County authorizes bid process for culvert repair and replacement contracts

Joe Naiman

Village News Reporter

San Diego County authorized the advertisement for bid and subsequent award of construction contracts to repair or replace culverts throughout unincorporated San Diego County.

The county Board of Supervisors voted 4-0 Wednesday, Sept. 27, with one vacant seat, to authorize the director of the county’s Department of Purchasing and Contracting to advertise and award multiple construction contracts for culvert repair and replacement. The supervisors’ action also designated the director of the county’s Department of Public Works as the county officer responsible for administering the construction contracts and found the repair and replacement of the culverts to be categorically exempt from California Environmental Quality Act review.

The Department of Public Works maintains more than 17,000 drainage culverts throughout the unincorporated county. Stormwater crews inspect all county-maintained culverts on a cyclical basis and prioritize them for rehabilitation or replacement. Field engineering staff members inspect the culverts nearing the end of their service life to determine whether replacing the culverts or rehabilitating them with new lining would be the more preferable option.

Lining a culvert involves the installation of an internal sleeve. Lining methods include cure-in-place pipe which utilizes 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.

Repair of holes and the restoration of capacity without replacing the culvert can also be accomplished by invert paving which 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 on the bottom of the pipe to fill existing holes and restore it to a structurally sound pipe floor. If the culvert is damaged beyond economical repair, a culvert replacement is more appropriate than rehabilitation in which case the existing culvert is removed and a new one is installed.

The list consists of 151 culverts planned for construction as part of the contracts and another 56 locations which are planned for the future, although some of those 56 culverts could be part of the contracts awarded if the construction costs are below the budgeted amount. The county has budgeted $10,903,622, including a 5% contingency, for the work. A road fund balance of $6,201,122 along with $4,702,500 of revenue from the Road Repair and Accountability Act which raised the tax on gasoline by 12 cents per gallon effective November 2017 and vehicle registration fees between $25 and $175 depending on the vehicle's value effective spring 2018 will be used to fund the culvert replacements and repairs.

The 151 culverts on the immediate plan list include 10 in Bonsall, six in Rainbow, three in De Luz, three in Fallbrook and one in Pauma Valley. All 10 Bonsall culverts will be replaced. Four of those are on Hutchison Street: one on each side of the 200 block, one in the 600 block and one in the 2500 block. Another four Bonsall culverts are along Gopher Canyon Road: one in the 1300 block, one in the 3000 block, one in the 3200 block and one in the 8900 block. The other two Bonsall culverts are in the 3000 block of Blackwell Drive and the 2000 block of Riviera Drive.

All six of the Rainbow culverts are along Rainbow Valley Boulevard. One in the 2700 block will be relined while replacement will be the treatment for two others in the 2700 block, two in the 2600 block and one in the 3100 block.

All three De Luz culverts will be replaced. Two are in the 40200 block of Rock Mountain Drive and one is in the 40500 block of Gavilan Mountain Road.

The three Fallbrook culverts will all be replaced. They are in the 500 block of West Aviation Road, the 200 block of Fallbrook Street and the 400 block of Fallbrook Street.

The Pauma Valley culvert, which will be replaced, is in the 14300 block of Old Cole Grade Road.

The list of potential future work includes seven culverts in Fallbrook, one in Pauma Valley and one in Rainbow. All nine of those will be replaced. Two of those Fallbrook culverts are in the 1700 block of East Mission Road and another culvert is in the 1900 block of East Mission Road. The other four Fallbrook culverts are in the 1100 block of Fallbrook Street, the 1300 block of Fallbrook Street, the 700 block of South Main Avenue and the 1200 block of South Main Avenue. The Pauma Valley culvert on the future projects list is in the 31900 block of South Grade Road while the Rainbow culvert is in the 4200 block of Old Highway 395.

The culvert repair and replacement on a countywide basis is scheduled to begin in winter 2024 and be complete by the end of 2025. Before the start of construction residents and businesses will receive mailers or notices on door knobs notifying them of the upcoming work. Traffic control measures will be implemented during the construction to limit impacts to community members and other travelers.

Joe Naiman can be reached by email at [email protected].