Central Arizona Project prepared for Arizona’s water future

Central Arizona Project (CAP) is the primary steward of Arizona’s Colorado River water supplies and places paramount importance on the health and sustainability of the river. Since 2000, the Colorado River basin has endured the worst drought in centuries, yet Colorado River water users in California, Nevada and Arizona have not had to reduce the volume of water they receive from the river. How has this been possible? Largely because our predecessors constructed a system of reservoirs (including Lake Mead and Lake Powell) that allow the Colorado River basin to store four times the amount of water it receives in a normal year. Fortunately, those reservoirs were full when the current drought started and even 14 years later are still nearly half full.

But there will be Colorado River shortages in CAP’s future, perhaps as early as 2016 or 2017. It is important for Arizonans to understand what will happen and what will not happen when that day arrives. When a shortage is declared on the Colorado River, the impacts will first be felt by CAP’s agricultural customers, who could lose more than half of their CAP water. CAP has been working with the agricultural community as they have prepared for anticipated reductions. For many farmers, a CAP shortage will mean a return to groundwater pumping.

But a shortage on the Colorado River in the coming years will not require any reduction in CAP water deliveries to cities, towns or other municipal water providers. That is because those customers enjoy a higher priority to water, meaning that those uses are among the last to be cut when CAP supplies are reduced.

Over the longer term, growing water demands—both within the CAP service area and along the Colorado River—and more severe shortages will likely reduce the amount of water available from the river for delivery to CAP’s municipal customers. But CAP has prepared for that, working with the Arizona Water Banking Authority (AWBA) to store Colorado River water in underground aquifers in central Arizona where it can be recovered during shortage. So far, the AWBA has stored about 3 million acre-feet to protect CAP municipal supplies. CAP has been working for several years with the AWBA, the Arizona Department of Water Resources (ADWR) and stakeholders to develop a plan for the recovery of that water.

CAP is also actively engaged with ADWR, the other six basin states, the United States and Mexico to address the long-term health and sustainability of the Colorado River system and the growing water needs of the region. Achieving those goals will ultimately require a combination of improved efficiency, increased supply and demand reduction.

To that end, CAP has invested in a number of programs within our service area and our region—building a new reservoir in California, operating the Yuma Desalting Plant, and funding conservation in Mexico to preserve Colorado River supplies in Lake Mead. CAP also supports innovations in water conservation in partnership with California and Nevada water providers. Augmenting Colorado River supplies through desalination of sea water or brackish (salty) groundwater is also being investigated.

Drought preparedness is not only a CAP priority; it is a shared responsibility among all water users in the southwest. There is no magic bullet that can resolve all of these issues. Importantly, individual efforts to use water more efficiently and local efforts to develop alternative supplies are every bit as critical to our water future as the larger, regional projects. At CAP, we are committed as individuals and as an organization to doing our part to address the great challenges ahead.