Enhancement
Why enhance the river habitat?
Changes in the Gila River have resulted in large-scale shifts in the flora growing along the river.
The flows of the Gila River have been altered by dams, water diversions, and groundwater pumping. and these changes have rippled across the ecosystem, transforming the native habitats along the river. In place of native cottonwoods, willow, and mesquite, there is now saltcedar - also known as tamarisk spp. - which is well adapted to the current hydrologic conditions. LGRC mostly focuses on habitat enhancement, rather than ecosystem restoration, which recognizes the irreversible changes have shaped the river while improving habitat for native species and providing beautiful areas for our community to recreate.
Saltcedar (or tamarisk) is a non-native plant that blocks river access, is low quality habitat, and can increase flood and fire risk.
Saltcedar can grow in thick stands, blocking access to the river. It is a thirsty plant, and one that doesn't offer wildlife the high quality habitat that native vegetation supports. In addition, introduced biological controls, the tamarisk beetle have made their way into the system. The beetles cause defoliation of the tamarisk. The tamarisk then become more susceptible to fire and flooding and do not provide habitat for wildlife. Once the beetles leave, the tamarisk will green back up and continue to outcompete the native species of vegetation for light and water and will deposit salts onto the soil raising the pH and salinity intolerable levels for native plants to grow.
The changes in the ecosystem cause many negative impacts.
These problems can be solved with enhancement projects.
Increased flood risk for communities, due to the loss of natural flood function of the river.
Decrease in high quality habitat for threatened and endangered species.
Lost river access for recreational, historical, and cultural purposes.
Changes in other ecosystem services and functions of the river, including increased wildfire risk.
Risk of additional and unknown changes due to future arrival of the tamarisk beetle. The beetle has been confirmed in 2021 to include the reach of the focus area.
Yuma Ridgway's (clapper) rail, an endangered species that lives in the Lower Gila River ecosystem.
How Do We Prioritize Restoration Sites as a Collaborative?
The Habitat Enhancement Working Group is studying surface and groundwater to identify reliable sources of water. Priority sites include those with the potential for secure water, those that provide marsh habitat for birds, and sites on or near active restoration efforts with willing landowners. Working together with agencies, businesses, and private landowners, the working group continues to identify new opportunities for restoration along the river.
The Lower Gila River & Restoration Priority Sites
The Gila River's headwaters are in New Mexico and its other tributaries, the Salt, Verde, and Agua Fria Rivers, originate in Arizona. The Lower Gila River begins near Phoenix at Tres Rios, where the Gila, Salt, Agua Fria come together, and terminates in Yuma where it joins the Colorado River. Our restoration efforts are focused on this lower reach, but are effected by upstream activities in the broader Gila River Watershed.
Highway 85 Bridge, Maricopa County Flood Control District
This is an areal photo of the Highway 85 Bridge, Maricopa County Flood Control District's restoration pilot site #1. The red polygon indicates area of salt cedar removal and replanting efforts.
Tres Rios Wetlands, City of Phoenix
These designed wetlands, located in Phoenix, feed water back into the river and provide for recreation and wildife habitat.
Rio Vista Trailhead, City of Goodyear
This restored area located in Goodyear provides recreation opportunities along the Gila River.
40-Acre Pilot Site, City of Buckeye
This 40-acre area provides recreational opportunities along the river. After saltcedar removal, the city planted native vegetation, restoring the habitat.
Confluence Lake Concept, City of Goodyear and Maricopa County Flood Control District
The Confluence Lake Concept would provide for recreation and enhance areas of habitat.
Arlington Wildlife Area, Arizona Game and Fish
Arlington Wildlife Area includes restoration of ponds, relocation of alignment of major wash back to the river and stabilization to decrease flooding potential.
Base and Meridian Partner Pilot Site, Arizona Game and Fish
Arizona Game and Fish Department Base and Meridian Partners Pilot Site /Gila River Indian Community
7.52-acre restoration site began in FY2020 and was completed in FY2021. This project opens up the area for safe recreation, lowers the fire and flood risk and allows for native vegetation to come back.
Pilot Site, Flood Control District of Maricopa County
Robbins Butte SR-85 Site, Arizona Game and Fish
44 acre pilot site just to the north of the Flood Control District of Maricopa Counties pilot site #1 at the highway 85 bridge and adjacent to their pilot #2 site. Another vegetation treatment to remove salt cedar and reseed with native vegetation. This project will highly reduce the fire risk to the area and allow for native vegetation to come back in to provide for wildlife habitat and recreational opportunities.
PLO1015 Burned Area Restoration, US Fish and Wildlife Service
The USFWS Avondale Burned Area Rehabilitation Project site is just outside of Avondale, Arizona, in the Phoenix Metro Area. The project was initiated after the June, 2020 Avondale Fire, which burned approximately 350 acres of riparian lands directly adjacent to the Lower Gila River. Much of the burned area was salt cedar thicket (Tamarix spp.) and approximately 75 acres within the fire boundary were considered susceptible to permanent damage if not responded to with agency intervention.
This area of the Lower Gila is very important habitat to three species listed on the Endangered Species List:
Southwest Willow Flycatcher
Yuma's Ridgeway Rail
Yellow-Billed Cuckoo
Because of the location adjacent to urban area, the heavy impact of non-native species, and the importance of protecting habitat for these listed avian species, this area was determined suitable to conduct a Burned Area Rehabilitation project at.
The main strategies being implemented at this BAR proejct site include:
Clearing of non-native tamarisk species
Replanting of native species and native seeding
Maintenance through herbicide use
Through implementation of these strategies, land managers hope that habitat value will increase for all species, especially those that are protected, competition from non-native species will decrease after clearing and replanting, ecological resiliency will be increased in the event of another wildfire, and consequently recreation opportunities, which are abundant, will increase due to increased aesthetic value of the site.
