Caltrans, Comcast agree to add new cables through Devil’s Slide tunnels

Aug 24, 2023

Elected representatives have been meeting with telecommunications company officials in an effort to bring greater redundancy to connections across the coast. They say Comcast will soon have a new line through the Devil's Slide tunnels.

Officials representing the Coastside have initiated a deal with the state and telecommunications companies to install fiber optic cables through Devil's Slide, bringing in a second source of connectivity service that advocates say is critical to keeping local emergency communication intact.

Earlier this year San Mateo County Supervisor Ray Mueller, U.S. Rep Anna Eshoo and representatives from Caltrans, Comcast, AT&T and PG&E agreed to add redundant fiber optic cables through a conduit maintained by Caltrans in the Devil's Slide tunnels by the end of 2023.

Comcast, which serves the largest number of coastal customers, has a single above-ground cable running from San Mateo through La Honda before turning north along Highway 1 and into Montara. This single track means that when the cable is damaged, Comcast cannot provide services from another direction. That lack of redundancy is unusual in populated suburban areas.

AT&T currently has a redundant fiber optic path through Devil's Slide. The Comcast cable would run alongside the AT&T cable in the tunnel.

"With only one wire connecting the coastline to the rest of the county, there needs to be a sense of urgency in creating cable redundancies in Devil's Slide so that our communities on the coast can communicate and emergency personnel can respond promptly during storms and other natural disasters," Eshoo said in a statement to the Review.

Power and internet outages are all too familiar on the Coastside, particularly in rural South Coast areas.

But Comcast's redundancy problem was underscored during the storms in early 2023. On Jan. 15, one tree knocked down a telecommunications line that hosted wires from AT&T, Verizon and Comcast. The incident caused widespread internet and cellular service outages across the Coastside. Advocates for redundant fiber optic cables say the service is critical for alerting people about emergencies or evacuation alerts.

Adriana Arvizo, a communication manager with Comcast, said that the utility company has been studying the problems connecting the Coastside in public forums and meetings since April 2019. Comcast provides services to nearly 15,000 people in Half Moon Bay and surrounding coastal areas.

"For years, Comcast has engaged — and continues to engage — with local, state, and federal elected officials, as well as public agency staff representing San Mateo County's Coastside communities to solve for the complexities of providing primary and backup service to our residential and commercial customers," Arvizo said in a statement to the Review. Two years ago, Comcast stated that running a cable through the Devil's Slide was impossible because of national security concerns from the U.S. Department of Homeland Security, but did not specify what those concerns were.

Comcast did not comment on what specific additional equipment would need to be installed for redundant service, nor if it planned to connect its cable to power poles jointly owned by AT&T and PG&E.

The deal to add a Comcast cable on Devil's Slide traveling south hinged on the fact that telecommunications companies submit designs. Caltrans has asked the county to streamline the permitting process.

August Howell is a staff writer for the Review covering city government and public safety. Previously, he was the Review's community, arts and sports reporter. He studied journalism at the University of Oregon.

Great news! We were isolated during the Great Storms of 2022/23 and this will go a long way to keep us connected when this happens again.

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