CORONA DEL MAR — Heavy construction in Lower Buck Gully is nearly complete, with structures in place that will prevent further erosion on the hillsides along Hazel Drive and Evening Canyon Road.
Crews have placed five rock weirs designed to change the flow of water streaming toward the ocean, along with three drop structures that include a total of 15 steps that slow the flow of water.
"As water flows and drops down each step, it flows off at a slower velocity," said Robert Stein, a Newport Beach assistant city engineer. "The water crashes and releases energy, and once the energy is released, it slows down. The energy dissipates, which means less erosion."
Construction on the erosion project began in September, when crews cleared the canyon and built a road to the bottom that allowed heavy equipment to move into place. Crews then began to build the three metal cages that they filled with rocks. The first cage has four steps and drops six feet, the second cage drops another six feet and the last cage drops three feet.
The rock weirs were created with rocks hauled in from Corona, each one weighing an average of 500 pounds.
"Creating those was the hardest part of the project," Stein said. "Access was difficult, and they have a certain configuration and height that redirects the water where we want it to go."
Now, instead of stormwater flowing from Newport Coast and hitting the Hazel hillside, it will be directed and slowed and prevent further erosion.
"These slopes are getting steeper and steeper," Stein said. The homes, especially along Hazel, have been spared from a collapse of the hillside, but Stein and other city officials feared that without the project, they were in danger.
"It was a 'not yet' situation," he said.
In February or March, crews will begin replanting the area with sycamore trees and a hydroseed mix of native plants, Stein said. They also will capture non-native cowbirds, which will be released in their natural habitat.
"This will look like a natural canyon again after that," Stein said.
Plans for the project were in the works for more than a year. This summer, the California Coastal Commission granted approval of the project.