California's State Route 1 (better known as the Pacific Coast Highway) is an internationally renowned north-south arterial that draws millions of tourists annually and provides interregional, recreational, commuter and local travel through both urban and rural corridors.
But heavy rains over the past few years have caused landslides, the collapse of road sections along its edges and a weakening of the mountainsides above and below the road, which passes through many tourist meccas, including Monterey, Carmel and Big Sur.
Photo courtesy of Caltrans
Crews from Security Paving Corp. are engaged in drainage improvements and the construction of a fish passage along a section of the PCH in Los Angeles and Malibu from south of the Temescal Canyon to the Ventura County line and in Ventura County from the Los Angeles County line to Tonga Street.
Within the project limits, the roadway consists of four lanes.
"The existing concrete culvert at PCH and Coral Canyon Road currently blocks the movement of the self-sustaining southern steelhead trout population formerly residing in Solstice Creek," said Marc Bischoff, a public information officer with Caltrans District 7. "This prevents the trout from accessing spawning and rearing habitat in the creek upstream. The inability of the steelhead to move back and forth between the ocean and the creek subsequently resulted in the population becoming locally extinct.
"Recognizing the fact that the population of trout is in danger of extinction throughout all significant portions of its range [from Santa Barbara County south to the U.S.-Mexico border], the National Marine Fisheries Services in August 1997 declared this population an endangered species under the Endangered Species Act of 1973."
The culvert at Solstice Canyon Creek will be replaced by a bridge, allowing trout to swim upstream. Twelve other damaged/defective culverts were assessed and require repair and rehabilitation or replacement.
"The assessment was based on inspection reports provided by the culvert inspection coordinator," Bischoff said. "Damages to drainage culverts include joint separation, culver misalignment, concrete spall at reinforced concrete pipe joints, circumferential cracks and longitudinal cracks. Further deterioration to these drainage culverts is expected if they are not properly repaired and rehabilitated or replaced."
The work also involves removing debris or flushing sediment inside the pipe; repairing the joint seal of pipes; relining culvert barrels; and replacing damaged sections of pipe, entire sections of culverts and the culvert at Solstice Creek with a bridge.
"The replacement of the Solstice Creek culvert with a bridge will provide access for the steelhead trout to the habitat upstream of the culvert," Bischoff said.
"Various types of culvert deficiencies were discovered, including joint separation, misalignment, buckling, cracking of pipe barre and clogged sediment," Bischoff said. "Repairs and rehabilitation are needed to restore functionality and to prevent further damage of drainage culverts. The performance measures for this project are 13 culverts rehabilitated or replaced."
The project was designed by the Caltrans District 7 Design Division. Work began in May 2024 and is expected to be completed in the summer of 2029.
Photo courtesy of Caltrans
"The challenges we had in design included lane closure requirements on PCH and space constraints during construction as we had the ocean on one side and mountains on the other." Bischoff said. "We had to have multiple stages of construction to keep lanes open for motorists and cyclists. For the bridge construction, we had to build the new bridge around the existing culvert and demo the old culvert and excavate after. We had challenges in design for fish passage and had to adjust for high stream velocities."
The new infrastructure has an expected lifespan of 40 years, he said.
Two drainage systems are complete. The bridge at Solstice Creek is 50 percent complete. Thirteen more drainage systems remain to be completed.
The work sites are reasonably large, allowing equipment operators to move about freely and for materials to be stored on-site, Bischoff said. Access to the individual sites is fairly easy, so material and equipment can easily be brought in and out and construction workers can park nearby.
Crews are using large drill rigs and excavators, telehandlers, loaders and have a variety of pickup trucks to move crews from site to site, Bischoff said. CEG
