What happens if San Francisco’s power is shut down to prevent wildfires?

Imagine The City with no working traffic lights. Cellphone networks and internet phone lines could fail.

The risk of a wildfire in San Francisco is pretty remote. But, as climate change worsens, the chances of a wildfire are increasing nearly everywhere else in the Bay Area. And that wildfire threat, especially in the East Bay, could have a huge impact on the City.

In a recent filing with the California Public Utilities Commission, PG&E explained that if the utility has to turn off, or “de-energize,” high-voltage transmission lines in the East Bay to prevent the start of a wildfire, power to the entire city of San Francisco could also be turned off. And it could be up to five days before power is restored.

Are we as a city — and each of us individually — prepared for that?

Imagine The City with no working traffic lights. Cellphone networks and internet phone lines could fail. People who depend on medical equipment, like oxygen machines, could be at risk. Food could spoil without refrigeration, both in restaurants and in homes. Schools would likely close for the duration of the outage. Hospitals, police stations, and the airport could continue to operate on backup generators, but with reductions in services offered.

And then there’s water and sewage. Gravity helps move water from Hetch Hetchy and other sources into the City’s largest reservoirs. But we need electricity to pump water from the reservoirs to homes and fire hydrants. And we need electricity to operate wastewater treatment plants.

We’re all used to the occasional power outage. But those tend to be very localized — a few blocks or maybe a neighborhood. And they’re usually over in a few hours, rarely lasting a full day.

If PG&E de-energizes the East Bay transmission lines that feed power into San Francisco, the entire city will be affected, not just a few blocks or a neighborhood. And it could be days before power is restored. That’s because the conditions — high winds, low humidity, dried-out vegetation — that lead to an increased wildfire risk can last for days. And, even if the weather improves, the utilities have to inspect every de-energized line before they restore power to it. And that takes time.

The North Marin Water District has spent more than $200,000 on portable generators to keep pumps working and water flowing in their service area. The East Bay Municipal Utility District is preparing to install 29 backup generators at water pumps throughout the East Bay. Both utility districts are warning customers that they will need to conserve water for the duration of a wildfire prevention power shutdown.

As for the City, San Francisco Public Utilities Commission Spokesperson Will Reisman told me in an email, “In response to the possibility of PG&E’s Public Safety Power Shutdowns, we are reviewing and validating our emergency generator inventory and capabilities. We have backup stationary generators at our most critical water facilities, which have enough fuel onsite to continue operations for extended periods of time without power. That includes facilities that serve as part of the Emergency Firefighting Water System. As the situation with PG&E evolves, we will continue to evaluate our backup power options to ensure continuity of our water and wastewater services.”

In past years, to prevent wildfires, PG&E shut down lower voltage distribution lines, which are the wires, usually attached to wooden poles, that deliver electricity to neighborhoods, homes, and businesses. But they left high-voltage transmission lines energized. Those are the electrical wires on tall metal towers that carry electricity across the state. But last year’s Camp Fire that devastated the town of Paradise appears to have started under a high-voltage transmission line. So, this year, to be safe, PG&E may de-energize the big transmission lines as well as the smaller distribution ones. And if enough of the big lines in the East Bay are de-energized, San Francisco could lose power.

I hope and pray conditions never get so bad that power to The City is cut off as part of a wildfire prevention power shutdown. But everyone — residents and businesses, not just city agencies — should be aware it could happen and should have contingency plans in place to handle up to a week without power.

Think of it as a test-run for when the Big One hits.

Sally Stephens is an animal, park and neighborhood activist who lives in the West of Twin Peaks area. She is a guest opinion columnist and her point of view is not necessarily that of The Examiner.

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