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Energy authority moves a step forward on Susitna dam

Alan Bailey

The Alaska Energy Authority has taken the next step toward construction of a major hydroelectric power plant at Watana on the upper Susitna River by filing a license pre-application with the Federal Energy Regulatory Commission.

The authority will eventually need a FERC license to build the power plant and put it into operation -- the pre-application marks the beginning of the formal licensing process, a process that includes a series of studies into the potential environmental effects of the hydropower facility.

PROJECT SCHEDULE

The energy authority expects to complete the required studies and submit a license application by mid-September 2015. The project plan for the facility also includes site surveys and preliminary engineering work, to be carried out this year, with an economic evaluation and financing plan to be developed early in 2013. A final design for the facility should be completed in 2016. Assuming that a FERC license is forthcoming in 2017, the authority expects system construction and startup in late 2023.

With a capacity of 600 megawatts, the dam would represent a major diversification from the region's heavy dependence on natural gas-fueled power stations. The facility would also be a major step toward achieving a state goal that at least 50 percent of Alaska's electricity come from renewable energy sources by 2025.

But it would also stop a major free-flowing river. Talkeetna residents have been organizing against the project.

For state officials, the pre-application was a critical milestone.

"This is an important day, not only for the Susitna-Watana hydroelectric project, but for long-term and stable electrical energy for generations of Alaskans," said energy authority Board Chairman Hugh Short on Dec. 29.

700 FEET HIGH

The pre-application document says the design of the dam is still being evaluated, but it would likely stand 700 feet above its foundation, with a crest length of about 2,700 feet, creating a 39-mile-long reservoir upstream. The site is about 90 river-miles northeast of the community of Talkeetna.

Three alternative routes are being considered for access roads to the area. One alternative would run west from the dam, staying north of the Susitna River, and meeting the Alaska Railroad and the Fairbanks-to-Anchorage electrical transmission intertie near Chulitna.

The second alternative would also run west, but south of the river, and meet the railroad and intertie near Gold Creek.

The third alternative would run north from the dam to connect with the Denali Highway, to the south of the Alaska Range.

Power transmission lines connecting the dam with the Fairbanks-Anchorage intertie, and then to the Alaska Railbelt power grid, would roughly follow one or more access road routes. A transmission line following the route to the north would continue along the Denali Highway to connect with the intertie at Cantwell on the Parks Highway.

600 MEGAWATTS

Although the design currently envisions an installed capacity of 600 megawatts using three generators, it's possible that could be increased to 800 megawatts by the time that the final FERC license application is submitted, according to the pre-application.

Once the system goes into operation, the topping up and drawing down of the system's reservoir would be timed to meet Railbelt demand, with peak loads during winter. The facility would produce an average of 250 megawatts of guaranteed power between November and April, but with power output perhaps varying briefly between 100 megawatts and 500 megawatts, the pre-application says.

STUDY TOPICS

The project is likely to require environmental studies on water resources and water quality, fish distribution and abundance, wildlife and botanical resources, subsistence resources, recreational land use, cultural resources and potential socioeconomic and transportation effects.

The energy authority says it is committed to planning for the protection and enhancement of environmental resources.

To view the planned project site in summer, FERC staff visited the site on Aug. 29. FERC now plans to hold scoping meetings in March for an assessment of the project under the National Environmental Policy Act. That scoping will ultimately lead to the preparation of an environmental impact statement, starting after the authority applies for the FERC license. The impact statement would have to be complete before FERC can issue the license.

The authority has established a project website at www.susitna-watanahydro.org. This website acts as a distribution center for key project documents. The schedule for the FERC scoping meetings will be published on the site.

The Coalition for Susitna Dam Alternatives also has a website: susitnadam alternatives.org.


By ALAN BAILEY
Petroleum News