By Pamela Pickard - Jun. 29, 2011 12:00 AM - Special for the Republic

One power plant, the Navajo Generating Station, provides nearly 95 percent of the electricity needed to deliver water from the Colorado River to Arizonans. It keeps the pumps running on the Central Arizona Project Canal from near Lake Havasu to the CAP terminus south of Tucson.

Now, the future of that power plant is uncertain.

The U.S. Environmental Protection Agency is set to release new emission regulations for nitrogen oxides, a haze-forming pollutant, at the Navajo Generating Station this year.

The plant has installed $45 million in new controls for nitrogen oxides. But the EPA favors a different control system that could cost up to $1.2 billion to install and require millions of dollars in additional expenses every year to operate.

The generating station, whose ownership includes Salt River Project and Arizona Public Service, faces other future uncertainties, including the renewal of land and water leases. If they're required to make a huge investment in pollution controls, the owners could simply choose to close the plant. The consequences would hurt all of us.

Recently, the CAP had the honor of appearing before a joint meeting of the Water and Power and the Indian and Alaska Native Affairs subcommittees of the U.S. House's Natural Resources Committee.

Along with other representatives from Arizona and the Navajo Nation, Hopi Tribe and Gila River Indian Community, we presented information about the importance of the Navajo Generating Station to our region and to the CAP in particular.

If the generating station closes, it will significantly increase the cost of energy for the Colorado River water we deliver.

These higher costs would affect water rates for most of Arizona's population. Higher water rates could make farming unaffordable for Indian and non-Indian agricultural users unless they return to the use of less expensive, but ultimately unsustainable, groundwater.