Suburban growth into areas with a history of flooding is putting more houses, businesses and lives at risk. Every new road, bridge, levee or other human-made structure further obstructs — and slows — the natural drainage patterns within the Amite River Basin, where the Amite and Comite rivers flow into Lake Pontchartrain. And long-discussed projects intended to mitigate flood damage in and around Baton Rouge remain under-funded and far from finished.
"Damage from these natural disasters is only going to get worse because we've overbuilt our capacity to manage existing risks," said professor Edward Richards, who has written extensively on coastal and floodplain issues as director of the program in law, science and public health at LSU's Law Center. "Our drainage system is blocked up."
The Louisiana Flood of 2016 killed 13 people, displaced tens of thousands of others, caused an estimated $8.7 billion in damage and destroyed some 60,000 houses. Gov. John Bel Edwards is requesting $2.8 billion in federal recovery money, and more than 73,000 households across 20 parishes have been approved for Federal Emergency Management Agency aid.
Louisiana hasn't seen a natural disaster of this magnitude since 2005, when storm surge from Hurricane Katrina or the failure of levees and floodwalls submerged much of New Orleans and St. Bernard Parish and parts of St. Tammany and East Jefferson. The causes of the two events were different, and the damage inflicted by Katrina was far more tragic and extensive. But both share this bond: Decisions by human beings to allow development in known flood areas, and their failure to complete flood mitigation projects, increased the devastation.
"We keep saying this won't happen again, but it does keep happening and it will continue to happen," said Craig Colten, the Carl O. Sauer professor of geography at LSU and a longtime student of why communities expand in harm's way. "After each one of these events we say we've learned our lesson, but then we ignore what we've learned."
Watch aerials of Baton Rouge area flooding
No one is suggesting that rainfall totals seen in mid-August— when some spots saw more than two feet of rain in 72 hours— will become the norm. But flooding in the Baton Rouge area and across the Capital region, as it has for centuries, will happen again. And rapid and largely unchecked growth in the suburbs of Baton Rouge and neighboring Livingston and Ascension parishes, coupled with a degraded natural drainage system, is putting more people in harm's way.
Absent drastic measures to make suburban growth safer and to improve watershed drainage, the widespread destruction caused by these floods will almost certainly become more common, more expensive and more deadly. "We keep rolling the dice hoping disaster won't strike twice," Colten said, "and we keep losing."
What's troubling is how much damage was done to property outside the "100-year flood zone," where there is a 1 percent chance of flooding in any given year. No doubt that's partly due to the freak nature of the August storm, considered a "1,000-year event."
Yet experts warn it's a mistake to chalk up this as a once-in-a-millennium happening. The accuracy of FEMA's flood-prediction maps is not perfect, and a recent study by the nonprofit Resources for the Future found someone living in the 500-year flood zone was as likely to be flooded as someone living in the 100-year flood zone. Those inside the high-risk 100-year flood zone are predicted by FEMA to have a 26 percent chance of flooding over the life of a 30-year mortgage.
"It's wrong to create a false sense of security by saying this flooding only happened because it was a 1,000-year rain," Richards said. "There's been numerous flooding in this area in the past, and it won't take a 1,000-year rain to do it again.
"If you got two or three feet of water in your home, it doesn't matter if the next storm is a 100-, 500- or 1,000-year event; your house is going to flood again."
Moreover suburban sprawl is pushing deeper into the floodplain. In the city of Central, incorporated in 2005, 75 percent of the property is in the 100-year flood zone, Colten said. The mayor, Jr. Shelton, said as much as 90 percent of the houses and businesses sustained flood damage.
In neighboring Livingston and Ascension, two of the fastest-growing parishes in the state, real estate developers are racing to build along the Comite and Amite rivers and in the area where the two waterways converge and spill into Bayou Manchac during floods. These are all areas that have repeatedly flooded in the past, yet local officials are doing little either to slow the growth — in fact, they're encouraging it— or impose stricter safety standards within the 500-year flood zone.
"This was a huge rainfall, but it didn't have to be such a huge flood with so much devastation," Colten said. "So much development has been allowed since 1983. We have created this situation."
The year 1983 is important. That's when much of the same area suffered extensive flooding, causing damage of $344 million -- $831 million in today's economy. It was the fourth flood along the Amite River in 11 years, prompting Rod Emmer, long-time director of the Louisiana Floodplain Managers' Association, to call for tougher flood zone construction standards, including elevation standards above FEMA's minimum requirements, and flood-reduction projects. Significant flooding in the Baton Rouge area also occurred in 1990 and 1993, and in 2001 Tropical Storm Allison dropped 19 inches of rain over a two-day period, swamping much of the region.
After the 1983 flood, local officials adopted a series of measures to improve water flow and better manage backwater flooding, which is water building up faster than it can be drained. By 1990, planning departments in Baton Rouge and Denham Springs had upgraded floodplain construction standards above the FEMA baseline, and Ascension Parish and Central largely followed that lead.
Those tougher standards are why Frank Duke, the Baton Rouge planning director, disputes blanket statements that explosive suburban growth everywhere amplified the flood damage. "Growth didn't contribute to the flooding," said Duke, citing post-1990 developments that did not flood in Baton Rouge. "I do agree that anything built prior to 1990 did have an impact."
