The only rail line connecting Encinitas and San Diego County to Los Angeles faces growing disruption from coastal erosion, with state officials now studying whether to move the most vulnerable stretch of track inland.

The California State Transportation Agency (CalSTA) is expected to launch a feasibility study before the end of 2026 examining what it would take to relocate the rail line in the San Clemente area of southern Orange County, CBS 8 reported Oct. 12. A spokesperson for the California Coastal Commission told the station the agency is very concerned about erosion and flooding along the railroad line.

When that segment closes, Encinitas riders lose service north. Railroad traffic connecting San Diego County with the rest of the nation was suspended in early September as high tides chewed away at the tracks in San Clemente, the San Diego Union-Tribune reported. The 351-mile corridor from San Diego to San Luis Obispo is San Diego County's only railroad connection to Orange County, Los Angeles and the rest of the country.

In some stretches, the tracks sit less than 200 feet from the waterline, according to Voice of OC. During high tide, waves can crash onto the tracks and passing trains.

An approaching El Niño winter raises the stakes. Paul Steward, a meteorologist at the National Weather Service San Diego, told CBS 8 that stronger-than-forecast seas increase the risk. "When we have these seas possibly being even a little bit greater than what's being forecasted, we definitely have a higher probability of these occurrences with erosion," Steward said.

The Coastal Commission has directed the Orange County Transportation Authority (OCTA) to develop a long-term adaptation plan, Joshua Smith, the commission's public information officer, told CBS 8. Top commission officials visited Orange County in early October to observe conditions and meet with state and local leaders, the station reported.

Darrell Johnson, OCTA's chief executive, warned in a Sept. 27 Associated Press report published by KPBS that if shoring up the tracks and relocation both fail, officials may have to consider halting the line entirely. OCTA plans to place about 560,000 cubic yards of sand onto San Clemente's shoreline by fall 2028 to buffer the railway, Voice of OC reported.

Closer to Encinitas, the San Diego County segment of the corridor has been studied extensively for relocation, CBS 8 reported. In Del Mar, an effort is underway to move the tracks off eroding coastal bluffs and into a tunnel. That project could be completed by 2035 if a final design is approved and funding becomes available, according to the Union-Tribune. The North County Transit District (NCTD) and OCTA are working with state officials on long-term plans to reroute endangered sections to inland routes.

State Sen. Catherine Blakespear, who represents Encinitas, has pushed legislation to improve rail reliability along the corridor. Her Senate Bill 1098, the Southern California Rail Revitalization Act, was signed into law in 2024. It directs CalSTA to create a prioritized list of capacity and climate-resiliency projects for the corridor, according to the Union-Tribune.

The CalSTA feasibility study, focused on the San Clemente segment, is expected to examine solutions beyond the next 30 years, including possible track relocation, Voice of OC reported. The study is expected to launch before the end of 2026.