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Coastal Hazards
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You are El Nino Administrator. |
| Coastal Hazards |
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Item 1 17-MAR-1998 16:46 Lesley Ewing (lewing)
State-wide California has had over $500 million (estimated) in damages from this year's El Nino, as of hte end of February. Some of this was damage to inland areas and much of it has been from flooding and landslides (which are not isolated to the coast). There was a massive media blitz prior to this winter which warned everyone about the possibility of storms and storm damage and satallite imagery provided us with almost instantaneous tracing of changes to sea level elevation and temperature. Despite all this effort, we have already suffered huge losses and more may occur.
Could these losses have been lessened? What could have been done differently? Did the early warning help prevent even greater losses?
For new coastal construction built in the past 15 years, California has used to use the 1982/83 storms as the design standard. Is anyone aware of any damage to structures which were built in the past 10 years?
Finally, Oregon enacted a coastal law which prohibits the construction of shoreline protection for any structure built after the enactment of the Shoreline Protection Law. Does this seem like an effective method for dealing with extreme storm hazards? Would it also be effective for flood hazards?
I have heard of homes that have succombed to landslides, that appear to have been built to code and have also passed geology tests, yet development on hillsides above them or road building activities have changed the hydrology of the slope increasing the liklihood of slope failure in wet years. Do you know of any steps that are being taken to solve this problem or any economic figures that show how disastrous i?
Offsite impacts have been a serious problem this winter. I live in Berkeley, CA and there has been damage to several homes where the owners are claiming that a city storm drain or street improvement was the root cause of their problems. I know that for most new development projects, the developer is required by the local government to insure that there will be no net increase in either the volume or intensity of runoff from their site. I do not know if cities require the same analysis of their own work.
Jim Slosson and Robert Larson, two geologsits who work in southern California have estimated that, in California, "losses from slope/ground failure average approximately $200,000,000 per year in wet years like 1993, 1983, and 1978 and other years exceeding the rainfall threshold causing the greatest losses (possibly as high as $500,000,000 statewide for 1993). Losses are greatly reduced during drought years." (From Slosson and Larson, Lessons to be Learned from teh 1993 Southern California Landslides, printed inthe 36th Annual Association of Engineering Geologists Meeting, October 1993, San Antonio, Texas.) These figures do not separate out losses to properties built directly on a slide versus those built to code and with geology tests, etc. but some of these properties must be included in these damage estimates.
Staggering financial losses for CA! Thanks for your perspective and info, Lesley. Is the damage subsiding a little now or are there still new problems occurring?
Tina, I live in Petaluma, Ca. about 20 miles south of a small village called Rio Nido. Rio Nido is a series of canyons running at angles perpendicular to the Russian River. Since February there has been a problem in Canyon #3. Essentially the side of the canyon is in process of "letting go" and the mountain is sliding down. Unfortunately there were several homes that have been destroyed and about 140 people evacuated. The geologists are trying to give the people the answers as to WHEN or even IF they can ever return to their homes. Some homes are completely destroyed, many are damaged, some have lost home and LAND as the whole hill is continuing to move. There are no definate answers for the people...we just do not know how long the hill will continue to move or be unstable. Just for the record this was not an unstable area. There were huge trees growing there and residents had lived there for 20-30 years. It seems that the constant rains in Feb. did not allow the soil to drain or dry out so it became saturated and gave way. I think this area will have problems for a while. But who knows the powers of nature!
The huge media blitz early in the year definitely got some people and local governments to prepare. Are there any estimates yet on the value of that preparation? For mudslides, I am not sure what could be done. For the flooding, some of the cleaning of storm-drains must have had some impact. Are there any data yet on this?
On another note, I was in Washington D.C. last week and I was somewhat surprized by the impression of California and the El Nino. They see the constant disaster coverage on TV and generalize that to everywhere. Many people wondered how we survived. In reality, the damage, though large, is still relatively isolated compared to the 30 million people who live in the state. I also noted that the press coverage of the beach closings from overflowing sewer systems or stormwater runoff from the storm drains also has left many people with the impression that all California beaches are unsafe, now and forever. We know that after a few days this stuff moves away or degrades, but the press doesn't do that followup. I wonder if we will see a dip in tourists this summer because of this? Any data from 1982/3?
