The recent U.S. Army Corps of Engineers' interim decision allowing local levee management agencies to leave trees and other vegetation on levees is a major win for local residents, taxpayers and the environment.

Many areas of California, including Contra Costa, rely on levees for flood protection. We now need to keep working to make sure this interim decision becomes permanent law.

For years, the Corps, believing that trees weakened levees, required local agencies to remove all vegetation from levees or lose their eligibility for federal disaster relief.

In some cases, the Corps even required a local agency to remove trees and other vegetation that provided habitat for an endangered species -- a true Catch-22.

We know from experience that removing trees, bushes and shrubs from levees could harm riparian habitat that supports fish and wildlife.

It is also very expensive -- it costs about $1 million per levee mile to remove vegetation. Also, there is strong evidence that trees and shrubs can actually strengthen levee structures.

Requiring local agencies to remove all the trees and other vegetation from the levees they manage is bad policy.

The "remove all vegetation" rule also conflicts with the California Department of Fish and Wildlife and the San Francisco Bay Regional Water Quality Control Board policies to protect water quality and riparian habitat value.

In fact, the Department of Fish and Wildlife sued the Corps over its policy. This is a classic case of one agency's rules interfering with the important goals and rules of another government agency.

The California State Association of Counties, in partnership with counties and local levee management agencies statewide, has worked with our congressional delegation to change the Corps' misguided approach.

With strong support from Rep. Doris Matsui, and Sens. Dianne Feinstein and Barbara Boxer, counties successfully made their case to the Corps to change its policy.

The Corps has now apparently seen the light. The recent interim ruling means local agencies will not be required to remove all levee vegetation, and they will remain eligible for disaster assistance if there is a flood.

This change of policy reflects the reality that local agencies should be able to make their own decisions based on risk and science to determine whether vegetation should be removed.

Making this new policy permanent will save Contra Costa County $2.5 million just in North Richmond alone.

That's what it would cost to remove the trees and shrubs along both San Pablo and Wildcat Creeks.

The vegetation along these creeks was originally planted as part of an original Corps levee improvement project, and the community strongly opposes the removal of the trees and shrubs along the creek banks.

Counties are continuing to work with Matsui, Feinstein, Boxer and the Corps to make this interim ruling permanent policy.

By making this new Corps policy permanent, no longer will local levee management agencies and taxpayers be forced to spend millions of dollars destroying riparian habitat just to maintain their eligibility for federal flood aid.

This is good for the environment and the taxpayer.

John Gioia is a member of the Contra Costa County Board of Supervisors and president of California State Association of Counties.