Applicable to OpenRoads Drainage, CivilStorm, and StormCAD

Bentley drainage software tries to do too much / it tries to do ALL the calculations, even if you don’t want to.

There have been times I have had separate drainage models: one for inlet spacing/gutter analysis, and another for the storm sewer network. This was necessary because the inlet spacing analysis required us to look at the system from the roadway high points to a sag for multiple roadway segments and highway on/off ramps. The storm sewer networks did not easily follow this delineation, so separate models were needed.

It would be nice for the drainage software to allow you to toggle on/off inlet computations. If you want perform inlet computations, the software can do check for road/gutter slopes, gutter shapes, gutter elements, calculate spread, etc…. But if you do not want to perform inlet computations, you could toggle this off and any drainage areas connected to an inlet will receive the runoff flow from the drainage area and no computations related gutters/inlets would be performed.

I've also run into this issue where the inlet calculations are performed separately using different criteria specified by the local jurisdiction, and the storm sewer are performed assuming all the flow from the catchment area is intercepted by an inlet and directed into the storm sewer.