Riprap funding for area bridges approved by James River Water Development District

Erik Kaufman, The Daily Republic, Mitchell, S.D.
·6 min read

Mar. 18—Four bridges in Davison County received funding to assist with repair work from the James River Water Development District Thursday at the organization's regular board of directors meeting.

The meeting was held via virtual online format.

The move comes after the four bridges in question were heavily damaged by the heavy rain events that plagued the region in 2019. The four bridges addressed at the Thursday meeting, all of which span Enemy Creek, some of which are currently impassable, are scheduled to be reopened sometime in the next three to eight months.

Chris Brozik, with Civil Engineering, Inc. in Brookings, the company that contracts with Davison County for bridge inspection and repair, said the funds approved by the James River Water Development District Thursday — about $57,820 — will go toward half the cost of riprap at the sites. The total cost of repairing or replacing the four bridges in question is estimated at $2.1 million.

Approximately 2,769 tons of rip rap will be used in the repairs, according to Brozik.

The damage incurred by the bridges was such that it necessitated rebuilding them entirely, Brozik said.

"(Davison County) ended up having two structures that completely failed, they completely washed out. And two others that were damaged beyond repair," Brozik told the Mitchell Republic. "It made more sense to do a full replacement."

The four bridges addressed Thursday are in the following locations:

*

Near the corner of 258th Street and 411th Avenue, approximately 4 miles south of Mitchell. Work is expected to be completed Nov. 15.

*

Near the corner of 259th Street and 406th Avenue, approximately 4.5 miles south southwest of Mitchell. Work on the bridge was completed in November of 2020.

*

Near the corner of 259th Street and 401st Avenue, approximately 6 miles southwest of Mitchell. Work is slated to be completed Nov. 1, though Brozik suggested work may be completed sooner thanks to an earlier-than-expected start by the contractor.

*

Near the corner of 258th Street and 397th Avenue, approximately 7 miles southwest of Mitchell. Work is expected to be completed Nov. 15.

The assistance with the cost of riprap will be of great value to the county, Brozik said.

"They've been very receptive to helping the county with that, and we're very grateful for the board considering the applications," Brozik said.

With traffic restricted on the damaged bridges, Brozik said crews will be working as quickly as they can get the damaged infrastructure back in working order so that local residents can again utilize their traditional routes in navigating the area.

"That is why we're pushing hard to get these completed as soon as possible, so there's no more inconvenience," Brozik said.

It's been a long year of repair work since the weather incident in 2019 and another in 2020 caused serious damage to area roads and bridges. Heavy, extended rainfall wreaked havoc throughout the region, leaving many washouts and other damage for counties and townships to deal with. For many structures, like the four bridges discussed Thursday, it was just too much water to deal with in too short an amount of time.

"My opinion is that it was a gusher and it came through there so violently in such a short timeframe that it was more than the structures could handle," Brozik said.

The repair work should not only get the bridges back in working order, but also prepare them for a long life of extended service.

"Some of the older structures are not substandard, but they're aged and maybe weren't designed to the same criteria they're designed to today," Brozik said. "These have better designs for a life of at least 75 years."

Water releases

The board heard that 2021 is expected to be drier with less chance of severe flooding in a report from the United States Army Corps of Engineers.

Jessica Batterman, a hydraulic engineer with the corps, said the past two years were an impressive and historic one for moisture.

"You're looking at historical annual flow going past the Jamestown Reservoir gauge. You all know 2019 was a historic year, and 2020 was another pretty high-flow year," Batterman said. "The provisional total is over 300,000 acre feet, which I think is in the top 10, or at least close to it, for a total flow volume for the whole year."

She said those conditions came with the higher than average amount of snow and the historically wet conditions in the James River basin going into spring.

On conditions at the Jamestown and Pipestem reservoirs in North Dakota, she said Jamestown is estimating no inflow, with Pipestem reporting a minimal flow of 10 cubic feet per second. There is no immediate release from Jamestown planned right now, and Pipestem is continuing its low-level water quality releases of a little over 10 cubic feet per second.

The elevation for both reservoirs are holding steady, she said, with Jamestown at 1,429.9 feet, which is about 1.1 feet below flood pool, and Pipestem at 1,440.1 feet, which is about 2.4 feet below flood pool.

"So, we'll be going into the spring with 100% of flood storage for use," Batterman said.

In terms of potential flooding this year, Batterman said chances for most areas along the James River stand at around 20%.

"It shows that the percent chance of moderate to major flooding occurring in the lower James River basin is less than 20%, and chances for flooding above minor flood stage, for the most part, is less than 20%," Batterman said. "Only Mitchell has a 21% to 40% chance of going above minor flood stage."

She said Jamestown is targeted for evacuation to 1,431 feet by June 1. Minimal releases from Jamestown are expected pending on the weather.

"For a lot of low-flow years, Jamestown does not fill, or barely fills. I'm not sure we're going to fill to 1,431 by June 1. Rain can always change that, but that's a question that's up in the air, so there may be pretty minimal releases for the rest of the spring to the beginning of summer," Batterman said.

Releases are more likely at Pipestem, she said.

"After Jamestown is evacuated, we will make constant summer release from Pipestem to target our evacuation to 1,442.5 feet by Sept. 1," Batterman said. "I do expect to fill at Pipestem and utilize some of our flood storage, however I don't expect combined releases to be above 200 cubic feet per second for this year."

Other business

Also included as part of Thursday's business at the Thursday meeting, the board:

*

Approved a request from the Hanson Conservation District for 2020 tree plantings in Hanson County.

*

Approved payment request from the city of Huron for costs associated with the design and engineering of the 3rd Street dam project.

*

Approved a funding request from the town of Hitchcock for improvements to an existing lift station.

The board set the next meeting of the board for May 13, to be held virtually. The meeting is set to begin at 9 a.m.