West Napa Fault History: Five, 5.0+ Magnitude Events Since 1969
Professor John Rundle, an expert at UC Davis on earthquake predictability and preparedness, stresses that seismic retrofitting must be done. This is especially true for structures in the impact region of the West Napa/Franklin faults just east of the Rogers Creek Fault between Napa and Santa Rosa. The West Napa/Franklin Faults have shown activity at 5.0 magnitude or above twice in 1969, and once each year in 1980, 2000, and 2014.

32% Probability For 6.7 to 7.4 Magnitude By 2030
The 1999 Working Group on California Earthquake Probabilities (WG99, 1999) concluded that the Rodgers Creek Fault system (less than 15 miles west of Napa) has a 32 percent probability of generating a large earthquake (Magnitude 6.7 to 7.4) by the year 2030. A 7.0 magnitude event on the Rogers Creek Fault west of Napa could seriously damage or destroy a majority of pre-1980 homes if they are not retrofitted.


Seismic Retrofitting Saves Far More Than it Costs
Based on extensive post-earthquake evaluations, experts agree that structural damage can be greatly reduced by following recommended practices of basic seismic retrofitting. Retrofitting will reduce the cost of repair, and may even prevent structural damage altogether.

Economical Ways To Budget A Retrofit
Often, the cost of fully retrofitting is beyond most homeowners' budgets. Though it is best to install a properly engineered, steel reinforced foundation, it has been shown that even a minimal, basic retrofit to tie the posts, beams, rafters, and girders in place can save a structure even if the foundation fails. (As shown in Example #1 on the "Seismic Preparedness" page.)

Sign-up For A Free, No-Obligation Seismic Evaluation
Forbes and Sons Construction, a local contractor with 35 years experience in this area, is offering to do a free, no-obligation Seismic Evaluation of residential and commercial structures in the Napa area.

To sign up for your free Seismic Evaluation, call 707.226.5994 or (click here) for the on-line sign-up form.