Critical bridge replacements still years away
The Nevada County Board of Supervisors has extended two contracts with Dokken Engineering to rehabilitate and upgrade structurally deficient bridges.
The county originally had contracts with Dokken that ran from 2014 to 2019, but both bridge projects have seen significant delays and amendments leading to the contracts’ expiration and requiring extensions into 2024.
Both bridge projects, the North Bloomfield Road Bridge at the South Yuba River and the Dog Bar Road Bridge at the Bear River, are funded through the Highway Bridge Program, which provides funds for infrastructure upgrades the state and the Federal Highway Administration determine are significantly important and structurally deficient, or functionally obsolete.
Work on the North Bloomfield Road Bridge, commonly known as Edwards Crossing, was in the planning stages of a rehabilitation in 2017 when the Pleasant Fire closed Highway 49 to traffic in the South Yuba River Canyon, raising questions in the community about evacuation routes and emergency vehicle access on the one-lane bridge. This led to the decision to amend the scope to include a replacement two-lane bridge that would accommodate evacuations and emergency response without creating a bottleneck.
“At the time the original contract was executed, the project was anticipated to be a rehabilitation of the existing crossing, adding some structural support and load capacity to the existing one-way bridge,” a staff report states. “This situation caused concern among the public and county staff that simply rehabilitating the one-lane bridge might be inadequate for emergency access purposes.”
The county is looking at two alternatives for the replacement bridge and still plans to rehabilitate the original bridge for pedestrian use and historic preservation, as the site is eligible for inclusion in the National Register of Historic Places, according to Dokken.
The first option includes a new bridge 60 feet upstream from the existing one and maintains the current route to and from the bridge. The second option would add a new bridge 1,000 feet upstream from the original at a higher elevation and level the sharp turn on the south side of the river.
According to documents by Dokken, the bridge is rusting, has damaged railing, has deficiencies in its lumber deck and features cracks and missing hardware.
The cost of the project is $635,045.
“The existing bridge is in critical condition, so it has to be repaired or replaced. This is just continuing that project with our design consultant,” Public Works Director Trisha Tillotson said at the December meeting when the contracts were approved. “We plan to add a new bridge downstream of the existing bridge, and we’re hoping to continue that process.”
According to staff reports, the changes to the design and studies needed for them have eaten into the original contract term. Dokken is now in the initial environmental review process and expects final design approval in 2022 with construction beginning 2024 and reaching completion in 2026.
DOG BAR ROAD BRIDGE
The Dog Bar Road Bridge Replacement Project was extended with a new maximum amount of $751,352. The project was originally supposed to cost $574,882 when approved in 2014, but the scope of work and payment was reduced $103,425 after plans for Nevada Irrigation District’s Centennial Dam conflicted and limited the bridge replacement project.
“This dam would put the bridge under water,” District Supervisor Ed Scofield said at the time.
However, as development on the dam project has been slow to materialize, the county now has to make progress on the bridge or risk losing its funding.
“Caltrans has informed the county that work must begin on the environmental and design stages of this bridge or the funding for the project will be cancelled and reassigned to other projects in the state,” a staff report states. “Members of the project team met with NID this spring and NID understood our funding constraints and agreed to cooperate with our project.”
The project will build a new two-lane bridge that spans Bear River either 30 feet upstream or 150 feet downstream of the existing bridge, which will be removed. The project will also level the horizontal approach to the bridge and increase its load capacity.
To contact Staff Writer John Orona, email firstname.lastname@example.org or call 530-477-4229.
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