The Colorado River was recently listed by the American Rivers organization as the most endangered river in the United States. Here at Central Arizona Project (CAP), we have long understood that the over-allocation of the Colorado River, coupled with growing water demands and the potential for long-term droughts, would require significant planning and carefully considered actions to address future shortages along the river.
In response to these challenges, and because CAP agreed to junior priority on the river in order to get legislative approval in 1968, CAP has led efforts or participated with other Colorado River stakeholders such as the Bureau of Reclamation, the seven Colorado River basin states, the Republic of Mexico and key water and environmental organizations to implement water management practices designed to protect water users from such shortages.
Some efforts came to fruition in 2012, but several have a long history in Arizona, such as recharging (storing) excess CAP water underground to ensure a backup resource during times when our river supplies are reduced.
Since 1997, CAP has stored more than 2 million acre-feet (650 billion gallons) within our three-county service area - Pima, Pinal and Maricopa. When coupled with the use of CAP water in lieu of groundwater for agricultural irrigation, that figure rises to nearly 8 million acre-feet. That's the equivalent of five years of CAP's annual deliveries of Colorado River water.
Our participation in the negotiations among the seven Colorado River Basin states was instrumental in developing a "blueprint" of the triggers for declaring a river shortage, and exactly how much water CAP would give up. This certainty helps us develop and take appropriate actions to forestall a shortage and to mitigate shortage impacts to our customers. Our municipal and Native American customers have first access to the water we deliver and water recovered from our recharge projects and so are well insulated from cutbacks in the event a shortage occurs.
CAP participated in the Bureau of Reclamation's three-year study of supply and demand along the Colorado. The results of the Basin Study show that river supplies will fall significantly short of demand in the next 50 years. The report is a call to action and highlights the need for renewed and sustained efforts to resolve these imbalances before we reach a crisis point. We will need to implement large-scale augmentation projects, strengthen water conservation programs, and develop new reuse projects. If we begin now, we will have the time necessary to address the challenges to our most important supply of renewable water.
A new agreement in the water treaty between the U.S. and Mexico is a major step forward. Under this agreement, Mexico can continue storing unused Colorado River water in Lake Mead and voluntarily share in shortages and surpluses on the river. In addition, Mexico and the U.S. will provide water for environmental purposes in the Colorado River delta.
Unlike river systems in the eastern U.S. that have many tributary waters, the Lower Colorado River has few tributaries with significant flows to mitigate water quality problems that may exist. Drought exacerbates this condition. While the Colorado River currently meets all water quality standards, our challenge in an era of drought will be to protect and maintain that quality for all our users. CAP, Metropolitan Water District of Southern California and the Southern Nevada Water Authority have joined together to form the Lower Colorado River Water Quality Partnership to identify and implement proactive, collaborative solutions to address water quality issues facing the Colorado River.
The water issues facing CAP, our state and the Colorado River Basin are complex and include aspects of both nature and politics. The CAWCD (CAP) Board of Directors, popularly elected by the residents of Maricopa, Pima and Pinal Counties, has taken a strong leadership role in discussions and activities on a regional, state and federal level to ensure Arizona's continued access to its share of Colorado River water.
CAP will continue to make every effort to plan wisely and act responsibly to support the economic and environmental sustainability provided by the delivery of renewable water supplies through the Central Arizona Project system.
David Modeer is general manager of the Central Arizona Project.