Are flooding and mudslides covered by most common homeowners insurance policies?
No. Standard homeowners insurance covers rain and wind damage but not property ruined by flooding, landslides or mud. The rule of thumb is that if the damage is caused by falling rain, it's covered; if it's caused by rising water, it's not.
Flood insurance is available but takes 30 days to activate and costs $300 to $600 a year, according to the Insurance Information Network of California.
Although no carrier protects against landslides, flood insurance may cover minor mud damage, said Pete Moraga, a spokesman for the network.
What's the difference?
"If it sticks to a shovel, it's a slide," he said. "If it doesn't, it's a mudflow."
What should one do if a tree is about to fall or there is rising water near the house?
Safety first is the rule, experts said. Homes can be fixed. Have a family evacuation plan mapped out, and if your house appears to be in imminent danger, get out. If there is time, check to see if a clogged storm drain is flooding the neighborhood. If so, call the city to get it cleared. Don't clear it yourself.
Why do some hillside homes fail while others do not?
Many factors come into play, but a home's stability essentially comes down to two things: geology and water, said Randy Jibson, a landslide expert at the U.S. Geological Survey. Homes built on weaker materials, such as clay, are more prone to slides, he said, while those built on rock are more stable.
There may be an ancient landslide that wasn't detected during the home's grading, he said. Problems occur when these slopes become so saturated that built-up pressure causes failure, Jibson said.
The steepness of a hillside also is an important factor. Riskiest locations include slopes of 26 degrees or steeper and homes near the foot of a steep slope or "benched" into a steep slope, according to the Southern California Area Mapping Project. Mudslides can move at avalanche speed, about 40 feet per second (27 mph). On gentler hills, slippage can be as slow as 1 foot per second.
The highest risk occurs when rain falls at the rate of more than 0.2 of an inch an hour for more than three continuous hours on a slope that has already received at least 10 inches of rainfall for the season.
What are the dangers for flatland homes?
Falling trees, wind damage and water damage are all possible, said Candysse Miller, executive director of the insurance network. Make sure rain gutters are clear so that water flows in the desired direction. If you don't have gutters, install them to prevent water flowing down the side of your house near the foundation, where it can cause rot and mold, she said. Swimming pools should be lowered at least 3 inches to prevent flooding.
What can I do to prevent rain damage?
Patch roof leaks, remove branches overhanging cars and homes, clean out drains and lower the water level in pools. Many claims are made by homeowners whose houses have sustained water damage from overflowing pools.
Sandbags can be helpful, but make sure to divert water away from the house. In areas prone to flooding, homeowners should consider flood insurance.
Finally, make an inventory of property for insurance purposes. This can be done with a video or still camera, or a written list.
Why does Southern California have so many potholes?
Most roads are made of asphalt. Asphalt is considered a good road material because its flexibility allows it to absorb the region's heavy traffic, but it tends to crack over time. During heavy rain, water seeps through those cracks to the road base of crushed rocks. When the base erodes, the asphalt can collapse, creating a pothole.