New FEMA Flood Maps

Frustrated homeowners look to new FEMA flood maps for answers, but there's no guarantee the advisories won't pose even more questions
Monday, March 27, 2006
By Gordon Russell
Staff writer

One of the biggest questions hanging over the nascent recovery of New Orleans and the surrounding area -- what will new federal flood maps look like? -- is expected to be mostly resolved soon with the release of FEMA advisories for each of the four parishes that still lack them: Orleans, Jefferson, St. Bernard and Plaquemines.

The new figures were originally supposed to be released in January, and then were delayed until mid-March. Officials with the Federal Emergency Management Agency now say they expect to make the advisories public by the end of March, nearly seven months after Katrina.

The long wait for the maps -- which has infuriated homeowners and state officials, who say the delay has crippled the pace of rebuilding -- owes in part to a debate over what assumptions will be used to design the new maps for the four parishes, all of which depend on levees to protect them. There is also the sheer complexity of modeling potential flooding in a region that is at risk of flooding in three distinct ways: from heavy rainfall, from high storm surge and to a lesser degree from a swollen Mississippi River.

Some believe the new maps, designed to model a "1 percent," or 100-year storm, should reflect the possibility that the levee system fails to keep Lake Pontchartrain at bay, as it did during Katrina. Bunk, others say, arguing that basing flood maps on catastrophic levee failures would amount to an admission by the federal government that its levee system simply doesn't or cannot work, and leaves a major metropolitan area in peril. In addition, there's the issue of whether the new maps will reflect ongoing improvements to the system, such as hurricane gates blocking outfall canals, and future improvements, such as armoring and relocating pumping stations.

"There's a fundamental contradiction between FEMA issuing advisory base flood elevations based on levee failures, not overtopping -- if they do issue them that way -- and the corps and all their public pronouncements that the levees are going to be rebuilt to pre-Katrina levels," said New Orleans resident Matt McBride, co-chairman of the Broadmoor Improvement Association's urban planning committee. "Even a 5-year-old can understand that if one agency says you're going to be safe, and the other says we're going to charge you more money because you're not going to be safe, they need to get together."

How maps will be drawn

It's anyone's guess which tack the new maps will favor, or whether they will have some sort of compromise that reflects the various scenarios. Gary Zimmerer, the engineer in charge of running FEMA's models, said that he couldn't comment on what the advisories will look like, only that they will show what is expected to happen in a 100-year storm. He said the maps will consider ongoing work by the Army Corps of Engineers.

Diana Herrera, natural hazards program specialist for FEMA, said the maps will "take the last 25 to 30 years of storm history into consideration," including Katrina. But how the different events will be weighted is still unclear.

The maps also are expected to factor in the city's subsidence, as measured by a system of 85 elevation markers around southeastern Louisiana maintained by the National Geodetic Survey. While subsidence varies by neighborhood, Dave Zilkowski, acting director of the Geodetic Survey, has said some parts of town may have fallen by as much as a foot since 1984. The new elevations are likely to shift by at least a corresponding amount.

Butch Kinerney, the liaison to FEMA's mitigation division, noted that the calculations that underpin the maps are enormously complex. The four-parish region has 18 different sub-basins for drainage, he said, "and every one of them has a tiny little nuance."

Kinerney hinted, but would not say definitively, that the new maps will not force radical changes in building elevations, although rumors persist that there will be substantial changes in St. Bernard and Plaquemines parishes.

"We can change nothing, or we could pretend the levees don't exist," which would result in dramatic changes, Kinerney said. "We're trying to take a reasonable approach in between there. We're looking at the 1 percent chance. "But we also know there's a 0.5 percent chance, and a 0.25 percent chance, and (the new elevations) are not going to cover you in those extreme events. It's going to cover you in garden-variety-type events. We're taking a measured approach. We don't want it to be so onerous that people turn away from the area completely. We're trying to take a middle ground, and there are still a lot of negotiations taking place."

Wait is excruciating

For local and state officials, the sooner those discussions end, the better. The wait for maps "has obviously been very frustrating to us," said Sean Reilly, a member of the Louisiana Recovery Authority. "We're all in a holding pattern, and it's incredibly frustrating. It's one of the last pieces of the puzzle, and it's got us throttled."

Theoretically, at least, there's plenty riding on the outcome. Maps that differ wildly from those now on the books, which date to 1984, could force property owners in various neighborhoods to rebuild substantially higher to qualify for flood insurance. In hard-hit coastal Hancock County, Miss., for instance, new flood maps in some cases required elevations 10 feet above the old ones. The maps also could affect the cost of flood insurance.

The new advisories will not have the force of law immediately. They'll be followed in April by new "flood recovery maps," Herrera said, which will in turn be replaced toward the end of the year with preliminary flood maps.