That's not the case elsewhere in the region. A residential development under construction in Watson, in Livingston Parish, flooded badly in August, and much of hard hit Central was built after 1990. Duke acknowledged that suburban growth in areas prone to flooding "does complicate issues if you don't provide for the proper mitigation."
One of those is the Comite Diversion Canal, designed to carry water surge from the Comite River west across East Baton Rouge Parish to the Mississippi River. It would reduce flooding risks, especially outside the 100-year flood zone -- if it's ever completed.
The project was authorized in 1986, and voters in East Baton Rouge, Ascension and Livingston parishes approved a property tax in 2000 to help fund construction. But much of it remains unfinished. U.S. Rep. Garrett Graves of Baton Rouge said 20 percent to 25 percent of homes that sustained flooding in August would have been spared if the canal were operational.
Even the diversion canal is no magic bullet solution, however. Some members of Louisiana's congressional delegation, already committed to securing an estimated $211 million in federal money to finish the canal, are now pushing to expand the project to include overflow from the Amite River.
Others, including Colten, wonder why local government officials gave the OK to new developments in floodplains near the Comite when it was clear that completion of the diversion canal was nowhere in sight? "Everyone understands the importance of growth and new tax revenues," he said, "but those decisions put lives at risk."
Rather than raising building standards to account for repeated flooding in the presumably lower-risk 500-year flood zone, officials now are scrambling to relax standards for rebuilding flooded houses.
The Baton Rouge Metro Council on Sept. 14 voted to waive existing regulations and exempt some 32,000 households outside the 100-year flood zone from having to elevate their flood-damaged homes. The night before, frustrated residents of Denham Springs, the region's hardest-hit city, packed a public meeting to complain about regulations that could require them to elevate their homes before securing a permit to repair or rebuild.
In Central, the mayor and City Council members vowed to roll back rebuilding standards to the FEMA minimum. "If we have to start elevating our houses and demolishing them, Central's going to turn into a ghost town," said Shelton, the mayor.
Colten argues these officials shouldn't be easing standards, but, rather, expanding them to make the 500-year flood zone the baseline at-risk designation. "It's a tough job because they're trying to protect the financial resources of their constituents, but long-term safety is more important than short-term finances."
Elected officials also are pushing to have FEMA not count the August flood when determining the region's base flood elevation, which is the height that inundation waters are expected to reach in a 100-year flood. New buildings and those significantly damaged by storms must be constructed one foot above that base elevation. "I don't want it to count," said Baton Rouge Metro Councilman Trae Welch, asserting it would be unfair for such a "rare event" to have such a significant impact moving forward.
"We just had a 1,000-year flood that literally was 6 feet above the 100-year base flood elevation," said Central City Councilman Jason Ellis. "It would be ridiculous if every single one of us had to go raise our houses above a 1,000-year flood event."
Colten, however, said those who want to exclude the August event as the flood of record are ignoring reality. "If you don't, then it's likely these homes will flood again in the future. People don't want to deal with the truth of the situation."
When Congress approved the Disaster Relief Act of 1950, enabling the federal government to provide relief and recovery funds, Colten said, it gave the region a false sense of security and a willingness to allow development in higher risk areas. Making the risk even more tolerable is the National Flood Insurance Program, created in 1968 after Hurricane Betsy flooded New Orleans three years earlier. The intent of the insurance program was to provide affordable, government-subsidized flood coverage for homes already at risk of flooding. In exchange, local communities are supposed to prevent new development in high-risk areas.
Not only have local governments largely ignored their role, but also local officials routinely threaten lawsuits whenever FEMA attempts to expand the 100-year flood zone, where homeowners must carry private flood insurance. Most of the houses damaged in the Louisiana Flood of 2016 did not carry flood insurance because they were located outside FEMA's high-risk zone. And instead of limiting development, the flood insurance program has opened the door for more expensive homes, constructed on concrete slabs, to be built in areas likely to flood.
"It's been 50 years of unintended consequences," said Richards, the LSU law professor. "A program designed to help has made the problem worse."
Louisiana leads the country in severe repetitive loss properties, according to FEMA records, with more than 7,200 of the National Flood Insurance Program's 30,000 multi-flood homes. One house in Batchelor, in Pointe Coupee Parish, according to the Natural Resources Defense Council, has flooded 40 times over the past four decades, collecting $428,379 in insurance payments. Since 1978, repeat loss properties in the state have received $1.22 billion in flood insurance payments — 22 percent of all repetitive loss claims in the U.S., according to the council's research.
"We need to change the emphasis of the NFIP from a rebuilding program to a risk mitigation program," said Rob Moore, a flood policy analyst at the council. "It currently addresses people's short-term need to get their life back in order, not the long-term risk."
The flood insurance program is $23 billion in debt, much of that due to massive payouts after hurricanes Katrina and Rita in 2005 and Sandy in 2012, prompting some to wonder whether federal officials will do what those at the local level will not: impose higher elevation rules on development, expand at-risk flood zones and broaden private insurance mandates.
"Why should the federal government keep bailing us out if we're not willing to build safer communities in areas that we know will experience flooding," asked Richards. "People are right saying what happened in August was rare, but what they won't acknowledge is a 100-year rain, which is common, may do 90 percent as much flooding. Are we ready for that?"
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JR Ball is a state correspondent with NOLA.com | The Times-Picayune in Baton Rouge. Email him at jrball@nola.com. You can also keep up with his local updates on Twitter (@jrball35), Facebook (jrball) and Google+ (+JRBall).