By raising the Blue Lake Dam 83 feet, and increasing the “head” of the entire hydro system, Sitka can generate more power. But the increased pressure on old infrastructure — like this control valve installed in 1959 — is unsafe, according to a recent engineering report. The question is: Fix the bulk water system now, or spend the same amount of money in two years and replace it entirely? (GPIP image)

Sitka’s future in the bulk water business has taken a complicated turn, after a recent engineering report concluded that the city’s bulk water system is unsafe to use.

The city has earned $1.4 million selling bulk water contracts over the last ten years, but no one ever took delivery. The new report suggests that delivery might not have been possible.

That leaves municipal officials wondering how to move forward with Sitka’s bulk water business which, under ideal circumstances, could be worth $95 million dollars a year in revenue.

The Sitka assembly will meet on Thursday (3-21-19) to figure out what to do.

The study by Seattle-based engineer Paul Carson is exhaustive.

But it really boils down to this:

“I believe that the two 36-inch valves, the way they’re configured in the existing system, they’re at a very high risk of not working properly, and the system is not safe,” he said via teleconference, to the board of the Gary Paxton Industrial Park on Thursday (3-14-19).

You can find Carson’s complete report on the Sitka Electric Department studies page.

Since 2007, the park has spent $1.5 million from various funding sources to develop a bulk water delivery system from the Blue Lake hydro project.

No one’s used the system, but over the last 10 years Sitka has sold $1.4 million in rights to buy the water. To put it very simply, due to high transportation costs and the decreasing price of desalination, the bulk water market has not developed — not yet anyway.

See a Powerpoint presentation on Sitka’s industrial water infrastructure.

So why not hedge your bets and replace a couple of old valves?

“The safe arrangement, using the most amount of the existing system is to install a new flow control valve down near the existing root valves,” Carson continued. “And that has some safety concerns. And that arrangement, I think, has a similar cost to an all-new system that does require a tunnel shutdown to install.”

Although it wouldn’t hurt, you don’t have to be an engineer to parse Carson’s advice. Sitka can spend a lot of money patching up the system now, or spend the same amount on a brand new system in the future — when the Blue Lake tunnel is shut down. The tunnel is what brings the water down from Blue Lake to the hydroelectric project. The bulk water pipeline is connected to the penstock, the pipe which feeds water from the tunnel to the generating turbines.

But the Blue Lake project won’t be shut down — and the tunnel drained — until 2020 at the earliest. And before that can happen, Sitka has to develop a federally-mandated alternative drinking water supply, at a cost of $18 million. What that project will look like — and where the money’s coming from — hasn’t been determined yet.

Some other information in the Paul Carson study:

— Sitka’s bulk water infrastructure was installed in 2007. The Blue Lake Dam was raised 83 feet in 2014, significantly increasing the “head” of the hydro system, and the pressure inside the penstock and all other water infrastructure.
— Bulk water customers would expect a flow rate of 100 cubic feet per second to fill a tanker, according to Carson’s research. Sitka’s system couldn’t supply that rate without another $3 million investment — from the customer, presumably — in a pumping equipment at the dock.

Garry White, the director of the industrial park, is the person who markets Sitka’s bulk water. He’s negotiated the contracts that have brought in $1.4 million for water rights. He says he feels like a used car salesman now, and both his and Sitka’s reputations are on the line.

White asked for direction from the park board.

“We’ve got to know what you want to do,” he said. “Because I’ve got customers calling me that want to take water. I don’t know what to tell them anymore. So we’ve got to get this figured out if we’re going to still move forward with bulk water, and if so what’s the time frame? Do we want to continue to market water? I’m of the opinion that I don’t want to continue to market water until it’s fixed.”

The members of the park board were in favor of continuing to market bulk water. Member Sheila Finkenbinder asked if Carson would be willing to condense his findings into layman’s language.

Board chair Scott Wagner recommended that Carson’s summary also include a recommendation, on a deadline.

“The cheapest, quickest way to do it, as well as the best long-term solution. And have it in a memo by next week.”

Wagner will present Carson’s findings to the Sitka Assembly in a special meeting on March 21.