Stay or go? Communities are eyeing retreat from sea - Science
http://www.msnbc.msn.com/id/47660947/ns/technology_and_science-science/t/stay-or-go-communities-are-eyeing-retreat-sea/
updated 6/2/2012 9:17:33 PM ET
Science
Stay or go? Communities are eyeing a retreat from sea
Ocean encroachment is a growing issue; some California towns decide not
to fight it
By Alicia Chang and Jason Dearen
The Associated Press
LOS ANGELES â€" Years of ferocious storms have threatened to gnaw
away the western tip of a popular beachfront park two hours drive north
of Los Angeles. Instead of building a 500-foot-long wooden defense next
to the pier to tame the tide, the latest thinking is to flee.
Work is under way to gauge the toll of ripping up parking lots on the
highly eroded west end of Goleta Beach County Park and moving a scenic
bike path and buried utility lines inland away from lapping waves.
Up and down the California coast, some communities are deciding it's not
worth trying to wall off the encroaching ocean. Until recently, the
thought of bowing to nature was almost unheard of.
But after futile attempts to curb coastal erosion â€" a problem
expected to grow worse with rising seas fueled by global warming â€"
there is growing acknowledgment that the sea is relentless and any line
drawn in the sand is likely to eventually wash over.
"I like to think of it as getting out of the way gracefully," said David
Revell, a senior coastal scientist at ESA PWA, a San Francisco-based
environmental consulting firm involved in Goleta and other planned
retreat projects.
Global issue
he issue of whether to stay or flee is being confronted around the
globe. Places experimenting with retreat have adopted various
strategies. In Britain, for example, several sites along the Essex coast
have deliberately breached seawalls to create salt marshes, which act as
a natural barrier to flooding.
In the U.S., the starkest example can be found in Alaska, where entire
villages have been forced to move to higher ground or are thinking about
it in the face of melting sea ice. Hawaii's famous beaches are slowly
shrinking, and some scientists think it's a matter of time before the
state has to explore whether to move back development.
Several states along the Atlantic coast have adopted policies meant to
keep a distance from the ocean. They include no-build zones, setbacks or
rolling easements that allow development but with a caveat. As the sea
advances, homeowners promise not to build seawalls and must either shift
inland or let go.
The problem with seawalls
Over the past half-century, the weapon of choice against a shrinking
shoreline has been building a seawall or other defense. Roughly 10
percent of California's 1,100-mile coast is armored. In Southern
California, where development is sometimes built steps from the ocean, a
third of the shore is dotted with human-made barriers.
While such buffers may protect the base of cliffs, and the land and
property behind them, they often exacerbate the problem by scouring
beaches, making them narrower or even causing them to disappear.
This is one reason state coastal regulators in 2009 turned down a
proposal by Santa Barbara County to fortify an eroding section of Goleta
Beach park lashed by periodic storms. A rock wall was built as a
temporary stopgap, but a long-term solution was needed. After the state
rejected the construction of another hard structure, park officials,
working with environmentalists, came up with a Plan B: Move gas, water
and sewer lines out of the risk zone. Relocate a bike path to higher
ground. Demolish 150 parking spaces and allow the acre of asphalt to be
reclaimed by the beach.
Last month, the county Board of Supervisors gave the go-ahead for an
environmental review. Work could begin next year if the $4 million plan
passes other regulatory hurdles.
Push for relocation
Around California, relocation of coastal infrastructure and development
is being pushed by the Surfrider Foundation and other environmental
groups. But the efforts also are being driven by increased awareness of
climate change. Sea level has risen by 7 inches over the last century in
California. By 2050, it's projected to rise between 12 to 18 inches.
San Francisco is mulling a significant retreat on its western flank
where the scenic Great Highway is under assault from the Pacific.
Erosion has inched closer to the roadway each year, and the U.S. Army
Corps of Engineers continues girding segments with broken-up rock, a
costly temporary fix that has had limited success.
The San Francisco Planning and Urban Research Association favors mixing
retreat with coastal armoring. City, state and federal agencies are
considering the group's plan, which calls for moving segments of the
Great Highway inland and allowing sand dunes to reclaim some of the
paved-over space. The group also wants a temporary seawall to protect a
sewer tunnel that's part of a multibillion-dollar sewage and storm water
system expected to be affected by sea level rise while money is raised
to relocate it in about 50 years.
Local vs. large-scale approach
South of San Francisco, the beach town of Pacifica has been an early
adopter of planned retreat as it battles constant erosion. The city in
2002 purchased some homes that were at risk of falling into the sea and
demolished them.
This summer, the city of Ventura is pressing ahead with its $4.5 million
retreat. Last year, crews removed a disintegrating oceanfront bike path
at Surfer's Point, a popular surfing spot, and built a new one farther
inland. The beach was widened and cobblestone was put down.
Mark Gold, associate director at UCLA's Institute of the Environment and
Sustainability, commended local efforts but thinks a large-scale
approach is needed.
"It's definitely something that needs to be taken a lot more seriously,"
Gold said.
So far, most of the scaling back in California has occurred on public
land. It's a harder sell for private property owners to take the same
action unless beachfront homes are on the verge of being submerged. The
state, however, has a built-in retreat: People who want to build new
oceanside construction agree not to build a seawall if their homes
become threatened in the future.
Charles Lester, executive director of the California Coastal Commission,
said planned retreat is an attractive option in theory, but it's hard to
execute in densely populated coastlines where there may not be room to
move back. Still, he said it's a tool worth using where possible.
Just don't call it surrender.
"I don't think it's giving up. It's about making a smart, sustainable
decision," said Gary Griggs, who studies coastal erosion at University
of California, Santa Cruz.
More about ocean encroachment:
West Coast erosion teaches climate lesson
Hawaii's beaches are being eaten up
Jason Dearen reported from San Francisco.
© 2012 The Associated Press. All rights reserved.
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