In a SWMM network, an aquifer is a subsurface permeable area or zone used to model groundwater which infiltrates from subcatchments that are located above it. An aquifer may also allow the infiltration of groundwater into the drainage system, and depending on the hydraulic gradient, it may also allow the removal of surface water from it.
An aquifer may contain an unsaturated as well as a saturated area, and can be assigned to one or more subcatchments to provide information about soil moisture, evapotranspiration and percolation.
Aquifer parameters are edited in the Aquifer Grid Window of the Subcatchments Grid or the Aquifer Property Sheet.