Climate, Soil, Environmental Concerns

Rivers are flooding, reservoirs are spilling over, levees are crumbling and the hillsides in Northern California are soaked and slipping.

In the land where a hillside home with a view sells for a premium -- or can be a bargain because of the precarious location -- ownership comes with the risk of losing it all to Mother Nature.

Blame it on La Nina, which cools the ocean's surface and exacerbates seasonal weather conditions or global warning, which can put more moisture in the air. Whatever the cause, wave after wave of rain storms have roared ashore from the Pacific Ocean and drenched the Golden State since the end of February.

Weather forecasters say April could end before a dry spell moves in and that gives hillsides plenty of time to weaken further and turn dreams into nightmares, putting an ugly spin on the phrase "a view to die for."

Homes built on hilltops, into hillsides and at the foot of hills are in danger of being tossed off the hill, slipping from their foundations, or buried by mudslides.

Conditions have worsened since landslide conditions first emerged earlier this year.

Gov. Arnold Schwarzenegger this week declared a state of emergency in seven counties (Amador, Calaveras, Fresno, Merced, San Joaquin, San Mateo -- just north of Silicon Valley -- and Stanislaus) as one of the top-five wet weather seasons raged on.

Another state-level state of emergency covering the state's fragile levee system has been in place since February and the governor is seeking a federal disaster declaration for financial help with the state's levee infrastructure.

Unfortunately, there is no real engineered protection from slides in slide-prone areas. Sooner or later, a given hillside will bow to nature and hurl chunks of earth. Not building where slides are likely to occur is the sanest protection, and in many cases, the only protection.

Cheap land and the cheap housing that can be built there often leads home buyers and builders to overlook a location's potential for danger.

Landslides are so potentially disastrous, insurance protection is rare and prohibitively expensive.

Mudslides or mud flows on the other hand, a highly liquefied form of landslide, is covered by flood insurance through the federal National Flood Insurance Program. Coverage, however, is usually limited to an amount that, in California, won't cover the loss of a mudslide totaled home.

That means residents in hilly or mountainous regions must remain vigilant about the potential for slides especially after a barrage of rain storms.

Initially, most slides aren't fast-moving and can be measured in inches or feet a day, giving you plenty of time to react. Of course, once the already creeping ground is saturated, the process accelerates.

Earthquakes can certainly trigger landslides, and the Big One now would be calamitous. However, slides are most commonly triggered when a combination of factors exist -- heavy rainfall, steep slopes, and loose or soft soil. The water can come from rainfall as it has in recent weeks, but broken pipes, intensive landscape watering, private septic system-laden land or misdirected run-off can also contribute to setting off a slide.

Where natural slopes have been disturbed by cutting away at the bottom of the slope, there is a higher chance of sliding in that area relative to the undisturbed hillsides. Landslides also can be man-made, caused by cutting roadways and building pads, or placing improperly engineered fill on steep slopes.

Home buyers and current owners who are concerned they are in a slide-prone area, may want to hire a professional to assess the potential for disaster. That could include a structural engineer to examine the home for signs of landslide activity and a soils engineer to inspect the earth.

Unfortunately, right now, finding an engineer who isn't busy will be tough.

Tell-tale signs the earth may be about to give way to gravity, include:

• Foundation cracking, doors and windows slightly rotated so they jam -- both on the downhill side -- are indications the land may be creeping.
• An ominous cracking of the ground in an arcuate, bowed or curved fashion -- an arch shaped crack rather than a linear crack.
• Hillside scalloping with a berm forming at the bottom of the slope is also an indication the hillside is succumbing to gravity.
• Hillsides with large areas without trees are likely bare because the trees slid down the hill. Hilly areas left barren of grasses, plants, shrubs and trees are particularly vulnerable to slides. Conversely areas dense with old trees indicates stability.
• New above-ground springs, excessive ponding, cracked soil or rocks, bulging slopes, new holes or bare spots on hillsides, tilted trees and muddy waters.

Only very early landslide prevention efforts are successful at holding back the earth. Once the earth starts to move you can protect yourself, but it's almost always too cost-prohibitive to stop the slide.

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