BERTRAM, Iowa — Of three Linn County bridges damaged in Monday's flooding, only one is on a federal list of structurally-deficient bridges.
The picturesque, red-arched Ely Street Bridge that washed into Big Creek near Bertram was considered structurally-deficient in the U.S. Department of Transportation's 2013 bridge inventory.
It's not a big surprise, considering the one-lane bridge was built in 1891, the same year Iowa artist Grant Wood was born.
Iowa ranks second worst in the nation for the number of structurally-deficient bridges. More than 1.6 million motorists a day travel over 5,043 such bridges in Iowa, which is 21 percent of all of Iowa's 24,398 bridges.
Linn County is above average, with just under 6 percent of bridges considered structurally deficient. Still, more than 30,000 motorists cross 28 of these bridges in Linn County every day, according to the inventory.
Public officials at the federal, state and local level caution that “structurally deficient” does not mean a bridge is unsafe, but rather that it “needs repair, closer monitoring or weight restrictions so that it does not become unsafe.”
Bertram's Ely Street Bridge had an overall sufficiency rating of 21.6 out of 100. The DOT also rates components of each bridge, with lower scores indicating poorer conditions. The Ely Street Bridge's superstructure scored a 4 out of 9 — a score that generally triggers a bridge's inclusion on the structurally-deficient list.
The bridge was ranked 29th on a list of nearly 100 city bridges the Iowa DOT would like to replace. The nearby Big Creek Road Bridge, a 1929 bridge that survived the deluge, is ranked 24th, said Cathy Cutler, a planner with the Iowa DOT office in Cedar Rapids.
The Iowa DOT had offered Bertram money to replace the bridges in recent years, but the city had to turn down the funding because it couldn't come up with the local match.
Two other Linn County bridges were damaged Monday, causing motorists to seek alternate routes.
A 15-foot hole in the approach to a bridge that crosses a drainage ditch on Highway 151 north of Fairfax could be repaired as soon as July 11, said Norm McDonald, director of the Iowa DOT Office of Bridges and Structures. A semi and tractor-trailer fell into the hole Monday, damaging the truck and injuring the driver.
Acoustic imaging Tuesday revealed some damage to one bridge piling, which means the DOT will accelerate replacement of the bridge from 2019 to 2017, McDonald said. The bridge also will be placed on electronic bridge watch.
The drainage ditch bridge, built in 1933, has an overall sufficiency rating of 80.5 out of 100, with component scores of at least 6 out of 9.
The Springfield Road Bridge over Abbe Creek north of Mount Vernon should be back in commission within two weeks, Linn County Engineer Steve Gannon said Tuesday. Crews will remove damaged asphalt on the bridge approach and replace it with a temporary rock surface that will allow driving, he said. Asphalt should be replaced in late August or September.
“I understand how inconvenient these closures are and have crews working to make repairs,” Gannon said. “Traffic safety is important and requires that we take some time making reviews and putting together proper repairs.”
The Springville Road Bridge, built in 1960, has an overall sufficiency score of 38.9, according to the federal inventory. None of its component scores appear to trigger a ranking of structurally deficient.