Illustration by Mark Pernice
Babe the Blue Ox in water
About 11 years ago, when Ed Pelava and his wife were in the process of buying their south Minneapolis home, they got some costly news from their banker. The house they wanted—a 1959 split-level, nestled between Lake Harriet and Minnehaha Creek—lay within the 100-year floodplain.
Because their mortgage depended on federal backing, the couple would be required to buy flood insurance from the National Flood Insurance Program.
Pelava, a former engineer, knew he could have hired a surveyor to contest the flood-zone designation. But that would have been expensive and there was no guarantee of success. He also knew that his street—the 4800 block of James Avenue—had suffered occasional flooding over the years when a nearby tributary to Minnehaha Creek backed up.
So he opted to lump it. Over the course of a decade, Pelava figures, he shelled out about $23,000 in flood premiums. During the big metro-area floods of 2014, he watched a neighbor’s sump pump run day and night from June to September while his home remained high and dry. The neighbor’s home, Pelava adds, didn’t even fall in the floodplain.
Relief came in November of 2016 when the Federal Emergency Management Agency approved a new set of high-resolution flood maps for Minneapolis. Produced with Lidar surveying technology, the maps showed precise elevations on the couple’s property. Their home didn’t sit in the 100-year floodplain. It likely occupied the 500-year floodplain.
The following month, he paid his last premium for flood insurance.
“We were lucky. We got taken off,” says Pelava. “A whole lot of people along the creek got added on.”
As it happens, the total number of parcels in Minneapolis deemed at risk of flooding actually dropped when the updated maps came out two years ago. According to city spokeswoman Sarah McKenzie, the tally went from 1269 to 721.
But that shift may prove short-lived.
When it comes to flood risk, coastal states like Florida and Louisiana hog the public’s attention—and for good reason. The Old Testament destruction and property damages inflicted by Gulf hurricanes occur on an unrivaled scale.
Still, Minnesota, like much of the Upper Midwest, finds itself increasingly at risk from two types of floods: fluvial, which is what happens when a river overflows its banks, and pluvial, which is what happens when so much rain falls that the ground can no longer absorb the water.
Minnesota’s flood zones include well-known wet spots, like the flatlands of the Red River Valley on the state’s border with North Dakota, and the tiled-and-drained farm country along the Minnesota River. They also include some more surprising locales. In the Twin Cities, that category includes the leafy enclaves that line Minnehaha Creek as it makes its 22-mile meander from the gilded shores of Lake Minnetonka to the confluence with the Mississippi River in south Minneapolis.
Why?
We might be able to blame it on the changing climate—particularly, the trend in Minnesota for both more rain and much more intense rain. The summer of 2018 has been a textbook illustration of these new patterns. In July, unrelenting rains submerged much of southwest Minnesota. A June deluge in northeast Minnesota and northwest Wisconsin dumped 15 inches on Drummond, Wisconsin: a tally that exceeded the benchmark for a 1,000-year rain event by a full two inches.
Talk to a Minnesota climate scientist these days, such as Kenny Blumenfeld, a senior climatologist with the Minnesota DNR State Climatology Office, and you may come away wanting to do more than just buy flood insurance. You might want to build an ark.
Though one-inch rainfalls (meaning one inch of rain in a 24-hour period) have increased by 20 percent this century, that’s not the biggest concern. “A one-inch rain isn’t going to destroy property or cause landslides. It’s more like, you’ll have to cancel your picnic,” Blumenfeld says. “But we’ve also seen a 65 percent increase in the number of three-inch rainfalls, which is where you start to see streams and rivers overflowing and streets and basements flooding.”
And then there is the even more alarming increase in so-called mega-rain events, defined as a rainfall of six inches or more, covering at least 1,000 square miles. According to the Minnesota Department of Natural Resources, the state experienced 12 mega-rain events between 1973 and July 2018. Eight of those mega-rains have occurred since 2000.
Those changes in precipitation patterns don’t yet show up on most flood maps. That could make for some major changes in floodplain designations on new maps slated for the coming years, according to Suzanne Jiwani, the floodplain mapping engineer at the DNR. Last fall, the DNR got a grant from FEMA to update maps for most of Hennepin, Ramsey, and Anoka counties.
“I think the discharges on Minnehaha Creek are going to go up,” predicts Jiwani.
In the view of Eric Waage, director of Hennepin County Emergency Management, it’s almost beside the point whether a property receives an official floodplain designation.
“In a lot of people’s minds, it’s this binary thing: You’re in or you’re out,” says Waage. But some of the notable recent floods that have hit Minnesota—he mentions the disasters in Wadena (in 2016) and Duluth (in 2012)—didn’t follow the insurance maps.
“Nature does not care if your house is in a designated floodplain or not,” Waage says.
Still, outside the Red River Valley, which has a long history of catastrophic flooding, most Minnesotans just don’t worry much about floods. And that worries emergency managers like Waage, who laments the “ridiculously low” number of Minnesotans who carry flood insurance. According to FEMA data from May, Minnesotans held just 8,805 active flood insurance policies. Only nine other states claimed lower totals—a remarkable fact, given what a watery place Minnesota can be.
Kris Johnson, a scientist who works out of The Nature Conservancy’s Minneapolis office, has studied the number of Americans who live within a 100-year floodplain. And he has concluded that previous estimates appear to be woefully low. The main reason: FEMA’s floodplain maps are a patchwork, and nearly half the country hasn’t been mapped at all. Many existing maps are decades old and don’t take into account changing precipitation patterns.
Johnson and a team of hydrologists from the University of Bristol in England have been attempting to fill that information gap by using supercomputers, census-tract information, and a big data approach. The result is an eye-popping study, published earlier this year, which concludes that approximately 41 million Americans live in a 100-year floodplain. That’s about three times as many people as previously thought.
“More people need flood insurance. And we as a country have to get more serious about this and not put any more property or people or assets in harm’s way,” says Johnson.
For his part, Ed Pelava says that he would be more concerned if he discovered his dwelling lay in the floodplain.
“But knowing my house—and knowing that we’ve had a lot of floods in the area and we’ve never been affected—gives me a lot of confidence,” Pelava says. “We don’t even own a sump pump.”
