Experts say there’s been a noticeably improved environment for the fish community along the 23-mile stretch of the Santa Cruz River ever since Pima County’s wastewater treatment facilities, the Tres Rios Water Reclamation Facility (WRF) and the Agua Nueva, were upgraded in 2013. The Sonoran Institute, joined by Pima County, has been working with the Arizona Game and Fish Department, the University of Arizona, the U.S. Geological Survey and the U. S. Fish and Wildlife Service to conduct an annual fish survey.
