Mower County Public Works is gaining ground in the race to replace deficient bridges.

Mower will replace at least eight township bridges this year. After those bridges are replaced, Mower County will have about 64 deficient bridges — 17 percent of the 369 total bridges. Other county bridges are up for replacement or waiting on state bonding dollars, like the Oakland Place Southeast bridge.

“Our intent is to remain aggressive,” Public Works Director Mike Hanson said. “But we depend on bridge bonding pretty heavily in Mower County.”

In 1998, Mower had 140 deficient bridges, and it had 99 deficient bridges in 2011, which ranked Mower among the highest counties in the state with 26.8 percent of bridges labeled deficient.

“We’ve done 150 bridges in the last 15 years,” Hanson said.

It’s difficult to remain caught up. As bridges are replaced, others age and go on the deficient list.

Hanson estimated it would cost about $17 million to replace all the deficient bridges at this time. In recent years, the county’s averaged about 10 township bridge replacements a year.

Deficient bridges can still be used, but they must be monitored and load limits are often enforced. In extreme cases, a bridge may be closed. That happened last year when a bridge on County Road 46 or 220th Street, the frontage road along Interstate 90 between the Austin Country Club and Nicolville. That bridge is slated to be replaced this year.

The average age of the deficient township bridges is 85 years, and the average age of deficient county bridges is 69 years, according to Hanson. The lifespan of a bridge is about 75 years, but Hanson said that depends on the bridge and various factors.

Thanks to a state law passed Feb. 12, 1885, Mower County is responsible for repairs on all bridges in the county, including township bridges and city bridges, which includes Austin and all small towns.

Hanson said Mower is one of the only Minnesota counties with this arrangement. In most counties, cities and townships handle bridges that are not on county roads.