01 05 17 Undergrounding

SDG&E Makes Further Investments to Underground Power Lines

Jan. 15, 2020
The project will allow several key facilities to remain powered during safety power shutoffs.

As part of its ongoing effort to reduce wildfire risk and the impact of Public Safety Power Shutoffs (PSPS) during extreme weather conditions, San Diego Gas & Electric is working to expand the underground electric infrastructure in the town of Julian in San Diego County, California.

The project will take place east of the commercial core of downtown Julian along Banner Road (State Route 78) and Cape Horn Avenue, which are currently served by overhead power lines.

Once completed, the project will allow several key facilities to remain powered during safety power shutoffs. Unlike overhead power lines, underground lines do not present a fire risk during high winds and elevated fire danger conditions. Facilities that will benefit from the undergrounding work include: the post office, county branch library, Julian Union High School, Julian Charter School, Julian Elementary School and the CAL FIRE Station, as well as a county public works maintenance yard and a school bus yard.

Existing overhead power lines in the area will remain, as they are needed to continue serving some customers.

Currently, the commercial heart of downtown Julian is served by underground power lines. As a result, SDG&E is able to power Main Street businesses with a 1-megawatt mobile generator during power shutoffs. However, the existing undergrounding infrastructure does not extend to key community facilities that are located just outside of the commercial core.

Undergrounding is Part of Strategic Wildfire Safety Program

Strategic undergrounding of overhead power lines is one element of a multi-pronged approach to reducing wildfire risk. Over the past decade, SDG&E has implemented, and continues to improve, its comprehensive wildfire risk mitigation program. This includes significant investments to replace wood poles with fire-resistant steel poles; building a sophisticated weather monitoring network and fire and weather forecast models; updating operating protocols; and building partnerships to enhance the region’s overall ability to respond to wildfires.

Its 2019 Wildfire Mitigation Plan outlines a suite of programs and initiatives to continue to advance wildfire safety. One of those initiatives is strategic undergrounding of overhead power lines. Burying power lines removes the risk of these lines sparking fires during adverse weather events, but more importantly, buried lines can remain energized during safety power shutoffs, reducing the impact of power outages to fire-prone communities.

Project schedule

The Julian project will be completed in two phases over the next few months. While SDG&E’s goal is to complete the project as quickly as possible to minimize impact on the community, rainstorms and other unforeseen weather conditions could affect the construction schedule.

Phase I construction is scheduled to take place from December 2019 – January 2020 and Phase II construction is currently in design and that schedule is being determined.

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