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St. Francis Dam Disaster

St. Francis Dam Disaster. Melissa Schlothan 15 February, 2007 Environmental Geology Dr. Sarah Gray. http://web.umr.edu/~rogersda/st_francis_dam/046.jpg. Outline. Geography and Geology Background Impacts Disaster Management and Response Why did the St. Francis Dam fail?

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St. Francis Dam Disaster

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  1. St. Francis Dam Disaster Melissa Schlothan 15 February, 2007 Environmental Geology Dr. Sarah Gray http://web.umr.edu/~rogersda/st_francis_dam/046.jpg

  2. Outline • Geography and Geology • Background • Impacts • Disaster Management and Response • Why did the St. Francis Dam fail? • What happened to the community? • Recommendations • Lessons

  3. Geography • Located 40 miles NE of Los Angeles • In city of Santa Clarita • Developing city • Agriculture, electricity (Edison), mostly immigrants • Inside San Francisquito Canyon

  4. St. Francis Dam Castaic Lake

  5. Geology • San Francisquito Fault line • Paleolithic landslide area • Schist (severely laminated, cross-faulting, interspersed with talc) • Sandstone • Conglomerate http://en.wikipedia.org/wiki/Image:Schist.jpg

  6. http://wps.prenhall.com/esm_keller_envgeology_8/0,7260,264377-,00.htmlhttp://wps.prenhall.com/esm_keller_envgeology_8/0,7260,264377-,00.html

  7. Background • Designed by William Mulholland, Dept. of Power and Water • 1924 – construction began • Originally • Capacity: 30,000 acre-feet • 180 ft high, 600 ft long • 1st change • 10ft height increase • Capacity: 32,000 acre-feet • 2nd change (July 1925) • 10ft height increase • Capacity: 38,000 acre-feet • Wing dyke added (600ft long) • 1926 – construction complete William Mulholland http://web.umr.edu/~rogersda/st_francis_dam/reassessment_of_st_francis_dam_failure.pdf

  8. St. Francis Dam Construction http://web.umr.edu/~rogersda/st_francis_dam/reassessment_of_st_francis_dam_failure.pdf

  9. St. Francis Dam construction Completed and filled reservoir http://www.scvhistory.com/scvhistory/scvhistory.htm

  10. 1926-1928 • Cracks developing in dam and abutments • Mulholland investigates and dismisses • 7 March 1928 • Reservoir fills to capacity • More leaks develop • Mulholland investigates and dismisses • 12 March 1928 • East side of reservoir roadbed sagging 1 – 5 feet • More leaks and cracks • Mulholland and assistant inspect and dismiss Evidence of leaks http://www.scvhistory.com/scvhistory/scvhistory.htm

  11. 12 March 1928 – Dam fails 11:57 pm • 12 bill gallons of water • 18 mi/hr initially, 5 mi/hr into Pacific • Traveled 55 miles to the Pacific Ocean • Took 5 ½ hrs Dam after failure http://www.scvhistory.com/scvhistory/scvhistory.htm

  12. http://web.umr.edu/~rogersda/st_francis_dam/Mapping%20the%20St%20Francis%20Dam%20Outburst%20Flood%20with%20GIS.pdfhttp://web.umr.edu/~rogersda/st_francis_dam/Mapping%20the%20St%20Francis%20Dam%20Outburst%20Flood%20with%20GIS.pdf View of water entering Pacific Ocean

  13. http://web.umr.edu/~rogersda/st_francis_dam/Mapping%20the%20St%20Francis%20Dam%20Outburst%20Flood%20with%20GIS.pdfhttp://web.umr.edu/~rogersda/st_francis_dam/Mapping%20the%20St%20Francis%20Dam%20Outburst%20Flood%20with%20GIS.pdf Reservoir Area

  14. http://web.umr.edu/~rogersda/st_francis_dam/Mapping%20the%20St%20Francis%20Dam%20Outburst%20Flood%20with%20GIS.pdfhttp://web.umr.edu/~rogersda/st_francis_dam/Mapping%20the%20St%20Francis%20Dam%20Outburst%20Flood%20with%20GIS.pdf Flood path

