Studying Water Quality in Colorado River Delta's Cienega de Santa Clara

A University of Arizona researcher is coordinating a project to monitor water quality in the largest wetland in the Colorado River Delta, the Cienega de Santa Clara in Mexico. The effort will evaluate how operation of the Yuma Desalting Plant (YDP) might affect the cienega.

Researchers will start gathering baseline information in August. The YDP is scheduled to conduct a 3-month trial run at 10 percent of its full capacity during the spring of 2007. The scientists will also collect water quality data during and after the YDP's trial run.

The Central Arizona Project (CAP) is funding the scientific monitoring effort.

"It's a critical first step in a long-term, bi-national effort to systematically evaluate how variation in water quantity and quality affects the delta's ecosystems," said the project's principal investigator Karl W. Flessa, a professor of geosciences at The University of Arizona in Tucson.

The Cienega de Santa Clara is an important stopover for birds that migrate along the Pacific Flyway and provides habitat and feeding grounds for an estimated 200,000 shorebirds, ducks and geese. It is also home to federally listed threatened and endangered species including the Yuma Clapper Rail (Rallus longirostris yumanensis), the Southwest Willow Flycatcher (Empidonax traillii extimus) and a species of desert pupfish, Cyprinodon macularius.

The cienega is also the basis of a growing ecotourism industry for nearby communities in Mexico.

"This project is a great example of how cross-border cooperation among federal agencies, state agencies, environmental groups and academic institutions can address critical problems in the use of water resources," Flessa said.

Jaqueline García-Hernández, a research scientist at Sonora's Research Center for Food and Development (Centro de Investigaci