A water tower, watershe, or elevated water tower is a very large elevated tower. Constructed for the purpose of holding a supply of water at a height sufficient to pressurize a water supply distribution system. Pressurization occurs through the elevation of water; for every 2.34 feet of elevation 1 PSI (pounds of pressure per square inch) is produced. 100 feet of elevation (@2.34=1PSI) produces 42.6 PSI of pressure, which is enough pressure to operate and provide for most domestic water pressure and distribution system requirements.