In the wake of hurricanes Harvey and Irma, large sections of southeast Texas and southern Florida were underwater. The massive flooding has claimed the lives of more than 100 people, and AccuWeather predicts that the economic cost of the two storms will be almost $300 billion.
Right now, California may be dealing with more fire than flood, but there are still important lessons that the state can learn from Harvey and Irma, says Nicholas Pinter, the associate director of the Center for Watershed Sciences at the University of California, Davis. In fact, says Pinter, there are lessons that the Western United States should learn from flood management around the country, and the world.
Water Deeply spoke with Pinter about lessons that he has learned from his work on flood management in other states and countries, how it can apply to California and his concerns about the future of the National Flood Insurance Program.
Water Deeply: How much have you looked into the flooding from Harvey and Irma?
Nicholas Pinter: With Harvey, it was challenging that the storm had stalled so long over the Gulf Coast that no one really knew how widespread the flooding was. You couldn’t fly a satellite. You couldn’t even really fly an aircraft. A guy in my lab, Nick Santos, pulled up the satellite imagery and analyzed it; this is radar imagery that sees through the clouds. We looked at the extent of flooding in these areas, and then analyzed it against different flood zones, different political jurisdictions and against the long-term history of flood damage in those areas.
There were suspicions that Houston may have been this year a victim of its own success. Success in developing, growing, adding population and infrastructure and a victim in the sense that that new population and infrastructure was underwater. That was indeed true. Large portions of the flooding this year as a result of Harvey were out of the mapped 100-year floodplain. In fact, nearly half were outside both the so-called 100-year and 500-year floodplains. Either the flooding was a much, much rarer event than the statistics would suggest – and that was not the case, probably; or Houston, we have a problem.
Widespread development has probably contributed significantly to the flooding this year.
Water Deeply: Can you translate any of that to the West and to California?
Pinter: Very much. Our group has been analyzing patterns of flood damage in California over the past several decades. In particular, we obtained several high-resolution and proprietary data sets from the Federal Emergency Management Agency (FEMA), which look at the National Flood Insurance Program (NFIP) and the pattern of individual policies across the country, including California, over decades. On the one hand, the picture in California is much better than in Texas. It’s much better than Alabama, Mississippi and many other states.
One of the metrics that we developed, is we just looked at national flood insurance programs by state and by individual jurisdiction – how much those jurisdictions have gotten out in flood damages and tax-funded repairs versus how much they paid in NFIP premiums. One of the worst offenders was Mississippi. This is a 21-year study period. They’ve gotten $5 out for every dollar of premium Mississippi policyholders have paid into the flood insurance program. If that was a private flood insurance company, they’d have dropped Mississippi’s policy years ago.
California, in contrast, has gotten just 14 cents in return for every dollar of premiums paid into the program. Some areas are even less. The Central Valley, historically, is even less. It’s 9 cents per dollar.
Water Deeply: Is that primarily just because a lot of Mississippi is wetlands and areas that will flood more readily, which don’t exist as much in California, or is that because of public policy?
Pinter: Choice B. California has enormous flood risk. The Department of Water Resources has estimated that 7 million Californians and nearly $600 billion worth of infrastructure, housing and crops are susceptible to flooding within the state. We have this very extensive flood exposure. California has invested massively and will probably need to continue to do so, in limiting its flood risk. It looks like at least right now the picture is much better here, but this is an ongoing process
Water Deeply: People don’t generally think of California as a state with high flood risk. It doesn’t have hurricanes as you have in the Gulf. Why does California have so much flood exposure?
Pinter: That question points out the real threat and challenge of flooding: that people’s memories are short. Go back into California history, and we’ve had massive flooding in every part of the state. The Central Valley was basically an inland ocean in 1861 and 1862 and repeatedly since then. The Los Angeles area was hit by multiple catastrophic floods through the late 1800s and the early 1900s.
What we did to control that is a combination of engineering measures like channelizing the Los Angeles River, building great big dams and levees and sound zoning, planning and management of the state’s flood plains.
Water Deeply: What have you learned from working in the Midwest and what should people in California and the West in general be learning about flood management from the rest of the world?
Pinter: One thing we talk about in flood science and flood management is that there are different toolkits in different areas. Different paradigms. We’ve worked with the Europeans, and they’ve got their own flood risk paradigm. The Chinese have their own flood risk paradigm. Sixteen years in the Midwest, I mostly believed that that was the U.S. paradigm. You come to California, and we’ve got a whole other toolkit out there. Different water issues. Different strategies used to manage flood risk like dams for the most part. Heavy reliance on the dams. There really is an awful lot to be learned by comparing the different toolkits.
Water Deeply: Do you have an example of a tool that you would like to take from the Midwest or maybe even another country and give it to the West or to California to use?
Pinter: We’ve been talking a lot with our British colleagues. In the United States we draw a line in the sand. This is the limit of the so-called 100-year floodplain. It is the area of land near a river that has a 1 percent chance of getting flooded every single year. We say on the river side of that: “Don’t build there. You have to mitigate. That’s where the flood risk is.” On the other side of the line we say: “Eh, don’t worry about it. We’re not going to legislate that. It’s not a concern.” In Britain what they do is they calculate the probability of any given spot. Behind the levee, in front of the levee, behind a partially completed or lower levee and the higher levee. Risk-based flood management. That is absolutely a superior product. California would reap tangible benefits from following that model.
Water Deeply: One of the big things that has come out, at least news-wise, of the flooding with Harvey and Irma is communicating the nuances of this flooding, especially as it relates to climate change. How do you communicate your research to policymakers and to the public as a whole?
Pinter: The one thing about being academic is that you really don’t want to be an advocate of specific policy or any part of the political spectrum. However, when the science points inescapably to a political solution, I’m not shy about pointing in that direction.
The U.S. Congress is right now debating reauthorization of the National Flood Insurance Program. Until a couple weeks ago it was set to expire at the end of this month, which would be a chaotic event. Very unsettling on national real estate, legal landscape.
Here’s my nightmare scenario: President Donald Trump and Congress have just extended the deadline for reauthorizing NFIP to Dec. 8 – a very minimal extension. My fear is that this particular Congress, in this current political climate combined with what will no doubt be enormous price tags for Harvey and Irma, may not be able to reach a solution at the end of this year and that, although everyone is saying: “No, no, no. It’s a political mandate. They must come up with a fix,” we could suddenly be left with no National Flood Insurance Program. That’s the worst-case scenario.