The Swimming Pools Act describes a swimming pool as an excavation, structure or vessel:

• that is capable of being filled with water to a depth of greater than 300 millimetres
• that is solely or principally used, or that is designed, manufactured or adapted to be solely or principally used for the purpose of swimming, wading, paddling or any other human aquatic activity.

A spa pool is classified as a swimming pool by the Act. The definition of a spa includes any excavation, structure or vessel in the nature of a spa pool, flotation tank, tub or the like, but not a spa bath.