California Landslide Damage Sites

Map of Major California Landslide Damage Sites

Activity related to recent heavy rainfall (1997-98)

Listings include landslides that damaged residences or caused casualties. Road blockages are too numerous to include. This is not a complete list, but probably represents most major landslide problem areas reported since the beginning of the 1997-98 winter season. The information is from a variety of sources, including the California Office of Emergency Services, the U.S.G.S., F.E.M.A., California Department of Mines and Geology, and the press.

Select by choosing an area name from the drop-down list, or click an area on the map:

California LS Map

Blucher Valley landslide, Sonoma County 

County inspectors have red-tagged one house and yellow-tagged another on the Blucher Valley landslide, southwest of Sebastopol. This slide, located on very gentle (10-20 degrees) dip slopes of the Wilson Grove Fm., originally moved in 1983, and is moving again. Tom Spittler (CDMG) visited the site on 3/9. Spittler reported that fractures are present down the face of the slide.

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Canoga Park, Los Angeles County 

A rain soaked hillside collapsed in Canoga Park area of the San Fernando Valley forcing the evacuation of 5 homes and threatening several other residences further down the hill.

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Cloverdale 

A chronic earthflow is beginning to show renewed movement. The earthflow passes under existing viaduct on U.S. 101 between Cloverdale and Squaw Rock.

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Cuyama River, Santa Barbara County 

A portion of the bank of the Cuyama River collapsed along highway 166. 13 miles east of Santa Maria, taking along a tractor-trailer rig and a half dozen cars, including a California Highway Patrol cruiser. Two people were reported killed.

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Daly City, San Francisco County 

February 6, 1998, unstable slopes threaten seven homes in Avalon Canyon, Daly City.

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Hurricane Point, Monterey County 

Hurricane Point/State Highway 1/Palo Colorado Canyon (from California Office of Emergency Services (OES) Situation Report. Monterey County of 3/10/98). S.H. 1 is closed by a landslide at Hurricane Point (8 miles NW of Big Sur). "Walkover" pedestrian traffic is now permitted from 5;30 to 6:30 a.m. aod 7:00 to 8:00 p.m. The "walkover" is steep, muddy, and covers a distance of 1/2 mile. Caltrans engineers reexamined the slide last week after new cracks were detected in the remaining roadway and the hillside above the road. The estimated time for repair is 4 weeks. In the meantime, Caltrans plans to utilize the Old Coast Road as a detour around the Hurricane Point slide. The Big Sur landslide situation remains dynamic; it will depend on the weather and on progress made by Caltrans on S.H. 1 repairs.

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Klamath River, Siskiyou County 

Klamath River, State Highway 96, debris flow. This debris flow occurred on about February 14 in Siskiyou County, 12.7 highway miles north of the Humboldt County line . It blocked about 2/3 of the channel of the Klamath River, covered several hundred feet of S.H. 96, and had an estimated length of 1000-2000 ft.

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Laguna Beach, Orange County 

A wall of mud plowed down Laguna Beach Canyon Road about 12:30 am, killing two people and injuring 10. It damaged two houses and eight homes were evacuated.

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Laguna Nigel 

Laguna Niguel. A USGS geologist reported that a landslide occurred between 2:00 a.m. and 3:00 a.m. this morning, March 19, 1998, confirming television news reports of the same. No injuries or deaths resulted from the slide. The landslide occurred in an engineered slope that had shown signs of distress for the last 3 years. Cracks had been opening for a few days before the slide and houses at the head of the landslide were red tagged. Movement accelerated last night and several homes were evacuated. The toe of the landslide impacted condominiums and flattened about 5 or 6 of them. Two houses fell over the edge of the head scarp. Three others are hanging over the edge and could fall as soon as the nearly vertical scarp retreats. The houses were built in 1986. Local officials are making some effort to stabilize the slope, but details are unclear. No further information is available at this time.

Laguna Nigel: House #1 fallen over edge of the head scarp. Laguna Nigel: House #2 fallen over edge of the head scarp.

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Lahonda, San Mateo County 

A USGS geologist reported that the main slide has been moving continually since at least 2/11; rain late last week caused accelerated movement. Three houses at the head of the slide are red-tagged and five other houses are on or adjacent to it. The slide appears to be enlarging in the downslope direction. USGS employees have been mapping the landslide and trying to determine its relationship to another, smaller landslide downslope from it. San Mateo County drilled three wells in a road that crosses the slide and has been pumping the wells since 2/26. Trenches were also dug and lined with plastic to provide drainage. The county geologist plans to drill exploratory borings and has been seeking USGS input on boring locations.

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Las Lomas, Monterey County 

Flora Drive slide continues to move toward Las Lomas Drive. The toe has reached into the yards of three homes on Las Lomas Drive at the foot of Flora Drive. Seven homes on the west side of Las Lomas Drive may have to be evacuated if sewers or other utilities are disrupted. Monitoring and assessment of the slide continues.

Update 3/20/98 Little change as of 3/17/98 . The slide continues to move at a reduced rate but could accelerate if significant rainfall occurs next week. Houses on the slide are holding together, the two worst-damaged homes are in the middle of Flora Drive. Access and utility problems continue.

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Malibu, Los Angeles County 

On Februarv 8, 1998, an ocean-eroded cliff buckled causing one home to collapse and threatened two others.

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Morro, San Luis Obispo County 

Reactivated landslides from 1995 storms are now affecting 34 homes, with 7-8 damaged.

