Hello all,

I am currently working with a 1D/2D coupled hydraulic model of a river in Infoworks ICM. My model includes the sewer network (combined and storm systems), the river that runs through the city and its surroundings, and the urban ground surface for which a 2D mesh was built with LiDAR data. These three systems are coupled and flows from a system to another are taken into account.

My aim is to estimate the velocities and the water depths on the ground surface during a severe flood that caused significant damage in the urban area (up to 2 meters of water depth).

During 1D/2D coupled simulations of the storm, I noticed that not enough water is present on the 2D zone compared to some measurements, because many of the manholes that are flooded and that release flood water on the ground surface are located outside of the 2D mesh, where LiDAR data is missing. I would therefore like to take that flood water and put it back in the 2D zone to observe the velocities and depths, using only 1D links and nodes.

I have tried several options that have already failed:

- using 2D points sources referring to inflow events calculated from the flood volumes : no water observed on the 2D zone despite matching 2D point sources with inflow events
- using overland conduits (representing the roads where flood water runs) from manholes outside of the 2D zone to manholes inside the 2D zone

The last option, using overland conduits to represent roads as channels for the flood water, seems to be the most promising. I however have issues regarding the discharge of the overland conduit to the 2D mesh.

I tried using Oufall 2D nodes to release the water into the 2D mesh but only in some very rare cases I was able to see water on the 2D zone, despite the fact that the ground level and the flood level of the Oufall 2D node are the same as the mesh element ground level in which it is located.
I checked that the cumulative DS volume of the conduit is the same as the flow volume into the 2D zone of the outfall 2D node.

I would really like to know why some outfall 2D nodes do not discharge any water on the surface. I saw in the log result file that some flows from nodes to 2D mesh were limited. Do you think it might cause that problem ?

If you have alternative methods to put that excess flood water into the 2D mesh, I would like to hear it too.

Cheers,

Nicolas