BUCKEYE — Salt cedar trees are invading the Gila River, causing flood and fire hazards and choking native vegetation and wildlife habitats, say local leaders. They say it’s time for the trees, planted a century ago to slow erosion, to make their final stand.

The trees are an invasive species and removing them is a priority, said Buckeye Mayor Jackie Meck. City officials’ long-term vision — years away — is to develop the Gila River area into a park, along the lines of the San Antonio Riverwalk.

Environmentalists worry removing the salt cedars without careful moves to replace them could leave endangered birds without a home.

The menace

Salt cedars — which look like oversized shrubs — have grown along swaths of the Gila River bed, stretching from a quarter-mile wide to more than a mile wide in some areas.

The 30,000 residents living in the river’s floodplain risk the chance of flooding during heavy rain, Meck said. A 1978 flood forced some residents to move. Steven Larson, a real-estate agent, said the flood was “horrendous.”

Fire is another danger. Salt cedars burn hotter than other trees and, because they are packed so tightly, fires can spread easily, said Adam Copeland, a Buckeye senior planner.

And salt cedar trees suck up water — 200 to 300 gallons of water a day — making it tough for native vegetation to survive.

Salt cedars, originally brought to Arizona in the 1800s, take over native plants’ territory. Only one to two cottonwood trees grow per acre along the river bed, Copeland said. About 3,000 to 4,000 salt cedars, also known as tamarisks, crowd into one acre.

The effort

It’s taken a decade, $5 million and many officials to come up with plans and permits to topple 18 miles of trees lining the river in the area, part of greater Phoenix’s southwest Valley. Trying to find money and tackling a complex bureaucracy of filing for federal permits has taken two decades, Copeland said.

But workers could start cutting down the trees by December. Buckeye, Goodyear, Avondale and the Maricopa County Flood District are collaborating to replace the salt cedars with other native vegetation. The restoration plan covers the river bed reaching from Litchfield Road in Avondale to Arizona 85 in Buckeye.

The takedown

Officials decided on the “hack and squirt” method. Workers will cut down the trees in 40-acre plots, spray the leftover stumps with herbicide and throw any remains into an incinerator to finish the job.

The concerns

Salt cedars have to be replaced with other trees to protect wildlife and birds that depend on the vegetation to survive, said Sandy Bahr, director of the Sierra Club’s Grand Canyon chapter. “It’s not just what needs to be removed but what needs to be planted,” Bahr said.

The Southwestern willow flycatcher, an endangered species, nests in the shade and foliage of salt cedars.

Robin Silver, co-founder of the Center for Biological Diversity, is worried tree removal would happen too quickly. “There needs to be a transition,” said Silver.

Kelly Wolff-Krauter, habitat design director for Arizona Game and Fish, said wildlife and birds will be protected. She’s working on the restoration plan.

She said protecting the flycatcher includes transplanting native cottonwood and willow trees to replace the salt cedar trees. That will happen during the season birds aren’t nesting in the trees. If there are complications, U.S. Fish and Wildlife will step in.