I’m running a model to simulate a very flat floodplain. My area of interest is near the confluence of 2 rivers which during high stages, due to the flat nature of the terrain, become one. I’m using a lateral structure to transfer flow from the main rive into the tributary. If I run select the option of taking the lateral structure Tail water between two XS’s of the tributary there is no problem. Once I select the option for the TW to be between multiple XS’s then HECRAS never runs. It doesn’t give me any error, it just gets stuck in computing water surface profiles. Any ideas in what the problem might be? (i’m checking the optimization option for divide flow)
I’m having a similar problem with getting stuck computing the initial backwater for optimizing at a junction. Unsteady flow analysis has been running nearly 4 hours reporting “Initial Backwater, Split flow optimization, iteration n” with values of n between 1 and 30.
I would not have used this option. For this situation I would have added a levy to the cross section and set it at a height at which overflow into the tributary would begin.