State of Alaska Devil's Canyon dam is envisioned as a double-curvature, thin arch to provide hydropower.

The state legislature has put $2.5 million into its fiscal year 2009 budget to help determine the feasibility of a Susitna River hydroelectric project. “A lot of people were against it 25 years ago when natural gas was cheap,” says state Senator Gary Wilken (R), whose Fairbanks constituency could be served by it.

The federal government first researched the Upper Susitna River as an energy source in the 1940s and the state spent $134 million studying its potential. In 1984, it submitted a Federal Energy Regulatory Commission application for a license to build two dams at a cost of $5.5 billion. It withdrew the application a year later when the price of oil dropped and funding sources disappeared.

The most recent proposal envisions a two-dam operation capable of providing 1,620 MW. Watana Dam, an 840-ft-high rockfill dam, would be built first and could yield 750 MW. An underground powerhouse would house six 170-MW turbines. A second dam at Devil’s Canyon, a concrete, double-curvature, thin-arch structure, would be added if capacity is warranted. Its powerhouse would hold four 150-MW Francis turbines.

The Susitna site sits midway between the state’s biggest population centers, about 150 miles from Anchorage and Fairbanks. Power would be wheeled through a double-circuit, double-tower 345-kV transmission system.

It would take up to four years to obtain licenses and 10 years to build the entire project, according to Eric Yould, who has studied Susitna dams since the 1970s for federal, state and private entities. He estimates the project’s costs would be at least double with what they were in the mid-1980s.