries sometimes produce crazy hydrographs. Have you found any work arounds for this issue?

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