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Encinitas exploring irrigation ordinance
CHRISTINA S. JOHNSON
ENCINITAS ---- To help prevent the kind of landslide
that killed a Leucadia woman last month, the city is
considering an ordinance that would limit irrigation on
Drier cliffs are stronger and lighter, and thus less
prone to collapse than over-watered ones, a geologist and
an engineer say. Solana Beach has an ordinance that limits
watering on all bluff-top properties, precisely to
increase public safety.
"We are not necessarily going to ask everyone to
dig up their yards" and dismantle their irrigation
systems, said Cathy Stone, a program manager for
She said the city is not exactly sure how to reduce the
amount of water sprinkled, hosed and piped on bluff-top
lawns without upsetting property owners.
That, she said, is the purpose of looking into an
"We will be talking about a comprehensive
bluff-erosion plan (this) week," she said.
Rebecca Kowalczyk, 30, was killed in a landslide Jan.
15 in Leucadia while sitting on the beach watching her
husband surf. Her death prompted the City Council to ask
city staff to investigate ways, such as limiting
irrigation, to prevent similar tragedies.
Encinitas has a 6.1-mile-long coastline, and its most
developed areas are on seemingly fragile sea cliffs. While
it is impossible to halt erosion, keeping cliffs from
becoming saturated with water is one way to slow the
frequency of bluff collapse.
To this effort, the city also is trying to rebuild
beaches with extra sand to help stabilize the cliffs
behind them. It also is considering building an artificial
offshore reef that would further protect the coast from
ocean waves and help retain sand.
Reducing irrigation ---- and thus ground water ---- is
not a new concept for staving off landslides and bluff
collapses, said Pat Abbott, a professor of geology at San
Diego State University. People have long suggested that
homeowners in San Diego County landscape with
drought-tolerant plants or switch to drip-watering
"Water cuts the strength (of the bluff) in half,
and it doubles its weight," said David Skelly, a
coastal engineer in Encinitas.
While San Diego County gets about 10 inches of rain a
year, sprinklers effectively drop 80 to 90 inches a year,
"This means we are aging the land at an eightfold
rate," Skelly said.
Still, rising sea levels are the No. 1 reason the
coastline is eroding and why halting erosion is nearly
impossible, scientists say.
In the past 18,000 years, the coastline has retreated
about 1 1/2 miles, while sea level has risen some 400
feet. Recent studies have suggested the sea level could
rise an additional 5 feet in the next century if the Earth
Not all bluffs in Encinitas are vulnerable to
over-watering. The effects of irrigation vary with local
The 200 block of Neptune Avenue, which is the first
street back from the sea along Leucadia, is less prone to
water damage than other areas because the cliffs there are
largely made of porous sandstone, geologists say. The
landslide that killed Kowalczyk occurred in that area.
Just four blocks away, the geology changes. By the 600
block of Neptune, Skelly said, "you are in an area
that is very susceptible to collapse." The walkway
down to Beacon's Beach is an old talus pile, debris from a
"The whole section of the coast is predisposed to
sliding," he said.
Just one leaky toilet in the 600 block of Neptune,
Skelly said, caused a failure of a retaining wall.
Farther up the coast, in the 800 block of Neptune,
there are a number of homes that are literally hanging off
the cliff's edges.
The Self-Realization Fellowship at Swami's in Encinitas
is one more area that has had to finesse nature to
survive. In the early '40s, the SRF building fell into the
sea because ground water from surrounding areas had
saturated the rugged cliffs. Today, its owners have wells
that keep the water table down, Skelly said.
Water greases up everything, Abbott said. It makes a
bluff both heavier and weaker. Water usually flows in
fissures in the ground or along junctures of distinct rock
layers. Too much water can destroy the bluff's structural
integrity by washing the cliff out from beneath itself.
"The city should pass an ordinance prohibiting
lawns and trees" that need watering, Abbott said.
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