Buying a property in a liquefaction zone: what you need to know.
What is a liquefaction zone and how do you know if a potential purchase is worth the trouble that lying in this zone entails?
From the Los Angeles Times:
“The California Geological Survey, in its publication “Seismic Hazards Zonation Program,” describes liquefaction as occurring when loose, water-saturated sediments lose strength and fail during strong ground shaking. That process transforms granular material from a solid into a liquefied state because of water pressure and can lead to significant ground settlement.
Cracks in buildings, driveways, sidewalks and stucco are all red flags for problems, as well as long-term poor maintenance that can lead to larger, future repairs…
For more information about earthquake, liquefaction risk and ground settlement, obtain the California Geological Survey’s “Guidelines for Evaluating and Mitigating Seismic Hazards in California.” It notes how some structures may actually “float” or rise out of the ground during an earthquake, explaining the seller’s description of being on a boat.
California Geological Survey reports are available at www.conservation.ca.gov. For Southern and Northern California liquefaction maps specifically, visit http://gmw.consrv.ca.gov/shmp/html/pdf_maps_so.html. It’s also a good idea in a tsunami zone to review a county’s evacuation information. See http://lacoa.org/ht_tsunami.htm for Los Angeles County’s tsunami resource and evacuation plan.”