LOS ANGELES (CBSLA) — The California Independent System Operator Friday declared a statewide Stage 3 Electrical Emergency due to high heat and increased electricity demand — initiating rotating outages throughout the state — for the first time since 2001.

“Several days ago we started seeing the weather forecast and we knew this was going to be a uniquely excessive, very hot heat wave,” Ann Gonzales, of Cal, ISO said. “And so we started at that point ordering our generators to stay online and to defer maintenance so that we would have everything in service.”

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On Thursday, Gonzales said the operator was looking to increase the capacity but were unable to secure additional power. On Friday at about 6:36, Cal ISO declared the Stage 3 emergency as demand outpaced availability.

“The California ISO is working closely with California utilities and neighboring power systems to manage strain on the grid and to restore the power grid to full capacity,” the operator said in a statement. “As portions of the grid are restored, local utilities will restore power in a coordinated fashion.”

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The rolling outages will not impact Los Angeles Department of Water and Power customers, according to the department.

“LADWP is a municipally owned utility and owns its own generation, but has the ability to buy and sell power back and forth to the rest of the grid as needed and as available,” the department said in a statement. “Our own generation and transmission are the reasons we aren’t affected.”

As of 7:12 p.m., Southern California Edison confirmed it had started rolling power outages but would not specify in which regions due to public safety concerns.

Throughout the evening, outages were reported in the following areas:

LOS ANGELES COUNTY

The Beverly Hills Police Department announced it was aware of a planned power outage by Southern California Edison occurring in our city, north of N. Santa Monica Blvd.

The San Gabriel Police Department reported a power outage along Valley Boulevard that was impacting traffic signals between New Avenue and San Gabriel Boulevard.

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The Pasadena Department of Water and Power said outages reported throughout its service area were related to the emergency declaration, though it said power would not be off for more than an hour. As of 8:45 p.m. the city of Pasadena reported that Cal ISO told officials outages from that region were no longer needed.

Calabasas said it was told SCE might start rolling blackouts in the city Saturday at 7 a.m. in an effort to decrease the expected heavy load on the power grid. These outages were expected to last for one hour.

ORANGE COUNTY

Anaheim said rolling power outages were occurring across the city due to the state’s Flex Alert, but said outages should not last more than 15 minutes.

San Diego Gas and Electric said it has been directed to initiate one-hour outages throughout San Diego and south Orange counties.

The Huntington Beach Fire Department said it was getting reports of multiple power outages and asked people to refrain from calling 911 unless there was a life-threatening emergency.

The Seal Beach Police Department said it was told by SCE that rolling power outages were expected in the area.

VENTURA COUNTY

The Simi Valley Police Department reported traffic signals were out due to a power outage in the area of Royal and Los Angeles avenues.

The Cal ISO Stage 3 Emergency was set to expire at midnight, though the agency had lifted the declaration by 9:45 p.m. The agency also said there were no additional outages planned.

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“We are still hoping that consumers are conserving and can bring some of the demand down so we can limit power disruption,” Gonzales said.