COLUSA, CA (MPG) – The Colusa County Board of Supervisors acted swiftly last week to authorize emergency repairs on the Colusa Weir Bridge following the discovery of critical structural damage that poses a potential safety risk to the traveling public.
At the urging of Colusa County Chief Executive Officer Wendy Tyler and Public Works Director Colt Esenwein, the board unanimously approved emergency repair efforts without going out to competitive bid after finding sufficient legal cause to do so at its July 25 meeting in Williams, which had already been scheduled and noticed.
Tyler said the cost of the temporary fix to “shore up” the bridge – located on River Road north of Colusa on the east side of the Sacramento River – is unknown.
“I wish I had more financial information,” Tyler told the board. “Unfortunately, we do not. But I can guarantee you that we will watch the cost as closely as we can. It’s not going to be cheap.”
The 500-foot Colusa Weir Bridge was constructed in 1933 when the concrete flood control structure was built to divert water from the Sacramento River into the Butte Basin when river levels exceed safe capacity.
The cost of the repair, likely in the hundreds of thousands, will come from the county’s bridge fund held for such p
Tyler said River Road access is an essential route for traffic and agricultural transport.
“The other option would be to close the bridge, which in my mind would not be an option,” she said.
Although the bridge is known for its ‘thump-thump-thump’ gaps that allow the bridge to expand and contract in tune with Mother Nature, Esenwein suspects similar repairs made on the 92-year-old structure about 40 years ago may be an indication there was some original design miscalculation.
According to a previous state inspection report, the Colusa Weir Bridge met minimum structural tolerability and needed monitoring, but was otherwise in fair-to-good condition.
Esenwein said the county was alerted to the recent problem after a citizen contacted authorities on July 14 to report the unexpected and noticeable bump on the bridge’s north end. Promptly responding to the call, the Colusa County Public Works Department and a consultant conducted an initial inspection and identified a 4-inch gap about 4-inches deep between the road and concrete, raising immediate concern.
Esenwein said he immediately requested an emergency structural review by the California Department of Transportation, which was reluctant at first to come out, but did so because the bridge was due this year for its biennial inspection.
Caltrans completed its inspection on July 22, uncovering significant structural deterioration beneath the bridge deck. The damage stemmed from a slipped joint seal between concrete slabs, which led to flexural cracking at the bottom of several pier columns that support the bridge, officials said.
Tyler said state engineers classified the deterioration as critical, necessitating the county to conduct urgent stabilization measures to prevent further damage or potential collapse.
Emergency repair crews are expected to begin work immediately to reinforce the compromised pier columns sufficient to ensure stability for the bridge to withstand the volume and weight of traffic anticipated in the coming weeks, as well as during winter hydrological flows with the weir is active.
Meanwhile, Esenwein, who the board authorized to secure the services needed, will prepare a state-required Plan of Action for permanent repair of the bridge. Eventual replacement is also a probability, given the bridge’s age, but would be dependent on state funding becoming available, officials said.
Due to the bridge’s compromised stability, county officials will post and try to enforce slower speed limits until repairs are made, and urges motorists to use caution.
Tyler said further updates will be provided to the board as repair work progresses and the bridge nears restoration.