This page is about the practice of infiltrating surface runoffThat potion of the water precipitated onto a catchment area, which flows as surface discharge from the catchment area past a specified point.Water from rain, snow melt, or irrigation that flows over the land surface. through an engineered soil with subterranean infrastructure. Simpler, residential installations are described in Rain Gardens. Linear installations, which convey flow, but otherwise have similar design are described in BioswalesLinear bioretention cell designed to convey, treat and attenuate stormwater runoff. The engineered filter media soil mixture and vegetation slows the runoff water to allow sedimentation, filtration through the root zone, evapotranspiration, and infiltration into the underlying native soil..