Repairs, upgrades to address Yuba-Sutter levee flaws
• Design or construction flaws.
Some levees had inadequate "freeboard" — extra height to prevent overflow, which can weaken the landward slope of the levee. For example, the Corps found there was not enough height in a levee along a 20-mile stretch of Mississippi's Yazoo River system, which came close to being overtopped in 2011 during historic flooding of the Mississippi River valley.
• Inadequate or crumbling infrastructure.
Many pipes built into levees to drain storm water were made of metal that has rusted. And pumping systems are giving out. In Brookport, inspectors found inoperable pumps and deteriorating pipes in its 6-mile-long earthen levee. Their report said a gaping hole just outside town has put the structure in "critical condition."
• Failure to control vegetation and invasive animals.
Corps specifications require that levee slopes be kept clear of plants and burrowing critters such as ground squirrels and gophers. The tunnels could weaken the walls by providing pathways for water. Thick vegetation also can conceal cracks, holes and unstable slopes. A 2010 Corps report found parts of a 2.2-mile-long Mississippi River levee in South St. Paul, Minn., dotted with trees, brush, weeds and tree stumps.
• Building encroachment.
Some of the flaws the US Army Corps of Engineers found in levees in Yuba-Sutter in surveys three years ago still exist, but upcoming repair projects should address them, according to local officials.
In 2010, the Corps' survey found levees in Marysville and Yuba City were in "unacceptable" status for various reasons, including problems with slope stability and underseepage relief wells.
Though one section of the Marysville levee was fixed, another, along the city's northeast edge, continues to be deficient, said Chris Gray, a spokesman for the corps' Sacramento division.
"It's all about levee maintenance and making sure standards continue to be met," Gray said. According to the Corps report card, the outstanding issue has to do with vegetation growing on the levee.
Marysville officials could not be reached for comment on Friday.
In 2010, City Services Manager Dave Lamon said a combination of the work being done to upgrade the ring levee and more code enforcement on property owners who were allowing shrubs to grow on levees would solve the issue.
Along the Feather River's western bank, the survey found problems with levees in several locations, including encroachments, unstable slopes and poor drainage. According to the Corps' report card, those problems persist.
Mike Inamine, executive director of the Sutter Butte Flood Control Agency, said his agency's multi-stage levee upgrade project, set to begin this summer, should address those issues.
"We're resolving all of those issues in the Feather River West Levee project," he said.
But other problems identified by the Corps for levees along the Sutter Bypass don't have an approved plan yet to address them, though they're still in the scope of the agency's planned work, he said.
Gray said the Corps' surveys and classifications of some levees as "inactive" doesn't mean they are in imminent danger of failing, merely that there's a chance they wouldn't perform as they should in a high-water event.
The "inactive" status also means local agencies wouldn't be in line for any federal money to make repairs to those levees as a result of storm damage, he said.
DEFICIENT LEVEES FOUND ACROSS AMERICA
NEW ORLEANS (AP) — Inspectors taking the first inventory of flood control systems overseen by the federal government have found hundreds of structures at risk of failing and endangering people and property in 37 states.
Levees deemed in unacceptable condition span the breadth of America. They are in every region, in cities and towns big and small: Washington, DC, and Sacramento, Cleveland and Dallas, Augusta, Ga., and Brookport, Ill.
The US Army Corps of Engineers has yet to issue ratings for a little more than 40 percent of the 2,487 structures, which protect about 10 million people. Of those it has rated, however, 326 levees covering more than 2,000 miles were found in urgent need of repair.
The problems are myriad: earthen walls weakened by trees, shrubs and burrowing animal holes; houses built dangerously close to or even on top of levees; decayed pipes and pumping stations.
The Associated Press requested, under the Freedom of Information Act, details on why certain levees were judged unacceptable and how many people would be affected in a flood. The Corps declined on grounds that such information could heighten risks of terrorism and sabotage.
The AP found specifics about the condition of some levees from federal and state records and in interviews with more than a dozen officials in cities and towns. The number of people who might be affected by a breach could not be determined because there are many different factors in a flood, such as terrain and obstacles.
The severity of the risk from any particular levee depends not only on its condition but also the population, infrastructure and property it protects. The Corps is currently conducting risk assessments of levees under its jurisdiction.
Local governments are responsible for upgrading unacceptable levees. Some local officials say that the Corps is exaggerating the dangers, that some deficiencies were approved or not objected to by the federal government and that any repairs could cost them hundreds of thousands, if not millions, of dollars.
"It's just not right to tell a little town like this to spend millions of dollars that we can't raise," said Judy Askew, mayor of Brookport, a hardscrabble town of about 1,000 on the banks of the Ohio River.
Compared with other types of infrastructure, the nation's levees, within and outside federal jurisdiction, don't fare well. They earned a D-minus for overall condition from the American Society of Civil Engineers in its latest report card in 2009, ranking behind dams, bridges, rails and eight other categories.
The condition of flood control systems came into dramatic focus in August 2005 when Hurricane Katrina's rain and storm surge toppled levees in New Orleans and tore up the Gulf Coast. It left 1,800 people dead and was the costliest storm in US history with damage estimated at $108 billion.
Afterward, Congress told the Corps to catalog federally overseen levees, many of which it built and handed over to municipalities to run and maintain. The Corps has spent more than $140 million on inspections and developing the inventory, which is posted online.