Donna Schmidt’s to-do list for work Tuesday:

1. Steer a 425-horsepower, 10-wheel dump truck onto the apron of the Bowersock Dam.

2. Back up to the edge of the roiling water.

3. Dump 17 tons of rock and soil.

4. Don’t slip.

“It’s scary,” says Schmidt, a driver for Kornbrust Equipment Inc. in Lawrence. “You’ve got a loaded truck, about 54,000 pounds. You’re driving on water. And mud. And moss.”

She’s laughing at the thought, now that she’s safely back on terra firma – idling in her vinyl-topped cab at the base of the Kansas River levee.

“It’s slick – very slick out there,” she says, then smiles. “This is weird.”

Schmidt’s trip was among 100 made this week by Kornbrust truckers for R.D. Johnson Excavating, the company hired to build a new cutoff dam for Bowersock Mills and Power Co.

The new dam – about 3.4 million pounds of riprap rock – juts downstream at an angle from the Bowersock Dam, toward an existing sandbar. The cutoff dam is designed to raise the level of the river, to help the power plant at downtown’s edge operate in lower-water conditions.

Not that it was easy. The $10,000 job challenged crews adept at all kinds of perilous work sites.

Justin Tucker, of R.D. Johnson Excavating, Lawrence, pushes a load of riprap rock deeper into the Kansas River below the Bowersock Dam. Tucker, using a trackloader, worked on a new cutoff dam built for Bowersock Mills & Power Co., which operates a power plant near City Hall.

Even Roger Johnson, owner of the excavating company, slipped on the thin layer of moss that covers the Bowersock Dam’s concrete apron, the foundation of 12-foot-thick concrete that supported his equipment and hired trucks Monday and Tuesday.

“You fall and you wonder if you’re going to go over the dam. It’s scary,” Johnson said Tuesday. “It’s about like a demolition job, when you don’t know which way the building’s going to come down – especially when it’s between two houses. You don’t know exactly what’s going to happen.

“But once you get started and you get going, you’re fine.”

One of Johnson’s equipment operators, Justin Tucker, drew the task of driving a trackloader and trackhoe off of the dam and out into the river, extending the cutoff dam ever farther from the Bowersock Dam.

“So far, so good,” he said Tuesday by cell phone, after pulling back onto the apron. “It’s not so bad, really. Safety first.”