USGS

Potential San Francisco Bay Landslides During El Niño


INTRODUCTION

FLY-BYS, PHOTOS, & ANIMATIONS

MAPS

'82 DAMAGES

SUGGESTED READING

Suggested Reading for Landslide/Debris Flow Hazards of the Greater San Francisco Bay Region

All publications listed here are available at the U. S. Geological Survey Library, Building 15, 345 Middlefield Rd., Menlo Park, CA 94025. Unless marked out of print USGS publications are available from the USGS Publications Warehouse. California Division of Mines and Geology publications are available from CDMG, 185 Berry St., Suite 210, San Francisco, CA 94107 Tel: 415-904-7707.


GeneralUpArrow

Ellen, S. D. and Wieczorek, G. F., eds., 1988, Landslides, floods, and marine effects of the storm of January 3-5, 1982, in the San Francisco Bay region. U. S. Geological Survey Professional Paper 1434: 310 p.

The catastrophic rainstorm in central California on January 3-5, 1982, dropped as much as half the mean annual precipitation within a period of about 32 hours, triggering landslides and floods throughout 10 counties in the San Francisco Bay region. More than 18,000 rain induced slides transformed into debris flows that swept down hill slopes and drainages with little warning, damaging at least 100 homes and killing 14 residents. Estimates of total storm damage, compiled for emergency purposes within 2 weeks of the storm, exceeded $280 Million (including flooding and other non-landslide damages);of which $66 Million was documented for landslides.


Nilsen, T. H., Wright, R. H., Vlasic, T. C., Spangle, W. E., and associates, city and regional planners, 1979, Relative slope stability and land-use planning in the San Francisco Bay region, California. U. S. Geological Survey Professional Paper 944: 96 p.

Landslides and associated types of slope failure have become major geologic hazards in the San Francisco Bay region. As increasing development of hillside areas has taken place, the annual cost of damage from slope failure can be in the tens of millions of dollars. These losses can be greatly reduced by using geologic information to recognize, evaluate, and map those areas of potential instability, and applying this information in planning, designing, and organizing the use of hillside areas. The report contains maps showing all landslides in the San Francisco Bay region that had been recognized by 1975. (Out of Print)


Gray, C. H., 1984, Landslides hazards in California. California Geology, 37(8): 171-172.

The Geologic Hazards Program of the Department of Conservation, Division of Mines and Geology provides basic geologic information to the public and local agencies so that they will be better informed of geologic conditions within their jurisdiction. Landslide mapping began in 1960 in southern California and this activity has since expanded throughout the State.


Kockelman, W. J., 1986, Some techniques for reducing landslide hazards. Bulletin of the Association of Engineering Geologists, 23(1): 29-52.

Landslides continue to cause costly damage and loss of lives. Twenty-seven techniques are outlined for reducing landslide hazard. Certain factors needed to ensure the lasting effectiveness of these techniques, however are usually beyond the control of the public planner, engineer, and decision makers.


Tyler, M. B., 1995, Look before you build: geologic studies for safer land development in the San Francisco Bay area. U. S. Geological Survey Circular 1130: 54 p.

In non-technical language, this Circular provides a general description of the types of geologic hazards that exist throughout the United States. Describes how geologic information can be incorporated in the land-use development process, with several examples from the greater San Francisco Bay area.


Taylor, F. A. and Brabb, E. E., 1972, Map showing distribution and cost by counties of structurally damaging landslides in the San Francisco Bay region, California Winter of 1968-69. U. S. Geological Survey, Miscellaneous Field Studies map MF-327: scale 1:1,000,000. (Out of Print)

Provides cost of landslides to the economy by county for the San Francisco Bay area. It also show which areas have the greatest landslide problems.


Keefer, D. K., Wieczorek, G. F., Harp, E. L., and Tuel, D. H., 1979, Preliminary assessment of seismically induced landslide susceptibility. In Brabb, E. E., editor, Progress on seismic zonation in the San Francisco Bay region. U. S. Geological Survey Circular 807: pp. 49-60.

Preliminary criteria have been developed for mapping some earthquake-induced landslides. These criteria are then used to prepare an experimental susceptibility map for the La Honda area.


