INSIDE TUCSON BUSINESS: Mon., May 12, 2008
The business of the CAP and Tucson's water future
Certainty. The major goal for businesses is certainty. Certainty in its sales, its personnel, its accomplishments. It is no different for the Central Arizona Project (CAP) and, in 2007, the CAP board achieved certainty for CAP and Tucson's water future.
We did it by participating in the development of the Colorado River Interim Guidelines for Lower Basin Shortages and the Coordinated Operations for Lake Powell and Lake Mead. Long title, but that agreement, signed in December, formalized rules among the seven states that take water from the Colorado River.
The agreement provides a plan to follow if supplies should be reduced due to the ongoing drought by establishing a series of shortage triggers based on water levels in Lake Mead, allows states to conserve and bank the water saved in Lake Mead, calls for Lake Mead and Lake Powell to be operated in tandem, and calls for finding new ways to stretch the water supply through desalination of groundwater, removal of non-native plants, weather modification and improved system management.
"This is the most important agreement among the seven basin states since the original 1922 compact," said Interior Secretary Dirk Kempthorne at the signing ceremony. Arizona Depart-ment of Water Resources Director Herb Guenther echoed Secretary Kempthorne. "It's the beginning of a new era of water management," Guenther said.
The agreement, in effect through 2026, sets out the timing and amount of water lost by Arizona if a shortage is declared on the river.
In order to get Congress to authorize construction of the CAP - the 336-mile-long system that brings Colorado River water to Maricopa, Pinal and Pima counties - the state had to agree to ac-cept junior water rights. That means in time of shortage, California could take its full 4.4 million acre-foot allocation before Arizona's CAP takes any of its 1.5 million acre-foot allocation.
The shortage will be based on the water level in Lake Mead. Should the water level in Mead drop to a level between 1,075 feet to 1,050 feet above sea level, Arizona's share of water would be reduced by about 320,000 acre-feet. If the level falls to between 1,050 feet and 1,025 feet Arizona would lose approximately 400,000 acre-feet. Should the level reach 1,025 or lower, the reduction is about 480,000 acre-feet.
It is important to understand any shortage to Arizona and CAP would be absorbed by any water banking (recharge), other year-to-year operations and, finally, by CAP agricultural users. The cities would continue to receive their normal supplies for the next few decades.
To help delay or offset lower basin shortages, the agreement also calls for conjunctive management of lakes Mead and Powell. That means the lakes will be operated in tandem. The water contractors in the lower basin states — Arizona, California and Nevada - also can under-take conservation measures and "bank" or leave the saved water in Lake Mead for later use. This also will help delay reaching the trigger points for a shortage declaration.
Finally, the states agreed to enhance the water supply. Cloud seeding will be done in the winter. CAP contributed $60,000 to the effort in 2006-2007 and an additional $100,000 in 2007-2008. The states will also cooperate in removing non-native species and replacing them with native species. For example, high water use tamarisk trees will be replaced with cottonwoods, which use less water. CAP is scheduled to contribute $40,000 to this effort in 2008.
Knowing the "trigger levels" when shortages could occur, operating Lakes Powell and Mean in tandem, conservation and augmentation measures give Tucson water "certainty."
Contact Carol Zimmerman at carol@zimmermancom.com . Zimmerman is a publicly-elected member of the Central Arizona Water Conservation District Board of Directors.