There are two primary types of water: surface water and ground water. Surface water is water found above ground — in seas, rivers, creeks and lakes. Ground water is water below the earth’s surface in deposits called aquifers. Some communities in Colorado use surface water while others use a mix of surface and ground water.
All of the water in Denver’s water system is surface water. It comes from snowpack in the mountains, which melts and runs off into four raw water collection systems: the South Platte system, the Moffat system, the Roberts Tunnel system, and the Williams Fork reservoir and power plant.
A large system of conduits and valves helps to transport water from collection systems to a series of reservoirs where it is stored. When the water is needed, conduits carry it to one of three treatment plants, where it is cleaned of impurities and made “potable” — ready to drink. Potable water is stored in a series of underground holding reservoirs until it is used. In 1998, Denver Water treated and delivered over 77 billion gallons of water to almost one million customers.