The original waterworks was founded in 1869 when the Burlington Railroad founded the City of Creston.  In 1935, the waterworks became municipally owned.  The original water supply came from Summit Lake built in 1894.  In 1953, Green Valley Lake was completed and was designed to provide more water during times of drought.  Eventually, Twelve Mile Reservoir was completed in 1983 and the Twelve Mile Water Treatment Plant was commissioned in 1986 and both still serve the City of Creston and surrounding areas to present day.

The Twelve Mile Treatment Plant is located near Twelve Mile dam.  It is a conventional surface water treatment plant that used ultra-filtration membranes to treat water from the Twelve and Three Mile reservoirs.  The plant produces approximately 4.3 million gallons per day.