Amid resident complaints that San Clemente beaches are losing sand and gaining piles of kelp, city officials decided Tuesday to mostly let Mother Nature run its course.
In adopting a package of measures to deal with sand erosion and bothersome beach cobble, kelp and other shoreline issues, San Clemente may have become one of the nation's first coastal cities with an overarching policy on beach ecology, officials said.
The goal of Tuesday's measures is to preserve the beach not only for recreation, but also as a habitat and ecological resource.
The city's hand in some ways may have been forced. Sand erosion from San Clemente beaches has been drastic over the past decade, and the city has been flooded with complaints about the mounds of beach cobble left behind. Some of the problem may be solved by an Army Corps of Engineers beach replenishment project set to begin soon, but it won't address some city beaches and may take years to complete, depending on federal funding.
Erosion and Cobble
Sand erosion is a natural process. Rough winter waves crash on the shore and wash back into the ocean with a strong current, dragging some sand out to sea, according to oceanographic research cited by staffers. In summer, the waves are gentler and deposit more sand than they remove.
The problem with San Clemente beaches is that spring tides in recent years haven't offset the amount of sand swallowed by winter storms, leaving the lower strata of pebble- to fist-sized stone cobble exposed.
"We're not seeing the same deposits of sand in the summer," said Beaches, Parks and Recreation Director Sharon Heider. "The cobble is a naturally occurring part of the strata that makes up part of the beach. We looked into whether we should be removing cobble. Recommendations are that we should leave it alone. It creates a stabilizing layer between bedrock and sand."
Heider said many residents assume the cobble is washed in with the storm, and become frustrated the city won't remove it. But removing it could have adverse consequences.
"It's a relatively delicate [ecosystem], and we can really alter it if we're not careful," said Beaches, Parks and Rec Maintenance Manager Dennis Reed.
Marine Safety Chief Bill Humphreys also warned against removing cobble.
"First, you're going to remove a ton of sand at the same time," he said. "Removing any material from the beach is the opposite of what we want."
Bill Hart of the city's Coastal Advisory Commission agreed.
"We've been losing sand since 1983," he said. "It's the result of systems we don't understand. The near-shore environment is a chaotic system. It's chaotic in the same way that a weather system is a chaotic system. No two events are the same."
The city will continue pushing sand into berms during the winter to spread during the summer, however. Reed said December brought an unprecedented amount of fine white sand to all San Clemente beaches except North Beach, which the city attempted to salvage with backhoes, but storms and swell have washed most of it away.
The City Council also voted to limit kelp removal to the summer months, recognizing its vital role in the beach ecosystem.
Heider said kelp "wracks" that wash up in piles help hold sand in place. Also, as kelp breaks down, it absorbs into the beach soil, nourishing insects and arthropods upon which shore birds feed.
Although kelp flies, which consume the kelp wracks, can annoy beachgoers, they don't present a health risk. They don't bite or go after human food, Heider said.
"If you want a pristine environment, go to the mall, not the beach," Hart said.
Although the kelp removal program is limited to summer months, the city manager with have the authority to do isolated removals at any time if the amount of kelp that washes up is overwhelming.
Southern California Edison recently completed its Wheeler North Reef off the coast of San Onofre State Beach, but city staffers said they hadn't seen more kelp wash up than in the past. But if that happens, Edison is obligated to pay for removal.
Other Beach Ecology Issues
Another area for concern along San Clemente Beaches is maintaining native plants in the dune areas. This is a minor issue in San Clemente because only a few small dunes have vegetation, Heider said. The railroad tracks cut a swath through the part of the coast that would have been dune land.
Also, the city adopted a comprehensive maintenance program for beach play and sports equipment.
The council also approved a public outreach program and a pilot ecology tour of the beach to explain to residents and visitors the important role of kelp, cobble and other components.