Alameda CountyUpArrow

Creasey, C. L., 1982, Landslide damage: a costly outcome of the storm. In Ellen, Stephen, and Wieczorek, G. F., eds., Landslides, floods, and marine effects of the storm of January 3-5, 1982, in the San Francisco Bay region, California: U. S. Geological Survey Professional Paper 1434, pp. 195-203.

Total direct costs of landslide damage for the storm in Bay area counties exceeded $66 Million. In Alameda County these costs total about $3.5 Million which were divided between utilities (10.4 %), private lands (52.8%), parks (3.9 %), transportation (32 %), and miscellaneous (0.9 %).


Nilsen, T. H., Taylor, F. A., and Brabb, 1976, Recent landslides in Alameda county, California (1940-71): an estimate of economic losses and correlations with slope, rainfall, and ancient landslide deposits. U. S. Geological Survey Bulletin 1398: 21 p.

A total of 335 landslides have caused damage to manmade structures, and 659 parcels of land have been devalued because of landslide damage from 1940 to 1971 in Alameda County. Over $5 Million worth of damage was caused by landsliding in 1968-69; this cost averages out for that year to about $100 per dwelling unit. This report also contains several references to landslide inventory maps of the entire County prepared by Nilsen. (Out of Print)


Nilsen, T. H., Wright, R. H., Vlasic, T. C., Spangle, W. E., and associates, city and regional planners, 1979, Relative slope stability and land-use planning in the San Francisco Bay region, California. U. S. Geological Survey Professional Paper 944: 96 p.

Landslides and associated types of slope failure have become major geologic hazards in the San Francisco Bay region. As increasing development of hillside areas has taken place, the annual cost of damage from slope failure can be in the tens of millions of dollars. These losses can be greatly reduced by using geologic information to recognize, evaluate, and map those areas of potential instability, and applying this information in planning, designing, and organizing the use of hillside areas. The report contains maps showing all landslides in the San Francisco Bay region that had been recognized by 1975. (Out of Print)


Smith, T. C. and Hart, E. W., 1982, Landslides and related storm damage January 1982, San Francisco Bay. California Geology, 35(7): 139-152.

Documents events which are considered typical examples of the damage and destruction which resulted from the January 1982 storm. It provides insight into the cause of these destructive landslides.


Waltz, J. P., 1971, An analysis of selected landslides in Alameda and Contra Costa Counties, California. Association of Engineering Geologists Bulletin, 8(2): 153-163.

Statistical analyses of data collected from landslides show that variables representing slope morphology provide the best indices of slope stability. In general the relative stability of a given slope is related to the degree of convexity of that slope.


Wieczorek, G. F., Harp, E. L., and Mark, R. K., 1982, Debris flows and other landslides in San Mateo, Santa Cruz, Contra Costa, Alameda, Napa, Solano, Lake and Yolo Counties, and factors influencing debris-flow distribution. In Ellen, Stephen, and Wieczorek, G. F., eds., Landslides, floods, and marine effects of the storm of January 3-5, 1982, in the San Francisco Bay region, California: U. S. Geological Survey Professional Paper 1434, pp. 133-161.

Debris flow and other landslides resulting from the January 3-5, 1982 storm were mapped throughout the San Francisco Bay region from aerial photographs. Larger landslides are examined in selected areas.


Contra Costa CountyUpArrow

Cannon, S. H. and Ellen, S., 1985, Rainfall conditions for abundant debris avalanches, San Francisco Bay region, California. California Geology, 38(12): 267-272.

Debris avalanches are shallow landslides which transformed into muddy slurries and travel down slope rapidly. On January 3-5, 1982, an exceptional rainstorm created debris avalanches (a.k.a. debris flows) throughout the San Francisco Bay area. These avalanches resulted in damages to at least 100 homes, and in the deaths of 15 residents.


Creasey, C. L., 1982, Landslide damage: a costly outcome of the storm. In Ellen, Stephen, and Wieczorek, G. F., eds., Landslides, floods, and marine effects of the storm of January 3-5, 1982, in the San Francisco Bay region, California: U. S. Geological Survey Professional Paper 1434, pp. 133-161.

