a plastic downspout extension that runs underground

any subsurface drainage structure which intercepts or diverts underground water flows.

A drain below the ground surface, the lower portion, or all, of which collects subsurface water throughout its length.

A pervious backfield trench, usually containing stone and perforated pipe, for intercepting groundwater or seepage.

Underground drain which collects subsurface water and disposes of it at a proper location.