On the night of 9 June 1972 thunderstorms stalled over the eastern Black Hills and dropped close to fifteen inches of rain in about six hours near Nemo. Rapid Creek rose through Rapid City between half past nine and ten, debris jammed the spillway at Canyon Lake, and the dam gave way at about a quarter to eleven. The creek peaked near fifty thousand cubic feet per second around midnight, more than four times any flow previously estimated for it, and was back inside its banks by five in the morning. The Red Cross counted 238 dead, 3,057 injured and 1,335 homes destroyed. The United States Geological Survey is careful to point out that Rapid Creek and its tributaries carried 86 percent of the peak flow, so the broken dam was not the flood. What Rapid City did afterwards is the part that outlasted the water. Rather than rebuild the bottom land, the city bought it and cleared it, working to a rule the Geological Survey states plainly: no one should sleep within the flood plain. Houses and motels in the floodway were razed or moved, while businesses were allowed to remain in the flood plain. The National Weather Service puts the result at 754 acres of floodway, paid for with about twelve million dollars of federal housing money. Memorial Park, twenty eight acres of it, was acquired in the year of the flood, and the path along the creek carries the name of Leonard Swanson, a public works director who died in 2008.
Getting there
44.0852, -103.2266
Locations are approximate and may be inaccurate, on private land, or otherwise inaccessible. Check before you travel.
Hear it from the road
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