KICKAPOO VALLEY - The overtopping and breaching of two dams in the headwaters of the West Fork of the Kickapoo River in Vernon County played a major role in turning the recent flood from large to historic.
Three dams that failed in the headwaters of Coon Creek in Monroe County, and flowed into Rulland Coulee, also impacted rural areas and villages downriver in Coon Creek and Chaseburg with unprecedented flash flooding. That water entered the Mississippi River near Stoddard.
In the late night and early morning between Monday, Aug. 27 and Tuesday, Aug. 28, areas straddling the Vernon/Monroe County border, north of Westby and Ontario, near Cashton, received large amounts of rain in just a few hours.
“We’d been out all evening responding to emergency calls and repairing driveways,” remembered Jeff Mlsna of the Monroe County Town of Jefferson Volunteer Fire Department. “We were just heading back in about 1:30 a.m. when it started to pour again, and didn’t let up until about 4:30 a.m. All those driveways we’d repaired were all washed out again by then.”
While it had rained off and on all day Monday, and continued to rain off and on all day Tuesday, it was the large volume between midnight and 5 a.m. early Tuesday morning that resulted in the Jersey Valley and Mlsna dams in Vernon County, and the Coon Creek 23 Dam, Coon Creek 29 Dam and another Coon Creek Dam in Monroe County overtopping, and eventually breaching. The Klinkner, Hidden Valley and Ostrem Dams in Vernon both suffered some damage as well.
When the dams breached, it sent a tsunami of water cascading down the West Fork, running over Bloomingdale, Avalanche, and Liberty, before joining the main channel of the Kickapoo River just north of Readstown.
In the same time frame, the 8.58 inches measured in Kendall and 7.25 inches measured in Cashton sent water rampaging into Ontario, Coon Valley, Chaseburg and Stoddard early in the morning of Tuesday, August 28. Ontario itself had only received 1.22 inches of rain at that point. Mere hours later, LaFarge and then Viola were inundated with floodwaters from the rain event.
Later on Tuesday, another front hovered over a section of the lower Kickapoo Valley around La Farge, Viola and Hillsboro, dumping another 4.14 inches in Hillsboro, 4.12 inches in Viola, and 4.10 inches on La Farge. The Hillsboro Dam also breached, sending water into the Baraboo River Watershed in Wonewoc, LaValle and Reedsburg. These additional rainfall amounts fell on areas already inundated from up valley rains earlier in the day.
All that water simultaneously moving down the West Fork Valley and the Kickapoo River Main Branch Valley finally met up in Readstown in two separate waves.
“We got the West Fork water at 10:30 a.m.,” Readstown Village President Chad Larson said. “And then, about 10 p.m. we got the Ontario water and that’s what shut down the Highways 14 and 61 intersection, and the bridge across the Kickapoo.”
Total rainfall amounts recorded from Monday, August 27 through Wednesday, August 29 included most impressively:
· Cashton: 12.86 inches
· Westby: 12.03 inches
· Hillsboro: 11.16 inches
· Ontario: 9.99 inches
· LaFarge: 9.75 inches
· Stoddard: 9.72 inches
· Wilton: 8.58 inches
Interestingly enough, during the entire rain event, from Monday through Wednesday, communities so catastrophically impacted by water from up valley themselves received only minor amounts of rain. Readstown got a total of 3.32 inches, Lynxville 2.17 inches, and Gays Mills 0.99 inches.
Damned if we do…
The two dams that failed in Vernon County were the Jersey Valley Dam and the Mlsna Dam. Both dams were created to hold back the floodwaters from the West Fork of the Kickapoo River.
Other dams in the same area that did not breach were the Klinkner Dam, just to the south and east of Mlsna, and the Ostrem Dam, just to the south and east of Jersey Valley.
“We’ve been very busy out in the field dealing with issues with the Vernon and Monroe County dams since last weeks rains,” DNR Water Regulations and Zoning Engineer Mark Stephenson reported. “Now we just got more rain overnight [on Monday, Sept. 3], and potentially more on the way today [Tuesday, Sept. 4]. In addition to the dams that breached, we’re worried about the ones that were damaged last week – Hidden Valley, Klinkner and Ostrem.”
In the 2007 and 2008 floods, those dams held, and did just what they were supposed to do. The Jersey Valley Dam has undergone extensive repairs since the 2008 flood, which compromised its integrity.
One only has to look at the flooding levels in this flood versus the record flood levels for Readstown, Gays Mills, and Steuben to see the difference in flood levels the dams make when they are intact and serving their purpose.
In Readstown, the record set in 2008 was 19.65 feet, and the level this year was 23.17 feet, a difference of 3.52 feet. In Gays Mills, the record set in 2008 was 20.44 feet, and the level this year was 22.31 feet, a difference of 1.87 feet. In Steuben, the record set in 2008 was 19.16 feet, and the level this year was 19.84 feet, a difference of 0.68 feet. In Soldiers Grove, which relocated out of the flood plane after the 1978 flood, the record set in 1951 of 21.63 feet may still stand. The National Weather Service is reporting thevillage got 21.06 feet this year, 0.57 feet less. However, this does not seem to be a settled fact, and most agree that the level seemed higher in 2018, consistent with the readings for villages above and below in the watershed.
