GreenGranny

Green Granny's Travels Part 2 : Landslides, A Threat With A Human Twist

As we travel south on the 101 freeway after departing Santa Barbara, we soon come to the small community of La Conchita, built along a narrow strip of land between ocean beaches and the hills.  It’s the sort of place of which many people would say, if only I could live here!   

When approaching La Conchita from the opposite direction, you can see the pile of earth that buried homes, with white crosses placed above where people were crushed to death.  That sight always sends chills down my spine, particularly knowing that a mother and her three young children were in one of those homes. The people of this community will never forget what happened there in the early afternoon of January 10, 2005.

It was California’s wet season, and the rains were welcomed.  Sometimes when rains come to this arid land, they come in a deluge.  Such was the case on that fateful day--about four inches had fallen in the area.    A landslide had occurred there in 1995, destroying some homes but taking no lives.  On this rainy day in 2005, some earth that moved during the 1995 landslide moved again, sliding on a deep vein of soil wet from water that had percolated far below the upper dryer layers.   The dry top layer smashed into the town with terrible force, crushing everything in its path.

In 20 seconds, 36 homes were destroyed or seriously damaged, and 10 people were dead.    In this close-knit community, everyone was a friend of the deceased. For the human toll, go to www.opl.ucsb.edu/grace/lc/index.html.

The area where La Conchita now stands was first settled by railroad workers.  In 1924 it became a subdivision with about 200 lots in a strip of land just 800 feet wide, beneath bluffs 600 feet high.  The land topping the bluffs was agricultural and became an avocado grove requiring extensive irrigation. Those trees are visible in the photograph.  After the 1995 landslide, community residents faulted over-irrigation of the groves above them as a cause of the slide, but lost a lawsuit to restrict this irrigation. 

The United States Geological Survey (USGS) did a study of the area after the deadly slide (http://pubs.usgs.gov/of/2005/1067).  This particular area has witnessed many pre-historic landslides.  The report indicated the 2005 slide was a re-mobilization of material from the 1995 slide.  A photograph of the slope in 2004 showed heavy vegetation on the soil that was to collapse on the town a year later—a telltale sign of the drainage pattern that would become catastrophic. 

Who is to blame for the La Conchita landslide?  Was it the people who built homes under the bluff, the county who issued building permits, the agricultural land use permitted up to the bluff’s edge, or the legal system that thwarted mitigation attempts after the 1995 slide?

Why didn’t the people move away after the 1995 slide?  Probably some did, but others would not be able to afford to live elsewhere after their property values fell. People loved where they lived.  They probably felt another landslide would be similar, in causing some destruction but not killing people, and accepted that risk.  The deep intrusion into the town by the 2005 debris flow was probably never imagined.

California soil is notoriously unstable.  Buildings are not built with basements there for a reason.  Two natural phenomena common to California, earthquakes and infrequent heavy rainfall, can mobilize the soil, particularly on hillsides.  (Another factor can be wildfires that kill vegetation that helps hold soil in place.) 

You can look at USGS soil-slip susceptibility maps of California.  I was relieved to see that the hills around Santa Barbara are mostly of low to moderate susceptibility.  Further to the south and east, susceptibility ratings of “high” are typical of hilly terrain.  Apparently Orange County has been plagued by soil movements damaging homes and infrastructure in many areas.  Once development has occurred on unsuitable terrain, there are no affordable fixes.

I’ve learned that landslides are likely immediately after heavy rains, and that the risk continues to be elevated for months afterward.  There is no way to accurately predict when or how far a landslide will travel before the fact.  Some say all of La Conchita remains at risk. 

After what I’ve learned about southern California, I know that the entire region is at risk— from wildfires, landslides, and earthquakes, not to mention air and water pollution.  Yet the climate, natural beauty, and booming economy will continue to bring more people and more development to this fragile land.

California is like the canary in the mineshaft.  It is no surprise that people there have supported environmental legislation so strongly.  This is a wakeup call to the rest of the nation.

