Safeguarding Coastal Communities by Informing Homeowners of the Actual Risks and Total Costs of Flooding

Carol Friedland, the Cajun Constructors and Performance Contractors associate professor in the LSU Bert S. Turner Construction Management department, is working toward safer homes and enhanced community resilience in the face of stronger hurricanes and more frequent floods. She and her team, including Jim Wilkins, Niki Pace, and Melissa Trosclair, will help Gulf Coast residents make smarter housing decisions—calculating the total cost of homes that might or might not flood, and what it would cost to protect them—thanks to a $3.4 million grant from the National Academies of Sciences, Engineering and Medicine’s Gulf Research Program:

 

Flooded houses

If your home is built to the 100-year flood standard, it has a 50/50 chance of flooding at least once in 70 years. 

“I did my graduate studies here at LSU in wind engineering under my advisor Marc Levitan, who’s now at NIST. I had an interest in understanding structural engineering—how buildings withstood hurricane forces. We went out on a field investigation after Hurricane Ivan in 2004 in Florida. That was my first. A year later, after Hurricane Katrina, we went to Mississippi, where there wasn’t a lot of wind damage, but the damage from storm surge was very significant. This wasn’t our domain and flood/building damage researchers were few and far between—flood research typically fell under the National Flood Insurance Program (NFIP) domain.
 
“I asked myself, why do we have researchers in all of these other areas, and yet FEMA drives research on flood hazards? I started looking into how the insurance market has driven improvements in building science for other hazards, but these same mechanisms were not really in place for floods. The NFIP is a federal government program that’s significantly in debt and just continues to cover flood losses while maintaining the 100-year flood standard.

 

“In my opinion, the house is our new first line of defense from a community sustainability perspective. Safe housing is incredibly important to individuals and communities.”


“In Mississippi I saw people lining up with jugs so they could get water, and I found myself just thinking about these people. They had nothing. I saw them picking out pieces of their memories from storm surge debris, and I thought, the house doesn’t care what it is that causes the damage, and the people don’t fundamentally care either—it’s just a matter of whether the house is still standing or not. At that point, I changed my dissertation topic to look at both wind and flood hazards, and the house as the unit that allows the individual and the community to continue their life in an area.
 
“We saw the great diaspora after Katrina. If you had a house that was safe and functioning, you didn’t have to leave. You could come home once schools were back open and businesses came back. In my opinion, the house is our new first line of defense from a community sustainability perspective. Safe housing is incredibly important to individuals and communities.

 

”If you’re going to buy a house, the only thing you have in order to assess flood risk is whether you are in or out of a mapped flood zone.“

 

Field work in Alabama after a tornado in 2011

Carol Friedland (right) in April 2011 with then PhD student in civil engineering Vipin Unnikrishnan conducting a damage survey in Alabama after the Hackleburg–Phil Campbell tornado.

“Let’s say you go camping. The first need is a safe place for your family to rest. Once you have that, you can begin doing all of the other things. I have two small kids, and we’re not going to be out doing whatever until we have a safe place to sleep at night.
 
“One of the biggest objectives of this grant is being able to provide the present value of life-cycle cost analyses that can be used to compare different houses or mitigation options. One of the issues right now is the lack of information. If you’re going to buy a house, the only thing you have in order to assess flood risk is whether you are in or out of a mapped flood zone. You don’t know how much you’re going to pay for flood insurance, or how much a future flood event could cost. If the only piece of information you have is if you’re in or out of a flood zone, this doesn’t give you a lot to go on, and it doesn’t necessarily have a lot of meaning for people.

 

”If you build your house to the 100-year standard, your house actually has a 50 percent chance of flooding at some point in its useful life ... roughly 70 years.“


“You have to spend a lot of time educating yourself. A regular person doesn’t know what it means to be in a 1 percent annual chance flood event area. The life cycle of a house is roughly 70 years. If you build your house to the 100-year standard, your house actually has a 50 percent chance of flooding at some point in its useful life. That’s the math. If your house has a 1 percent chance of flooding the first year, it also has a 99 percent chance of not flooding. If you take 0.99 and raise it to the 70th power, the chance of the house flooding in 70 years goes to roughly 50/50. The probability of continuing to be lucky, lucky, lucky—at some point it tips. If you’re elevating houses in a community to the 100-year standard, approximately half of the homes will flood, based on the math. Within 70 years, some may flood three times and some may flood two times, but about half would flood at least one time.
 
“One thing people can understand is cost. Once you include things like lower premiums for flood insurance, lower probability of flooding, and lower severities of flooding, the upfront construction cost of elevated houses can absolutely be less expensive. In our experience, you can get better and more resilient homes for less money, but nobody knows that. So far, we’ve elevated thousands of homes in Louisiana. I don’t know how many billions of dollars we’ve spent. It costs about $100,000 to elevate a pre-existing home, and what we’ve found is that it’s cost effective, since it reduces the amount of flood loss. However, the upfront construction cost to elevate new homes can be around $5,000. This means that you can elevate 20 homes instead of one if you do it at the time of construction. This way, we can maximize resilience and minimize investment.
 

Dr. Carol Friedland

Dr. Carol Friedland

“Our goal is to give people actionable information; information they can understand and use. Should you buy? Should you elevate?“

“Now, I can tell you all of this information, but you still don’t have anything to act on, do you? This is why it’s important to us, with the help of this grant, to synthesize all of this information and make it actionable. In the future, how much can insurance premiums be reduced? How much is a flood loss going to cost? What are the probabilities? By discounting all of this back to the present value, consumers will be able to look at the numbers and make decisions for themselves and their families. It’s sort of like the Energy Star on your water heater or your dishwasher that tells you how much you can expect to pay for the energy it consumes—and it has to be in dollars; putting kilowatts on there is meaningless to people unless they work in the energy market.

 
“Our goal is to give people actionable information; information they can understand and use. Should you buy? Should you elevate? Most people don’t build their own homes; a developer does. But the developer is long gone when the people who live in those homes have to deal with the ramifications of the decisions that were made when those houses were built.
 
“My husband, who’s in construction, gets really frustrated when they say that there’s a 40 percent chance of rain on a given day. What does this even mean? Does it mean that it will rain in 40 percent of all areas, or 40 percent of the day in some areas, or all areas? He makes or breaks it depending on the weather, whether he can pour concrete or not. Telling people what the risk is really has no meaning; we don’t even know what a 40 percent chance of rain means, and that’s something we talk about every day. People don’t have a good knowledge of what risk is unless you translate it to something they can understand.”



For more information on Friedland's research and the other LSU and Louisiana Sea Grant project funded by the National Academies of Sciences, Engineering and Medicine’s Gulf Research Program, head on over to the LSU Media Center.

 

 

Elsa Hahne
LSU Office of Research & Economic Development
225-578-4774
ehahne@lsu.edu