By Ted Cooke, General Manager, Central Arizona Project


The U.S. Bureau of Reclamation recently released the news that there will not be a shortage on the Colorado River in 2017.  This positive declaration can be attributed to water left behind in Lake Mead by CAP and its partners.  However, Reclamation’s projection shows, that without additional conservation actions, 2018 could be the first year of shortage on the Colorado River.  CAP and its local and interstate partners are working to extend existing conservation tools to avoid shortage in 2018, and to develop longer-term solutions to address the risks of critical shortages on the Colorado River. 

For the past few years, Central Arizona Project (CAP) has been working with the federal government, partner states in the Colorado River basin, and Mexico to address the declining level of Lake Mead, the country’s largest reservoir. The decline is not just because of extended drought, but also a structural deficit, which is the imbalance between supply and demand on the Colorado River. This  results in more water being taken out of Lake Mead than is flowing in, causing the lake level to fall approximately 12 feet per year, rapidly increasing the risk of shortage to Arizona and CAP.


CAP and its partners have been addressing the structural deficit on three levels – reducing demand (conservation), increasing supply (augmentation) and implementing system efficiencies. Two programs – a Memorandum of Understanding and Pilot Conservation Program – have made the difference.

In late 2014, CAP and the Arizona Department of Water Resources executed a Memorandum of Understanding (MOU) with the U.S. Bureau of Reclamation and municipal water agencies in California and Nevada. The agreement identified the need for proactive and voluntary actions to develop between 1.5 to 3 million acre-feet of new water for Lake Mead by the end of 2019. CAP is making significant contributions by storing 345,000 acre-feet in Lake Mead, completing its contribution this year.  To make this contribution possible CAP has entered into agreements with eleven irrigation districts in central Arizona to reduce their use of CAP water. CAP is also working with the City of Phoenix, Scottsdale, Glendale, and Peoria to replace a portion of their CAP water delivery with local supplies held by CAP, thus reducing the use of Colorado River water and conserving water in Lake Mead.

Another impactful effort is the landmark Pilot System Conservation Program, aimed at funding water-efficiency projects capable of effectively reducing demands on the Colorado River and bolstering water levels in Lake Mead and Lake Powell. The program was recognized by the White House earlier this year as an example of a collaborative program that can address long-term water supply risks in the Colorado River system.  Examples of projects already underway include enhancing agricultural irrigation systems, removing turf grass, forgoing underground storage and expanding water reuse.

Through conservation and cooperation, CAP and its Arizona stakeholders will have left more than 380,000 acre-feet of Colorado River water in Lake Mead by the end of the year, an effort that proved to be successful in avoiding shortages in 2016 and 2017.  However, current projections indicate a shortage is likely in 2018 unless existing conservation actions are extended, so CAP is committed to continuing current conservation programs.  In addition, CAP, following the leadership of the Arizona Department of Water Resources, is working to develop new programs, in cooperation with Reclamation, California, Nevada, and Mexico. Together, we are addressing the long-term risks to the Colorado River and improving the health of the entire system, united in our commitment to ensure an adequate water supply for the communities we serve.

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