The U.S. levee system — once considered the second largest piece of the country’s infrastructure ”rivaled only by the highway system” — is now nearly a century old and failing inspections far more often than it passes them. Only one in 25 federal levees are rated Acceptable. … Those systems can be found nationwide, from the Sacramento region in California to the south Florida seaboard; from Appalachia to North Dakota to the Mississippi River Valley. And the people who maintain those vulnerable levees say their problems are remarkably similar: systems that are too old and far too expensive for locals to fix, much less replace.