County engineer outlines emergency repair plan after Mattany Bridge stringer failure

A county public-works official told Klamath County commissioners on March 31 that a stringer in the middle span of the Mattany Bridge snapped after an "incredibly heavy load" crossed the structure, leaving one lane closed and prompting a proposal for expedited in-place repairs.

The official said the bridge is weight-restricted to 32 tons because of foundation issues, that the failed stringer is in the worst possible location for a repair (the middle span over water), and that out of 21 support piles 14 showed rot. He said repairing the bridge in place — removing the deck and stringers, repairing or replacing piles and reinstalling stringers with steel foundations — would produce a long-lived timber-and-steel structure and could be completed this summer if the county can hire engineers and a contractor while Cascade Civil Group is in town with a 100-ton crane.

"There's no easy way to repair it, so we have to essentially take the deck off, take all the stringers off, and then put them back on," the official said. He estimated a full replacement using concrete beams would cost about $3,000,000 and take several years of design and permitting, while the expedited repair would be substantially less and quicker.

Why it matters: The bridge carries local traffic and has detour options but the middle-span failure reduces capacity and increases maintenance urgency. Staff argued an emergency declaration would allow the county to hire designers and contractors on an accelerated schedule and save money versus a multi-year replacement.

What’s next: Staff said it would return to the board with a formal emergency-declaration request and associated contracts and designs for the board’s consideration.