Total direct costs of landslide damage for the storm in Bay area counties exceeded $66 Million. In Sonoma County these costs total about $7 Million which were divided between utilities (5.4 %), private lands (60.7%), parks (3.3%), transportation (29.2%), and miscellaneous (1.4 %).


Nilsen, T. H. and Turner, B. L., 1975, Influence of rainfall and ancient landslide deposits on recent landslides (1950-71) in urban areas of Contra Costa County, California. U. S. Geological Survey Bulletin 1388: 18 p.

Most landslides that caused damage to manmade structures in the urbanized parts of Contra Costa County from 1950 to 1971 occurred on preexisting ancient landslide deposits. Most of the recent landslides occurred during or immediately after storm periods in which more than 7 inches (18 cm) of rain fell, particularly if the ground was already wet from previous storms. (Out of Print)


_____ Wright, R. H., Vlasic, T. C., Spangle, W. E., and associates, city and regional planners, 1979, Relative slope stability and land-use planning in the San Francisco Bay region, California. U. S. Geological Survey Professional Paper 944: 96 p.

Landslides and associated types of slope failure have become major geologic hazards in the San Francisco Bay region. As increasing development of hillside areas has taken place, the annual cost of damage from slope failure can be in the tens of millions of dollars. These losses can be greatly reduced by using geologic information to recognize, evaluate, and map those areas of potential instability, and applying this information in planning, designing, and organizing the use of hillside areas. The report contains maps showing all landslides in the San Francisco Bay region that had been recognized by 1975. (Out of Print)


Waltz, J. P., 1971, An analysis of selected landslides in Alameda and Contra Costa Counties, California. Association of Engineering Geologists Bulletin, 8(2): 153-163.

Statistical analyses of data collected from landslides show that variables representing slope morphology provide the best indices of slope stability. In general the relative stability of a given slope is related to the degree of convexity of that slope.


Wieczorek, G. F., Harp, E. L., and Mark, R. K., 1982, Debris flows and other landslides in San Mateo, Santa Cruz, Contra Costa, Alameda, Napa, Solano, Lake and Yolo Counties, and factors influencing debris-flow distribution. In Ellen, Stephen, and Wieczorek, G. F., eds., Landslides, floods, and marine effects of the storm of January 3-5, 1982, in the San Francisco Bay region, California: U. S. Geological Survey Professional Paper 1434, pp. 133-161.

Debris flow and other landslides resulting from the January 3-5, 1982, storm were mapped throughout the San Francisco Bay region from aerial photographs. Larger landslides are examined in selected areas.


Marin CountyUpArrow

Cannon, S. H. and Ellen, S., 1985, Rainfall conditions for abundant debris avalanches, San Francisco Bay region, California. California Geology, 38(12): 267-272.

Debris avalanches are shallow landslides that transform into muddy slurries and travel down slope rapidly. On January 3-5, 1982, an exceptional rainstorm created debris avalanches throughout the San Francisco Bay area. These avalanches resulted in damages to at least 100 homes, and in the deaths of 15 residents.


Clague, J. J., 1969, Landslides of southern Point Reyes National Seashore. California Division of Mines and Geology, Mineral Information Service, 22(7): 107-110, 116-118.

Some of the largest ancient landslides in the San Francisco Bay area are on a four-mile stretch on the coastal side of Inverness Ridge at the south end of Point Reyes. Most of the area is now stable, but several lakes there owe their existence to these slides.


Creasey, C. L., 1982, Landslide damage: a costly outcome of the storm. In Ellen, Stephen, and Wieczorek, G. F., eds., Landslides, floods, and marine effects of the storm of January 3-5, 1982, in the San Francisco Bay region, California: U. S. Geological Survey Professional Paper 1434, pp. 133-161.

Total direct costs of landslide damage for the storm in Bay area counties exceeded $66 Million. In Sonoma County these costs total over $18 Million which were divided between utilities (5.5 %), private lands (43.5%), parks (15 %), transportation (34.6%), and miscellaneous (1.4 %).