“We did all kinds of stuff to Jersey Valley after the 2008 flood,” Vernon County Board Chairman Dennis Brault said. “It’s never the dams themselves that go – it’s the hillsides with all their karst geologic caves and fissures that are the weak spot. We tried to shore up the hillside by filling in some of those cracks and faults, but it’s hard to engineer to the kinds of rains we’re increasingly seeing.”
Brault reported that after the 2008 flood, Vernon County spent over $12 million dollars repairing six of the 22 dams managed by the County’s Land Conservation Department. Vernon County is home to 22 of the 80 PL-566 dams (Watershed Protection and Flood Control Act of 1954) in the State of Wisconsin. That is about 25 percent.
“Vernon County had to spend that $12 million out of our general fund after 2008, and then wait to get reimbursed from FEMA and other private grants,” Brault reported. “It’s only been in the last five years or less than we have gotten paid for the repairs to dams, bridges and roads that we did then. And our townships have also been impacted by delays in payment.”
Brault reported that the county has not yet received payments relating to the 2016 and 2017 flooding.
“Right now we’re just putting bandaids on the damage done to Jersey Valley and Mlsna,” Brault said. “It’s going to take a lot of conversations, a lot of fact finding, and a lot of tough decisions to try to figure out what to do with those structures going forward.”
Brault emphasized that in his view, he sees that we are clearly in a period where the weather has changed, and the rainfall events have gotten bigger and more destructive. He said that he moved with his family to the area about 20 years ago, and brought a rural property in the Seas Branch area of the West Fork of the Kickapoo River.
“When we first lived there we didn’t get these rains and it was wonderful,” Brault said. “Then we got several feet in our basement in 2007, and five feet in 2008. I’m almost 70 now – it was one thing when I was 60, and quite another now at my current age. When it rains, I can’t sleep, I am constantly looking at the radar, and I feel like I have PTSD.”
Jersey Valley Dam
Jersey Valley Dam is a 371-acre county recreational facility, with a 52-acre lake, just to the east of Westby. The lake is formed by the dam on Peaceful Valley Creek. The dam was built in 1969.
Jersey Valley is known as a ‘wet damn,” because of the lake or ‘impoundment’ that it created. By contrast, the other dam, Mlsna Dam, is typically a ‘dry dam,’ with no impoundment of water behind it most of the time. The area behind the Mlsna Dam will fill up with water in extreme rain events, to be released slowly over time through its ‘spillway.’ The Johnstown Dam in Crawford County is a similar such structure.
Mlsna Dam
The Mlsna Dam is located in Vernon County, less than a mile south from the Vernon-Monroe County border. It dams a narrow valley that feeds into the Knapp Creek tributary of the West Fork Watershed. Typically a dry dam, the valley behind it can fill up with water in an extreme rain event.
“My grandfather built that dam, and it was one of the first PL-566 dams built in the state of Wisconsin,” Jeff Mlsna said. “Grandpa went up there to a field on the top, took off all the topsoil, and then used the clay to build the dam.”
Mlsna is a member of the Monroe County Town of Jefferson Volunteer Fire Department, and also sits on the town board. He reports that his township is still owed by FEMA for $150,000 from the 2017 flooding event.
“Do you know what $150,000 means to a little town like ours?” Mlsna said. “It makes all the difference in us being able to take care of our bridges and roads.”
Mlsna said that he is a big believer in the value of the dams for flood control, and says in addition to the large PL-566 structure, his family has also built many smaller dams on their land in Monroe County.
“The dams do what they’re intended to do,” Mlsna said. “But anymore, with the larger rains we’ve been seeing, we have to engineer them better to withstand these events.”
Mlsna’s feedback was that he believes that the spillways should be made not out of earth, but rather out of concrete.
Pandora Flores lives on Kelbel Road, just to the south and east of the Mlsna Dam. The bridge just up the road from her was washed out, but the Klinkner Dam, which controls water from Knapp Creek as it flows into the West Fork Watershed, held in the rain event though some water had spilled over the top.
“Thank God the Klinkner Dam held,” Flores said. “My house would likely have been okay, but I think that Bloomingdale and Avalanche just wouldn’t be there anymore.”
Next steps
Mark Erickson, Vernon County Land Conservation Department PL-566 Dams Manager reported that next steps for the dams inVernon County are to obtain engineering assessments. After that, it will go to the Land Conservation Department, and eventually to the County Board.
“We have to get the assessments to determine what the future of the dams is going to be,” Erickson said. “After that we’ll have to decide whether to repair or eliminate them.”