Local communities have the right to dicker with FEMA for a year or more before those maps become law, meaning it could be two years before the final versions are on the books.

Rather than maps with specific numbers, the new advisories -- which describe in text what changes FEMA expects to make -- will require property owners to do some figuring to determine their new recommended base flood elevation. For instance, for Calcasieu Parish -- available on the Internet at http://www.fema.gov/hazards/floods/recoverydata/katrina_la_resources.shtm#guidance -- the advisory says that FEMA expects to raise base flood elevations for the parish by about 1 foot.

The advisories are important to homeowners expecting financial aid. Officials from the LRA, which probably will be dispensing most of the billions in federal dollars expected to pour into the region, have clearly stated that they will provide money only to individuals who rebuild according to the latest flood elevation advisories. The authority has also said, however, that it will try to make money available for homeowners who need to elevate to the new levels.

Repetitive flood loss

A clue to the shape of the new flood advisories may be found in maps that show what parts of the region were most apt to flood before Katrina inundated 80 percent of the city. The maps show which areas had the most "repetitive loss" properties -- that is, flood-insured properties that submitted at least two claims over any 10-year period since 1978.

Many homeowners would be perfectly happy if the new maps were largely based on those events. For instance, homeowners in Lakeview, Lakewood South and other areas of New Orleans that, despite their low elevations, tended to drain reasonably well after heavy rains, say it would be absurd to force them to build higher because of what Katrina wrought.

"The mindset is that you get flood insurance because it's required, and to the extent you think about flood possibilities, it relates to some highly unusual torrential rainfall and accumulation that overpowers the pumping system," said Larry Orlansky, who six months before Katrina bought a home in Lakewood South in an area that had never flooded. "The notion of the 17th Street Canal breaking and getting 6 feet of water in the houses is not something anyone talked about or contemplated."

The maps confirm what Orlansky knew anecdotally: Since the birth of the flood program, relatively few properties in the heart of Lakeview or Lakewood South have flooded repeatedly. For many homeowners, Katrina was the first time they'd made a flood insurance claim. If the new maps draw heavily on repetitive-loss data, the biggest shifts in elevation requirement probably would be seen in areas like Broadmoor -- often referred to as the "bottom of the bowl" because of its position in the center of the walled-in city.

But that could be a mistake too. While historically speaking Broadmoor may be the most flood-prone area in the city -- and old-timers will tell you stories of fishing in a shallow lake that once existed there -- a group of researchers based at the University of New Orleans' Research and Technology Park has assembled evidence that that may no longer be the case.

The area contains 167 insured properties that, before Katrina, had been the subject of at least two flood claims, and sometimes more. New Orleans and Jefferson Parish, meanwhile, are ranked first and second in the country among counties with the highest number of such properties. Based on those rankings, Broadmoor may have the highest concentration of repetitive-flood properties in the nation.

The new Broadmoor

But the research team, led by professor Shirley Laska, who directs UNO's Center for Hazards Assessment, Response and Technology, used data cobbled together by McBride and FEMA and found that recent drainage improvements have dramatically reduced flood claims in the area.

Where storms in the 1990s produced a barrage of claims from Broadmoor -- in the May 8, 1995, flood, for instance, nearly every one of the neighborhood's structures filed a claim -- that wasn't the case for storms beginning in 2001.

By 2002, the expansion of the canals under South Claiborne and Napoleon avenues, financed under the Southeast Louisiana Urban Flood Control Project, along with improvements to the nearby Broad Street pumping station began to have an impact.

Though a series of named tropical storms, as well as a spate of anonymous gully-washers, have struck New Orleans since then, just a handful of flood claims resulting from them have been filed from Broadmoor addresses, the group's research shows. Katrina is the lone exception.

"Why would you deny the continuance of a part of the city whose problem has been solved except when the levees breach?" Laska asked, harking back to a proposed city map released by Mayor Ray Nagin's Bring New Orleans Back Commission that showed much of the neighborhood being converted to green space. "It's going to be very interesting to see how the planning process responds."

Zimmerer, the FEMA mapper, said generally that the federal flood models take into account public-works improvements. For instance, he said, they will factor in the levee work that the corps is doing now, including armoring of the levees and installing gates at the mouths of major drainage canals.

But it's not clear how the historical flooding data, which may not be relevant in every case because of recent improvements, will affect the maps. (The data has other limits as well: Homes in an older neighborhood such as Broadmoor may be more vulnerable to flooding in part because they were built at elevations lower than what federal maps would now require. More modern areas such as Lakewood South presumably have few homes built below required elevations.)

