The EPA WaterSense New Home Specification states that:
Ornamental water features financed, installed, or sold as upgrades by the homebuilder must recirculate water and serve a beneficial use.
Ornamental water features, such as fountains, ponds, waterfalls, man-made streams, and other decorative water-related construction that are financed, installed, or sold through the homebuilder must recirculate water and serve a beneficial use (e.g. wildlife habitat, stormwater management, and/or noise reduction).
The water consumption of an ornamental water feature can be reduced if smaller pumps, lower pumping rates, and/or pressure-reducing valves are used to reduce water flow. The higher the water flow, the more water wasted due to evaporation. Ornamental water features should be supplied by recirculating the water from the feature itself, increasing its water efficiency.
Recirculating the water reduces the amount of potable water used in an ornamental feature and helps to maintain any plant growths in the feature. Two types of pumps are available for recirculating water—submersible pumps and surface (or line) pumps. Both are normally powered by standard household electrical current. Submersible pumps sit on the bottom of the pool or feature. They may have attachments that power fountain jets or sprays or that supply waterfalls or streams. Surface pumps are concealed near the pool or feature, and water is drawn from the feature and delivered to various outlets through plastic tubing. Surface pumps are not only more expensive than submersibles, but many also require extra plumbing.