Santa Cruz River, Redux 

Historic Waterway Could be State’s First Urban National Wildlife Refuge

By Tara Kirkpatrick

The birthplace and lifeforce of Tucson, the Santa Cruz River has ebbed and flowed throughout its vast desert existence, from year-round flows to completely drying up due to overuse to a modern revival through responsible water management.

The vision forward for this landmark waterway could help preserve it for perpetuity.

A coalition of 50-plus community partners aims to turn a 90-mile stretch of the river from Mexico to Marana into Arizona’s first Urban National Wildlife Refuge. The designation, by the U.S. Fish & Wildlife Service, would be a pivotal step forward in protecting the river’s ecology and sustainability.

“We are in the third and final administrative step toward establishing the refuge,” said Luke Cole, director of the Santa Cruz River program for the Sonoran Institute, a coalition member and nonprofit dedicated to conservation. “This is a project with statewide appeal. I cannot emphasize how important this is to Tucson, Pima County, our indigenous partners and more.”

The federal refuge designation will recognize the ecological, indigenous and cultural values of the Santa Cruz River, while improving wildlife habitats and ensuring community access to the river and landscape. The proposed refuge boundary, which runs from the U.S.-Mexico border north to the Pima-Pinal County line, would include multiple properties and many access points along the river. 

“These refuges benefit the economies, tourism…create jobs,” Cole noted. “This is everything that every political appointee wants to bring to communities.”

The Santa Cruz River Valley is one of North America’s longest inhabited regions. The river, a vibrant water source for over 12,000 years, was farmed extensively by our indigenous ancestors and fostered not only the origins of Tucson but also a rich variety of wildlife. Yet, fueled by fierce Western expansion and overuse, the river’s perennial flows ended in 1913 and seasonal flows died off in 1940.  “It was a non-entity,” Cole said. “That’s four or five generations lost.” 

Until the early 2000s, partially treated wastewater constituted the Santa Cruz River’s year-round flows. It wasn’t until 2013 in Pima County that the treatment processes were completely overhauled and improved. Today, parts of the Santa Cruz are flowing once again, and wildlife has returned.

“One of the most amazing examples of this is the Gila topminnow,” said Cole. “It was in the Santa Cruz River historically but was absent for 100 years. In 2015, during our fish survey, they returned. That’s a really good sign. Additionally, we are seeing things like dragonflies. Half of the entire species in the state is now being seen in the Santa Cruz River.”

University of Arizona ecologist Michael Bogan has studied the Santa Cruz River ecology for more than a decade and runs a National Science Foundation-funded Biological Research Experience for Teachers Site on the Santa Cruz.

“They leave realizing that Tucson has a river, that there’s wildlife, and that it’s a spot they can come back to and enjoy with their families,” said Bogan, an associate professor in the UA School of Natural Resources and the Environment who has also assisted with the coalition efforts. 

A $600,000 grant from the National Fish and Wildlife Foundation, secured in January, will help the Sonoran Institute, UA and project partners with the resources needed to support the U.S. Fish and Wildlife Service as they work toward designating the refuge. It ensures a two-year, funded process to engage the community and conduct scientific research. 

“The Santa Cruz River is the reason humans have inhabited this area for millennia, and encompassing it in a Santa Cruz River Urban National Wildlife Refuge will give it the protection it deserves for generations to come,” said Pima County Supervisor Adelita Grijalva, a coalition member whose district includes Downtown Tucson and its Santa Cruz boundary. 

“This type of refuge is not a singular geographic entity, but a network of publicly owned areas needed to preserve the river’s integrity and its values for wildlife habitat and human enjoyment.”

Pictured: “Santa Cruz River” by Mary Schaefer. Courtesy of the Schaefer Family