The San Diego County Board of Supervisors approved the advertisement for bid and subsequent award of a contract to repair or replace various culverts throughout San Diego County.
The supervisors’ 5-0 vote May 21 approved the refurbishment or replacement of up to 4,165 linear feet of culvert including 112 feet along Reche Road, 100 feet along Camino Del Rey, 72 feet along Alvarado Street, 60 feet along Winter Haven Road, and 35 feet along Gird Road while appropriating $600,000 from the county’s road fund balance for the project. The contract is structured to include a base bid containing 23 locations with additive alternatives, or clusters of locations which can be added to the contract should funding permit, for 21 additional locations.
“Timely rehabilitation and replacement of drainage facilities in unincorporated San Diego County will save the county and neighborhoods from unpleasant surprises and higher repair costs,” said Supervisor Bill Horn. “The competitive bidding process for the construction contract means the county can shop for the best deal possible while stimulating the local economy.”
The county’s Department of Public Works maintains more than 18,000 drainage facilities, including more than 14,000 culverts, in the county’s unincorporated area. Stormwater crews inspect all county-maintained culverts on a cyclical basis and prioritize them for rehabilitation and replacement. Field engineering staff members inspect the culverts nearing the end of their service life to determine whether the more preferable option would be replacing the culverts or rehabilitating them with new lining.
Invert paving consists of preparing the invert surface area, or the bottom of the culvert, to receive concrete, installing bar reinforcement and anchorage devices, and paving the inverted area with concrete. Invert paving allows the repair of holes and the restoration of capacity without replacing the culvert.
Lining a culvert involves the installation of an internal sleeve. Lining methods include cure-in-place pipe utilizing resin-impregnated fabric inserted into the existing culvert, slip lining insertion of solid wall surface into the existing culvert, and insertion of spiral-wound pipe which will expand and line the culvert. The internal sleeve restores the pipe’s structural integrity while reducing excavation and thus minimizing traffic impacts.
If the culvert is damaged beyond economical repair, a culvert replacement is more appropriate than rehabilitation. The existing culvert is removed and a new one is installed in such cases.
The estimated cost of the contract, including contingency, is $1,100,000. The $600,000 road fund money will supplement $500,000 of Highway User Tax Account revenue obtained from sales tax on gasoline.
All culverts included in the base bid are either within county right-of-way or in locations where right-of-way access has been acquired. The county will negotiate for right-of-way access on the additive alternatives while the higher-priority culverts are being rehabilitated or replaced, and the additive alternatives will not be awarded if all necessary rights for construction have not been secured.
The base bid includes 100 feet of invert paving on Camino Del Rey, 40 feet of lining along Reche Road, and 35 feet of lining along Gird Road. Additive Alternative 1 includes 36 feet of replacement along Alvarado Street. Additive Alternative 3 includes the lining of 72 feet along Reche Road, 60 feet along Winter Haven Road, and 36 feet along Alvarado Street.
The construction is scheduled to begin in fall 2014 and be complete in early 2015.