Year after sinkhole, city is set to repair pipes near Johnson County high school
Almost a year after a failed stormwater pipe caused a sinkhole to form on the Mill Valley High School campus, Shawnee is making more repairs on campus over the summer as part of ongoing efforts to improve Shawnee’s aging infrastructure.
The City Council unanimously approved a nearly $1.2 million contract with Infrastructure Solutions LLC on Monday night to repair pipes underneath the Mill Valley High School football field on the back side of the school and replace pipes along Monticello East and 51st Place.
The projects are a part of a much larger effort in Shawnee to replace its miles of corrugated metal pipes — an outdated technique commonly used in the 1990s and early 2000s that has since been replaced by reinforced concrete pipes to help prevent pipe erosion.
For this project, the city’s contractor will replace about 1,178 linear feet of aging and deteriorating, corrugated metal pipe and 270 feet of pipe lining, according to the staff report. Shawnee has about a million linear feet of pipe in the city — close to 200 miles. Corrugated metal pipes make up about half of the city’s stormwater system.
Pipes along Monticello and 51st will be replaced by reinforced concrete pipes.
At Mill Valley, the city plans to install a polymer lining, a technique that can help the city “get more life out of the pipes” without tearing up the area, Public Works Director Kevin Manning said during the meeting.
The city opted for this route to limit the removal of bleachers, track surface and recently replaced artificial turf at the field, city spokesperson Doug Donahoo added in an email.
De Soto Schools spokesperson Alvie Cater told The Star in an email that the project “will not be a major disruption to our operations.”
“The city has been great to work with regarding the pipes,” Cater said. “Some of the work has been completed and our understanding is that the city is planning to complete the project later this summer.”
What happened to the sinkhole?
The preventative project at Mill Valley kicked off shortly after Shawnee completed an emergency repair project on the campus.
Last April, the city allocated $2 million to replace a failing stormwater pipe that caused a 10-foot sinkhole to form on the northeast corner of the Mill Valley High Campus, near the tennis courts.
The corrugated metal pipe eroded, causing the pipe to separate into segments — allowing dirt inside and water to rust the bottom of the pipe. A gaping hole didn’t form, but the surface was starting to sink down when the city took action.
During discussions in April, the city wanted to make repairs before school started in mid-August. Donahoo told The Star that the project to address the sinkhole “was complete as of February 2026 after sod was installed.”
Along with the pipe repairs at Mill Valley set for the summer, Shawnee plans to embark on repairs in at least 18 other locations citywide as part of its 2026 Annual Stormwater Repairs, according to its website. Projects are prioritized by “known sinkholes or pipes under roads scheduled for pavement” and overlay work in the next two years.
For repairs at Mill Valley, Donahoo said that the project will start “very soon” with the portion that is outside campus and will extend onto campus once the school year wraps up. The goal is to have the repairs done by the time school starts in August.