Celebrating a Healthy Santa Cruz River

Newly Released Living River Report Highlights Return of the Gila Topminnow

The health of the Santa Cruz River continues to improve significantly. The return of aquatic wildlife to the river is proof that clean, reliable water benefits this unique desert ecosystem. In the newly released Living River report, Pima County and Sonoran Institute highlight the return of the endangered Gila topminnow, a native species of fish that was absent from the river near Tucson for over 70 years until last November.

In honor of this finding, Pima County Board Supervisors signed a proclamation last week designating October 2018 as Return of the Gila Topminnow Month. In addition to the return of the Gila topminnow, Living River report highlights include: a record-breaking amount of aquatic invertebrate diversity, steady improvement of water quality and clarity, and higher infiltration to the water table.

“The Santa Cruz River is the reason we’re able to call this region home. So for me, the return of the topminnow and other aquatic life is exhilarating—it’s the visible proof that we have a healthier river and that we can maintain our rich river heritage,” Sonoran Institute Ecologist, Claire Zugmeyer, said.

The river flows year-round through northwest Tucson and Marana, with most of the water coming from Pima County’s two regional water reclamation facilities—Tres Rios and Agua Nueva—which began operations in 2013 following $600 million in improvements. The high quality of the water has been the key ingredient in the rebirth of the lower Santa Cruz, now the longest stretch of river in Arizona dominated by effluent and Pima County’s principal wetland.

“Return of the Gila topminnow highlights the importance of a lot of Pima County efforts along the Santa Cruz, from identifying the river as an important riparian area in the Sonoran Desert Conservation plan, to cleaning up the water that flows into the river, to managing this river for both flood protection and other community benefits,” Evan Canfield, Civil Engineering Manager, Pima County Regional Flood Control District, said.

The Living River reports are modeled on the series Sonoran Institute pioneered for the river near Nogales. In collaboration with Pima County, the series was expanded in 2012 to include the reach near Tucson. The latest report is the fifth annual of this series, and is available online.

The community is invited to join Sonoran Institute and Pima County in celebrating the Santa Cruz River and the return of the Gila topminnow.

  • Meet the Gila topminnow at Tucson Meet Yourself at the Pima County Library in the Regional Flood Control District display, Friday and Saturday, Oct. 12-13.
  • Attend the Living River Celebration and Report Release, 8-10 a.m., Sunday, Oct. 14, hosted by Sonoran Institute and Pima County, at the outfall of the Agua Nueva Wastewater Reclamation Facility to celebrate our healthier river and the return of the endangered Gila topminnow. To join a 5 mile bike tour to the event, meet at 8 am on the west side of Santa Cruz River and Speedway Blvd. Or, drive and park near the end of Sweetwater Dr, just past the Sweetwater Wetlands and walk north .2 miles along the Chuck Huckleberry Loop. Maps available for driving and biking directions.


Sonoran Institute
Claire Zugmeyer
520-290-0828 x1143

Pima County Regional Wastewater Reclamation Department
James Dubois