AEA honing $4.5B cost estimate for Susitna-Watana dam

The Alaska Energy Authority is standing by the $4.5 billion estimated price tag for the Susitna-Watana hydroelectric project, but also contracting for a review of the Level 4 engineering estimate and creating a permanent “board of consultants” of five experts to monitor the megaproject through conclusion.

Current timelines project federal licensing by 2017, construction over the next five years and by 2023 annual generation averaging 2.5 million Megawatt hours, or nearly 50 percent of Railbelt electrical demand, according to the AEA.

Meanwhile, opposition to the project is forming. The Coalition For Susitna Dam Alternatives — which opposes any construction and claims membership of more than 1,000 persons growing by 50 per day, according to spokesman Richard Leo —also has plans to collect support through the summer but has other immediate plans.

Wayne Dyok, project manager for the AEA, also said it is on schedule to meet the July 16 deadline under its licensing plan for submission of its so-called study plan with the Federal Energy Regulatory Commission.

The study plan will include all the environmental, engineering and other studies needed to back the FERC permit application.

“I think right now we have lots of work to do to make sure we get the study plans in as good shape as we can by July 16,” Dyok said on June 5. He noted that the list of projects, with fieldwork in 2013 and 2014, was approaching 2,000 pages.

The current cost figure was released in April by MHW Global, a contract consultant to AEA on the project. A Level 4 estimate includes a -30/+50 percent margin of error.

The estimate “is a good number to use for the elevation 2,000 (feet above sea level) configuration,” Dyok said.

He was hired to his job last November, but was a contract consultant on a 1978 proposal that included two dams.

The current project is a single, 700-foot tall dam on the Susitna River, 165 miles north of Anchorage. It would also create a 39-mile long reservoir up to two miles wide in some areas.

The earlier project did file a FERC application. It was withdrawn in 1986, in large part because the low cost of oil and natural gas from reserves now nearing depletion.

Its cost estimate was $5.4 billion (in 1985 dollars). The current proposal’s estimate is based on modeling from the earlier project, according to Emily Ford, AEA spokeswoman.

The seemingly low cost against its 27-year old predecessor is also based on the use of “roller compacted concrete.”

Developed in British Columbia in the 1970s, use of the technique would vastly decreases the amount of fill needed, but it has never been used in a project of this size in Alaska.

“We have found no fatal flaw in the basic concept of building the Full Watana Dam or High Devil Canyon dam using RCC,” according to a 2009 review of the earlier project completed by R&M Consultants Inc.

A rockfill dam at the new project would require 60 million cubic yards of material.

“With the development in this RCC methodology, we’re looking at a little over five million cubic yards,” Dyok said.

Concern with the use of RCC in Alaskan weather conditions was raised at that time and is still lingering in some quarters. Ford noted RCC dams that have been built in Russia, China, Mongolia and at 7,000 feet above sea level near Stillwater, Utah.

“Temperature swings at that elevation are much higher than in the Susitna-Watana Hydroelectric Project area,” Ford wrote in an email.

The Upper Stillwater Dam is 815 feet tall and 2,673 feet wide. Completion of RCC on that project took two years and came in October 1987 after two seven-month winter closedowns, according to the website of Malcolm Dunstan & Associates, a consulting engineer.

The Asian dams are at longitudes south of the Watana site and were completed relatively recently. The 456-foot high Bureya Dam is located about 210 miles northwest of Khabarovsk, Russia, and the same longitude as the northern end of Vancouver Island. It was begun in 1976, but not completed until 2009 and is still being commissioned for generation last year.

The 11 MW Taishir, Mongolia, hydroproject, about 1,100 miles northwest of Beijing, at the longitude of Willapa, Wash., is almost 7,700 feet above sea level and began generating electricity in 2008.

“We are going to be issuing an RFP to have another entity with construction experience in Alaska and also with RCC-type hydro dams to come in here and do an independent verification of our consultant’s costs,” Dyok said.

The RFP is one of two he expects to issue in July. The other, still being designed, will establish a five-member board of consultants, each with a specific expertise, for the life of the project.

The anti-dam coalition gained 400 members through its booth at the March sportsman’s show in Anchorage and that some 90 percent of those who stopped at the booth left it opposing the project.

“Pretty much everybody who actually understands what’s going on with this dam are opposed to it,” Leo said June 20. The group will have booths at the Alaska State Fair in Palmer and the Salmon Stock Music Festival, in Nikiski, Richard Leo said.

Membership requires a signed statement, on its website, through Facebook or on paper, opposing the project, he explained. How it will bring the influence to bear on the project remains to be seen.

“There are no plans to bring any signatures to the legislature next session. The whole focus on outreach is education,” Leo said.

The coalition says the dam is unnecessary because state-subsidized production of natural gas from Cook Inlet, and increasing alternative energy production, could supply the needed power with far less environmental impact.

“Financing by the state to find and develop its Cook Inlet gas resource could be as little as 50 percent of the required investment in the hydropower dam ... An affordable, stable, long-term source of energy for the Railbelt will only occur with state subsidy. This is just reality,” the group said in formal comments on project scoping filed with FERC in May.

Updated: 
06/28/2012 - 2:21pm

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