Ellen, S. D., Cannon, S. H., and Reneau, Steven L., with contributions by Langholz, B. M., Mark, R. K., Peterson, D. M., and Robinson, S. W., 1982, Distribution of debris flows in Marin County. In Ellen, Stephen, and Wieczorek, G. F., eds., Landslides, floods, and marine effects of the storm of January 3-5, 1982, in the San Francisco Bay region, California: U. S. Geological Survey Professional Paper 1434, pp. 133-161.

Debris flow and other landslides resulting from the January 3-5, 1982, storm were mapped throughout the San Francisco Bay region from aerial photographs. Larger landslides are examined in selected areas.


Nilsen, T. H., Wright, R. H., Vlasic, T. C., Spangle, W. E., and associates, city and regional planners, 1979, Relative slope stability and land-use planning in the San Francisco Bay region, California. U. S. Geological Survey Professional Paper 944: 96 p.

Landslides and associated types of slope failure have become major geologic hazards in the San Francisco Bay region. As increasing development of hillside areas has taken place, the annual cost of damage from slope failure can be in the tens of millions of dollars. These losses can be greatly reduced by using geologic information to recognize, evaluate, and map those areas of potential instability, and applying this information in planning, designing, and organizing the use of hillside areas. The report contains maps showing all landslides in the San Francisco Bay region that had been recognized by 1975. (Out of Print)


Napa CountyUpArrow

Nilsen, T. H., Wright, R. H., Vlasic, T. C., Spangle, W. E., and associates, city and regional planners, 1979, Relative slope stability and land-use planning in the San Francisco Bay region, California. U. S. Geological Survey Professional Paper 944: 96 p.

Landslides and associated types of slope failure have become major geologic hazards in the San Francisco Bay region. As increasing development of hillside areas has taken place, the annual cost of damage from slope failure can be in the tens of millions of dollars. These losses can be greatly reduced by using geologic information to recognize, evaluate, and map those areas of potential instability, and applying this information in planning, designing, and organizing the use of hillside areas. The report contains maps showing all landslides in the San Francisco Bay region that had been recognized by 1975. (Out of Print)


Wieczorek, G. F., Harp, E. L., and Mark, R. K., 1982, Debris flows and other landslides in San Mateo, Santa Cruz, Contra Costa, Alameda, Napa, Solano, Lake and Yolo Counties, and factors influencing debris-flow distribution. In Ellen, Stephen, and Wieczorek, G. F., eds., Landslides, floods, and marine effects of the storm of January 3-5, 1982, in the San Francisco Bay region, California: U. S. Geological Survey Professional Paper 1434, pp. 133-161.

Debris flow and other landslides resulting from the January 3-5, 1982, storm were mapped throughout the San Francisco Bay region from aerial photographs. Larger landslides are examined in selected areas.


Wright, R. H. and Reid, G. O., 1975, Photointerpretive map of landslides and surficial deposits of northernmost Napa County, California. U. S. Geological Survey Map, Miscellaneous Field Studies, Map MF-677; scale: 1:24,000.

This map shows various types of landslide deposits, scarps, and related topographic features, in addition to other types of surficial deposits, in northernmost Napa County.


San Francisco CountyUpArrow

Creasey, C. L., 1982, Landslide damage: a costly outcome of the storm. In Ellen, Stephen, and Wieczorek, G. F., eds., Landslides, floods, and marine effects of the storm of January 3-5, 1982, in the San Francisco Bay region, California: U. S. Geological Survey Professional Paper 1434, pp. 133-161.

Total direct costs of landslide damage for the storm in Bay area counties exceeded $66 Million. In San Francisco County these costs total nearly $400 K which were divided between private lands (78%), parks (11%) and transportation (11%).


Nilsen, T. H., Wright, R. H., Vlasic, T. C., Spangle, W. E., and associates, city and regional planners, 1979, Relative slope stability and land-use planning in the San Francisco Bay region, California. U. S. Geological Survey Professional Paper 944: 96 p.

Landslides and associated types of slope failure have become major geologic hazards in the San Francisco Bay region. As increasing development of hillside areas has taken place, the annual cost of damage from slope failure can be in the tens of millions of dollars. These losses can be greatly reduced by using geologic information to recognize, evaluate, and map those areas of potential instability, and applying this information in planning, designing, and organizing the use of hillside areas. The report contains maps showing all landslides in the San Francisco Bay region that had been recognized by 1975.


