California Levees Face Massive Corps of Engineers Tree Removal

A compromise is being negotiated, but unless the policy changes, tree-lined banks on 1,600 miles of levees in the Valley could be transformed into barren culverts within a year.

The conflict highlights a difficult dance by federal and state officials who must weigh the need for no-frills flood control and California's tradition of also using levees for environmental protection and visual esthetics.

At issue is a national Corps of Engineers policy now being applied in California. It requires levees to be cleared of all vegetation to preserve channel capacity and allow access for inspection and repair. The policy is largely based on conditions on the Mississippi and Missouri rivers, where ample wildlife habitat exists between levees and the water's edge.

But in California, levees were built close together after the Gold Rush to create high water velocities to flush mining debris out of rivers. In most areas, there is little space between levees and the water, and vegetation on levees provides the only riverside habitat.

The issue first came to light in February 2007 when the corps released a national list of levees that failed maintenance standards. That review was ordered by Congress after deadly levee failures in New Orleans during Hurricane Katrina.

A revised list released Monday shows that 32 levee districts in California failed maintenance standards.

The corps' maintenance manual for the Sacramento River flood control system actually encourages planting vegetation on levees.

"We have coordinated with environmental agencies for a number of years now to incorporate vegetation in our flood control systems to provide shade and habitat for endangered species here in California," said Jim Sandner, operations and readiness chief at the Sacramento Corps of Engineers district.

Dana Cruikshank, a spokesman at the agency's headquarters in Washington, said an exemption is not in the works for California. But the corps is drafting a new national standard to allow some vegetation on levees. That standard should be finished by year-end.

The corps' regional commander, Brig. Gen. John McMahon, said Friday that removing trees won't necessarily make levees safer, because rotting roots left behind could provide a path for seepage that could compromise the levee.

McMahon hopes to tailor the forthcoming standard to California's needs. The goal, for instance, would be to remove trees where levee-strengthening is needed, but also to allow some vegetation where strength is not a concern.

"There's no doubt in my mind our headquarters would like one standard applied broadly across the full spectrum of levees," said McMahon. "I personally don't think that's the right tack to take in this situation. Not all vegetation on levees is bad."

Until the new standard is released, local corps officials are telling levee districts not to cut trees.

But time is running out: Local levee districts have three months to develop a plan to satisfy the corps, then nine months to carry it out.

If they fail to comply, districts will be ineligible for federal assistance to repair levees after a flood. Because most districts can't afford repairs on their own, the burden could fall on state and local taxpayers.

To make matters worse, local districts are squeezed by other rules that protect vegetation, said Mike Hardesty, president of the Central Valley Flood Control Association. If they remove all trees and shrubs, as the corps headquarters wants, they could face penalties from other state and federal agencies for destroying habitat.

The state Department of Water Resources next week will launch a routine spring inspection of Central Valley levees. It has increased its inspection staff from six to nine people to measure the habitat that would be lost if the current national policy is ultimately enforced.

Jeremy Arrich, chief of Water Resources' flood project integrity and inspection branch, said the goal is to persuade the Corps of Engineers to consider natural resources in its maintenance policies. Without that consideration, he said, many of Sacramento's urban levees are likely to fail the national policy when next evaluated by the corps.