Released on Oct. 29 by the Federal Energy Regulatory Commission was a draft environmental impact statement on the 19.8-MW Sweetheart Lake Hydroelectric Project in Alaska, with the draft EIS now up for comment until Dec. 29.
The project would be located on 5.4-mile-long, 0.6-mile-wide Lower Sweetheart Lake, which flows into Sweetheart Creek, which is located in the City and Borough of Juneau, Alaska. The proposed project would occupy 2,058.24 acres of federal lands within the Tongass National Forest, administered by the U.S. Department of Agriculture, Forest Service. The proposed project would generate an average of about 116,000 megawatt-hours of energy annually. In May 2014, Juneau Hydropower Inc. filed an application for an original license for this project.
The proposed project would consist of new facilities that include:
- a 280-foot-wide, 111-foot-high roller-compacted concrete dam to be constructed at the existing natural outlet of Lower Sweetheart Lake, with a 125-foot-wide ungated overflow spillway at a crest elevation of 636 feet;
- an arched reservoir outlet tunnel at the right dam abutment;
- a 9,612-foot-long horseshoe-shaped, unlined underground power tunnel;
- a steel penstock installed within the lower portion of the power tunnel;
- three buried steel penstocks connecting the lower portion of the power tunnel to the powerhouse;
- a 160-foot-long, 60-foot-wide, 30-foot-high concrete and steel powerhouse;
- three 7.1-MW Francis turbines with 6.6-MW generators with a total installed capacity of 19.8 MW;
- a 541-foot-long, 30- to 90-foot-wide rock tailrace with a fish exclusion structure, discharging to Sweetheart Creek;
- an 8.69-mile-long, 138-kV transmission line traversing Gilbert Bay, the Snettisham Peninsula, and Port Snettisham;
- a 22,000-square-foot fenced switchyard adjacent to the powerhouse;
- a 4,800-foot-long, 12.47-kV service transmission line and communication cable extending from the powerhouse to the dock and caretaker’s facility, providing operational electricity and communications; and
- a 10,000-foot-long, 12.47-kV service transmission line and communication cable extending from the powerhouse to the dam site, providing operational electricity and communications.
Said the draft EIS, written by FERC staff: “Based on our analysis, we recommend licensing the project as proposed by Juneau Hydro with some staff modifications and additional measures.”