Editing Malibu, California (section)

===Mudslides===
One of the most problematic side effects of the fires that periodically rage through Malibu is the destruction of vegetation, which normally provides some degree of topographical stability to the loosely packed shale and sandstone hills during periods of heavy precipitation. Rainstorms following large wildfires can thus cause mudslides, in which water-saturated earth and rock moves quickly down mountainsides, or entire slices of mountainside abruptly detach and fall downward.

After the 1993 wildfire stripped the surrounding mountains of their earth-hugging [[chaparral]], torrential rainstorms in early 1994 caused a massive mudslide near Las Flores Canyon that closed down the Pacific Coast Highway for months. Thousands of tons of mud, rocks, and water rained down on the highway. The destruction to property and infrastructure was exacerbated by the road's narrowness at that point, with beachside houses abutting the highway with little or no frontage land as a buffer to the mudslide.<ref>{{cite web |url=http://www.colorado.edu/hazards/research/qr/qr107.html |title=Mudslides in Malibu, etc |publisher=Colorado.edu |access-date=November 3, 2007 |archive-url=https://web.archive.org/web/20070713111554/http://www.colorado.edu/hazards/research/qr/qr107.html |archive-date=July 13, 2007 |url-status=dead  }}</ref> Another large mudslide occurred on [[Malibu Canyon Road]], between the [[Pepperdine University]] campus and HRL Laboratories LLC, closing down Malibu Canyon for two months.<ref>[http://www.wrh.noaa.gov/sgx/document/weatherhistory.pdf Malibu Mudslides] {{Webarchive|url=https://web.archive.org/web/20160120153201/http://www.wrh.noaa.gov/sgx/document/weatherhistory.pdf |date=January 20, 2016 }} from noaa.gov</ref> Yet another behemoth slide occurred on [[Kanan Road/Kanan Dume Road|Kanan Dume Road]], about {{convert|1|mi|km|spell=in}} up the canyon from the Pacific Coast Highway. This closure lasted many months, with Kanan finally fixed by the California Department of Transportation (Cal-Trans)<ref>{{cite web |url=http://www.dot.ca.gov/ |title=Cal-Trans official web site |publisher=Dot.ca.gov |access-date=November 3, 2007 |archive-date=February 4, 2016 |archive-url=https://web.archive.org/web/20160204232255/http://dot.ca.gov/ |url-status=live }}</ref> over a year after the road collapsed.

Mudslides can occur at any time in Malibu, whether a recent fire or rainstorm has occurred or not. [[California State Route 1|Pacific Coast Highway]], [[Kanan Dume Road]], and [[Malibu Canyon Road]] (as well as many other local roads) have all been prone to many subsequent mudslide-related closures. During any period of prolonged or intense rain, Caltrans snowplows patrol most canyon roads in the area, clearing mud, rocks, and other debris from the roads. Such efforts keep most roads passable, but it is nevertheless typical for one or more of the major roads leading into and out of Malibu to be temporarily closed during the rainy season.