A large piece of the Quinn Dam was washed away Tuesday morning leading Pennington County officials to temporarily close a section of Highway 14 and give evacuation orders to downstream residents.
Later in the day, however, Pennington County Emergency Management said on social media that after evaluating damage to the dam there was no immediate danger to nearby residents.
"An engineering assessment is currently underway to evaluate the breach reported this morning," the officials said in a tweet. "Officials are confident the normal drainage, culverts and area floodplain can handle the anticipated outflow."
Quinn Dam Update: An engineering assessment is currently underway to evaluate the breach reported this morning. Officials are confident the normal drainage, culverts and area floodplain can handle the anticipated outflow. No current danger to structures, Hwy 14 is now open.— Penn Co Emg Mgmt (@penncoem2) March 26, 2019
Residents of the Pennington County town of Quinn, which has around 60 residents, woke up Tuesday to learn that the nearby dam may fail due to a growing hole in it.
"Quinn Dam appears to be failing. Large amounts of water may be uncontrollably released soon. Anyone downstream should seek higher ground," said a message from Rapid City-Pennington County Emergency Management.
The South Dakota Department of Transportation announced at 10:20 a.m. that U.S. Highway 14 would be closed from Wall to Philip due to the potential flood risk.
"At this time, there is no water over the roadway but that could change very quickly should the dam fully breach so the road has been closed as a precaution," DOT said in a news release.
Around the same time, the National Weather Service in Rapid City issued a flash flood warning for east central Pennington County, southwestern Haakon County and northwestern Jackson County.
The National Weather Service said flash flooding "is expected to begin shortly, especially if the dam fails." It said locations along Cottonwood Creek would be affected, including Quinn and Cottonwood, a tiny community east of Quinn along Highway 14.
A hole in the dam "seems to be growing," Alex White, deputy director of Rapid City-Pennington County Emergency Management, told the Journal on Tuesday morning. She said her office alerted 32 homes and businesses in Quinn via phone calls, emails and/or texts.
"We err on the side of caution," White said.
She said deputies didn't knock on doors or make people evacuate. While water has been released from the dam since a recent blizzard caused flooding, White said, Tuesday's warm temperatures will melt more snow, creating more water for the dam to contend with.
"We just don't know," what will happen, and its unclear what caused the hole, White said.
Following the "bomb cyclone" earlier this month that deluged the area with snow and rain, heavy spring flooding has been wreaking havoc across the Midwest, including much of South Dakota.
Many residents of the Pine Ridge Indian Reservation have been stranded for nearly a week as high water has made many roads impassable, prompting South Dakota Gov. Kristi Noem to send 13 National Guard units to the reservation to help distribute drinking water. Ice jams caused flooding along vast stretches of the Cheyenne and White rivers across central and western South Dakota.
On the eastern side of the state, communities near the Big Sioux River and James River prepared sandbags, and some people moved to higher ground. Farther south, a swollen Missouri River crept toward people's homes and yards.
Just across the state line, the Nebraska community of Niobrara was all but swept away after the Spencer Dam failed. Huge chunks of ice slammed through the dam and down the Niobrara River, which meets up with the Missouri, eventually ending up strewn across highways and in fields.
Officials across South Dakota have been urging people to take flood preparation seriously. The state also activated its Emergency Operations Center in Pierre, with state and federal agencies in close communication.
Public warning messages are automatically sent to landlines during emergencies, White said. She encouraged people to visit rcpcem.com to sign up to receive such alerts on their cell phones and emails.