Hardening a Great and Growing City's Water Supply

Cities across the West face the threat of dwindling water supplies. Issues such as climate change, competing supplies, and litigation threaten water availability for municipal uses. In Colorado, where approximately 86 percent of water is used for agriculture (CFWE 2005) and the system of administration is prior appropriation, adequate water supply in an increasingly competitive market is no longer a certainty. Many municipalities whose systems are based on junior water rights have been forced to turn to innovative — and expensive — projects to develop the water supplies of the future. The City of Aurora, Colorado is a suburb to Denver and the third largest city in the state, with a 2008 population of nearly 312,000. For Aurora Water, meeting the increased thirst of a burgeoning city is a challenge. Continued growth and a possibly dwindling water supply have necessitated an evaluation of the city's water infrastructure and "out-of-the-box" planning to ensure that a reliable water supply is available for the future. In 2002, low rainfall and runoff brought the system's vulnerability to attention. With seemingly no water available to increase storage levels, reservoir levels fell to 25 percent full in March 2003, well below the desired minimum level and an adequate supply for only six months of indoor use in the City. This situation made perfectly clear the need for guaranteed reliability in the face of continued pressure on available water supplies.