Mon May 2, 2011
Softening the Blow of Coastal Erosion
By John C. Cannon
Monterey, CA – Brad Damitz stands on Wharf Number two in Monterey. He's gazing at the wide sandy beach that arcs north toward Moss Landing. As an environmental policy specialist for the Monterey Bay National Marine Sanctuary, he knows that each crashing wave is slowly eroding that beach. Scientists estimate that the coast is receding by 6 to 8 feet a year in some spots, especially during the harsh winter storms of El Nino years.
In the past few decades, the most obvious solution to erosion has been coastal armoring. That often means constructing a seawall around a threatened building. But that has consequences. Over time, the edge of the ocean can creep up to the wall, and Damitz says that can leave the beach unusable. "Usually you can walk along this entire stretch of coastline, 22 miles or whatever it is, along the beach and not be blocked," Damitz says. "But as more coastal armoring structures are put in place, you have areas where the access is blocked off."
So the National Marine Sanctuary created the Southern Monterey Bay Coastal Erosion Workgroup to bring together scientists, city planners, community members and experts like Damitz. "The effort that we're working on now is to try and study the coastal processes, learn more about erosion rates and where the sand is coming from and where it's going." Damitz says their goal is to develop a broad-reaching plan to protect buildings and Monterey Bay's wide beaches as much as possible before they're threatened.
So the group went in search of other solutions. Workgroup member Kim Cole is a principal planner for the City of Monterey. She works on strategies to deal with erosion. "Our preliminary study gave us a range of alternatives," Cole says. "I think there was something like 25 different things that could be employed or could be used to help stop coastal erosion."
One would use native plants to anchor the beach's sand and maintain the habitat. A promising alternative that rose to the top is called beach nourishment that is, replacing some of the sand that the sea swallows up. For example, when a construction project involves a lot of digging and sand removal, the workgroup looks to relocate that sand elsewhere on the beach. But even this is not a permanent solution. "Maybe that's enough protection over a 5-year timeframe, giving us a little breathing room," Cole cautions.
That breathing room opens the door for researchers to explore the reasons behind erosion. But in the end, Damitz says the approach that will likely have the most traction is "managed retreat." He describes that approach as "Moving out of the way of the ocean as it causes a threat. It's anticipating when the erosion is going to hit and having plans for removal of certain portions of development as erosion occurs."
So while they can't fight back the ocean, Damitz and his colleagues hope to stay at least a step ahead.