FARGO — Fargo and Clay County engineers are looking into options for rehabilitating, replacing or eliminating the North Broadway bridge across the Red River.
Fargo City Engineer Brenda Derrig told city commissioners on Monday night, Feb. 22, that the 1990 bridge that closed on Feb. 11 has a pier that is tilting, and if it gave way the bridge would collapse "immediately."
Thus, she said, even pedestrians or cyclists won't be allowed on the bridge that falls under the purview of both North Dakota and Minnesota.
She said the options will hopefully be presented to the two commissions in the next three to six months.
The estimate for rehabilitating the bridge that includes building a dam around the damaged pier and replacing it is estimated at about $2 million. Derrig described that as a short-term fix.
Reconstructing the bridge at the same height, a long-term option, is estimated at about $4 million.
During routine monitoring earlier this month, officials learned of an increase in the tilt of a bridge support caused by the movement of surrounding clay soil that is susceptible to weakness, especially with constant flooding.
Thus, traffic has been rerouted to the nearby Cass County Road 20 bridge along 40th Avenue North, about half a mile to the northwest.
Derrig said a bridge engineering consulting firm, SRF Consulting of Minneapolis, was hired by the city in 2018 to do a study of the bridge and the soils supporting it.
The bridge was monitored for 19 months. At the end of that time, SRF recommended funding be sought to rehabilitate or replace the bridge and that in the short term the tilt angle of the north pier supporting the bridge be monitored regularly.
In a monitoring of the bridge earlier this month, SRF determined the pier had moved 0.44 degrees in one year and recommended weekly checks or closure.
It's uncertain where funding would come from for the project, as Derrig said money hasn't been set aside for the bridge.
She added that the North Broadway roadway on the west side of the bridge also wasn't stable, which could add to the cost.
Derrig said the bridge floods at 23 feet, and it's closed when the river reaches 22 feet.
Commissioner Dave Piepkorn, who lives in north Fargo, said he wouldn't support permanently closing the bridge as it would continue to increase traffic into the residential neighborhoods in the area of 12th Avenue North.
He also said the bridge should remain because Amazon is building its new packaging and distribution center in the nearby County Road 20 area near Interstate 29, not far from the bridge.
Commissioner John Strand said perhaps it was time to look at raising the bridge, and possibly the one on 12th Avenue North, too, to above the flood stage that will be at 37 feet at its maximum when the new Fargo-Moorhead Flood Diversion is completed.
A study from five years ago determined about 1,800 vehicles a day cross the bridge, compared to about 6,000 vehicles that use the Cass County Road 20 bridge and the more than 10,000 vehicles that daily use the 12th Avenue North bridge, formerly known as the toll bridge.