As used in this chapter, the following terms shall have the meanings indicated:
Any production or piece of work artificially built up or composed of parts and joined together in some definite manner which requires location on the ground or attachment to something having a location on the ground and used accessory to a private residence.
Any watertight container open at the top resting on the ground, not exceeding four feet overall in height from existing ground level and capable of being wholly or partly filled with water or other liquid and so constructed that it may be readily taken apart and stored at the end of the swimming season.
Any watertight container open at the top having a depth of 12 inches or greater or a volume in excess of 100 cubic feet, constituting an accessory structure.