Supervisors approve Live Oak Park Bridge replacement

The San Diego County Board of Supervisors approved the replacement of Live Oak Park Bridge.

The supervisors' 5-0 vote Feb. 10 authorized the advertisement for bid and subsequent award of a construction contract for the new bridge, established $4,072,280 of new appropriations for the bridge replacement project, and found that no new circumstances required changes to the environmental Mitigated Negative Declaration adopted in April 2018.

The existing 25 foot long triple arch culvert bridge will be replaced by a concrete slab bridge approximately 58 feet in length with the ability to handle large storms. The project will also improve the alignment and sight distance for that portion of Live Oak Park Road.

"This project will enhance driver safety, meet stormwater requirements, and complete a project that's been in the works since 2011," said Supervisor Jim Desmond.

Live Oak Park Bridge is on Live Oak Park Road and crosses the San Luis Rey tributary 160 feet south of Gum Tree Lane. The bridge was constructed in the 1950s by placing three corrugated metal arched culverts side by side in the streambed and connecting them together with Portland cement concrete headwall and endwall composition.

Past inspections of Live Oak Park Bridge revealed a vertical deflection of 1 1/2 feet. Water leaking from one culvert to another was also observed. The deficiencies found included distorted and corroded pipes, bent and crushed pipe sections, pipe deflection, and pipe section loss.

Bridge flooding concerns were also noted, as reviews of the bridge determined that the existing metal culverts would not be able to accommodate a 100-year flood event, and the driver sight distance was deemed to be inadequate.

The bridge was determined to be structurally deficient, which makes it eligible for the Federal Highway Administration's Highway Bridge Program. That program funds 88.53% of the bridge's estimated construction cost.

The Highway Bridge Program is administered through state transportation departments, and the county's Department of Public Works submitted a grant application for Live Oak Park Bridge to the California Department of Transportation in 2010. The funding for the preliminary engineering work was approved in 2011.

An inspection as part of the planning process found one pipe to be failing, and a December 2012 Board of Supervisors action appropriated $68,500 for the emergency repair.

"Staff has worked closely with the utility companies and other agencies," Desmond said.

DPW had to address San Diego Gas & Electric power lines, AT&T telephone lines, and Rainbow Municipal Water District water pipes. Biological resources and site constraints extended the process of the county obtaining U.S. Army Corps of Engineers, California Department of Fish and Wildlife, and Regional Water Quality Control Board permits.

The process also involved Caltrans review and approval to ensure compliance with Highway Bridge Program requirements.

The replacement was actually ready for construction in 2017 and DPW requested approval from Caltrans for the funding, but that funding was not granted until July 2020.

Caltrans prioritizes funding based on needs which need to be addressed. The Highway Bridge Program will fund $4,072,380 of the construction cost while the county will use Highway User Tax Account revenue derived from the sales tax on gasoline for the $527,620 matching amount. The $4,600,000 total budget includes contingency.

Two members of the Fallbrook Community Planning Group were absent when the November 2019 meeting included a recommendation to approve the bridge replacement project, but the other 13 planning group members all supported the recommendation.

Construction is expected to begin in summer 2021 and be complete in spring 2022. Tree trimming in the area may precede construction.

The construction will be staged so that one lane of the road remains open to traffic. "The road will be open at all times. There's no closure," said DPW project manager Sam Chrum.