San Mateo CountyUpArrow

Brabb, E. E. and Pampeyan, E. H. 1972, Preliminary map of landslides in San Mateo County, California. U. S. Geological Survey Map MF-344, scale 1:62,500.

A compilation of landslide number, extent and distribution in San Mateo County. Nearly 2,000 landslides are shown on this map, which is a 10 fold increase from previous maps. (Out of Print)


_____, and others, 1972, Landslide susceptibility in San Mateo County, California. U. S. Geological Survey Map MF-360; scale 1:62,500.

A derivative map of San Mateo County shows areas susceptible to landsliding. It conveys the information in a non-technical form so that it is intelligible to non-geologists. The map is the legal basis for the County's low density development in landslide-prone areas. (Out of Print)


Cannon, S. H. and Ellen, S., 1985, Rainfall conditions for abundant debris avalanches, San Francisco Bay region, California. California Geology, 38(12): 267-272.

Debris avalanches are shallow landslides that transform into muddy slurries and travel rapidly down slope. On January 3-5, 1982, an exceptional rainstorm created debris avalanches throughout the San Francisco Bay area. These avalanches resulted in damages to at least 100 homes, and in the deaths of 15 residents.


Creasey, C. L., 1982, Landslide damage: a costly outcome of the storm. In Ellen, Stephen, and Wieczorek, G. F., eds., Landslides, floods, and marine effects of the storm of January 3-5, 1982, in the San Francisco Bay region, California: U. S. Geological Survey Professional Paper 1434, pp. 133-161.

Total direct costs of landslide damage for the storm in Bay area counties exceeded $66 Million. In Sonoma County these costs total nearly $7.5 Million which were divided between utilities (4.9 %), private lands (48.2 %), parks (4.7%), transportation (40.1%), and miscellaneous (2.1 %).


Mark, R. K., 1992, Map of debris-flow probability, San Mateo County, California. U. S. Geological Survey Miscellaneous Investigations map I-1257M: scale 1:62,500.

For San Mateo County shows areas with a high probability of debris-flow movement.


Nilsen, T. H., Wright, R. H., Vlasic, T. C., Spangle, W. E., and associates, city and regional planners, 1979, Relative slope stability and land-use planning in the San Francisco Bay region, California. U. S. Geological Survey Professional Paper 944: 96 p.

Landslides and associated types of slope failure have become major geologic hazards in the San Francisco Bay region. As increasing development of hillside areas has taken place, the annual cost of damage from slope failure can be in the tens of millions of dollars. These losses can be greatly reduced by using geologic information to recognize, evaluate, and map those areas of potential instability, and applying this information in planning, designing, and organizing the use of hillside areas. The report contains maps showing all landslides in the San Francisco Bay region that had been recognized by 1975.


Wieczorek, G. F., 1982, Map showing recently-active and dormant landslides near La Honda, central Santa Cruz Mountains, California. U. S. Geological Survey Miscellaneous field Studies map MF-1422, scale 1:4,800.

This map shows more than 230 dormant and recently active landslides in a 5 square mile area northeast of La Honda, San Mateo County, California.


Wieczorek, G. F., Harp, E. L., and Mark, R. K., 1982, Debris flows and other landslides in San Mateo, Santa Cruz, Contra Costa, Alameda, Napa, Solano, Lake and Yolo Counties, and factors influencing debris-flow distribution. In Ellen, Stephen, and Wieczorek, G. F., eds., Landslides, floods, and marine effects of the storm of January 3-5, 1982, in the San Francisco Bay region, California: U. S. Geological Survey Professional Paper 1434, pp. 133-161.

Debris flow and other landslides resulting from the January 3-5, 1982, storm were mapped throughout the San Francisco Bay region from aerial photographs. Larger landslides are examined in selected areas.


Santa Clara CountyUpArrow

Creasey, C. L., 1982, Landslide damage: a costly outcome of the storm. In Ellen, Stephen, and Wieczorek, G. F., eds., Landslides, floods, and marine effects of the storm of January 3-5, 1982, in the San Francisco Bay region, California: U. S. Geological Survey Professional Paper 1434, pp. 133-161.