  15. Impacts • Deaths: 450 estimated • Many found downstream • Tent residents of unknown count • +900 homes destroyed • 1,200 buildings damaged • 10 bridges knocked out • Power lost in multiple cities • Crops, businesses and livestock affected

  16. Debris and overturned cars Overturned railroad tracks http://www.scvhistory.com/scvhistory/scvhistory.htm

  17. Damaged highway Flood path http://www.scvhistory.com/scvhistory/scvhistory.htm

  18. Damaged pecan fields Broken electric poles http://www.scvhistory.com/scvhistory/scvhistory.htm

  19. Waterline http://www.scvhistory.com/scvhistory/scvhistory.htm

  20. Disaster Management • Awareness and preparedness • No disaster plan • No one ever thought it would break • Mulholland was aware of cracks/leaks and maximum capacity • Dismissed them because said, “This is typical for a concrete dam of this size.”

  21. Disaster Response • Immediate response by Red Cross • Set up national fund drive • 100’s of volunteers • Provided: • Search and rescue • Care for injured/needy • Clearing debris and dying or dead people and animals • Total spent: $237,190 http://news.softpedia.com/images/news2/1-Week-After-Katrina-The-American-Red-Cross-Is-Setting-A-Record-Relief-Pace-2.jpg

  22. Los Angeles County • Took full responsibility for event • $1 million set aside for programs and funds • “Council of Fourteen” • Continued work on clean-up • 1,000’s volunteers and 100’s tractors utilized • Completed in 90 days

  23. Reconstruction Phases I and II • Mulholland Dam • Reinforced with rocks and earth on face • Built like St. Francis • Fears of similar dam break • Bouquet Reservoir – 1934 • 15 miles west of Palmdale • Part of L.A. Aqueduct system • Castaic Dam – 1973 • Near Castaic • Hydroelectric power plant

  24. Why did the dam fail? • Major reasons: • Rock Formations • Conglomerate: expands with water • Schist: badly laminated, interspersed with talc • Fault line • Erosion • from running water at cracks along sides • Paleolithic landslide http://wps.prenhall.com/esm_keller_envgeology_8/0,7260,264377-,00.html

  25. Why did the dam fail? • Cracks • Created when conglomerate on side swelled when wet causing the dam to rise and crack • Construction • Underground base missing steps • Tilting • from extra capacity unaccounted for with increased height • Sabotage theory • Previous unrest about taking water into aqueduct from Owens River Valley

  26. How was the community affected? • Many people lost jobs • Edison electric power plants ruined • Agriculture crops devastated • Agriculture devastated • 7,900 acres • Citrus, walnuts, apricots, grapes, alfalfa, pecans • Tent residents • Lost jobs and displaced • Rebuild homes and businesses • Took very long for people to get back on their feet

  27. Recommendations • Warning system needed • You can never be too careful, the risk of failure will always be there no matter the confidence • More response by police force • Efficiency needed with system of communication • Reservoir shouldn’t have been built there • The geography is extremely dangerous

  28. Lessons • More geological knowledge of area • Complete reinforcement for changes is always needed

  29. Sources • http://www.scvhistory.com/scvhistory/scvhistory.htm • http://en.wikipedia.org/wiki/San_Francisquito_Canyon • http://web.umr.edu/~rogersda/st_francis_dam/lessons_learned_from_the_st_francis_dam_failure(geostrata_mar-apr_2006).pdf • http://web.umr.edu/~rogersda/st_francis_dam/reassessment_of_st_francis_dam_failure.pdf • http://web.umr.edu/~rogersda/st_francis_dam/Mapping%20the%20St%20Francis%20Dam%20Outburst%20Flood%20with%20GIS.pdf • Outland, Charles F. Man – Made Disaster: the story of St. Francis Dam. Glendale, California: The Arthur H. Clark Company, 1963.

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