About the Project

Background

The proposed Chakachamna Hydroelectric Project (Chakachamna Project or Project) is located approximately 85 miles west of Anchorage and 42 miles west north west from the Chugach Electric Association (CEA) Beluga substation that feeds power to the “Railbelt” grid system. The power potential of the Project has been investigated for more than 60 years with the first studies conducted by the U.S. Geological Survey (USGS) in 1948 and published in a report entitled Report on Reconnaissance of Lake Chakachamna. Additional studies were carried out initially by the U.S. Bureau of Reclamation and later by the U.S. Army Corps of Engineers (USACE). Power potential from Chakachamna, depending on various development scenarios, ranges between 300 and 400 megawatts (MW) based on a 50% plant factor. While this is a substantial amount of power, neither federal agency chose to pursue the project because each was vying for its own much larger project in the 1960s: Susitna (1,600 MW) for the Bureau of Reclamation and Rampart (6,400 MW) for the USACE.
The State of Alaska, through the Alaska Power Authority (APA), carried out the most definitive investigations of the potential development of Chakachamna (Cited hereafter as Bechtel, 1983). Although the Power Authority had begun investigations of the Susitna Hydropower Project in the late 1970s, it chose to investigate the merits of Chakachamna as well. Chakachamna was viewed at the time as a fairly straightforward project that could be brought on line prior to Susitna to meet the growing power needs of the Railbelt (the load center from Fairbanks to Anchorage and the Kenai where roughly 70 percent of Alaska’s population resides).
The Power Authority contracted with Bechtel Engineering (Bechtel) to evaluate the viability of the Chakachamna Project in the late 1970s and early 1980s. The Bechtel studies resulted in the recommendation of a 330 MW development that would include a 183-meter (m) (600-foot) long and 15-m (49-foot) high rockfill embankment structure located at the outlet of Chakachamna Lake, a lake tap at Chakachamna Lake and a tunnel to an underground powerhouse and tailrace at the McArthur River. Section 1.3 below describes how this early configuration has evolved in response to stakeholder questions and comments into the project being proposed by TDX.
The Chakachamna Project was ultimately put aside in deference to the Susitna hydropower project; the latter was ultimately terminated in 1985 when the price of oil fell below $10 per barrel. Hindsight suggests that the Railbelt market may well have been better served by the smaller Chakachamna Project.