PIERRE, S.D. (KELO) — The state Department of Transportation delivered some unwelcome, and potentially very expensive, news Thursday to the South Dakota Transportation Commission.
Four bridges that county governments have received state approval to rebuild or rehabilitate, through a combination of state and local funds, will need more funding.
And they might need much more in the months ahead, if they have to be extended to greater lengths, such as across the Big Sioux and James Rivers.
They’re not the only ones, either. Officials and consultants have identified at least 28 other county or municipal bridges that could be affected.
Prompting the added costs is a new hydraulic-scouring guideline the Federal Highway Administration published in January for some types of bridges.
The sliver of good news Thursday was the guideline doesn’t affect box culverts that many local governments use in South Dakota.
The state commission, on a split vote, approved additional funding for the four bridges in Moody, Day, Turner and Union counties. The analysis alone will cost more than $92,000, according to a SDDOT memo.
“No, not at this time,” commissioner Mike Vehle of Mitchell said.
The program now gets $15 million annually. The commission oversees distribution of the money twice per year.
Steve Johnson, chief bridge engineer for the department, presented a report to the commission in May on the potential effects of the revised federal direction that was previously distributed in a technical briefing.
Tammy Williams, a department administrator, told the commission Thursday that scours along bridge embankments can be 30 feet or deeper.
She said Moody County officials plan to visit the DOT headquarters in Pierre on Monday to further discuss their project across the Big Sioux River.
One estimate is that the rebuilt bridge, under the new guideline, could have to be four times longer than its current length, Williams said.
“This was not anticipated,” she said about the federal emphasis that some bridges should be longer to be safer. “It is still something we feel the BIG program needs to address.”
Covering just the re-analysis for the 32 bridges could exceed $1 million, she said. That would be followed by needing many millions more for the new designs and constructing the greater lengths.
There’s another twist: County governments must commit to paying at least 20 percent of the cost for a bridge preservation or reconstruction project under the BIG program.
Counties received bonus points in the state scoring system for agreeing to pay more than 20 percent. Day County, for example, committed to 40 percent of its bridge project.
Vehle was prime sponsor of SB 1 in 2015 and helped lead it to passage.
“We were grappling with how we help the counties out,” Vehle said Thursday. “The idea was to help with the bridges.”
He added, “It was a very good program, a very innovative program, I feel.”
Under current rules, counties would be responsible for at least 20 percent of the additional costs. Williams said the department might recommend in August that state government pay the full bill.
And there’s yet another twist: Some state bridges have been found with deep scours too, she said.
Special inspections already are under way at some locations.
“I know the consultants working for the counties have great concerns about the counties coming up with the funds,” Williams said.
Vehle referred to “the conundrum” now facing county governments that have received BIG funds. “And there may be more coming down the pike,” he said.
Mike Behm, the department’s director of planning and engineering, said highway and bridge engineers try to look years into the future, while making adjustments along the way as new information comes to light.
“We’re iterative and we want to make sure we do the right things,” Behm said.