Total direct costs of landslide damage for the storm in Bay area counties exceeded $66 Million. In Sonoma County these costs total about $583 K which were divided between private lands (55.4 %), parks (3.6%), transportation (41.0 %).


Nilsen, T. H., 1972, Preliminary photointerpretation map of landslide and other surficial deposits of parts of the Los Gatos, Morgan Hill, Gilroy Hot Springs, Pacheco Pass, Quien Sabe, and Hollister 15-minute quadrangles, Santa Clara County, California. U. S. Geological Survey, Miscellaneous Field Studies Map, MF-416; scale 1:62,500

Provides information about landslide deposits in the southern and southeastern part of Santa Clara County. (Out of Print)


_____ and Brabb, E. E., 1972, Preliminary photointerpretation and damage maps of landslide and other surficial deposits in northeastern San Jose, Santa Clara County, California. U. S. Geological Survey, Miscellaneous Field Studies Map, MF-361; scale 1:24,000.

This map presents preliminary information about landslide deposits in northeastern part of the city of San Jose. (Out of Print)


Nilsen, T. H., Wright, R. H., Vlasic, T. C., Spangle, W. E., and associates, city and regional planners, 1979, Relative slope stability and land-use planning in the San Francisco Bay region, California. U. S. Geological Survey Professional Paper 944: 96 p.

Landslides and associated types of slope failure have become major geologic hazards in the San Francisco Bay region. As increasing development of hillside areas has taken place, the annual cost of damage from slope failure can be in the tens of millions of dollars. These losses can be greatly reduced by using geologic information to recognize, evaluate, and map those areas of potential instability, and applying this information in planning, designing, and organizing the use of hillside areas. The report contains maps showing all landslides in the San Francisco Bay region that had been recognized by 1975. (Out of Print)


Santa Cruz CountyUpArrow

Cooper, Clark and associates, 1975, Preliminary map of landslide deposits in Santa Cruz County, California. In Seismic safety element; published by Santa Cruz County Planning Department, Santa Cruz, CA: 132 p.

Map shows all the landslides in the County that had been recognized by 1975.


Creasey, C. L., 1982, Landslide damage: a costly outcome of the storm. In Ellen, Stephen, and Wieczorek, G. F., eds., Landslides, floods, and marine effects of the storm of January 3-5, 1982, in the San Francisco Bay region, California: U. S. Geological Survey Professional Paper 1434, pp. 133-161.

Total direct costs of landslide damage for the storm in Bay area counties exceeded $66 Million. In Sonoma County these costs total over $26 Million which were divided between utilities (3.8 %), private lands (70.6%), parks (0.4%), transportation (21.5%), and miscellaneous (0.1 %).


Griggs, G. B., 1982, Flooding and slope failure during the January 1982 storm, Santa Cruz County, California. California Geology, 35(7): 158-163.

Landsliding, mudflows, and flooding caused 22 deaths and totally destroyed about 100 homes in Santa Cruz County. Hundreds of other houses on steep slope areas of the Santa Cruz Mountains or along flood plains were severely damaged, many dwellings remain perched in precarious positions either above or below active slides or potential slide areas.


Nilsen, T. H., Wright, R. H., Vlasic, T. C., Spangle, W. E., and associates, city and regional planners, 1979, Relative slope stability and land-use planning in the San Francisco Bay region, California. U. S. Geological Survey Professional Paper 944: 96 p.

Landslides and associated types of slope failure have become major geologic hazards in the San Francisco Bay region. As increasing development of hillside areas has taken place, the annual cost of damage from slope failure can be in the tens of millions of dollars. These losses can be greatly reduced by using geologic information to recognize, evaluate, and map those areas of potential instability, and applying this information in planning, designing, and organizing the use of hillside areas. The report contains maps showing all landslides in the San Francisco Bay region that had been recognized by 1975. (Out of Print)


Wieczorek, G. F., Harp, E. L., and Mark, R. K., 1982, Debris flows and other landslides in San Mateo, Santa Cruz, Contra Costa, Alameda, Napa, Solano, Lake and Yolo Counties, and factors influencing debris-flow distribution. In Ellen, Stephen, and Wieczorek, G. F., eds., Landslides, floods, and marine effects of the storm of January 3-5, 1982, in the San Francisco Bay region, California: U. S. Geological Survey Professional Paper 1434, pp. 133-161.

