Abstract: A system for controlling ground water level in a particular surrounding area is disclosed. In particular, a dewatering system to safeguard the integrity of an in-ground swimming pool against damage or disruption caused by excess water accumulating at or near the soil surrounding the swimming is described. Such contiguous ground water, when it rises to an undesirably high level, for example, such as at a level higher than the level of water in a swimming pool, as a consequence of the resulting hydrostatic pressure, will cause adverse effects. The invention provides a system for the removal of ground water accumulating in a given area in excess of a predetermined level, such as around a swimming pool, until the desired level is restored.

Abstract: A floating therapy apparatus or "spa" is provided which is adapted to be floating in and to utilize the filtration and heating systems of a conventional swimming pool comprising a substantially water impermeable enclosure, which is immersed and supported in a conventional swimming pool, having only the upper peripheral edge of said enclosure above the surface of said pool. A water supply inlet is used to circulate heated filtered water from said pool filtration system into said enclosure, the spa water may be discharged into the main pool and/or a water return may be used to discharge water from the enclosure. Valving means for channelling substantially all or at least a disproportionately high amount of the capacity of the swimming pool water heater water is used as the feed water for said enclosure.