A study by a noted hydrologist earlier this year of major Midwestern rivers in the Journal of Earth Science found that Federal Emergency Management Agency (FEMA) and the U.S. Army Corps of Engineers (USACE) have grossly underestimated the threat of severe floods in many communities.
The implications of the error are alarming, as calculations of flood severity and frequency are used to determine how high to build levees and floodwalls, where to approve development in floodplains, and also guide flood insurance requirements and costs. Consider the impact for residents in Mark Twain’s hometown of Hannibal, Missouri. In 2013, Hannibal had a 50-year flood, meaning a severe flood event calculated to occur once every 50 years. In 2014, Hannibal had another 50-year flood. Of course, each year the odds of such an event are the same, 1 in 50, so statisticians would urge us to take a longer view.
Here’s a longer view: the Mississippi River also reached its 10-year flood stage in Hannibal in seven of the last eight years. Hannibal also had a 200-year flood in 2008, as well as 1993. For those keeping score: 100 year floods twice in 25 years, 10 year floods 7 in 8 years and a 50 year flood twice in 2 years. Experts in statistics have examined the odds and decided to search for a more plausible explanation. By the way, for those who suspect global warming is the cause, climate change seems to be only a small part of the problem. The bigger contributor: the unintended effects of engineered river control systems.
Since you likely don’t live in Hannibal, Missouri, why does this matter?
Floods are becoming more frequent and severe, and if the calculations used to project the likelihood of severe flooding by the Army Corps of Engineers are so flawed in Hannibal, isn’t it possible those flaws are also distorting the risk of severe flooding where you reside? To learn more about the study being referenced: www.sciencedaily.com
My Suggestion: review the few residential flood facts below and consider contacting an insurance professional to learn about the cost and benefits of adding flood insurance protection for your home(s).
- In the past 5 years, all 50 states have experienced a flood.
- Each year, floods are the number 1 natural disaster in the United States.
- Everyone is at risk, even those who do not live close to rivers and lakes or a large body of water.
- More than 20 percent of all flood claims are for properties located outside of areas designated as high-risk flood zones.