During the winter rainy season, the Los Angeles Basin is periodically subject to floods causing substantial property damage. Such damage is intensified by debris flows in foothill areas where vegetation has been destroyed by major brush fires. In such cases, storm water comes down off the hills carrying soil, rocks, trees or brush. The Los Angeles County Department of Public Works offers these tips for homeowners:
Never underrate the power of debris flows.
Try to direct debris flows away from improvements using material such as sandbags, sand or lumber.
Avoid trying to confine the flow more than is absolutely required. Always use protection to deflect debris, not to dam or stop it. Make sure to clear a path for the debris.
Use your house or building as a deflector if necessary.
Debris will often enter a building through windows. Board them up during a flow.
Protect your most valuable property first--your home. Then consider what time and money are available to protect other less valuable objects, such as swimming pools or plantings. Be prepared to sacrifice the use of portions of your property to achieve good protection.
Be prepared to personally observe and maintain your installations during storm periods because in many cases a minor correction will prevent major failure. But do not take unnecessary risks.