Marina del Rey channel dredging provides multiple benefits
November 1, 2012
MARINA DEL REY, Calif. -- "In dredging, you don't usually see the results, it's just deeper water," Andrew Hunt, the Dutra Dredging Company project manager for the Marina del Rey entrance channel dredging project, said Oct. 15 as the project ended. Standing atop nearly 75,000 cubic yards of clean sand the project placed on Redondo Beach, he continued, "I'm standing here looking at a beach we built. If we were here a month ago, I'd be standing in the surf zone."
Being able to stand on a freshly-replenished beach was one of several critical and significantly beneficial results of a six-month, $11 million navigational maintenance dredging project at Marina del Rey, whose primary purpose was to restore safe navigational depths to one of the nation's busiest man-made marinas and home port to more than 5,000 recreational, commercial and first responder vessels.
"We've had problems over the years with sediment," Los Angeles County Supervisor Don Knabe said at the project's start in April about the boating conditions at Marina del Rey. "This project will improve safety for our first responders and other boaters and has the added benefit of providing material the Port of Long Beach needs. This is truly a win-win."
The dredging project removed nearly 800,000 cubic yards of sediment that had accumulated in the Marina del Rey entrance channel. That accumulation had reduced the depth and narrowed the width of the channel, making routine vessel transits more difficult and adding a safety risk for first responders like the Coast Guard, the Los Angeles County Sheriff Department and the county's Lifeguard Service which often must act under less than optimal sea conditions.
"We're doing what needs to be done to make the harbor safe," Knabe said at the time.
Knabe also said the project is an example of how coordination among several levels of government can resolve regional issues.
"We're saving over $85 million and eliminating 47,000 truck trips," Knabe said, referring to the financial and environmental impact if managers had been required to transport the dredged material to an authorized land disposal area.
Through extensive coordination with the Port of Long Beach, the U.S. Army Corps of Engineers and Los Angeles County hammered out an agreement to deliver about 476,000 cubic yards of material dredged from the Marina del Rey entrance channel to the port's middle harbor redevelopment project. The material, transported by barge, provides a foundation that will allow the port to transform two aging shipping terminals into one modern terminal, upgrading wharfs, water access and storage areas, expanding an on-dock rail, cutting air pollution, improving cargo-movement efficiency and environmental performance, and adding about 14,000 jobs in Southern California.
"The Middle Harbor Redevelopment Project is an opportunity for us to work with other agencies to provide a place for their dredged sediment," said Rick Cameron, Director of Environmental Planning at the Port of Long Beach. "We receive fill material that we need for our terminal modernization project, and agencies like the Los Angeles County Department of Beaches and Harbors find a place to ship sediment, like that from Marina del Rey. It's mutually beneficial and sustainable, dramatically reducing costs and eliminating the need to truck material to remote disposal sites inland."
John Kelly, deputy director for the Los Angeles County Department of Beaches and Harbors, agreed.
"If we had to transport that material to an appropriate landfill, it would have cost around $150 to $200 a cubic yard," he said at the conclusion of the project. "To transport it to the Port of Long Beach middle harbor project (by barge) cost $14.50 a cubic yard. That was a phenomenal cost saving. The Corps and Dutra worked up until the final minute of the final day to bring the last loads in until the Port of Long Beach said, 'Enough, we can't take any more.'"
Another benefit realized from the project was the delivery of material to two popular recreational areas south of the project, eventually placing about 150,000 cubic yards of material offshore at Dockweiler Beach and about 82,000 cubic yards offshore and 75,000 cubic yards on the beach at Redondo Beach.
"A major benefit of this project is repurposing that sand instead of just taking it off and disposing of it somewhere," Hunt said. "Is there a need, is there a use for that material? We delivered material to the Port of Long Beach for port development, and we placed sand on Redondo Beach during the height of active beach season. It's very satisfying."
Although Hunt previously had performed navigational dredging projects for the Corps, this was his first time conducting beach replenishment, so he sought renourishment expertise to assist with the planning.
"It happened just as they predicted," Hunt said. "They said, 'We're first going to have to build the foundation out there (in the water). For a couple weeks, it'll seem like nothing is happening.' Once we had the foundation built, we raced down the beach, and everybody's coming up every day saying, 'I can't believe how much sand is on the beach.'"
Performing heavy construction in a heavily trafficked entrance channel or on a popular Southern California beach can lead to numerous questions about the methods involved, the anticipated schedule, environmental impacts, impositions on residents and visitors and a host of other issues relating to the safety and comfort of those performing the work and those affected by it.
"All projects with a scope like this are challenging, and you're going to find complexities that present hurdles along the way," Kelly said. "And the ability of the team to partner and decide how to solve problems and move forward without delay, I think that is the key. We had that all along with this project: logistics during construction, dealing with mariners' issues, monitoring of the environment, positioning of the dredge here at Redondo Beach, sand placement. There was no catastrophic outcome from any of that, but if you look at it, those were the challenging moments you expect, and you need to have the relationships to move forward and solve them.
The opportunity to bring material from the harbor to the Port of Long Beach was enormous. Those are the kinds of opportunities that we in government have to recognize."
The onshore placement widened the beach by about 60 to 100 feet along a 1,300 segment south of the Redondo Beach pier. That Dutra pumped the material from a dredge moored offshore reduced the project's environmental impact. As with the Port of Long Beach project, had sand not been pumped from offshore, to place a similar amount would have required about 7,500 dump truck deliveries, an economic and environmental cost that could have been too much to accept.
"Being able to pump the sand from offshore and have everything be very low impact for the beach goers during the end of the beach season up until Labor Day was very good," Kelly said.
"We're very happy with the conclusion of the project," said Elaine Jeng, a civil engineer for the city of Redondo Beach, who worked on the project. "The amount of people that came together to bring the project to fruition was amazing. There were concerns from citizens about the length of project and some other issues. But once the project began, we didn't hear much until the end. If you look, we have a bigger, wider section of the beach."
"Constant communication among all parties was the key to moving forward," said Cesar Espinosa, a department facilities planner for the Department of Beaches and Harbors. "We learned there are different ways to renourish a beach. There were concerns about the methodology the contractor was using at the beginning, but in the end, it proved there are different ways of doing things."
"This project required everybody to be onboard all the time," said Jeffrey Cole, the Corps' project manager for Marina del Rey dredging. "We couldn't have been successful without the County's input, without the contractor, without the City of Redondo. The relationships started out strong and ended stronger."
Although the 2012 project for maintenance dredging and beneficial material reuse has come to an end, the effort to maintain navigational safety and to restore and protect California's shoreline continues.
"Harbor dredging and beach replenishment is not a project with a beginning and an end," Kelly said. "It's really a maintenance activity, and as soon as you finish one of these projects, you have to start thinking about your next dredging and your next beach replenishment."
That thinking will continue with surveys that determine more precisely the amount and location of sand placed at Redondo.
"Monitoring the width is crucial in understanding the natural processes of the beach here," Espinosa said. "So in the future, if we need to come back, we have a better idea of how to approach that."