The Great Flood of 2011 (and 1993, 1965, 1951, 1927): Time to Put Lessons Learned into Action
With millions acres of land already flooded in Missouri, Illinois, Kentucky, Ohio, Indiana, Arkansas, Tennessee and Mississippi -- and Louisiana still bracing for the worst -- this flood will surely be remembered by many as the Great Flood of 2011. While it will be months before we know the full extent of the damage, it’s clear the cost will be measured in the billions and the impact to the lives of many will be immeasurable. Our thoughts and prayers are with the people struggling in the face of rising waters on the lower Mississippi.
And even as efforts are still underway to protect against the worst, people are already beginning to ask what can be done to prevent such devastation in the future. Unfortunately, it is an inescapable fact that there will be major floods events in the future just as there have been in the past century on the Mississippi in 1993, 1965, 1951 and 1927. But fortunately, we have learned some ways to better protect our communities.
In the wake of the 1993 flood, which devastated the Midwest, the federal government released a report, commonly known as the “Galloway Report,” on how to improve our preparedness for future disasters. Among other things, it emphasized a need for integrated planning and shared responsibility for flood management at all levels of government and to recognize flooding as a natural function of rivers. The report was particularly ground-breaking because it focused not just on traditional measures like building more levees, but on the need for non-structural measures to improve flood management such as setting levees back to increase the ability to convey floodwaters, and using building codes to require raised foundations when there is still a risk of flooding.
In the years since the Galloway report there has been progress toward implementing the recommendations, but change has been slow. That’s particularly because political will to make changes often diminishes within a year or two of a disaster and real improvements in flood management are complex, requiring a lot of effort. But the cost of inaction – as we’re seeing all too clearly – is far too costly to continue this way. We must learn from this disastrous event and ensure better protection from future disasters by implementing flood management policies that include the following elements to improve public safety and provide other benefits to communities:
Increase managed floodplain corridors. Floodplains are those lands adjacent to rivers where flood waters naturally spread outside of the main channel periodically. Floodplains act as a form of short-term storage for flood waters, sometimes for just a few hours and other times up to several days. Allowing for temporary storage of flood waters in this space can reduce the peak height of a flood event and related damages. Unfortunately, traditional flood control has largely relied on building levees right along rivers – disconnecting the main channel from its floodplains. This has greatly exacerbated flooding in recent years. However, there is a growing awareness of the need to reconnect rivers with their floodplains in appropriate places in designated places, called flood corridors. As a matter of fact, this month the US Army Corps of Engineers has used the intentional inundation of floodplains in an attempt to protect communities downstream. To do this safely, these floodplain areas need to be kept free of infrastructure and have only flood compatible land uses such as open space or recreational areas. Where feasible, floodplain corridors should be expanded and incorporated into regional flood management systems.
Increase level of flood protection. Most communities use a 100-year event standard when planning for flood protection. Often misunderstood, this means that in any year there is a 1 percent chance of flooding. That means, for a standard 30-year mortgage on a house, there is almost a 1 in 3 chance that the property will be flooded over the course of the loan. Risking these kinds of odds simply does not make sense given the high cost of flooding and associated risks to public safety. We need a higher planning requirement to bring into balance the costs and risks associated with floods. In the Netherlands, a country with vast low lying areas, they employ much higher standards protecting against up to a 10,000-year event out of recognition of the risks and impacts of flooding. In recent years, the US Army Corps of engineers has collaborated with the Netherlands in an effort to improve our nations approach to flood management. Federal, state and local flood management agencies should increase the minimum flood protection requirement in urbanized areas, to 200-year level or greater.
National Flood Insurance Program (NFIP) reform. While initially created to discourage high-risk development in floodplains, the NFIP has inadvertently done the opposite and actually managed to facilitate floodplain development. All property owners within the 100-year floodplain who are using federally insured loans are required to purchase flood insurance. Ironically, the NFIP is often the only source of flood insurance available, as private companies generally avoid providing it because of the high risk and costs. Therefore, the NFIP enables development in floodplains where it might otherwise not be possible due to the inability to get insurance. NFIP reform needs to address this unintentional result and encourage better practices through requiring such things as greater levels of flood protection, updated building standards and other measures to improve public safety.
Using more green infrastructure: smarter practices on land to decrease flooding. The urban environment plays an important role in determining flood impacts. Impervious surfaces like roads and concrete prevent rainfall from infiltrating into the ground, instead turning it into runoff that makes its way directly into rivers. This results in storms producing bigger flood events than would occur otherwise in undeveloped areas. By using smarter, greener development practices like green roofs, roadside plantings, parks and porous pavement (collectively called green infrastructure) -- we can stop rain where it falls and either store it or allow it to soak back into the ground. This can not only reduce runoff and flood events, but also recharges groundwater aquifers for water supplies, and reduces the amount of pollution reaching our streams.
As the damage from the Mississippi River flooding continues to unfold, we’ll be looking to the government to first and foremost protect those in harm’s way. And as the waters recede – we’re counting on them to put these lessons learned into practice, so the next big flood will cause less harm.