On Feb. 6, the California Department of Fish and Game (DFG) issued a notice that signals its intent to sue the United States Army Corps of Engineers.
According to the department, the Corps has failed to comply with the federal Endangered Species Act with the adoption of a new national policy that requires the removal of all trees and shrubs growing on federal levees. The Corps developed this national policy shortly after the Hurricane Katrina disaster.
The DFG notes the Corps’ national policy fails to account for regional differences among levees. What’s unclear to the department is how, as early as 1955, the Corps encouraged and at one point even required that trees and shrubs be planted on California levees.
California conducted various studies in 1967, 1999, and 2008, which show that riparian vegetation growing along levees can often reduce flood damage. According to the DFG, the Corps’ own studies from 1991 and 1999 confirm that post-flood damage rates for levees with vegetation were less than those with no vegetation.
The department states that about 1,600 miles of federal project levees along the Sacramento and San Joaquin rivers will likely be affected by the Corps’ new policy. Several miles of levees in the Bay Area and Southern California will be affected as well.
Currently, only 5 percent of the Central Valley riparian forest remains intact. However, this remaining vegetation would be removed under the new policy. The riparian habitat, according to the DFG, is crucial for several endangered species, including the Chinook salmon, Central Valley steelhead, valley elderberry longhorn beetle, riparian brush rabbit, the Western yellow-billed cuckoo, and Swainson’s hawk.
According to DFG communications officer Jordan Traverso, the DFG has had numerous roundtable discussions with the Corps over the years while this policy was being drafted. However, the DFG never agreed to the removal of vegetation.
The DFG believes the Corps’ flood concerns can be addressed with a regional variation that would allow riparian habitat to remain intact.
“We hope the Corps will rescind the policy or provide for regional variations,” Traverso said. “The Corps said they are working on providing guidance for regional variations, but they have yet to provide us with this part of the policy.”
Representatives for the U.S. Army Corps of Engineers failed to return phone calls as of press time.
This article appears in Feb 16-23, 2012.