Marie Pearthree

Marie Pearthree is deputy general manager of Strategic Initiatives and Public Policy at Central Arizona Project.

In response to extended drought in the Colorado River Basin which is increasing the risks of shortage to Arizona and the Central Arizona Project (CAP), CAP and its partners throughout the Colorado River Basin system are investing in ways to put more water in Lake Mead, which is the country’s largest reservoir. According to our latest calculations, by the end of 2016, we will have boosted the lake level by nearly 5 feet. To put that in perspective — that’s the difference between being in a shortage and not being in a shortage this year.

This is due in large part to collaborative efforts and to everyone’s contributions making a difference. Together, we’re improving the health of the Colorado River and the prospects for continuing an adequate supply to the people it serves.

We have been working with the federal government, our partner states, and Mexico to address what we call the structural deficit — the imbalance between supply and demand on the Colorado River that leads to more water being pulled out of Lake Mead than is put in — roughly 1.2 million acre feet a year, resulting in a drop of 12 feet a year.

We’ve 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 already made a noticeable 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 and state parties in California and Nevada. The agreement identified the need for proactive and voluntary actions to develop 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. To make this contribution possible CAP has entered into agreements with 11 irrigation districts in central Arizona to reduce their use of CAP water. CAP is also working with the city of Phoenix and other municipalities 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. By the end of 2016, it’s estimated these efforts will result in 345,000 acre-feet saved in Lake Mead, which may reduce the risks of shortages in 2017 and possibly in 2018.

Another beneficial undertaking has been 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. Recently, the U.S. Bureau of Reclamation announced that it would be allocating up to $5 million, in addition to the initial $11 million, for conservation projects along the Colorado River. In addition, the program was recognized by the White House as an example of a collaborative program that can help address long-term water supply risks in the Colorado River system. Examples of projects already underway include enhancing agricultural irrigation systems, removing turf grass and expanding water reuse. By the end of 2016, CAP and our customers will have conserved about 35,080 acre-feet in Lake Mead.

Going forward, Arizona, Nevada, California and the Bureau of Reclamation are working to develop a new set of tools and a shared strategy to go above and beyond what’s already in place to protect Lake Mead. CAP has played an integral role in creating this “Drought Contingency Plan” and will be heavily involved in putting the plan into action.

All Colorado River water users have a responsibility to safeguard the health of the river, conserve water wherever and whenever possible, and seek opportunities for cooperative programs that benefit the river system. CAP is fully engaged and will continue our efforts to protect and secure Arizona’s future water supplies. More information about what CAP is doing can be found at

— Marie Pearthree is deputy general manager of Strategic Initiatives and Public Policy at Central Arizona Project.

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