A Simple Hydrologic Model for Sewer Inflow/Infiltration

Deen et al. found that a dual non-linear storage model was suitable for modelling the rain-related inflows to foulwater sewers. This paper extends their approach, showing that a storage of the form S = KQ{2} is applicable for the infiltration component. The runoff-routing model RORB can be used to simulate the observed behaviour, with the derived loss parameters indicating the proportions of rainfall entering the sewer as inflow and infiltration. An example application is included.