Novato: an interesting landslide triggered by heavy rainfall in California
Last week, the latest in a long series of large storms struck California, triggering another round of flooding and landslides. One particularly interesting slope failure occurred at Novato in Marin County. The San Francisco Chronicle has a nice image of the aftermath:-
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A Tweet by Sarah Klieves, a senior producer for NBC Bay Area, provides the best perspective though:-
Our @nbcbayarea SkyRanger flew over a landslide that crumpled a section of Redwood Blvd near Olompali State Historic Park. This is the only public road into the park, so rangers say it will be closed for awhile. pic.twitter.com/saQqDMff9d
— Sarah Klieves (@sarah_klieves) March 24, 2023
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This is a view from that video, showing the landslide:-
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The location of the landslide appears to be [38.1444, -122.5652]:-
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Interestingly, Redwood Boulevard, which is the road damaged by the landslide, was constructed in 2015. A Google Earth image from March that year shows that the slope at the site of the landslide was cut and reprofiled, and that drains were installed:-
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It is interesting that at this site the slope is a little steeper than in the adjacent areas, which presumably is the reason for the additional works, including the drains. That failure is a classic slump. Fortunately the toe has not extended to the main highway, and the limited mobility of the debris has meant that this road is unaffected. However, the landslide has caused disruption to a watermain and to a gas pipeline.