If you live anywhere from Dublin to Oakland, you already know an earthquake is a question of when, not if. The Hayward and Calaveras faults run right under a lot of these neighborhoods. Most of the time the smart move during shaking is simple: drop, cover, and hold on. The part people get wrong is what comes after, especially around gas and water.
Here’s the short version up front. You do not automatically shut off your gas after every quake. You shut it off only if there’s a real sign of a leak. Water is different, and shutting it off is often a good idea. Let’s walk through both so you know exactly what to do before the ground starts moving.
Find your valves now, not during the shaking
The single most useful thing you can do is locate everything on a calm afternoon. Trying to find a shutoff in the dark, with adrenaline running, is how people get hurt or waste twenty minutes.
Your gas meter is usually outside, often on the side of the house or near where the service line comes in. PG&E serves nearly all of this region, so most Bay Area meters look the same. Look for the main shutoff valve on the pipe coming up out of the ground, just below the meter itself. It’s a rectangular nub or tab. When the long side of that tab is in line with the pipe, the gas is on. When it’s turned crossways to the pipe, the gas is off.
Your water shutoff comes in two flavors. There’s the main valve at the meter, usually out by the curb or sidewalk under a concrete or plastic lid. You’ll need a meter key or a wrench to reach it. Many homes also have a house-side valve where the supply enters the building, often near the front hose bib, in the garage, or down in a crawlspace. That house valve is the one most people can turn by hand, and it’s the easier choice in a hurry. If your home runs on EBMUD, Cal Water, or a Tri-Valley system like Zone 7, the meter setup is similar even if the lid and key vary.
Keep the right tool tied to the meter
A gas valve doesn’t turn with your fingers. You need a wrench. A 12 to 15 inch adjustable wrench works, and so do the cheap dedicated gas shutoff wrenches sold at any hardware store. Buy one, and zip-tie or wire it right next to the gas meter so it’s there when you need it. Don’t store it in a kitchen drawer that might be blocked by fallen cabinets.
For water at the meter, a meter key or a large adjustable wrench does the job. If your main reach is the house-side valve, you may not need a tool at all.
When to actually shut off the gas
This is the part worth repeating, because shutting gas off needlessly creates its own headache.
Leave the gas on unless you notice one of these:
- You smell that rotten-egg odor (it’s added to natural gas on purpose so you can detect it).
- You hear hissing or blowing near the meter or an appliance.
- You see a broken gas line, a tilted water heater that’s pulled its connection, or a fire.
If any of that is happening, get everyone out first. Then, from a safe spot, use your wrench to turn the main valve a quarter turn so the tab sits crossways to the pipe. Don’t use light switches, don’t flip the garage door opener, and don’t strike a match. A spark in a gas-filled space is the real danger.
Once that valve is closed, you’re done with it. Do not try to turn it back on. PG&E has to come out, check the system, relight pilots, and confirm there are no leaks. After a major quake that may take days, which is exactly why you don’t shut it off without a reason. If you smell gas but can’t safely reach the meter, leave and call PG&E or 911 from outside.
If you want an extra layer of protection, some homeowners install an automatic seismic gas shutoff valve that trips on its own during strong shaking. A few Bay Area cities even require them on certain remodels or sales. Those have to be installed to code by a qualified pro, so treat that as a separate project, not an after-the-quake task.
Shutting off the water is usually the smart move
Water is more forgiving and the math is different. After real shaking, turning your water off protects the house two ways. It stops a cracked pipe from flooding your floors while you’re not looking, and it keeps possibly contaminated water from the street main out of your home’s plumbing if the line was damaged.
To shut it off at the meter, turn the valve clockwise until it stops. At a house-side ball valve, give the lever a quarter turn so it’s crosswise to the pipe. Either way, righty-tighty until it won’t go further.
One bonus: your water heater holds 40 to 50 gallons of clean drinking water you can tap if service is interrupted, but only if you shut the incoming water off first so dirty water can’t backflow into it. That’s a good reason to close the water early.
While you’re thinking about the heater, check that it’s strapped to the wall framing with two metal straps. An unstrapped tank can topple in a quake, snap its gas and water lines, and turn into both a leak and an ignition source. Strapping is required by California code and it’s an easy thing to verify ahead of time.
After the dust settles
Once shaking stops and you’ve handled any immediate leak, slow down. Don’t rush to turn everything back on. If you shut the gas, wait for PG&E. If you shut the water and you didn’t see or smell any problem, you can usually reopen the house valve slowly and watch for leaks at fixtures and under sinks.
In the East Bay, keep the EBMUD Private Sewer Lateral program in mind too. A quake can crack an aging sewer lateral, and if you’re near a point of sale you may already be on the hook to test and repair it. Older Bay Area homes with galvanized steel or early copper supply lines are also more likely to develop pinhole leaks or joint failures after a jolt, so give those a careful look.
When to call a licensed plumber
After any earthquake strong enough to knock things off shelves, it’s worth having a licensed plumber inspect your supply lines, water heater connections, and any visible joints before you rely on the system again. Call right away if you see standing water, hear running water with everything off, notice a sudden pressure drop, or smell sewage. Those point to a break you don’t want to leave alone.
When you hire someone, confirm they hold a current California contractor’s license. You can look up any plumber by name or license number at cslb.ca.gov before they start work. A quick check there protects you from unlicensed operators, who tend to show up in force right after a disaster. For gas line work specifically, remember the utility, not a plumber, restores gas service at the meter.
A little prep now, knowing your valves, keeping a wrench handy, and strapping that water heater, means you’ll act fast and calm when it counts.