Carlsbad moving forward with plan to realign stretch of Highway 101

Above: An April 3 report from KUSI's Dan Plante on the Highway 101 realignment project.

CARLSBAD, Calif. — The city of Carlsbad is charging ahead with a plan to relocate a segment of a historic boulevard amid rising sea levels and heightened flooding concerns.

Last week, the city's Beach Preservation Commission voted unanimously to recommend realigning a one-mile stretch of the coastal Highway 101, also known as Carlsbad Boulevard, in an all-encompassing approach referred to as "retreat now."

The alternative would have been a phased approach where changes would be made to the impacted roadway, which runs from Manzano Drive in the north to Island Way in the south, incrementally over a 96-year period.

The southern tip of Highway 101 has a long history of erosion and instability, particularly near Las Encinas Creek. City officials say events like high surf or coastal storms have often rendered the roadway inaccessible due to flooding.

Carlsbad officials have looked to solve this coastal overflow by doing emergency work under temporary permits from the state's Coastal Commission, such as extending the rock barriers that line the roadway — a step the city has taken at least twice since 2015.

As a condition of these temporary permits, however, the state instructed Carlsbad to seek a more permanent solution. That's where the realignment project comes in.

According to city documents, the realignment project includes two main components: a guide for how the road could be moved from the coastline, and an adaptive management plan to put those changes into motion.

Four segments of the southbound side of the roadway — including biking and walking paths — will be re-routed into a two-lane street with several roundabouts. A design concept from city officials of what this could look like is pictured below.

The project would also allow for habitat restoration along the roadway in the areas where the southbound plan is currently route.

The plan will now move to the Carlsbad City Council for another vote on April 23. According to city documents, the goal is to have preliminary design and permitting completed for a 2028 groundbreaking.

A cost estimate for the project has not been determined at this time, although previous studies on the realignment have been funded by a grant from the California Coastal Conservancy.