Gate a two-edged sword

Ironically, another proposed improvement to the flood-protection system -- the gates that the corps is installing in the mouths of the major drainage canals -- could temporarily undo some of the recent work that has made Broadmoor and other bottom-of-the-bowl districts less flood-prone.

Officials at the Sewerage & Water Board of New Orleans recently conceded that the plan to install gates, designed to prevent storm-surge-driven lake water from pouring into the city a la Katrina, will reduce pumping capacity during hurricanes. If substantial rain falls while the gates are closed, sections such as Broadmoor, Hollygrove and parts of Uptown and Old Metairie could well flood, officials said. "It seems like once again, we're being sacrificed for the greater good," McBride said.

The tradeoff -- give up pumping capacity to prevent Katrina-type flooding from storm surge -- is intended as an interim solution until proposed pump stations in New Orleans are built along the lakefront over the next three years.

Not everyone agrees that the new flood maps should focus solely on rainfall patterns. Bob Hunter, a former administrator of FEMA's National Flood Insurance Program and now director of insurance for the Consumer Federation of America, believes that the possibility of levee failure should at least be taken into account when drawing up the maps.

"Levees fail," he said simply. "I proposed to Congress recently that when people live behind levees or dams, you need to have some consideration of that in the mapping. What you ought to do is assume there's no levee, and figure out what would happen, and then factor in that there is a levee, and lower the risk accordingly."

Risk of levee failure

Hunter said he believes all areas located behind levees should be considered part of the flood plain because of the risk of failure. That way, more people would be required to buy flood insurance and would thus be protected. Meanwhile, the rates wouldn't have to be exorbitant, he said. Such a mandate would not have a dramatic impact in Orleans and Jefferson parishes, which already are in the nation's top 10 counties in participation in the federal flood insurance program.

While corps officials have promised the reconstructed levees will keep people and property safe, Hunter noted that there has been a robust debate about whether that's true. That suggests there's some risk, he said. "Even a 100-year levee or a 200-year levee can be overtopped," he said. "I think they should require people behind it to buy insurance, and offer a very low rate accordingly."

And while the levee failure of Katrina is generally seen as wrought by man rather than nature, it's worth remembering that had the storm been more powerful, it could have easily overwhelmed better-designed and better-built levees.

The city's levee system was meant to hold back the sea in the case of a fast-moving Category 3 hurricane. Jack Beven, a hurricane specialist with the National Hurricane Center, said his research shows that a Category 5 storm is likely to strike within 75 nautical miles of New Orleans on average every 53 years. For a Category 4, the "return interval" is once every 29 years, and for a Category 3, it's once every 19 years.

Those numbers could be used to make an argument that the "1 percent" storm FEMA models could be more powerful than Katrina. But Beven noted that his estimates have many subvariables as well -- for instance, a storm striking within 75 miles could have minimal impact on the city. There are other factors as well: the size of the storm, its speed and its direction, to name a few.

Zimmerer, the FEMA mapper, said the "1 percent" storm used in creating models "does not relate" to a specific hurricane strength, size or speed.

How Katrina -- and the possibility of future hurricanes -- will affect the new maps is perhaps the biggest question on the minds of those following the issue. While on the one hand the storm proved that many areas that previously sustained little flooding were in fact vulnerable, many believe that Katrina should essentially be ignored because flawed levees rather than nature caused the flooding. They also note that, had the 17th Street Canal breached on the Jefferson rather than the Orleans side -- which easily could have happened -- the map of devastation would have looked entirely different. They believe it would be patently unfair to "punish" New Orleans for the misfortune it's already suffered.

"It makes no sense to me to have flood elevations altered based on the assumption the levees will break," Orlansky said. "And if you were to do that, there's certainly no rationale for making that adjustment east of the 17th Street Canal and not west of it. Why not make the assumption the levee breaks on the Jefferson side? Or that the Lake Pontchartrain seawall breaks? Or the river levee?"

Others prefer to view the wholesale destruction as an opportunity to make sure history doesn't repeat itself. Of course everyone wishes New Orleans hadn't flooded, said Drew Sachs of James Lee Witt & Associates, the consulting firm formed by the former FEMA director that is working with the Louisiana Recovery Authority. But it did, and that presents the city with a chance to build safer and better, Sachs said.

"A levee should not be viewed as a 100 percent solution," Sachs said. "It's not an issue where there's no risk if you're behind a levee. And it's valid in this case to say this was a man-caused disaster.

"But now that we have damaged homes and buildings down there, the opportunity to make us safer is in the reconstruction period. As you build these places back, we have to keep our eyes on the prize in terms of trying to build back a community that's stronger and safer and more secure than before. When a home is destroyed, when it's gone, that's the least expensive time to mitigate the risk."

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Gordon Russell can be reached at grussell@timespicayune.com or (504) 826-3347.