Oak Grove Bridge alternatives announced


During a special scoping meeting held Tuesday, Feb. 23, at the Three Rivers Memorial Building, the Mineral King Bridge Project design team unveiled three alternatives that would cost up to $5 million and ensure that the existing bridge would not be demolished, depending on the outcome of the public process that includes NEPA (National Environmental Policy Act) and  CEQA (California Environmental Quality Act) evaluations.

Both levels of analysis are required because federal funding is involved. The normal funding structure for a bridge replacement-rehab project is 88 percent federal and a 12 percent state or county contribution.

“In this case, because of funding available from toll credits, federal funding will pay for 100 percent of the costs,” said Jason Vivian, Tulare County project manager.

(A state may use as a match toward the non-federal share of a project “toll credits,” i.e., revenues, to build, improve, or maintain highways, bridges, or tunnels that serve the public.)

The 108-foot-long bridge was built in 1923 to span the East Fork of the Kaweah River on the Mineral King Road and is potentially eligible for listing in the National Register of Historic Places. It is one of only a handful of similar concrete arch bridges built in the 1920s still standing in California. 

The bridge project is deemed necessary because of potential public safety concerns and liability.  Currently, it could withstand 14 tons; federal standards maintain that the structure safely carry 36 tons.

In addition, if a crash into the barriers occurred, it is probable the concrete railing would fail and a vehicle might plunge more than 20 feet into the river gorge.   

The scoping portion of the project is seeking public input in the form of written comments to identify potential environmental issues and indicate a preference among the alternatives that have been proposed by the Cornerstone Group’s team of structural engineers. Comments on this initial phase of the project are due by Wednesday, March 23. 

Alternative 1 (estimated cost $4.5 million) is a retrofit/rehab of the existing bridge and preserves the original structure and aesthetics while maintaining the existing alignment. According to Shawn Cullers, project engineer, there are some inherent construction risks and a temporary bridge would have to be built to keep the Mineral King Road open during bridge construction.

Alternative 2B (estimated cost $4 million) provides for a new low-maintenance bridge to be built upstream while preserving the existing bridge. This alternative costs less but requires the acquisition of right-of-way and would have greater environmental impact. The existing bridge would no longer be eligible for federal funding.

Alternative 3  (estimated cost $5 million) would be a hybrid of the bridge with new materials but retain the aesthetics of the original bridge. There would be only one, retrofitted low-maintenance bridge. The project would need minimal roadwork and cause less environmental impact. It requires a temporary bridge be built during construction and essentially replaces the existing bridge.

For further information, contact Jason Vivian at (559) 624-7135. Comments may be mailed to Jason Vivian, Tulare County Resource Management Agency, 5961 S. Mooney Blvd. Visalia, CA  93277-9394, or emailed to jvivian@co.tulare.ca.us.   

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