A drainage system for engaging and removing accumulating drainage water with a sump pump liner, a sump pump disposed within the liner, and at least one contiguous void with an inner volume in fluidic communication with an inner volume of the liner. The void can comprise a low pressure void compartment disposed distal to the bottom of the liner, or the void can comprise a water harvesting arm with a proximal end retained by the main body of the liner and a body portion that projects from the main body. Liner-void apertures can be disposed in the bottom of the main body of the liner, and void-environment apertures can be disposed in a void bottom partition. The main body can have a rectangular cross section with a lateral water harvesting arm projecting from each sidewall.