Depth to Soffit on Manhole Types

Within Flow, I believe that we have found something where a feature could be slightly amended to aid some standard design processes.

Currently, within “MH types”, there is a section where standard/minimum manhole diameters can be set by depth. We previously understood this to be depth to the soffit of the pipe, however, this looks to be depth to invert. For adoptable networks, standard manhole diameters and depths are set by the depth to soffit for systems designed in line with DCG.

For example, we have attempted to use values which result in a manhole diameter being 1350mm for depths to soffit of less than 1.5m. We had a manhole chamber with a total depth to invert of 1.572m, but a pipe diameter of 300mm. As the depth is greater than 1.5m, this was setting the manhole at 1200mm diameter, however, this should have been identified as 1350mm diameter as per our parameters.