The Gila River West of Phoenix

The Gila River (pronounced HEE-luh) originates in southwestern New Mexico high in the mountains in designated Wilderness Areas and flows westward, into and across Arizona, providing water for rural towns and agriculture along the way.   

The Gila’s flow is interrupted by Coolidge Dam, creating the San Carlos Reservoir on the San Carlos Indian Reservation west of Safford, Arizona. Water from the reservoir is managed by the San Carlos Irrigation and Drainage District for communities, farms, and ranches downstream. As the river flows into Pinal County, the Ashurst-Hayden and Florence diversion dams send what remains of the Gila River water to central Arizona farms. The remainder of the Gila is a dry river channel, unless there is a rain or snow melt event.    

The Gila River once flowed 500 miles, joining the Colorado River near Yuma, Arizona and the border with Mexico. The combination of dams, diversions, and drought earned the Gila River the title of Most Endangered River in 2019 from American Rivers.    

Today, Audubon and partners are working together as the Lower Gila River Collaborative to revitalize the Lower Gila River—from the City of Phoenix’s Tres Rios Wetlands southwest along the river to Gillespie Dam west of Buckeye—by removing salt cedar (also known as tamarisk), planting native vegetation, creating public access points and trails, encouraging nature based economic development, and engaging environmental justice communities along the river. 

History  

Native peoples have inhabited the Gila River for thousands of years. In the 1800s, upstream diversions of the Gila River by settlers severely impacted the Akimel O’odham and Pee-Posh —Indigenous people who resided along the Gila River for centuries before the arrival of Euro-Americans. Today, the Akimel O’odham and Pee-Posh people form the Gila River Indian Community.  

After years of negotiations, the Gila River Indian Community now receives Colorado River water delivered from the Central Arizona Project (the 336-mile-long canal that brings Colorado River water to Maricopa, Pinal, and Pima Counties) to restore some of what they lost when the Gila River dried up through their homeland as part of a water rights settlement.   

Revitalization and Collaboration 

Significant changes have occurred in the ecosystems of the Lower Gila River due to historic land and water management practices combined with the hotter and drier climate. These changes have contributed to invasive plants (including salt cedar and stinknet) replacing native vegetation. The expansion of salt cedar within the 36-mile lower reach of the Gila River has resulted in the highest risk in the state for wildfires and flooding, increased soil salinity, decreased water quality, reduced recreation access, and created an overall decline in riparian ecological health and resilience. These changes negatively impact birds and people and threaten critical infrastructure and communities. 

Building upon decades of work to advance the revitalization of this stretch of river, the Lower Gila River Collaborative  was formed.  

The Lower Gila River Collaborative is “a voluntary partnership to restore the lower Gila River ecosystem while encouraging stewardship, recreation, and compatible development,” comprising more than 30 state agencies, non-governmental organizations, Tribes, and recreation and agricultural water users, including the Gila River Indian Community; the cities of Avondale, Buckeye, Goodyear, and Phoenix; Maricopa County Parks and Recreation Department; Flood Control District of Maricopa County; Arizona Department of Game and Fish; Arizona Department of Forestry and Fire Management; and U.S. Fish and Wildlife Service. 

The Lower Gila River Collaborative is the western extent of the Rio Reimagined initiative, a regional approach to further the ecological restoration and economic growth in the Salt and Gila River corridors. 

Important River Corridor 

The Lower Gila River Collaborative focus area encompasses designated land and river corridors, including: 

• Important Bird Area: The Lower Salt and Gila Rivers Ecosystem Important Bird Area (IBA) spans 36,645 acres. In addition to being a global IBA for Yuma Ridgway’s Rail, this ecosystem provides habitat for the federally threatened Western Yellow-billed Cuckoo and hundreds of other species. 

• Urban Waters Federal Partnership: The Environmental Protection Agency designated Rio Reimagined as an Urban Waters Federal Partnership to reconnect communities with our waterways, (LGRC is the western extent of the Rio Reimagined Initiative). The program strives to bring federal, local, and tribal partners together to improve water systems and promote economic, environmental, and social benefits.   

WaterSMART Grant 

In 2024, Audubon Southwest, in partnership with the Lower Gila River Collaborative, was awarded a $298,014 grant through the U.S. Bureau of Reclamation’s (Reclamation) WaterSMART Cooperative Watershed Management Program to improve ecosystem health and water management. This funding was part of the $8.9 million investment from the Bipartisan Infrastructure Law to protect watershed health and build more resilient water supplies in the western U.S. 

Over three years, Audubon will manage the grant funds to implement the Lower Gila River Collaborative 2024-2029 Strategic Action Plan. The Strategic Action Plan strives to:  

• Expand outreach to include under- and unrepresented voices  

• Engage landowners through outreach and workshops to catalyze projects  

• Synthesize existing plans, studies, and data to evaluate and prioritize potential projects  

• Consolidate hydrologic, ecologic, and social data into an interactive online platform 

We look forward to continuing our important work and mission with our local partners. Stay tuned for updates as we achieve project milestones.