Debris flow and other landslides resulting from the January 3-5, 1982, storm were mapped throughout the San Francisco Bay region from aerial photographs. Larger landslides are examined in selected areas.


Solano CountyUpArrow

Creasey, C. L., 1982, Landslide damage: a costly outcome of the storm. In Ellen, Stephen, and Wieczorek, G. F., eds., Landslides, floods, and marine effects of the storm of January 3-5, 1982, in the San Francisco Bay region, California: U. S. Geological Survey Professional Paper 1434, pp. 133-161.

Total direct costs of landslide damage for the storm in Bay area counties exceeded $66 Million. In Sonoma County these costs total nearly $2 Million which were divided between private lands (46.6%), transportation (52.9%), and miscellaneous (0.5 %).


Nilsen, T. H., Wright, R. H., Vlasic, T. C., Spangle, W. E., and associates, city and regional planners, 1979, Relative slope stability and land-use planning in the San Francisco Bay region, California. U. S. Geological Survey Professional Paper 944: 96 p.

Landslides and associated types of slope failure have become major geologic hazards in the San Francisco Bay region. As increasing development of hillside areas has taken place, the annual cost of damage from slope failure can be in the tens of millions of dollars. These losses can be greatly reduced by using geologic information to recognize, evaluate, and map those areas of potential instability, and applying this information in planning, designing, and organizing the use of hillside areas. The report contains maps showing all landslides in the San Francisco Bay region that had been recognized by 1975. (Out of Print)


Wieczorek, G. F., Harp, E. L., and Mark, R. K., 1982, Debris flows and other landslides in San Mateo, Santa Cruz, Contra Costa, Alameda, Napa, Solano, Lake and Yolo Counties, and factors influencing debris-flow distribution. In Ellen, Stephen, and Wieczorek, G. F., eds., Landslides, floods, and marine effects of the storm of January 3-5, 1982, in the San Francisco Bay region, California: U. S. Geological Survey Professional Paper 1434, pp. 133-161.

Debris flow and other landslides resulting from the January 3-5, 1982, storm were mapped throughout the San Francisco Bay region from aerial photographs. Larger landslides are examined in selected areas.


Sonoma CountyUpArrow

Creasey, C. L., 1982, Landslide damage: a costly outcome of the storm. In Ellen, Stephen, and Wieczorek, G. F., eds., Landslides, floods, and marine effects of the storm of January 3-5, 1982, in the San Francisco Bay region, California: U. S. Geological Survey Professional Paper 1434, pp. 133-161.

Total direct costs of landslide damage for the storm in Bay area counties exceeded $66 Million. In Sonoma County these costs total nearly $400 K which were divided between utilities (2.6 %), private lands (5.8%), parks (2.3%), transportation (84%), and miscellaneous (5.4 %).


Frizzell, V. A., Jr., 1974, Reconnaissance photointerpretation map of landslides in parts of the Hopland, Kelseyville, and Lower Lake 15-minute quadrangles, Sonoma County, California. U. S. Geological Survey, Miscellaneous Field Studies Map, MF-594; scale 1:62,500

This map is a photo-reconnaissance of land slide deposits in the northernmost portion of Sonoma County. For additional landslides and susceptibility maps see the report by Nilsen and others in the General section.


Nilsen, T. H., Wright, R. H., Vlasic, T. C., Spangle, W. E., and associates, city and regional planners, 1979, Relative slope stability and land-use planning in the San Francisco Bay region, California. U. S. Geological Survey Professional Paper 944: 96 p.

Landslides and associated types of slope failure have become major geologic hazards in the San Francisco Bay region. As increasing development of hillside areas has taken place, the annual cost of damage from slope failure can be in the tens of millions of dollars. These losses can be greatly reduced by using geologic information to recognize, evaluate, and map those areas of potential instability, and applying this information in planning, designing, and organizing the use of hillside areas. The report contains maps showing all landslides in the San Francisco Bay region that had been recognized by 1975. (Out of Print)


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