Flood thy neighbor: Who stays dry and who decides?
some of this on themselves.”
Since 1993, growth in the floodplain includes extensions of several Fenton subdivisions and hundreds of new residential lots scattered across unincorporated St. Louis County between Pacific and Arnold, an analysis of county tax parcel data and Federal Emergency Management Agency flood insurance maps shows.
By taking up space that would otherwise hold water during a flood, new buildings inside the floodplain drive the river higher. For people living nearby, those extra inches of water can mean the difference between soggy front yards and replacing the furniture, carpet and walls in the first floors of their homes.
“You put a stone into a bucket of water, it’s going to raise the level of water,” said Devin Brundick, the owner of that little green house in Pacific. Now, every time he drives past new construction sites in the floodplain, he envisions the river near his home rising another fraction of an inch.
“The real estate’s cheap because it’s in a floodplain,” he said, and local governments like the tax revenue from new development. “So far, no one’s been held accountable.”
Development outside the floodplain, on higher ground, worsens flooding in a different way.
As the suburbs sprawl across open land, soil that might have absorbed rainfall is paved over, sending water rushing faster toward the river and creating more frequent floods. Some of this is driven by Valley Park subdivisions built after 1993, near two small creeks that funnel runoff straight into the Meramec.
Phillip Eydmann, a retired engineer with the Corps who helped design the Valley Park levee, said conditions along the river have changed since 1993.
“We are encroaching on the rivers more and more and increasing the runoff,” he said. “Those (flood) heights are probably going to go up.”
The second variable is climate change. It was a fairly new concept for federal policymakers in the early 1990s, but by the time the levee was complete, scientists were highly confident that human-driven climate change would affect rainfall all over the country. There’s now a consensus that rainstorms across the Midwest
