I am currently using SWMM 5 to model the Upper Bukit Timah catchment in Singapore for my master thesis. I have already tested several events of precipitation to model the flow on the outfall node. The results were reasonable, the modeled flow was closed to the observed one. Now, I am trying to model the flow for exceptional events (eg. 19Nov09: 90,64mm/h) for which I know the basin was flooded. And I have just realized that I get a negative flow for link C4 and other ones - see attached file. Consequently, the model does not show any flood in my basin...
Could someone help me with that? :-(
Thanks for your answer,