ENCINITAS — The Cardiff Beach Living Shoreline Project is running about two months behind schedule, due in part to weather delays, and is now slated to wrap up at the end of April.
Protecting habitat for the western snowy plover and California grunions could lead to additional delays, should the plovers choose to nest or the grunions to spawn on Cardiff State Beach in March.
The Living Shoreline, which aims to protect Cardiff State Beach and Highway 101 from coastal flooding while fostering dune habitat for native plants and animals, has been the product of various partnerships between federal, state and local agencies.
It is hoped that the newly created dunes — built of 2-ton rocks covered with sand — will act as a buffer against storm surges and the impacts of potential sea-level rise.
Highway 101 in that area varies in elevation from about 15 to 20 feet above sea level, which has made it particularly vulnerable to coastal flooding during large storms.
In fact, the combination of a king tide — an exceptionally high tide caused by natural gravitational forces — and storm swell this winter caused the ocean to breach Highway 101 along the Living Shoreline’s stretch.
“It’s ironic that we had a rare surge and flooding during construction, as that’s what the project is intended to protect against,” Pete Milligan, project engineer for the city of Encinitas, said.
Milligan explained that the project’s coordinators will focus first on completing work in the sensitive dune areas with habitat constraints. There’s a chance that western snowy plovers, a threatened species, might attempt to nest in the dune areas in March, which would shut down construction.
To minimize disruption to the birds’ habitat as well as the construction plan, the aim is to finish the dune building as soon as possible. About 100 feet of dune construction remains.
A monitor from the U.S. Fish and Wildlife Service is on hand each day to ensure that the plovers are not being disturbed.
Milligan said he’s been told that about 60 to 70 plovers have been congregating in the southern part of Cardiff State Beach. To provide the plovers with space to forage, the dune habitat was intentionally built one-third at a time rather than all at once.
A potential California grunion run could also pose a problem should these unique fish choose to spawn on Cardiff State Beach, which would temporarily halt the project.
To allow construction to proceed with minimal interruption from road traffic, one southbound lane of Highway 101 will be closed from south of Restaurant Row to South Cardiff State Beach. The closure will remain in effect until the project finishes in April.
The bike lane and one southbound vehicle lane will remain open along the entire stretch of the construction site. The closure will not affect any existing street parking.
The San Elijo Conservancy recently planted the tops of the dunes along the northern part of the Living Shoreline with native plants like sand verbenas, beach evening primrose and Orcutt’s pincushion.
Sand for the project’s dunes came from the annual excavation of the San Elijo Lagoon inlet, a process intended to cleanse the lagoon of stagnant water and to maintain a healthy ecosystem.
At project completion, six lateral entryways, delineated by timber posts with rope handrails, will provide access through the 60-foot-wide dunes to the beach.
In addition, a pedestrian pathway will run parallel to Highway 101 and connect with the sidewalk at the southern end of the beach.
Grant funding from the California Ocean Protection Council financed the majority of the project, while SANDAG provided grant money for the pedestrian pathway. The city’s matching grant contributions have come in the form of employees’ labor.
The Cardiff Living Shoreline Project is a collaborative effort by California Ocean Protection Council, State Coastal Conservancy, California Coastal Conservancy, California State Parks, San Elijo Lagoon Conservancy, U.S. Fish and Wildlife Service, SANDAG, University of California Los Angeles and the city of Encinitas.