I haven’t been able to find this question asked previously in the forum. If it has been, please send me the link to the answer!
I have a large model that has a main river (with many cross-sections) and a lot of interconnected storage areas surrounding the river (representing overland flow that occurs when the main river floods, as well as overland flow from tributaries). The model keeps getting stuck at a single storage area, hitting the max iterations over and over again. Strangely, the elevation it gets stuck at isn’t on the steep lower portion of the storage area curve, it’s up on the higher end where the curve flattens out quite a bit. The elevation also doesn’t seem to be significant relative to the geometry of the 2 storage area connections or the lateral structure connecting the SA to a river reach (the troublesome water surface elevation is well above the lowest point on all the connections, so it doesn’t seem to be an issue of a small amount of flow going over a very long weir, which I’ve seen in the past). The storage area that’s causing the problems is being used to represent a very small stream that has water backing up into it during large events on the main river, but this technique has been used at other confluences with no problems. Is the backwater issue what’s causing the problem? Or is there something else I can look at to get this instability to stop ocurring? If anyone has any ideas I’d love to hear them. Thanks!