One of the most popular questions we get asked from our clients thinking about relocating to the Scottsdale, AZ area or thinking about purchasing a second home is about our water in Arizona. So, Don Matheson sat down with the Director of Water Resources for the City of Scottsdale, Marshall Brown, to answer questions about our water supply.
Arizona places a high priority on managing our water supply and securing water supplies that are available now and well into the future. Marshall states there are basically four categories of water supplies available in Arizona: Colorado River water, surface water other than Colorado River water, groundwater and effluent. The utility of each type of water depends on its quantity, quality, reliability and economic feasibility.
Surface water from lakes, rivers and streams is Arizona’s major renewable resource. However, because of our desert climate, the amount of surface water available can vary dramatically from year to year, season to season, and place to place. In order to make the best use of the surface water when and where it is needed, storage reservoirs and delivery systems have been constructed throughout the state. Most notable are the major reservoir storage systems located on the Salt, Verde, Gila and Agua Fria rivers. Almost all of the natural surface water in Arizona has been developed.
A separate category of surface water in Arizona is the water supplied through the Colorado River. The federal government constructed a system of reservoirs on the River to harness its supplies for use in several states. Arizona, California, Nevada, New Mexico, Utah, Colorado, Wyoming and Mexico share the River’s resources. Rights to use Colorado River water are quantified by a string of legal authorities known as the “Law of the River.” Based on this body of law, Arizona has the right to use 2.8 million acre feet annually of Colorado River water.
About 43 percent of the state’s water use comes from groundwater sources. Groundwater is found beneath the earth’s surface in natural reservoirs called aquifers.
Reclaimed water, or effluent, is the one increasing water source in our state. As our population and water use grows, more treated wastewater will be available. Reclaimed water is treated to a quality that can be used for purposes such as agriculture, golf courses, parks, industrial cooling, or maintenance of wildlife areas.