Bridge more likely for West Fargo
Engineers debating what kind of structure to build over the Sheyenne River on Main Avenue in West Fargo are now leaning toward a bridge instead of a box culvert, which they say has become twice as expensive and can't be completed this year.
"And even with a bridge, it will be a challenge" to finish the project before winter, said Bob Walton, Fargo district engineer for the North Dakota Department of Transportation.
Efforts to replace the existing bridge hit a major snag in late June when a cofferdam built to divert the river around the construction site began shifting in the loose soil below.
Based on an analysis of the ground conditions presented by subcontractor Industrial Builders Inc. to NDDOT officials Tuesday, shoring up the cofferdam and soils for a box culvert would add roughly another $1 million to the culvert's bid price of about $1.1 million, Walton said.
"It brings them very close and maybe even pushes the box culvert, from a cost standpoint, (to) more than a bridge," said Joe Peyerl, NDDOT project engineer.
However, it was the timeline for finishing a box culvert that convinced the state to take it off the table for this year, Walton said.
Instead, officials are looking at building a two-span bridge with a center pier, similar to what's in place now. The preliminary cost estimate was $2.4 million, but Walton is hoping for a lower, revised estimate.
A shorter, one-span bridge with no center pier was estimated at $4 million and considered to be too expensive, Walton said.
The Federal Highway Administration has agreed to pay 80 percent of the project cost, with the state and city each picking up 10 percent. That means West Fargo likely would be on the hook for $200,000 to $240,000 instead of about $100,000, Walton said.
The city will cover the additional cost with revenue from its 1 percent sales tax for infrastructure, City Administrator Jim Brownlee said.
A bridge will need more long-term maintenance by the city, but it also is more aesthetically pleasing than a box culvert, he said.
"Hopefully they can get it in this year," Brownlee said, adding that the rest of the Main Avenue project is on or ahead of schedule.
Additional federal dollars tagged for the bridge would need to be made up in 2010, meaning a future project could get scrapped or delayed, Walton said.
The state will negotiate this week with the Main Avenue project's primary contractor, Dakota Underground, to determine if a bridge can be finished this year and at what cost. If it can't be done this year or if the cost is unreasonable, the bridge work will be delayed until next year, Walton said.
The condition of the existing bridge, which has two sections each carrying two lanes of traffic, is not a safety concern, he said.
"It just made sense to replace them when we're doing the roadway adjacent," he said. "They're not going to fall down or anything."