Our clients are more and more trying to figure out if damage to a property is caused by water from the public area (which is the responsibility of the client) or from private areas (which is not). When rainfall on mesh can pick up a tracer (eg. from existing objects like infiltration zones or roughness zones) we think we'll be able to better help our clients.
As a workaround can't you have a 2D Node that floods right away to the mesh with the 2D node having a inflow pollutograph?