Is our downtown San Jose house still sinking from the old groundwater pumping?
Probably not from that cause. The U.S. Geological Survey says the Santa Clara Valley was the first place in the country where subsidence from groundwater pumping was recognized, and that it was effectively halted by about 1969, after imported water let the aquifers be recharged. Downtown dropped from about 98 feet above sea level in 1910 to about 84 by 1995. The city's geology report does not expect regional subsidence to return unless pumping outruns recharge, so a fresh crack points to something local, such as clay, fill, drainage or a nearby dewatering well.
Can we get an Earthquake Brace + Bolt grant for a San Jose house?
The address is not the obstacle: the program's Northern California ZIP list includes every San José ZIP code. The house has to be a wood-framed, pre-1980 home on a raised foundation, the program has to accept you while registration is open, and the work has to be done by a contractor from its directory, or by you as an owner-builder. In San José that contractor applies online for the Brace & Bolt permit and builds from the state's Standard Plan Set A.
Who should see the cracks first, a structural engineer or a foundation contractor?
For anything beyond a standard bolting plan, usually the engineer. California's engineering board notes that cities usually require a licensed engineer to design foundations where soil may be a problem, and that in general the engineer draws the plans and the contractor does the construction. Bids written against an engineer's plan compare the same scope; bids written from a walk-through can describe quite different repairs. Most engineering work requires a written contract, so read what it covers.
Our lot is in a liquefaction zone. Will every foundation permit need a geotechnical report?
The rule is written for development sites: a site inside a state liquefaction zone needs the City Geologist's Geologic Clearance, based on an approved geotechnical seismic hazard evaluation report, before a grading or building permit is issued. The city's geology report adds that minor residential additions may be exempted by the Building Department. Ask Public Works counter staff which clearance, if any, applies to your repair before the plans are finished.
Our old Naglee Park house needs a new foundation. Can it be raised higher at the same time?
A little. The city's guide for historic houses says to keep a house near its historic elevation when the foundation is rebuilt: raising it slightly is acceptable, lifting it substantially above the ground is not, and changing the height of the floor level is discouraged. The guide favors a simple concrete foundation that looks like the historic one, screened by siding or matching paint where it shows.
