Pipeline Infiltration
Infiltration-Inflow is the water that enters the system from the ground through defective pipes, pipe joints, connections.
The SWMM solver supports a user-defined infiltration flow (Flow /Additional Infiltration) and other solvers have additional support to allow a few different load types, see "Conduit-Infiltration/Inflow and Seepage" for details.
Seepage is the flow loss from the system; it is the seepage of the conduit (or channel) from its bottom and side walls into conduit's surrounding soil. Only SWMM solver supports the conduit seepage loss calculation among the four solvers. User can specify a seepage loss rate and the solver calculates the seepage loss at each time step using the loss rate and conduit flow area (based on the length and wetted-perimeter).
To model infiltration along a pipeline, it is possible to specify infiltration as:
The first four types of infiltration are constant rates while the last two are time varying inflows.
Conduit infiltration flow is added after the upstream section of the conduit by the calculation engine. Therefore, when viewing flow results, you will see the infiltration flow in the middle section and the downstream section of the conduit.