Construction Begins on Riverside Transmission Project Nearly Two Decades After 2007 Outage

Construction has begun on the Riverside Transmission Reliability Project, a $730 million infrastructure initiative addressing an electrical grid vulnerability that Riverside Public Utilities first identified in 1966. State grid operators gave initial approval for the project in 2006, with a 2007 power outage that left the city without electricity for more than four hours shortly after emphasizing the critical need for the upgrade.

The project will create a 10-mile, 220-kilovolt transmission line providing Riverside with a second connection to California's power grid. Southern California Edison and Riverside Public Utilities expect to complete the work by late 2028, with Riverside's portion of the cost totaling approximately $208.8 million.

Work began in 2025 with underground installation along portions of the route, including vault construction that started in late June. The project includes four miles of underground transmission lines and six miles of overhead construction using towers up to 180 feet tall, though the towers are not yet visible as crews focus on underground infrastructure and preparation work.

The Riverside City Council voted 4-3 in May 2024 to approve the project after years of community opposition centered on demands for more underground construction. Councilmembers Jim Perry, Philip Falcone, Steven Robillard and Sean Mill supported the motion, while Clarissa Cervantes, Chuck Conder and Steve Hemenway voted against it.

The transmission line will originate at a connection to the grid near the Ontario, Jurupa Valley and Eastvale borders, then cross the Santa Ana River near Goose Creek Golf Course and run along the river trail north of the Western Hills neighborhood and Hidden Valley Wildlife Preserve. Community members cited wildfire risks, aesthetic concerns and property value impacts in their opposition to overhead construction.

Riverside currently relies on a single 69-kilovolt connection to the statewide power grid, making it unique among major Southern California cities. Riverside Public Utilities has documented the need for a second connection since 1966, and the city formally requested one from SCE in 2004. The California Independent System Operator first approved the project in June 2006 after studies showed the need for additional transmission capacity. The 2007 outage demonstrated the vulnerability of the single-connection arrangement when damaged transmission lines cut power citywide.

The project, estimated to cost $730 million, is expected to be completed by late 2028, with Riverside's portion of the cost totaling approximately $208.8 million.

The California Public Utilities Commission approved construction in March 2020 after extensive environmental review, but work was delayed while the city explored underground alternatives through an outside consultant.

The City of Norco filed a petition seeking project modifications in 2023, but regulators unanimously denied the request in March 2024, finding that undergrounding concerns had already been adequately studied.

Construction timelines show underground work continuing through 2025, with overhead tower installation and restoration work extending into 2028. The project crosses portions of Riverside, Jurupa Valley, Norco and unincorporated Riverside County areas.

Riverside ratepayers have paid a reliability charge on their electric bills since 2008 to fund the project's planning and construction phases.

The new transmission line will connect to Wildlife and Wilderness substations being built east of the Riverside Regional Water Quality Control Plant. More information about the project is available on Southern California Edison and Riverside Public Utilities websites.