Abstract: Apparatus for controlling the moisture in the ground surrounding a building comprising a circumferential conduit extending around the building approximately ten inches below the ground level and from six to twenty-four inches away from the foundation of the building. The circumferential conduit is composed essentially of porous flexible hose capable of permitting seepage of water from the inside of the hose to the outside thereof through the pores of the hose when water under pressure is fed into the interior of the hose. A supply conduit connects at one end to a water main, and at its other end through an on-off valve, a pair of check valves connected in series, a pressure regulating valve for reducing the pressure from the water main to about 1 to 5 psi, to a terminal conduit for conducting water under 1 to 5 psi into a tee connection in the circumferential conduit.