Sinkholes closing part of Sprigg Street

As the sinkhole problem continues to plague South Sprigg Street, with four new sinkholes opening up in three months, city officials have decided to shut down part of the road so repairs can be made.

The city council will vote Tuesday to ask the U.S. Army Corps of Engineers to help the city determine a specific cause of the 11 sinkholes that have opened up along the road, as well as a permanent solution to the problem.

"It's a unique problem," said Ken Eftink, development services director for the city.

Federal assistance may be needed as well. Both U.S. Rep. Jo Ann Emerson and Sen. Kit Bond have been keeping abreast of the problem and expressed interest in securing federal funds to assist with solutions, city officials say.

The section between Cape La Croix Creek and La Cruz Street will be closed to traffic starting at noon Tuesday and will remain closed until repairs to the road's base are complete.

City officials hope to reopen at least the northbound lane of the road to traffic within 10 days to two weeks, Eftink said.

AmerenUE moved power lines off this sinking pole due to the sinkhole at right, in south Cape Girardeau near Sprigg Street. (Kit Doyle)

Residents needing access to the city Transfer Station, Buzzi Unicem and Hunze Dairy Farm will need to take South Kingshighway and Highway 74 to get to South Sprigg Street.

The embankment along Sprigg Street has been eroding since late September, and city workers had been using rocks and grout to lend it support. But now, action must be taken to mitigate some of the damage, Eftink said.

One particular sinkhole continues to worsen, rendering that part of the road potentially dangerous because the pavement could give way under the weight of a heavy truck.

Preventive repairs

For that reason, the repairs include precautions extending well beyond the area influenced by the sinkhole, Eftink said.

Starting Wednesday, excavators will dig out the subsurface rock from underneath the depression, seal the bedrock and refill the area with dirt, he said.

The bridge over Cape La Croix Creek remains safe for the time being, but Eftink said officials continue to keep a close watch on it for signs of sinking.

The sinkhole problem began in July, when the first one started to cave in, causing an AmerenUE gas main to rupture.

Since then, AmerenUE has had to relocate two gas lines to accommodate the depressions that have formed in fields and along the road, Eftink said.

The sinkholes have also interfered with the quarry at Buzzi Unicem's cement plant, causing it to fill with seeping groundwater faster than pumps could empty it out. The sinkholes leave the quarry vulnerable to floodwaters during high river stages, Eftink said.

"Anything threatening a major employer is serious," Eftink said.

A major aim of any project to address the sinkholes, Mayor Jay Knudtson has said, is to keep Buzzi operating. Knudtson has said he doesn't want the sinkholes to be a reason for the company to shut down.

Representatives from Buzzi, as well as those from Burlington Northern Santa Fe Railroad and SEMO Port railroad, have forged a relatively strong partnership with the city in monthly discussions about the sinkhole problem, and city department heads have held weekly meetings to talk about potential solutions, Eftink said.

Both the Southeast Missouri Port Authority railroads and Burlington Northern have been filling the sinkholes that have opened up near the tracks.

Though an exact cause of the sinkholes has not been determined, officials have pored over geographic documents and seismic records trying to pinpoint a reason for why the ground along Sprigg Street has been so active.

One theory is that this past summer's rainfall shortage caused dry cavities in the soil to separate, with a lack of moisture to hold them together, Eftink said.

bdicosmo@semissourian.com

335-6611, extension 245