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Grant Lake hydro project a step closer FERC accepts license application, initiates environmental assessment for hydropower plant near Moose Pass on the Kenai Peninsula ALAN BAILEY Petroleum News
The Federal Energy Regulatory Commission has accepted a license application by Kenai Hydro LLC for the construction of a modest-sized hydropower facility at Grant Lake, near the town of Moose Pass, on the Kenai Peninsula, and has launched an environmental assessment for the proposed plant. Kenai Hydro LLC is a subsidiary of the Alaska Electric and Energy Cooperative, the business entity that operates power generation and transmission facilities as a part of Homer Electric Association. The proposed project lies within the Chugach National Forest.
FERC requires comments on the scope of the environmental assessment by Oct. 10. The agency has scheduled public meetings in the community of Moose Pass on Sept. 7 and 8, and an on-site review on Sept. 7.
In recent years Homer Electric, having switched from buying its power from Anchorage-based utility Chugach Electric Association, has brought on line its own gas-fired power generation capacity on the Kenai Peninsula. The utility also has a goal of meeting 22 percent of its peak annual generation from renewable energy sources by 2018 - in common with other Alaska Railbelt utilities, Homer Electric already obtains some of its power from the Bradley Lake hydropower facility in the southern Kenai Peninsula.
Near Moose Pass Grant Lake is an L-shaped water body in the hills above and to the east of the Seward Highway, where the highway runs through the valley of Moose Pass, with Grant Creek flowing from Grant Lake into Lower Trail Lake, just south of the southern end of Upper Trail Lake. According to Kenai Hydro’s license application, construction of the five-megawatt hydro facility would involve diverting water from Grant Lake through a tunnel to a powerhouse near the outlet of Grant Creek canyon, a natural rock canyon. The powerhouse would contain two turbines, with a maximum design water flow of about 385 cubic feet per second. The project would require an access road to the powerhouse and the water intake at the lake.
With a potential water drawdown from the lake’s natural water surface elevation of 703 feet to a minimum elevation of 690 feet, the hydropower system would have access to about 18,791 acre-feet of water storage in the 1,741-acre lake, the license application says. To provide the maximum volume of stored water following the spring runoff, the drawdown to the minimum elevation would take place during the winter. Although the project would change the natural water flow regime in Grant Creek, the change would have little, if any, impact on the existing aquatic resources, the license application says.
Development schedule Following land acquisition, permitting and the completion of engineering, Kenai Hydro sees the possibility of FERC approval of facility construction by January 2019. Construction could be completed in the fall of 2020, with commercial power production starting in early 2021. The estimated total cost of construction, including final engineering, is $52 million. Kenai Hydro says that developing its license application for the Grant Lake project cost $5.5 million, $2.1 million of which came from an Alaska Energy Authority grant. In the interests of minimizing the cost of power from the plant, Kenai Hydro will apply for whatever low cost loans and grants may be available for the project, the license application says.
Original application in 2008 The story of the Grant Lake project goes back to 2008, when Kenai Hydro applied to FERC for a preliminary permit for the project and for another proposed hydro project at nearby Falls Creek. The projects raised environmental concerns from local residents and others.
In March 2011 Kenai Hydro abandoned the Falls Creek concept, telling the FERC that it had determined that the project was not feasible. However, the company continued to pursue its Grant Lake proposal, conducting extensive environmental studies for the hydropower concept.
The company investigated several possible designs, including the construction of a 10-foot high concrete dam at the lake’s output. The eventually selected design eliminates the dam and involves a water intake below the level of the lake’s natural water surface, to the east of the lake’s outlet into Grant Creek. The license application says that this design “presents the optimum environmental configuration by eliminating the dam, eliminating the diversion of Falls Creek and placing the powerhouse tailrace upstream of the prime aquatic habitat.” A bypass pipe to Grant Creek from the project’s water intake in the lake would enable a required minimum creek flow rate to be maintained as necessary.
The project has raised numerous concerns about possible impacts on the Kenai River watershed. The historic Iditarod Trail from Seward to Nome also passes through the project area, a situation that has required discussions over any conflicts with the trail route. In 2010 FERC conducted a scoping study for an environmental assessment under the National Environmental Policy Act. However, the agency now says that, because the project has changed significantly since that earlier scoping study, it is re-initiating the scoping process.
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