In landscape architecture and garden design, a water feature is one or more items from a range of fountains, pools, ponds, cascades, waterfalls, and streams. Before the 18th century they were usually powered by gravity, though the famous Hanging Gardens of Babylon are described by Strabo as supplied by an Archimedean screw.[1] Other examples were supplied with water using hydraulic rams.
Since the 18th century, the majority of water features have been powered by pumps. In the past, the power source was sometimes a steam engine, but in modern features it is almost always powered by electricity. There is an increasing range of innovative designs as the market becomes more established and people become more aware of alternate installation methods, such as solar power. The advantages of using solar power include environmental benefits, no electrical lines in the garden, and free energy.