In answer to your questions, Tony, about the impressions that people have in California...one of the things we have long tried to combat is the notion around the country that California beaches are filthy and unswimmable. Much of this idea comes from the fact that California does in fact monitor its beaches and coastal waters fairly often and effectively, and issue beach closures when quality is not up to standards for e.coli and other pathogens. States that do not have these kinds of monitoring programs and do not post signs warning their publics about these dangers to public health APPEAR to have cleaner beaches. Witness the pfiesteria scare in North Carolina, when the state was caught quite behind in issuing public health warnings for river and estuarine systems. We've tried to make this clear to the national press, with varying degrees of success.
Then we get to that question in an economic frame about the cost of beach closures themselves, and also the costs of the PERCEPTION that the beaches are dirty. We have seen dips in tourism already in many years when we've had beach closures...but as far as I know, quantification efforts are pretty new.
This article is somewhat lengthy, but very illustrative of the range of beach hazards associated with El Nino in Southern California:
Los Angeles Times
Friday, March 27, 1998
El Niño Brings Lingering Peril to Beaches
Safety: Storms have washed away sand, creating rip currents that could make the swimming season one of the most dangerous in years.
By DAVID REYES, Times Staff Writer
El Niño storms that are battering the coast with record amounts
of rain and pounding surf have littered almost every beach in Southern California with tons of debris and are washing away sand and creating rip currents that could make this one of the most dangerous swimming seasons in years. “I’ve been lifeguarding for nearly 30 years,” said San Clemente state lifeguard Mike Brousard, 47, “and this is the worst water danger I’ve seen.”
Storms have sent mountains of debris down from rivers and streams. Two uprooted 60-foot eucalyptus trees made their way into the surf at Trestles, the famed surfing break in northern San Diego County. Car parts are scattered along the beach in Ventura. Kitchen appliances and rattlesnakes are washing up on Los Angeles County shores.
Worse, the season’s huge waves have washed away beach sand, leaving bare rock in some places and holes just offshore where rip currents abound. Already, two swimmers have died in accidents. In San Diego, Lifeguard Chief B. Chris Brewster summed up the potentially deadly combination of warm water and roiling rip currents: “There’s no question in my mind that this spring, rescues will be among the highest in our history. No question.” Last year, there were 52,000 ocean rescues and 50 drownings in California, figures considered low, given there were 116 million beach visitors in 1997. Of the deaths, only eight occurred while lifeguards were on duty.
The two drownings so far this year have already shown the lethal impact of El Niño-powered surf and rip currents. On Feb. 14, Christopher Fankhouser, a 27-year-old Utah college student, died after being trapped in an offshore hole while swimming at Calafia Beach County Park, the south Orange County beach that Brousard patrols. In mid-March, Paul Korber, a 46-year-old Ventura Harbor patrol officer, was killed while attempting to rescue three people caught in a rip current at Ventura’s South Jetty Beach.
“We’re looking at a hellish spring down here because of the inshore holes and the channelization that’s going to cause the rip currents,” said Los Angeles County Lifeguard Lt. Jon Moryl. The strong swells of winter storms traditionally raise havoc along the coast by dredging the sand. But this year’s storms have hit California with an unusual vengeance. So much beach sand has been washed away that lifeguards have been unable to answer some emergency calls because they can’t maneuver their rescue vehicles in the narrow space left between surf and sea walls. Adding to the peril, storm drains and pipes that empty into the ocean cause a scouring action that creates holes where swimmers can get caught in rips. San Diego’s Mission Beach, near an amusement area, is one stretch where limited access poses a problem for lifeguard vehicles.
“Essentially, we’re forced to go up on a street with our lights and sirens, and for lifeguards, that’s dangerous because we lose sight of the swimmer,” Brewster said. Ocean water temperatures that usually dip into the 50-degree range this time of year have instead been considerably warmer. Pleasant water temperature is expected to attract even more swimmers this summer.
“We really think we’re going to get 70-degree water this spring,” Brousard said, “and if we get some warm weather, we’ll probably have lots of people going to the beach and it definitely is going to be a lot of trouble.”