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Niles Canyon Debris Flow 

There are a few newly initiated debris flows and several others reported earlier show signs of recent activity.

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Oakland, Alameda County 

Oakland, Alameda County, seven homes have been red-tagged, an additional seven homes have been yellow tagged, and 11 others are being monitored for potential trouble.

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Orange, Orange County 

Accelerated movements are occurring on a reactivated landslide (from 1995) in the Anaheim Hills, part of the City of Orange. The Vista Summit Way landslide damaged 2-3 houses and may affect 3 city blocks.

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Orinda, Contra Costa County 

Orinda, Contra Costa County, three houses remained in precarious situations after a mudslide threw them off their foundations.

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Pacifica, San Mateo County 

Residents of seven homes evacuated on Esplanade Drive, Pacifica on February 22 as a result of sliding and erosion of the cliffs. In the last two weeks the 30 foot tall cliff has retreated 10 feet to the rear edge of the homes.

Update 3/20/98: Esplanade Sea-cliff Erosion, Pacifica—Cliff erosion, soil falls, and rock falls have slowed. There is still water seeping from the face. Material that is failing is mainly a fluvial deposit on top of a marine terrace deposit. Plans are progressing for seawall and other mitigative designs.

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Ventura County Pipeline 

A hillside gave way rupturing an oil pipeline sending 8000 gallons of crude oil flowing into the ocean and severing a natural gas pipeline that sparked a 100 foot flame.

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Rio Nido, Sonoma County 

Rio Nido, Sonoma County, 167 houses have been evacuated. Debris flows initiated on February 6 (10:35 p.m.) first failure, followed by a larger failure at 1:30 am on February 7 with destruction of 3 or 4 homes.

Updated 3/20/98: Following last Thursday's rain, a small debris flow (30 cubic yards according the Sonoma County Web page) occurred at Rio Nido. A monitoring station (E-1) appeared to register 1-2 inches of movement a few days afterward, however a USGS geologist indicated that the apparent movement was caused by the instrument wire being caught on a twig which deflected it out of line. The only real movement recorded since the instruments were installed occurred late in February at E-3, on the toe of the south chute. This movement slowed gradually to a stop. Landslide problems continue in nearby areas including the Fitch Mountain-Healdsberg area where two homes remained red tagged, and Goldridge where three homes were red tagged.

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San Bruno, San Mateo County 

Crestmore Boulevard, San Bruno The Crestmore landslide began to occur in manmade fill in 1997 in steep-sided, manmade fill on top of the Merced Fm. On February 12-13, 1998, it became an active, fully saturated debris flow. It now runs 600 feet long down the canyon and has impacted 2-3 homes on Madison Avenue. The volume is about 50,000 cubic yards. Planning is underway for remedial measures.

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San Leandro, Alameda County 

A massive landslide is threatening seven homes on Hillside Drive, including two that had to be moved off their foundations over the weekend (2/21-22) to save them from the encroaching wall of mud. Bill Cotton, geologist, determined that the slide was about 90 feet high by 200 feet wide.

Update 3/11/98: The San Leandro slide now has a volume of 65,000-70,000 cubic yards; it has moved a total of about 5-6 feet on a slope of 1 ½ to 1. The slide is a translatory failure in decomposed and highly sheared gabbro near the Hayward fault. The subdivision was built in the late 1970s and early 1980s. Two homes have been moved by the slide. The slide has now been mapped and inclinometers positioned. Remedial measures are being planned.

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Scott's Creek area, Santa Cruz County 

A debris flow occurred in this area and several old fills on existing roads have begun to crack and fail.

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Sebastopol, Sonoma County 

Sebastopol, Sonoma County, a landslide threatened three homes in a rural area two miles west of Sebastopol. The slide - which is roughly 1,000 feet long by 200 feet wide - knocked one of the homes off its foundation. A second home is sliding down a hill, and a third is heavily damaged.

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Shasta Lake, Shasta County 

Shasta Lake landslide, Interstate-5. This slide occurred in fill beneath the north-bound lanes of I-5 along the shore of Shasta Lake on about 11 February. The main slump heads outside the right guardrail; cracks have formed between the outside and inner northbound lanes. The outside lane has been closed to traffic for the past several days.

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Studio 

A landslide cascaded down a steep hillside on March 1 and destroyed a home. This landslide occurred more than five days after the rain stopped. It occurred in response to gradual infiltration of groundwater from rain that fell several days before.

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Sycamore, Santa Barbara County 

Tons of mud flowed down onto a home ripped it from its foundation and shoved it about 5 feet down the hill. The landslide began about 8:45 p.m. Monday (23 February). There were no reported injuries.

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Ukiah, Mendocino County 

A house in Ukiah is being affected by a rotational slide and has been red-tagged. There has been 12 feet of movement in 2 days. Area is within landslide mapping done by Sydnor and Bawcom for Mendocino county.

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Ventura County 

A hillside gave way rupturing an oil pipeline sending 8000 gallons of crude oil flowing into the ocean and severing a natural gas pipeline that sparked a 100 foot flame.

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West Lake, Los Angeles County 

On February 6, 1998, mud crashed into an apartment building in the Westlake area; more than 100 residents were evacuated.

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Little Whiskey Creek area, Sonoma County 

Two small landslide failures occurred on roads along Little Whiskey Creek, a tributary of the Russian River. No sediment had reached the watercourse.

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