53 drainage structures are targeted as crews prepare roads and storm systems for the 2026-27 rainy season
San Diego County, Calif. (San Diego News Online) — San Diego County Public Works is stepping up drainage maintenance and culvert replacements in unincorporated areas as Southern California heads into the rainy season and El Niño intensifies. The County expects around $4.5 million in investments for work on 53 culverts related to approximately 90 miles of resurfacing of roads.
As part of their routine, year-round activities, County Public Works carries out inspections and cleaning of drainage systems, street sweeping, tree trimming, pothole filling, and maintenance of thousands of items of transportation infrastructure.
The timing is important this year because, on September 10, the National Oceanic and Atmospheric Administration’s (NOAA) Climate Prediction Center said that El Niño had already begun and is building momentum with a greater than 90 percent probability of becoming a very strong event during the autumn and winter of 2026-27. According to NOAA, a strong El Niño increases the odds of impacts that typically come with El Niño, but it doesn’t mean that there will be abnormally high rainfall in any specific area.
The importance of culverts
A culvert is a drainage structure in the form of a pipe or enclosed channel that transports storm water underneath or next to roads. Although they usually remain unnoticed, damaged or clogged culverts may cause floods, erosion, and pavement damage during periods of heavy rain.
The San Diego County Department of Public Works manages more than 19,000 culverts in unincorporated San Diego County. Engineers and maintenance workers check these systems and prioritize the repairs based on their condition, needs of the community, readiness of the projects, and available funding.
During fiscal year 2026-27, Public Works identified 53 culverts requiring maintenance in connection with the County’s annual road resurfacing program. The estimated project cost is about $4.55 million, including contingency funds for unexpected construction conditions. The funding comes from the state Senate Bill 1 road-maintenance gas tax money.
The culvert replacement projects are coordinated with approximately 90 miles of road resurfacing projects that allow completing the maintenance of drainage systems as a part of road maintenance, instead of conducting them separately.
A system covering nearly 2,000 miles
Drainage maintenance is just one part of road maintenance conducted by San Diego County.
Currently, Public Works is responsible for nearly 2,000 miles of county roads, about 19,000 culverts, 223 traffic signals, and 39,827 traffic signs. San Diego County also reports that they manage more than 1,200 miles of bike lanes and more than 500 miles of sidewalks.
The regular activities carried out by road crews include cleaning storm drains and channels, replacing culverts that deteriorated, repairing guardrails and traffic equipment, painting traffic markings, and clearing vegetation that might obstruct motorists’ view. The mountain crews take care of winter storm response and clearing operations.
In its budget for fiscal year 2026-27, San Diego County allocated $71.3 million to maintain approximately 2,000 miles of County roads and $4.8 million specifically to clean culverts, channels, and storm drains in order to prevent storm flooding. The funds mentioned above are not related to major projects of culvert replacement and road resurfacing.
Annual program of culvert replacement
Such a practice became possible after the adoption of Senate Bill 1, the Road Repair and Accountability Act, by California in 2017. San Diego County instructed the County’s Public Works to utilize additional transportation funds in a long-term resurfacing program meant to improve conditions of pavements on County-owned roads. The drainage facilities, bridges, and culverts have been included gradually in this asset management approach.
During fiscal year 2025-26, San Diego County’s officials identified 48 culverts in need of maintenance, estimating their cost at approximately $3.9 million. As you see, the next year’s identification of 53 sites reflects the fact that the inspection and replacement of culverts have become annual elements of resurfacing program.
Also, the County has been developing its Green Streets Clean Water program, which evaluated nearly 1,200 miles of roads in unincorporated areas to find ways to enhance capturing and treating storm water while integrating such improvements as sidewalks, bicycle facilities, vegetation, and other community assets.
Citizens can report problems with roads and drainage
Resident of unincorporated San Diego County can help identify problems before the rains by reporting potholes, drainage problems, and other non-emergency infrastructure issues.
Using the County’s free Tell Us Now! mobile application, citizens can report problems and track the status of their reports. Service requests of Public Works include potholes and drainage-related problems in unincorporated areas.
Additionally, County’s storm preparedness tips advise owners of properties to clean the leaves, sediment, and other debris in privately owned gutters, drains, ditches, and culverts before significant rainfall.
With El Niño gaining strength and approaching 2026-27 rainy season, such a combination of routine cleaning, culvert replacement and road resurfacing demonstrates efforts of the County to address drainage issues before storms test the system.