There has already been trouble.
Fankhouser, the Utah student, waded into the water and immediately got trapped in a hole gouged out by the storm-tossed surf.
“He was facing [toward] shore, and the two witnesses who saw him said he did make a call for help,” San Clemente state lifeguard Steve Long said. “Those two friends attempted to wade out to help, but they were fully clothed. He was in deeper water, and [then] a wave washed over him. That’s pretty much it. They couldn’t see him after that.”
The victim’s body washed ashore a day later. In Ventura, Korber dived from a Harbor Patrol boat to try and save a mother and her two children who were caught in a powerful rip current.
Korber “was apparently injured during the rescue,” said Harbor Officer Merv Larson. “The lifeguards managed to grab the victims and take them to the boat safely and when they turned around he had disappeared under the water.” Bouncing along the San Clemente beach in his pickup, Brousard complained profusely about the El Niño year. “The sand has gotten so soft here I’ve got to watch it because we’ve been getting stuck,” he said, deftly gunning the truck over a rise. “We’ve got trees in the surf line, trash, and lobster cages everywhere. With this year’s heavy rains and storms, each day you pull out here, it’s another surprise.” In Los Angeles County, officials this season have built a long sand berm on parts of the coastline to help hold back the surf and safeguard property.
Preparations for spring break crowds include pulling lifeguard towers out from behind the protective berm and putting them in more prominent positions. But moving the towers closer to the surf could make them vulnerable to late-season storms. “This year, it’s going to be quite a balancing act,” Moryl said. “We’re going to pull some towers out from behind the berm but keep a real close eye on them. Because if another El Niño storm hits, we don’t want to lose a $20,000 tower.” Los Angeles County tractors are hauling away the debris that storms have washed onto the beaches from rivers and streams, said Wayne Schumaker, chief of facilities and property maintenance for the county Department of Beaches and Harbors. “We have crews working seven days a week, and we’ve found anything and everything on the beaches,” Schumaker said. “We’ve found couches, a refrigerator, sinks, beams from houses that collapsed in Malibu, even rattlesnakes.” The snakes get washed out to sea and then float back on the tides.
“Our work crews see them when they pick up wood; [the snakes] usually hide under the wood. You hear the rattle,” Schumaker said. “But we call Animal Control, and they come out and remove them.”
No workers have been bitten.
Since Dec. 1, Los Angeles County maintenance workers have collected more than 2,000 tons of debris from 31 miles of county beaches. When the season is over, officials expect more than 4,000 tons to have been removed, compared to an average year of 2,500 to 3,000 tons per year, Schumaker said.
Smaller beach cities have chosen to clean what they can. With small municipal budgets, beach cleanup can be difficult. Some coastal cities are waiting for El Niño to make its exit, which could be as early as next month, before ordering cleanup tractors on the beach.
For Brousard, dealing with a beach full of litter ranks low among his concerns. Brousard’s face turned grim when he thought about Fankhouser’s drowning. “That was the ugliest day of winter,” he said.
It is amazing that an adult actually drowned while wading in the water. That is an indication of how deceptive things are about the danger, even in closer to shore.
Phyllis--Thanks for sharing that article. Does anyone have a personal experience of dealing with this year's beach hazards?
Santa Monica Bay is one of the areas which has had beach closures this year. Many of the homes in the mountians and adjacent to the Bay are on septic systems or leach lines. As a routine matter, Los Angeles County closes the beaches after an intense rain to let the flood waters mix with the salt water. I hope it does not affect tourism to California's beaches; but, on a sunny day, I wouldn't mind having a bit more room for my towel. It is not likely that people will change their vacation plans, and many of our beach users are locals already.
El Nino did affect the winter tourist business. I heard ont he radio that tourism was down by 15%, but do not know if the number is correct.
Finally, there was a lot of good preparation for the winter -- cleaning gutters, emptying debris basins, clearing stream and river channels. I have not seen any estimates about what might have happenend if we have not planned early. That would be great lesson for the future; anyone looking for a thesis topic?. I am sure we prevented many millions of dollars in damage by acting prudently early in the rainy season.
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