Corps approves Sacramento-area levee vegetation variance

By Chris Gray-Garcia

Sacramento, CA (June 25, 2010)- The U.S. Army Corps of Engineers has approved the vegetation variance requested by the Central Valley Flood Protection Board and the Sacramento Area Flood Control Agency, allowing trees to remain on nearly 42 miles of Natomas, Calif., levees.

All but a 0.4-mile stretch of the Natomas East Main Drainage Canal was approved under the variance, endorsed by the Corps’ Sacramento District and South Pacific Division, and approved by Corps headquarters June 16. While some trees in this short stretch were approved to remain in place, the Corps could not approve keeping all the trees in place based on their location along a steep slope and the uncertainty of the levee’s ability to protect if the trees fell and pulled out part of the levee. The Sacramento District has initiated consultation with the National Marine Fisheries Service to ensure no net loss of habitat or species results from the possible removal of trees on this stretch to meet levee safety standards.

“This decision highlights the intent of the Corps’ vegetation variance process: to allow the Corps and its partners to conserve trees on levees where they don’t pose a risk to public safety,” Sacramento District Commander Col. Thomas Chapman said. “As we move forward with levee improvements in Natomas and elsewhere, we will continue to balance our mission to protect the public with our strong commitment to preserving natural resources.”

Trees on approved reaches will be allowed to remain in place permanently, as long as the approved levee sections continue to meet approved design and maintenance standards. If at any time the Corps finds conditions in the variance area that threaten system reliability and public safety, the Corps will work with its partner agencies to revise the approved variance to address them.

The Corps’ levee vegetation policy prohibits trees on levees, which can pose risks to levee stability, and to hamper ongoing levee inspections and maintenance needed to continuously gauge levee integrity. The vegetation variance policy allows levee maintaining agencies to request that trees remain on levees where they don’t threaten public safety, levee integrity or levee system reliability.

“Preserving these trees through the variance is a result of the successful partnership between SAFCA, the CVFPB and the Corps under the California Central Valley Flood System Improvement Framework,” Chapman said. “We’re glad these trees will stay. And we’ll continue to work with our partners to find safe solutions that value these important resources and habitats.”

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Corps approves Sacramento-area levee vegetation variance