Mt. Burdell stands above Novato, California
Much of the hummocky topography around the base of the mountain
has long been recognized as the result of large landslides.
|In 1996-97, the area shown below suffered mass movements that have damaged the homes identified by numbers. An 18 month investigation produced a geotechnical report that was released on Feb. 18. 1999. According to a March 19th story in the Marin Independent Journal on the report, the slide resulted from natural factors including heavy rains saturating the hilly area combined with the manmade aspects of excavating for homes and roads and the huge dirt berm built to screen the Buck Center from nearby residents of the affected Partridge Knolls subdivision. The combination of opening the toe of the landslide when excavation was done for residential development exacerbated by loading the top of the slide by placing the dirt berm at the top. The report concluded "The primary natural factors include: moderately steep hillside terrain; extremely weak serpentinite bedrock materials; high ground water levels and introduction of additional water into the slope by heavy and sustained winter storms (El Nino of 1997-98). The primary manmade factors include: excavation of earth materials at the toe of the landslide for residential subdivision development and road construction and loading of the slope at the head of the landslide by construction of a landscape berm on the Buck Center property. It appears that cutting at the toe of the slope was not sufficient to initiate the BC/PK landslide. Although this activity likely reduced the hillside stability, landsliding did not take place until the landscape berm was constructed. There was a direct correlation between the removal of the landscape berm and the reduction of landslide movement. At the present time, with the landscape berm removed and lower ground water levels, the landslide activity appears to have stopped."|
Images of the area and the slide
Examples of displacements