City Utilities Department employees then restored power within 30 minutes to the estimated 28,000 customers left without electricity due to a small plane that severed main transmission lines serving Palo Alto.
Contrary to earlier reports that a larger area was impacted, the outage affected just Palo Alto, officials said.
PG&E crews struggled all day to restore power, finally erecting temporary power poles in the late afternoon.
Most city facilities, including City Hall and the Police Department, lost power, though police had limited power through a generator. City officials had also activated an Emergency Operations Center to oversee the response to the power outage, which included increased traffic patrols. Most of the city's traffic lights either lost power or flashed red throughout the day, but there was no surge in accidents beyond the eight to 10 reported on a rainy day, police reported.
Police Chief Dennis Burns said there were simply too many intersections to staff them with officers to do traffic control, and they were needed for regular patrol duties and to deal with situations relating to the outage.
He said the state Vehicle Code is specific on power-outages at signalized intersections and says that motorists should treat it as a four-way stop intersection.
He said in the first hour of the blackout there were 220 9-1-1 calls, a number of which needed specific police responses.
"We had to pick and choose" how to use the 14 or 15 officers on duty, he said.
Also, he said a worst-case possibility was that the outage could last 24 hours, which added to the challenge of staffing intersections.
Mayor Pat Burt said city workers from the Utilities, Public Works, Police and Fire departments all took part in the city's emergency response following the outage.
The transmission tower is located west of Palo Alto Airport and includes three transmission lines that carry power to Palo Alto, said Joe Molica, PG&E spokesman. The plane damaged both a tower and the lines.
Molica said no PG&E customers lost power as a result of the crash. A small pocket of residents in East Palo Alto, near the crash site, also lost power.
PG&E workers installed two wooden transmission poles on Cypress Road in East Palo Alto Wednesday afternoon, he said.
Molica said once the new line is installed the company would focus on repairing the damaged lines and creating redundancies in the power system.
The city repeatedly asked residents to conserve water because of the outage affecting pumps. But that warning was precautionary, according to Linda Clerkson, the city's information officer.
The city's Utilities Department said it has backup generators for its four pump stations that lift water to reservoirs in the hills for the gravity-fed system.
"Because we did not know for sure how long the citywide power outage would last, we urged water conservation to minimize strain on water storage and the backup generators on the pump stations," according to a department statement.
In addition, reducing water use also cuts flow to the wastewater treatment plant, "which reduces strain on the system operating under backup generation," the statement said.
To community questions about pumps to prevent flooding, the city's Public Works Department said major improvements have been made since the big flood of 1998, funded by a storm drain fee approved by voters. All four major storm-water pumping stations have back-up generators that start automatically when needed: at the Palo Alto Airport and at Matadero, Adobe and San Francisquito creeks.
Four minor pumping stations have receptacles for portable generators when needed, the department said.
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