If Buying on a Hill, Hire a Geologist

Times Staff Writer

Landslides such as the one in Laguna Beach this month, which left two dozen homes uninhabitable, are rarely covered by insurance. That can leave homeowners with devastating losses.

The fact that living in a hillside home can be a risky proposition is often overlooked in the hunt for the best views.

“The problem is that when people see a piece of land, they are often so intent on the gorgeous view that they don’t look too carefully at whether this is a good site to build,” said Susanna Knight, administrator of the Oregon State Board of Geologist Examiners.

Fortunately, the risks are often easy to spot -- and sometimes easy to mitigate. Simple clues, such as crooked tree trunks or cracked driveways, can provide warning signs of a potential slide area, geologists say.


What’s more, state law requires sellers to provide notice of known risks, said Charles Real, supervising geologist at the California Geological Survey in Sacramento. Homes that are in so-called hazard zones are sold with a standard disclosure sheet notifying buyers of the risk of landslide, flood or “liquefaction,” a phenomenon that can magnify the effect of an earthquake.

But these disclosures are made at the end of the purchase transaction, when buyers often feel emotionally or economically tied to the deal. The disclosures are easily overlooked in the raft of documents that buyers sign at closing.

That’s one reason that experts such as Knight suggest that anyone buying or building a home on a hillside, or in the shadow of one, hire a geologist to conduct at least a cursory review of the site.

The reviews are not cheap, ranging from $500 to $1,000 for a standard examination, which does not include drilling, said Jeffrey R. Knott, assistant professor of geological sciences at Cal State Fullerton. But they can help determine whether the property can be stabilized economically or whether the cost would prove overwhelming.


“When you’re squeezing your finances to get into your dream home, spending $1,000 on a geologic inspection seems like a lot of money,” Knott acknowledged. “But it is my experience that many, if not the majority, of landslides ... were readily identifiable by a competent geologist before the sale.”

The fact that a home is in a hazard zone isn’t necessarily a signal of imminent disaster, geologists said. Most risks can be reduced or eliminated -- it’s merely a matter of cost, said Wolfgang Roth, a geotechnical engineer at URS Corp., an engineering firm in Los Angeles.

How much? That varies dramatically depending on the site and the nature of the risk, geologists say.

For earthquake and flood risks, homeowners can buy insurance. That coverage can sometimes double the cost of annual premiums, but spending an extra $1,000 annually may be a small price to pay to avoid a catastrophic loss.

Landslide insurance, however, is so rare and hard to find in high-risk areas that engineering solutions may be the only option.

Sometimes those solutions can be downright cheap -- the cost of a little preventive maintenance, Knott said. “People will tell you that they don’t know why their slope fell, but you go out there and find that the sprinkler pipe is broken and the sprinklers are on timers,” he said. “So every day, for 20 minutes, they shoot water down the hill and erode their hillside.”

Fixing the sprinklers and clearing blocked drainage ditches can go a long way to reducing slide risks, he added. If a property doesn’t have sufficient drainage, however, the homeowners may need to spend a few hundred -- or a few thousand -- dollars putting in drains and covering sensitive ground with deep-rooted plants, such as oleander and rosemary, he said.

“There are plants that act as a reinforcement to hold the soil particles together and can strengthen a hill slope,” Real said. “Plants also help reduce erosion.”


Installing wire netting or ground spikes and even covering hillsides with concrete are other cost-effective ways to stop erosion, Real said.

If the water problems are deep beneath the ground rather than on the surface, stabilizing the property might require drilling horizontal drain pipes into the soil. “It’s like sticking a straw into a sponge,” Roth said. “You try and take out some of the moisture before it does real damage.”

These drains usually cost $20 to $40 a foot, he said. And they can be quite lengthy. Roth has placed 500-foot drains in some properties along Pacific Coast Highway, he said, although more commonly the drains are 100 to 200 feet long. Most properties need more than one, so the cost can run well over $1,000.

Houses that are situated below a hill or at the crest of an unstable piece of land could require even more costly fixes, such as slide walls and retaining walls, geologists said. Slide walls are V-shaped retaining walls aimed at diverting sliding debris around a residence. Retaining walls also can be designed to hold large stretches of land in place to support a residence above them.

But, Roth said, “retaining walls can cost more than the house.”

For potential buyers, that sort of news may suggest walking away. For those who already own, the choices are more difficult and costly.

“There is always some engineering solution,” Knott said. “It’s strictly a matter of money.”



Kathy M. Kristof, author of “Investing 101" and “Taming the Tuition Tiger,” welcomes your comments and suggestions. Write to Personal Finance, Business Section, Los Angeles Times, 202 W. 1st St., Los Angeles, CA 90012, or e-mail For previous columns, visit