An infiltration gallery is a structure including perforated conduits in gravel to expedite transfer of water to or from a soil.
Primarily, upright plastic pipes capped with simple grates are placed every 5–8 metres along the low point of a slope, to handle heavy surface runoff.
About ten per cent of the surface area of a horizontal pipe is then perforated slightly and surrounded by gravel.
Initially, runoff will exit the pipe and infiltrate the gravel to the soil beyond, dissipating naturally.
Thus, a catchbasin is placed at the lowest point of the sloping ground, which is connected to the storm sewer system at large.