PEDESTRIAN UNDERPASS STUDIED

Carlsbad looks to improve access to beach, lagoon trail links across Highway 101

A pedestrian underpass beneath Carlsbad Boulevard that would connect Agua Hedionda Lagoon with the Tamarack beach parking lot is recommended in a new report on ways to improve Carlsbad State Beach.

The report by consulting firm Chen Ryan Associations of San Diego looks at the costs and feasibility of the underpass. A separate report by the firm presents conceptual designs for ramps to improve handicapped access to about eight blocks of the beach between Pine and Tamarack avenues.

Two ramps are proposed. One would be built at the northern end of the beach near Pine Avenue, where the bluff is about 30 feet high, and would go from a corner of the Ocean Street parking lot to the restroom building on the lower seawall. The other ramp would be near the end of Tamarack, from the restroom building there to the state beach parking lot.

“I’m very excited about the project,” said Carlsbad Parks and Recreation

Director Kyle Lancaster at a presentation last week to the city’s Parks and Recreation Commission. “I foresee this as a great benefit to the city.”

Plans for the ramps and the underpass are expected to go to the City Council for approval later this month. Money for the work is included in the city’s capital improvement budget.

Construction is expected to cost about $2.8 million for each ramp and $3 million for the underpass. The underpass probably would be a “cut

and cover” tunnel south of Tamarack and just north of the bridge across the inlet to the Agua Hedionda Lagoon. The tunnel would connect the parking lot and seawall trail to the trails along the lagoon.

To build a cut and cover tunnel, workers essentially dig a trench, in this case across Carlsbad Boulevard, also known as Highway 101, then replace the roadway across the top. In this case, most of the planning and staging would be done in advance. Construction probably would require sections of the highway to be closed, one direction at a time, for a few nights.

Both ends of the state beach now have asphalt ramps, one to the lower seawall on the north and the other to the Tamarack parking lot on the south. There also are six “switchback” stairways from the sidewalk on the upper seawall down to the lower seawall and the beach that are generally inaccessible to the handicapped.

Both the existing ramps allow pedestrians, lifeguards trucks and emergency vehicles to get to the beach but are too steep to meet requirements for handicapped access under the Americans with Disabilities Act. The existing ramps each now serve more than 5,000 people on a busy weekend day, Lancaster said. They would remain in place.

The new ramps would be longer and less steep, and the surfaces would be supported by piers above the ground to minimize disruption to the steep slope.

The city’s parks and recreation commissioners said they support the project.

“As someone who has taken a wheelchair down that ramp, anything is going to be an improvement,” said Commissioner Amy Allemann.

The tunnel under Carlsbad Boulevard also would have an ADA accessible ramp up to the eastern sidewalk on Carlsbad Boulevard.

At present, the only way to legally get from the parking lot to the lagoon is to go up the ramp or stairs to the crosswalk on Carlsbad Boulevard at Tamarack Avenue.

Preliminary planning for the underpass included a review of the city’s Sea Level Rise Vulnerability Assessment. The assessment showed the highest waves now can reach 12 feet below the surface of the Carlsbad Boulevard bridge and by 2100 the highest waves could be 5.6 feet beneath the bridge.

The underpass would have a 4-foot-high berm to keep water out, would be sloped toward a drain, and could be closed with a gate when f looded.

The state Department of Parks and Recreation owns about six of Carlsbad’s seven miles of beach, from about Pine Avenue south to Encinitas. However, the city has an agreement with the state under which Carlsbad maintains the heavily used northern areas to a higher standard than the state can afford to provide.

philip.diehl@sduniontribune.com