Best Practice: Construction design saves money, prevents future damage

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SHERRILL TOWNSHIP, Mo. – “The way we put them together, they work,” said Steve Booker, an operator for the Sherrill Township Road Department in Licking, Mo.

Booker and Nathan Tatroe, the foreman for the Road Department, installed many low-water crossings across the 108 miles of roads that make up Sherrill Township in Texas County, Mo. The low-water crossings are an affordable alternative to building bridges on the mostly dirt roads in the area. Most of these crossings sit over dry creek beds that may fill quickly in heavy rainfall. The crossings are designed for water to not only flow through, but also flow over.

“God himself would have to move it,” Tatroe said of the concrete crossings. “Water can’t get underneath it.”

Flood waters may not move one of these low-water crossings, but they can move a vehicle that tries to cross when water is over the road. It is important that drivers do not attempt to navigate a low-water crossing when water is flowing over it. Less than a foot of water is enough to push a vehicle and sweep it off a road of low-water crossing.

Although drivers should never try to cross a flooded low-water crossing, Tatroe and Booker want their crossings to be stable and usable after the waters have receded. That is why they take a very specific approach to constructing the low-water crossings.

Tatroe and Booker make the crossings by digging down to solid ground. From there, they layer concrete and one-foot woven horizontal squares of rebar with a stem wall to make a solid base. The concrete is filled with fiber and also is used to cover culverts that allow water to continue to pass. On top of the slab, more concrete is poured to form 8 to 10 inches of roadway. The edges of the crossings are then hardened to prevent drivers from going off the edge of the crossings. Some crossing may contain as much as five tons of rebar.

The cost for each crossing is $2,000-$6,000, much less than building a bridge over the same areas.

Booker said the crossings are expensive on the front end. Because they are designed to withstand a wash out, the crossings provide places that the road crew does not need to worry about or repeatedly repair.

“It takes millions of gallons of water. It never affects the footer. The stem wall on top is tied with the steel so it can’t go anywhere,” he said.

Tatroe said the crossings may be over-built by some standards, but they are built to their standards. Looking at one crossing built in 2007, he said, “It has been here through all the floods I’ve been through.”

Another crossing pre-dated Tatroe and Booker’s employment with the township. They estimated it was built in 1950s using much of the same technique they employ today. The newer crossings are constructed mostly by Tatroe and Booker with the assistance of part-time workers or temporary laborers.

 

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