A binational team is studying whether running the Yuma Desalting Plant will affect Mexico's Cienega de Santa Clara, the largest wetland on the Colorado River Delta.
The cienega, a 15,000-acre wetland, is home to several endangered species and is a major stopover for birds migrating north and south along the Pacific Flyway.
The desalting plant, or YDP, is scheduled to begin its latest trial run May 3.
"The plant will use U.S. agricultural runoff that would otherwise flow to this Mexican wetland," said team leader Karl W. Flessa, director of the UA's School of Earth and Environmental Sciences.
About 30 percent of the water now flowing into the cienega will be diverted into the plant for desalination. The plant's effluent, a smaller volume of much saltier water, will be returned to the canal that flows into the cienega.
The Mexican community of Ejido Johnson operates a small ecotourism business at the wetland. Birdwatchers are attracted by the birds found there, including the Yuma Clapper Rail, listed as an endangered species by the U.S. and Mexico.
"We've been monitoring the water level, water quality, bird populations and vegetation in the cienega to find out if the operation of the Yuma Desalting Plant will affect the ecosystem," said Flessa, who is also head of UA's geosciences department.
The team, scientists from both Mexico and the U.S., has been collecting baseline data since 2006 and plans to continue during and after the desalting plant's trial run. The plant is scheduled to operate for a total of 12 months out of the next 18.
"It's really unusual to have this level of cross-border collaboration on such a sensitive water issue," said Flessa. "We've expanded our efforts since September, thanks to support from the three major western water agencies and INE, the Mexican National Institute of Ecology."
The agencies are the Central Arizona Water Conservation District, the
|Contact: Mari N. Jensen|
University of Arizona