Scott County’s bridge stock in good shape, engineer says

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By Tom Saul | Tuesday, November 13, 2007 7:33 PM CST | () comments

(KEVIN E. SCHMIDT/ QUAD-CITY TIMES) Buy this Photo

The short concrete slab bridge south of his acreage on 250th Street north of Eldridge, Iowa, seems sturdy enough, said Don Claussen, who rents his land out for farming.

“We drove a semi across it the other day,” Claussen said. “This fall, we used it for a big combine and grain carts, but they were empty.”

The bridge, built in 1952 with an estimated remaining useful life of two years, got a new addition recently — weight limit signs. An inspection this past year found rotting pilings and earned it a recommendation that it be inspected every year instead of every other year, said Jon Burgstrum, county engineer.

During a presentation to the Scott County Board of Supervisors on Tuesday, Burgstrum said inspections of the county’s 116 bridges found eight that required posting for weight limits and one that was posted as one lane.

According to a summary of the inspections by Calhoun-Burns and Associates of West Des Moines, eight bridges are in need of replacement and 31 need repair or rehabilitation, based on sufficiency ratings that offer a picture of the general condition of bridges.

Although there is little money available for repair and replacement of bridges, Burgstrum said the county’s bridge stock is not falling apart. The posted spans represent less than 10 percent of all the bridges the county is responsible for.

“The bottom line is, none of them are in serious or dire straits,” Burgstrum told the supervisors. “We’ve been taking care of our bridges.”

The county’s bridge stock ranges in age from 107 years to just two years old, according to the report, which is based on inspections done this past spring and summer. Those that were posted have wooden pilings and other wooden components that are more easily subject to rotting.

A mounting chorus of public works professionals, bridge builders and others have been warning that the nation’s bridges are being neglected and left to deteriorate. Their claims picked up renewed urgency Aug. 1 with the collapse of a major freeway bridge across the Mississippi River in Minneapolis, which left 13 people dead.

A Quad-City Times investigation published in August found that 458 bridges of the 1,890 in Clinton, Muscatine and Scott counties in Iowa and Henry, Rock Island and Whiteside counties in Illinois were in need of repair or replacement.

Both the Iowa and Illinois legislatures have been asked to approve more money for building of transportation infrastructure, including the repair and replacement of bridges. In the meantime, Scott County’s bridges got a closer look earlier this year as the state Department of Transportation began more strict enforcement of federal standards for bridge inspections.

“We have one engineer who devotes 60 percent of his time to oversight (of county and city bridge inspections),” said Bruce Brakke, the Iowa DOT’s chief bridge maintenance engineer. “There is also a federal bridge inspection database that we run periodically to see that bridges are being inspected when and how they should be.”

Scott County last spent $8,000 for its biennial bridge inspections, but the most recent round cost $18,000, Burgstrum said. New federal standards prompted closer inspection of potentially troublesome components of some bridges, especially wooden piles that are in place on older spans.

The inspection report helps the county determine the bridges most in need of repair or replacement and moves them into its five-year capital improvement plan, Burgstrum said. However, the amount of money available from the state has remained flat in recent years while costs for construction material have skyrocketed, meaning less bridge work can be done.

In recent years, Iowa’s 99 counties have had $26 million a year in federal bridge money to be divided among them, said Larry Jesse, director of the Iowa DOT’s office of local systems, which administers a bridge repair and replacement fund.

“The money is distributed based on the condition of bridges and on the percent of state road tax money each county gets,” Jesse said. “We look at whether they are structurally deficient or functionally obsolete, not how many bridges a county has or its population.”