"When American jobs are at risk, FEMA should use the methods readily available to it rather than settle for an all-or-nothing approach," the senators said.
Promoting growth in the wrong places?The "without levee" approach will be replaced with a suite of possible scenarios, such as floodwater pouring over the top of some levees, or tunneling through them to cause total collapse, or simply being too low to prevent major inundation in a 1 percent annual flood.
In the end, the policy could enlarge the amount of land behind unaccredited levees that is free from rigorous flood plain regulations, like building standards and mandatory insurance. That could make it easier to build new developments in flood-prone areas, some experts on flooding say.
"It either delays or avoids the really necessary prospect of having more and more people get flood insurance in the flood plain and practice good land use. That's my concern," said Jeffrey Mount, the founding director of the Center for Watershed Sciences at the University of California, Davis. "What bothers me more is not the fact that those people are behind [unaccredited levees]. It's that you're adding people to these places. You're promoting growth in these places."
That's concerning to him and other experts because even accredited levees are bound to buckle eventually. When they do, the damage can be worse than if there were no levee at all, because floodwater can get trapped on the dry side of the wall.
That happened during the landmark Mississippi River flooding of 1993; water broke through agricultural levees before moving along the wrong side of the walled networks until it reached populated areas.
FEMA's plan will rely on improved digital mapping and increased communication with local flood plain officials to determine the risks behind unaccredited levees.
"In many cases, a decertified levee does something," said Eli Lehrer, who heads the Center on Finance, Insurance and Real Estate at the Heartland Institute. "It may not protect against a 100-year flood, but it's foolish to ignore that the levee is in fact there. This does lead to better mapping and better assessment of risk."
The 'funny math' of certificationHe also said the plan could relieve political pressure on FEMA to maintain the accreditation of levees that should not be. That pressure is widespread, as lawmakers and wealthy communities fight to maintain a development-friendly status that comes along with an approved levee. Lehrer said if a portion of the population behind an unaccredited barrier were free from strict flood regulations, the intense lobbying might subside.
"There are a lot of levees that should be decertified but aren't, and everybody knows that," Lehrer said. "If you allow this designation to happen, a lot of the funny math that goes on right now, it'll be a lot easier to stop it if not everybody behind a levee has to buy flood insurance."
But FEMA's plan doesn't address what many experts say is the agency's biggest mistake: the use of the 1 percent annual flood, known as a 100-year flood, as the minimum standard that levees must protect against.
Many experts say the standard should be much higher, like one that requires levees and homes to be built to the 0.02 percent annual standard, commonly called a 500-year storm. Warnings that the current standards are too weak can be traced back to the 1970s, when the Army Corps of Engineers called them "imprudent."
A pioneer of levee policy has been saying the same thing. Gerald Galloway, an expert on flooding at the University of Maryland, is among the strongest voices calling for expanded flood insurance coverage behind levees. The impact of climate change on flooding is one reason for that. There's concern that heavier rainfall combined with increased runoff caused by expanding development is overpowering FEMA's standards.