Those maps are the Canoga Park, Calabasas, Newhall, Oat Mountain, and Van Nuys quadrangles. The schedule for the release of the remaining 24 maps has been refined. Twelve will be released in late June 1998. The remainder will be released in September 1998. For the complete schedule, see the index map below.
Mudslides are common in the rainy season through-out California where slopes are steep.
In arid southern California, frequent wildfires contribute to instability by removing vegetation that helps stabilize the soil. Debris avalanches move at speeds exceeding 10 mph. Debris flows move more slowly. Most fairly steep slopes have enough soil and loose rock for potential mudslides. To be safe, assume that all drainages in steep, hilly, or mountainous areas are capable of carrying debris flows, especially if relatively loose, sandy soils are present in the watershed.