FERC issues Grant Lake hydro license
Hydropower system on Kenai Peninsula will involve 5 megawatt powerhouse using water diverted from lake in hills near Moose Pass
The Federal Energy Regulatory Commission has issued a license to Kenai Hydro LLC for the construction of a hydropower system at Grant Lake on Alaska’s Kenai Peninsula. The agency published a final environmental impact statement for the project in May. Kenai Hydro is a subsidiary of the Alaska Electric and Energy Cooperative, the entity that generates and transmits power as part of Homer Electric Association. HEA wants to build the facility in support of a goal for the use of the renewable energy as part of the utility’s power generation inventory.
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. The 5 megawatt hydro facility would use water diverted from Grant Lake through a tunnel to a powerhouse near the outlet of Grant Creek canyon, a natural rock canyon.
Environmental impactsWhile the project proposal has raised numerous concerns about possible impacts on the Kenai River watershed, the FERC has recognized that the hydro facility would provide power for the Alaska Railbelt and thus displace some power generated from nonrenewable resources. The project will clearly have some environmental impacts, but the approved design of the system includes features targeted at keeping those impacts to a minimum. For example, rather than using a dam at the outlet from Grant Lake, a water intake below the lake’s natural water level will be installed, in conjunction with a diversion weir and an underground bypass pipe that will be able to maintain the required minimum flow rate in Grant Creek.
A 3.6 acre detention pond will store water that can be used to boost power generation without causing rapid fluctuations in the flow rate in Grant Creek, at times when the hydropower system has to provide reserve power in support of peaks in power demand on the Alaska Railbelt electrical system.
Although salmon and other fish species spawn in the lower reaches of Grant Creek, there are impassible falls that prevent anadromous fish from reaching Grant Lake.
The Iditarod TrailOne particular challenge results from the fact that historic Iditarod Trail from Seward to Nome passes through the project area. The FERC license says that Kenai Hydro has proposed some rerouting of the trail to accommodate the hydropower system and that the EIS had found that the proposed project does not conflict with the character of the trail. Under the terms of the license, Kenai Hydro, in consultation with the relevant state and federal agencies, must develop a plan for rerouting the trail - the U.S. Forest Service must approve the plan. There are stipulations regarding trail maintenance and maintenance costs within the impacted section of the trail route.