City edges closer to reopening sinkhole-ravaged street

After years of struggling with sinkholes on South Sprigg Street, Cape Girardeau city officials say the city is in a good place to continue efforts to reopen the roadway.

The city received federal funding last year to perform an investigative study, design and construction to mitigate the sinkhole issue and determine whether the street could be reopened.

South Sprigg Street has been closed since 2013. The area has battled its most significant sinkhole problems since 2007. One large sinkhole collapsed part of the street, and another formed near the bridge over Cape LaCroix Creek, causing concerns about the bridge's structural security.

Action taken last summer by the city council allowed the city to enter into an emergency relief program agreement with the Missouri Highways and Transportation Commission for the study and remediation of the South Sprigg Street sinkholes. The program offers an 80/20 grant, with funds administered through the Missouri Department of Transportation. The federal share is not to exceed $1.2 million.

A Delta Regional Authority Grant of $100,000 will go toward the city's 20 percent match, with remaining funds coming from stormwater sales tax revenue.

The city awarded a contract to Horner & Shifrin to complete the investigation and create a report with findings and possible solutions. The contractor worked with architectural and engineering firm Stantec, which spent three weeks in October on a geotechnical survey to understand the sinkholes and the surrounding subsurface better.

City traffic engineer Stan Polivick said the report has been delivered to the city, and the recommendation aligns with the city's goal to keep the street open, although it will require some work.

"The end goal is we would restore that roadway and bridge to service. The recommendation is to take out that existing structure, put in a new bridge structure," he said. "Then, we will have to build a little bit of roadway on the ends, of course, but it would ... remain in the same alignment. So at the end of all this, there will be a new and a little bit longer bridge than what there is now."

To build a structurally sound bridge that would not be threatened by any existing or new sinkholes, Polivick said during the construction, crews will dig down to the bedrock and begin building from that.

The field work last year has given them some idea of where the bedrock is and indicated it is sturdy enough for the project.

The recommendation is the best outcome the city could have hoped for, Polivick said.

"We're very pleased with where we are at this point," he said. "The work that's been done so far has gone well and on schedule. Our recommendation doesn't require someone to invent a new way to build a road or bridge. We can use fairly standard construction methods, and at the end, we'll have a good roadway that has a stronger defense against future sinkholes, should any form."

So far, the plan has received city and the state approval, Polivick said. Once the federal approval is granted -- and he said he believes it will be on board with the plan -- the next step is to begin the design phase.

It's one of the final steps before preparing a bid for construction. The federal grant requires a contract be awarded by September.

Besides the bridge project, Polivick said there also is interest in looking at other sinkholes in the area and determining whether they could be "permanently closed" by some method. Past estimates from city officials place about 20 sinkholes in the South Sprigg area, though calculating an exact number is difficult because some openings could be part of the same underground system.

srinehart@semissourian.com

388-3641

Pertinent address:

2524 S. Sprigg St., Cape Girardeau, Mo.