County closes Dillon Bridge over Wapsi River

     Tom Durgin met with the Jones County Board of Supervisors during their Oct. 19 meeting to discuss the condition of and the future of the Dillon Military Road (pedestrian) Bridge over the Wapsipinicon River.

     Durgin, who spent over 30 years diving off dams and bridges, commented that the Dillon Bridge “is the worst bridge I’ve ever been around, period.” Durgin prefaced his comments by saying he is not an engineer nor a bridge inspector, but images and video he took of the bridge, he said, prove its deteriorating condition.

     In one particular section of the bridge, Durgin measured a gap in the stone structure at 8 inches.

     “It’s grown 5 inches in the last three years,” he reported.

     He said should the bridge fail, typically there would be no warning of a collapse.

     “The abutment is really bad,” continued Durgin. “There is a tree growing (inside the bridge) to the point that it’s cracked the stone.”

     Durgin also presented his findings to the Anamosa City Council. The Dillon Bridge appears to be part of a 28E agreement between Jones County and Anamosa.

     “The county and city share responsibly,” Durgin noted. That responsibility also includes maintenance expenses.

     The supervisors added that the DNR is mentioned in the agreement as well.

     Supervisor Jeff Swisher, referring to the agreement, said that the county and Anamosa entered into an agreement for engineer serves on the bridge with IIW (which is now Origin Design).

     “Is the project still out there?” Swisher asked of documentation.

     In addition, Swisher said several floods have impacted the bridge. “Why was it (damage) not reported to FEMA?”

     County Engineer Derek Snead said his department did remove debris from the site either in 2008 or 2009.

     Snead, who’s been working with Origin Design on analyzing the Ely Stone Bridge, said there are very few contractors who do this type of work regarding historical stone structures. The board asked whether any work could be performed on Dillon Bridge to protect it from failing. Snead said that would depend upon whether the governing entities involved wanted to maintain its integrity and design.

     Durgin offered that the bridge is not on the history registry.

     “That’s a gray area,” said Snead. “Anything over 100 years is eligible.”

     He recalled at one point, Rose Rohr with the Jones County Historic Preservation Commission “was looking at a decking project” associated with Dillon Bridge.

     Beth Brincks, Anamosa city administrator, was also present at the board meeting. She said that while the city council heard from Durgin, the council voted to bring the issue to the county for their recommendations.

     “The DNR needs to be at the table, too,” said Supervisor Joe Oswald.

     Brincks said Anamosa also works with Origin Design on bridge projects.

     After much discussion, the county voted to close the bridge immediately to the public and all traffic.

     The board of supervisors tentatively set a date of Oct. 27 to meet with the Anamosa City Council on the matter.

In other county business:

     • Snead updated the board on the Stone Bridge load-rating test, being performed by Origin Design.

     Origin’s subcontractor will offer a presentation to the board of supervisors during the Nov. 9 meeting. The presentation will be done remotely from the contractor’s office in Colorado.

     “They’ll go through what they came up with regarding the existing capacity for the structure and cost estimates,” said Snead.