Modelling 'free flowing' foul sewer networks

when a foul sewer is simulated within flow, the software assumes a blockage within the network. This is not very useful when trying to design a network that just drains under normal circumstances.

The current work around suggested by Causeway is very time consuming and frustrating, especially on large networks.

Please can this amended to allow for a 'free flowing' foul sewer, similar to a surface water network. Dwelling(s) would be allocated to a foul drainage node, then add in the frequency of use. The software just simulates the flow rates into the network, and indicates where there is a surcharge/flood within the network.