Sunday, September 19, 2010

Weak Levees Need Strong Dams

While the levees in our area are the secondary protection from flooding, the first level of protection are the dams that can hold back the water during those periods when too much rain or too much snow thaw overwhelm the existing dams.

Our current system gives Sacramento a 200 year level of protection, but the eventual construction of the Auburn Dam and the raising of Shasta Dam—hope springs eternal, info posted here and here—would bring us to a 500 year level; and for one family that lives in the flood plain, we would be very happy to see that happen.

In the meantime, we need our levees to be strong, and this article from the Sacramento Bee indicates they may not be.

An excerpt.

“Most levees in the city of Sacramento have technically failed a maintenance inspection by the U.S. Army Corps of Engineers because they are bristling with trees and other structural intrusions. But the city won't be penalized – for now – while long-term solutions are being developed.

“Other areas fared even worse: Levee sections in Marysville, Stockton and Lathrop were deemed "unacceptable."

“As a result, those levee systems were placed on an "inactive" list that makes them ineligible for federal repair dollars in the event of flood damage.

“In Sacramento's case, the decision amounts to a provisional pass.

“The inspections focused on maintenance practices and not the strength of the levees.

"Our goal here is really to encourage the local maintaining agencies to fix these deficiencies as quickly as possible," said Meegan Nagy, levee safety program manager at the Corps of Engineers Sacramento District. "It is important for communities to understand: If they live behind a levee, there is always a risk."

“Tuesday's news marks another chapter in a policy arena that has become far more confusing in recent years.

“In the wake of Hurricane Katrina in New Orleans in 2005, the Corps of Engineers began imposing maintenance criteria uniformly across the nation. This meant, in California's case, that previous agreements allowing trees and other intrusions on levees are now called into question

“For instance, homeowners along the south bank of the American River were previously allowed by the corps to plant landscaping and build stairs on levees to access the river, said Timothy Kerr, general manager of the American River Flood Control District. Now those levees have been marked down for those changes.

“Such levees would have been declared "unacceptable" according to corps' criteria if not for an agreement reached in 2009 with state and local agencies. The agreement, known as the Central Valley Flood System Improvement Framework, also allowed Natomas levees and those on the east bank of the Sacramento River to pass earlier inspections.”