Sierra Pacific replaces cable in Emerald Bay | TahoeDailyTribune.com

Sierra Pacific replaces cable in Emerald Bay

Sierra Pacific has replaced more than 3,000 feet of underwater cable that was originally laid in Lake Tahoe 77 years ago.

In 1929 the stock market crashed, Connie Mack’s Philadelphia Athletics won the World Series and Sierra Pacific Power’s only underwater electric cable was lowered into Lake Tahoe at Emerald Bay.

Now, after 77 years of service, Sierra Pacific has replaced the submarine cable with a new 3,300-foot span of cable manufactured by Connecticut-based Kerite Cable Services, the same company that installed electrical cable on the bottom of the Panama Canal over 100 years ago.

The old electrical cable at Lake Tahoe has never failed, but was replaced as a preventative maintenance measure, according to Randy Kelly, area service manager for Sierra Pacific’s South Lake Tahoe District.

The Tahoe Regional Planning Agency issued a permit for this project, intended to improve utility infrastructure. The project is important for the community’s power reliability and telephone service and TRPA worked closely with the project applicants to ensure the construction created no environmental harm.

“TRPA understands how important power and telephone reliability is to the community, and we worked closely with the project applicants to ensure the construction caused no environmental harm,” said TRPA spokeswoman Julie Regan. “It’s projects like this where we can work together to be environmentally responsible and to improve community infrastructure that demonstrate a true win-win,” Regan said.

The new cable, consisting of a copper core wrapped with steel and then dipped in plastic, is 4.5 inches in diameter, approximately the same size as the cable that was replaced. As part of the project, the existing underground electrical vaults along the shoreline on both sides of the bay were also removed.

The cable provides the only direct electrical link on the west shore between the north and south shores of Lake Tahoe. An overhead power line that serves the west shore from a South Lake Tahoe substation terminates at the south end of Emerald Bay while another overhead line that serves the west shore from a substation at Tahoe City terminates at the north end of the bay. If either line fails, the underwater cable is energized and power is delivered to residents of west shore communities by the line that’s still in service. The new cable will be operated in the same manner.

Jeff Matthews, senior utility designer at Sierra Pacific’s South Lake Tahoe office, said the company originally decided to place the cable underwater rather than stringing it overhead on power poles because the terrain above Emerald Bay is extremely steep and subject to avalanches in the winter.

A specially-equipped barge was used to install the underwater cable. The barge was shipped to South Lake Tahoe by truck and assembled at the Tahoe Keys Marina by contractor Durocher Marine of Cheboygan, Michigan, Matthews said.

Durocher Marine also installed a new fiber optic cable for AT&T as a part of the project. Sierra Pacific and AT&T partnered in coordinating their work so that both cables could be installed simultaneously, minimizing the cost of installation and environmental impacts. The old power and phone cables were not removed from the lake because of their historical significance and because environmental studies of the project concluded it was best to not to stir up sediment by pulling them up, Matthews said.

Sierra Pacific’s portion of the Emerald Bay project is expected to cost approximately $650,000.

“The Emerald Bay submarine cable provides a valuable service to our customers at Lake Tahoe especially in the winter when storms can knock out overhead service,” explained Kelly. “Our objective with the project is to ensure this important link between the north and south shores of Lake Tahoe will be available to customers for many more decades to come.”

– Tribune City Editor Jeff Munson contributed to this report.