Michigan DOT Assesses Needs, Starts Repairs After Extensive Flooding
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The Michigan Department of Transportation is in the process of assessing and restoring infrastructure after severe flooding swallowed roads and bridges in the east-central portion of the state.
The flooding, precipitated by heavy rainfall, prompted Gov. Gretchen Whitmer to issue an emergency declaration May 19 and impacted Midland, Gladwin, Arenac, Saginaw and Iosco Counties. Each of these counties lies near Saginaw Bay, the body of water that separates the thumb and index finder in the glove of Michigan.
Jocelyn Hall, MDOT’s Bay Region media relations representative, said the flooding caused 23 road and bridge closures when it reached its peak. These closures affected state trunkline and local structures. Trunkline refers to the state highway system, meaning routes with an M, Interstate or U.S. designation that fall under MDOT’s jurisdiction. The Edenville and Sanford dams, which are about 10 miles apart, were breached, contributing to the flooding.
Gov. Gretchen Whitmer (center) tours US-10 bridges over Sanford Lake during repair work from flood damage. (MDOT Photography Unit)
“Flooding has a ripple effect in a sense,” Hall said. “So we experienced heavy rains for a couple days, and combine that heavy rain in a short time frame with multiple dam failures, and we had the flooding event.”
Hall identified a couple of areas where closures remain in place. Two bridges that carry state Route 30 through Midland and Gladwin counties remain closed to traffic. The bridge in Gladwin County was washed away, and the other structure will require “extremely heavy maintenance,” according to Hall. She said MDOT won’t know the extent of the damage until teams can remove debris and inspect abutments and piers. Abutments are used at the ends of bridges, connecting the deck to the ground. Piers extend to the ground or water below a bridge, supporting the structure.
M-30 flooding damage in Edenville, Gladwin County. (MDOT Photography Unit)
Maintenance also is required for bridge scour on the structure that carries state Route 46 in Saginaw County, Hall said. MDOT has been able to open a lane in each direction on that bridge as the agency prepares for scour maintenance.
Scour occurs when fast-moving water removes the sediment surrounding a bridge’s footing, leaving behind a hole. Matt Chynoweth, MDOT’s chief bridge engineer who oversees the agency’s Bureau of Bridges and Structures, said department crews will have to probe to assess damage. He participated in a recent episode of MDOT’s Talking Michigan Transportation podcast that focused specifically on the flooding.
“Scour’s a big deal,” Chynoweth said. “The main thing when you’re dealing with a water event is making sure the footings have not been undermined.”
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The span carrying U.S. Route 10 in Sanford also sustained damage to the abutment walls and the bridge approach. Through its emergency contracting process, MDOT secured a contractor that already has started work on these repairs. Hall said the contractor intends to reopen the eastbound part of U.S. 10, with a lane of traffic moving in each direction, by June 4. Both sides of the route are expected to be reopened by June 18.
Hall noted it is difficult to say what sort of repairs will be necessary for the dams, which are privately owned. On May 27, Whitmer sent a letter to the Michigan Department of Environment, Great Lakes and Energy directing agency officials to investigate what caused the Edenville and Sanford dams to fail. Additionally, the letter asks the agency to review dam safety throughout the state.
“This flooding forced thousands to evacuate their homes, destroyed public infrastructure, ruined homes and businesses and caused major natural resource damage,” Whitmer said in a statement. “We must ensure accountability and prevent a disaster like this from happening again.”
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