Beginning in November, Kansas Turnpike travelers on a two-mile stretch where seven people have died in flooding will have better protection from encountering rising water on the roadway.
Workers are about halfway into a project that will improve drainage at mile marker 116, where six people died in flooding in 2003, and at MM 118, where one person died last summer. Those spots are 8 and 10 miles south of Emporia.
On Wednesday, turnpike officials took reporters on a tour of the $2.7 million project at those two locations to explain efforts to increase the flow of water in massive box culverts that run beneath the highway.
The goal is to keep rising water – from flash flooding in the surrounding Flint Hills – off the roadway. When the new culverts are complete in November, the design should keep water off the roadway in a 100-year storm. That is a storm with a 1 percent chance of happening in a year, said David Jacobson, the turnpike’s director of engineering.
“We’re not eliminating the chance of water on the roadway, but we’re decreasing the chance,” Jacobson said.
It “wouldn’t be feasible” to build a structure that would provide more protection than a 100-year flood design, he said, explaining: “Again, Mother Nature’s in control.”
No matter what the Turnpike Authority does to improve the roadway’s drainage capacity, drivers still need to slow down when weather conditions demand it, said spokeswoman Rachel Bell.
Original plans had called for improving drainage to handle a 50-year storm, which is a storm with a 2 percent chance of occurring in a year, Bell said.
But design work showed that a 50-year storm would bring water close to the roadway, so the Turnpike Authority opted for better protection, Bell said.
“We just wanted to give the travelers a little bit of extra sense of security,” she said.
At MM 116, six people, including five in one family, died in 2003 when flooding on Jacob Creek sent a wall of floodwater across the interstate.
Workers there are removing a 7-by-7-foot box culvert beneath the highway and replacing it with two larger culverts, each 14-by-12-foot.
Part of the work at MM 116 has been affected by a work schedule and design that has been arranged to protect a small fish called the Topeka shiner, Jacobson said.
“There’s some minnows right there,” he said Wednesday afternoon on the tour. He pointed to a pool spilling out of the new culvert. He wasn’t sure if the minnows were the protected Topeka shiner. The culverts there are imbedded down a foot into the earth to allow for more water flow, helping fish migration.
At MM 118, a 21-year-old Texan died last summer when his Ford Mustang ran into rising water on the highway, veered into a flooded ditch and was sucked through the culvert beneath the turnpike that drains a tributary of Jacob Creek.
Workers there are adding two 14-by-8-foot culverts to the existing 8-by-8-foot culvert.
Crews are doing the section of the culverts on the southbound side first, then will move to the northbound lanes. Meanwhile, traffic in the two-mile stretch is limited to one lane each way.
They are working to complete the job before winter to avoid head-on accidents on slick pavement, Bell said.
The Turnpike Authority will continue drainage improvements by spending $3 million to $5 million a year over the next decade, Bell said.
The Kansas Turnpike, which opened almost 60 years ago and is part of the I-35 interstate system, relies almost completely on tolls for funding and doesn’t receive state tax money or federal funds.
The Turnpike Authority has its own chief executive officer and board; the secretary of the Kansas Department of Transportation serves as director of the turnpike through a partnership, Bell said.