Bridge work: Report shows 10 bridges in Otter Tail County are 'structurally deficient'; that's better than average
Otter Tail County is doing slightly better than most when it comes to the condition of its bridges. According to a report released last week by The Washington Post, more than 130,000 bridges in the United States are structurally deficient or func...
Otter Tail County is doing slightly better than most when it comes to the condition of its bridges.
According to a report released last week by The Washington Post, more than 130,000 bridges in the United States are structurally deficient or functionally obsolete. That doesn't mean all those bridges are about to fall down, but it does indicate a need for repairs.
The report states that in counties nationwide, on average, 9.4 percent of bridges are considered structurally deficient. In Otter Tail County, that percentage is less, at 6.8.
Most of Otter Tail's neighboring counties also fare better than the national average. In Becker County, 5.8 percent of bridges are structurally deficient; in Wadena County, that percentage is 2.7; in Douglas, 10; Wilkin, 7.6; Clay, 5.4; Grant, 9.4; and Todd, 3.8.
The report lists 148 classified bridges in Otter Tail County. Of those, 10 are structurally deficient, 1 is functionally obsolete and 137 are considered good. Those numbers are based on 2015 data from the National Bridge Inventory, so the status of some bridges has changed since the inspection referenced in the report.
Rick West, OTC Public Works Division Director, said the county's numbers are actually better now than they were in 2015, as two of the structurally deficient bridges have since been removed, and a third has been replaced.
There's also a discrepancy between the number of Otter Tail County bridges listed in the report, 148, versus the actual number maintained by the county, which is 142. West said county bridges include some along county road systems, and others on township roads.
Bridges are given sufficiency ratings based on inspector ratings of various aspects of their top decks and underlying structures, according to the report. The worst bridges, with scores generally falling around 50 percent or below, are classified as structurally deficient. Bridges with scores that are higher than that, but still less-than-perfect, are considered functionally obsolete.
Bridges deemed structurally deficient in Otter Tail County
• The one nearest to Perham is on County State Aid Highway 8 north of town, where the highway crosses the Otter Tail River. That bridge has a 58.4 percent sufficiency rating. The bridge is slated for replacement in 2018, according to the county's Transportation Plan.
• Two cross Leaf River northeast of Deer Creek, according to 2015 data. One is on CSAH 67 (this one has a 65.5 percent sufficiency rating) and the other is on 530th Avenue (19 percent sufficiency rating). However, West said one of these has since been removed.
• Two cross the Otter Tail River southwest of Amor. One is on CSAH 45 (61.2 percent) and the other on CSAH 35 (65.2 percent).
• One is in far eastern Otter Tail County, east of Bluffton right near the Wadena County line. This bridge is along Leaf River Road, crossing Mill Creek. It has a 65.8 percent sufficiency rating.
• Four others were further west in the county at the time the data was recorded. In Pelican Rapids, an alleyway bridge that crosses the Pelican River was given a 71 percent sufficiency rating in 2015 (it has since been removed); south of there, on CSAH 28, a bridge crossing the Pelican River has a 66.9 percent rating (this one has since been replaced); west of Fergus Falls, a 160th Avenue bridge crossing the Pelican River has a 65.8 percent rating; and southwest of there, a CSAH 15 bridge over the Otter Tail River has a 49.7 percent rating.
• The one bridge in the county considered functionally obsolete is located on U.S. 59 southbound at the Interstate 94 crossing, with a 90 percent sufficiency rating.
Bridge funding and maintenance
According to The Washington Post, President Trump "campaigned on a $1 trillion infrastructure plan that includes fixing the nation's bridges," and federal financing has been prioritized for bridges with the lowest sufficiency scores.
If that funding comes to fruition, West said Otter Tail County would be vying for dollars against other neighboring counties within its state district. He said state aid is usually used for smaller bridge projects of less than $1 million, while federal dollars are used for larger projects.
He's hopeful for more federal funding: "There's no doubt, having been in this profession for a long time, that the need is there for public infrastructure funding, and it's been there for quite some time."
Lack of funding is one of the major challenges to keeping bridges structurally sound. Other challenges are fluctuations in climate and higher, heavier traffic than a bridge is designed to handle.
West said the county engineer is responsible for conducting safety inspections on culvert-style bridge structures every two years, and other bridges (such as the larger kind that go over rivers, etc.) every year.
If a bridge is found to need repairs, a weight limit may be posted, it may be partially closed down for further inspection by the state, or, in the most serious cases, it could be closed down entirely. He thinks Otter Tail County's better-than-average bridge safety ratings are due to a number of factors, including the county's "fairly aggressive" bridge replacement program, which has been in place for decades. Also, the majority of the county's bridges are culvert-style, he said, "and those typically have less maintenance and have a longer life than a larger bridge."
Regular routine maintenance is also a factor, though West said most bridges are designed to last about 50 years and so, no matter what, eventually "every bridge will reach a point where it will need to be replaced."