Repairing lines after avalanche a tricky business

JUNEAU, Alaska — The avalanches that thundered out of the coastal range near Juneau last month uprooted old-growth forest, mangled transmission towers and ripped out a portion of the high-voltage lines that link the Snettisham hydroelectric plant to Alaska's capital city.

Now, with ratepayers on the hook for an estimated $18 million in fuel to power backup diesel generators for three months, the power company is pressed to repair the damage as soon as possible.

It's a tricky business.

The massive slides April 16 left in their wake a jumble of snow — at least 10 feet deep in places — mud, rock and splintered trees while even more snow hung menacingly along the steep slopes above.

Forty years ago, the U.S. Army Corps of Engineers built the Snettisham plant in a spot where the annual 180 inches of precipitation is three times the average at the Juneau airport.

It's good for keeping the lakes filled; not so good for avalanches.

Burrowing into the base of a mountain, the engineers hollowed out a rocky bunker that would be fitting digs for a James Bond villain.

This is where water from two high mountain lakes, cascading down tunnels more than a mile long, powers three generators capable of producing a total 78 megawatts of power — almost enough juice for a city of 30,000 people.

Snettisham is still producing electricity but just enough to keep its own lights on while it serves as a staging area for some 20 people either working on repairs or as support.

Though some residents in Juneau grumble at what they consider to be foolhardiness, Alaska Electric Light and Power is restoring the towers and line just where they were.

Company officials determined early on that it would be the quickest way to restore power and, with diesel priced at $4 a gallon, the most economic.

This month, ratepayers are facing a 400 percent increase in their bills to pay for the fuel.

"This is a $7 million fix," said Alaska Electric general manager Tim McLeod. "The real cost though is the cost of oil in the meantime. So the time it's down is worth a lot more than it used to be."

Only later will they review other options such as submarine cables, reinforced towers and avalanche-diversion structures, balancing the risks with each options' total life cycle costs.

None would be quick or cheap, McLeod warned. Each would likely require years of surveys, engineering and review and cost millions of dollars to finance.