When the Governor Decides … And the Levee Breaks

Jun 25, 2014

By Cory Allen Heidelberger

Last week, South Dakota’s southeastern goatee faced its second hundred-year flood in three years. The floods came from two different rivers — the Missouri in 2011, the Big Sioux last week — so we haven’t violated any statistical rules yet.

As was the case in 2011, Gov. Dennis Daugaard responded with swift and serious civil engineering. To keep the storm-swollen Big Sioux from sweeping North Sioux City down to Omaha, Gov. Daugaard turned Exit 4 into a levee to divert Big Sioux overflow across Interstate 29 into McCook Lake and down into the Missouri River a couple miles upstream from the usual Big Sioux–Missouri confluence.

When I first heard the plan, I had visions of bulldozers, Guardsmen and inmates heaping dirt under the Exit 4 overpass into a Great Wall of Union County. All we got was a measly-looking line of Hesco baskets filled with dirt and packed in a tight line across the roadway.

While not as visually impressive as I’d imagined, that 4-foot wall showed the Governor’s willingness to accept two major costs. First, building that line meant closing Interstate 29 from Vermillion to North Sioux City. The shortest detour — to Vermillion, across the Missouri, through Ponca and back to Sioux City — adds 35 minutes to a trip. The default detour would have diverted southbound truckers at Sioux Falls east on I-90 to Albert Lea, then down to Des Moines and back to Council Bluffs, adding around four hours. Multiply the lost travel time by the productivity of 11,000 car drivers and 2,500 truckers for each day I-29 would remain closed, and I suspect you’d get a small but significant impact on the economy of the Upper Midwest.

Also on the red side of the emergency response ledger are the 300-some houses around McCook Lake. Plugging Exit 4 meant McCook Lake would bear the full force of the Big Sioux overflow. Officials guesstimated up to a 10-foot increase in the lake’s water level. With less than two days to prepare, McCook Lake residents waited in line for two hours to get 20 sandbags from the National Guard and not much else. However much water was coming, the Exit 4/McCook Lake decision showed that the Governor was willing to sacrifice those few hundred homes to protect the rest of North Sioux City.

That’s a big decision. It’s a gutsy decision. And, luckily for almost everyone, it turned out to be an unnecessary decision. A levee broke upstream, near Akron, flooding some farmland and homes. The Big Sioux spread out, lowering the flood level downstream. The river crested at North Sioux City Friday morning a few hours early and 4 feet below the predicted max. Exit 4 stayed dry, as did the homes at McCook Lake. By noon Friday, one day after we cut off I-29, the Hesco baskets were gone and I-29 was open again.

Emergency response is one of the hardest parts of the Governor’s job. He had to evaluate lots of variables, many of them unpredictable (how much more rain will fall? will every levee hold?), choose priorities and make sacrifices. The Big Sioux was rising. The water had to go somewhere. Gov. Daugaard chose McCook Lake, and nature chose Akron. What would you have chosen?

Cory Allen Heidelberger writes the Madville Times political blog. He grew up on the shores of Lake Herman. He studied math and history at SDSU and information systems at DSU, and has taught math, English, speech, and French at high schools East and West River.