What’s the go-to software (2d-hydraulic modeling software) to use for simulating consequences from big rainfalls in planned urban areas?
Also, what kind of digital elevation model is needed (what format) to simulate the planned topography (does LandXML work)? Existing topography models are often GIS-raster data. Is this a must?
Sorry for answering your question quite late...Nevertheless, I suggest an open-source solution called Giswater. It's aimed for the integral water cycle managament (water supply, sewerage or flood risks). You can find more about it at https://www.giswater.org/software/?lang=en.
you may want to contact Will Shepherd from Sheffield University, who is coordinating a program CENTAUR, in which entities from several countries are involved
For drainage design we develop a software package called MicroDrainge (for UK) or XPDrainage (for International projects). If you are wanting to model larger catchments to simulate flooding, capacity issues etc, you might want to consider InfoWorks ICM. The 1D and 2D capability is integrated in one user friendly interface. I would be happy to speak with you or put you in the direction of more information.