Green Granny's Travels Part 1 : Living With Wildfires

The time has come for me and my husband to leave our trailer and beautiful Santa Barbara to return home for another Iowa springtime. I suppose you could call us “snowbirds” – the human variety that flees northern winters for sunny climes.  Fellow traveling Seniors, it is time to put your road trips to good use.  What those trips may do to our overall carbon footprint, and whether we should be making those trips at all, is a story for another day.  The objective today is to show we can learn an enormous amount about our environment as we travel, particularly if we are lucky enough to travel with a laptop and can access the Internet for information while at motels or hotels along the route.
    

As we prepare to leave, I look up into the hills clearly visible from the front yard, some of them rising to 4,000 feet above sea level.  Seventeen years ago my relatives watched a fire burning in those hills from the same spot where I stand.  The Painted Cave Fire of June 1990 developed into one of California’s most devastating fires.  As they stood watching that fire, wondering whether to flee, the fire burned 4,900 acres to within a mile of their home, destroying or damaging 641 structures.
 

By the time most people attempted to get out of town, the roads were gridlocked.  To the east of Turnpike Road, the fire jumped across Interstate 101 while it was filled with panicked people in stopped vehicles, to destroy apartment buildings on the south side. It looked as if it might burn through to the harbor. And then, the wind changed.
 

We have known for some time that fire suppression practices by people interrupted the natural burning pattern that had existed for millennia.  When an area is prevented from burning for too many years, it burns hotter and grows larger.  Even the controlled burns now done routinely may not fully duplicate nature’s former patterns.  Meanwhile, there are building and landscaping techniques that minimize the chance of a home being lost in a wildfire.  The landscape plantings of homes in the photo above are beautiful, but they are too thick and close to buildings for fire safety.  Many homes still have cedar shingle roofs.

You can find much written about the Painted Cave Fire by searching on the name.  The same holds for other major fires like the Paradise and Cedar Fires that ravaged San Diego County in October of 2003.
 

For general information on wildfires go to the National Interagency Fire Center (www.nifc.gov/stats/index.html).  It was there I learned that total acres burned in wildfires in the entire USA each year occasionally topped 5 million acres throughout the last 47 years of records.  But, the first year it topped 8 million acres was in 2004.  In 2005 it was almost 9 million acres and in 2006 it was almost 10 million.
   

During the 2006 fire season, Canada sent over 200 firefighters and Australia and New Zealand sent over 100, to help the United States.  Later in the season, around the end of 2006 and the beginning of 2007, the United States sent firefighters to help both Canada and Australia with wildfires.

Even though we think of wildfire as being a characteristic of California and the West, the NIFC historical fire list shows that any area in any state can burn under the right conditions, and often has.  This continues today:  On March 9, 2007, there were seven large fires--Florida (2), Oklahoma (3), Texas (1), and Virginia (1).  Yet this fire activity is low: the National Preparedness Level for that day is only a 1 on a scale of 1-5, with 5 being the greatest threat.

If you are traveling into an area with an active fire, or hear about a fire near places and people you love, it can be almost impossible to tell where the fire is from TV news reports.  You may be able to do much better by looking at http://activefiremaps.fs.fed.us.

Two satellites carry Moderate Resolution Imaging Spectroradiometer (MODIS) instruments that give startling and accurate visualization of fire areas around the globe. Other satellite photography helps.  For a particularly dramatic photo from space of Southern California during the October 2003 fires, take a look at Treebeard’s web page.

The amazing thing is that wildfires are so common and the information about them so remarkable, yet many people remain unaware and unprepared.  People keep building homes in scenic canyons with narrow winding roads that provide few escape routes and poor access by fire equipment.  Many who understand the risk are unwilling to take the necessary steps to alter the landscape around their homes. 

Wildfire is a natural element present to some degree in every ecosystem.  It is but one of many types of events (such as landslides, flooding, and tidal waves) that people tend to ignore until it happens.  If you frequent areas with a high prevalence of wildfires, it is wise to utilize the wealth of information at your fingertips.  Then when you look at a scenic view, you will see with knowing eyes what has happened there, and what will happen there again some day.