Eightmile dam needs federal approvals

May 23, 2020

The Forest Service foresees the need for two permits and presidential exceptions on a rebuilt Eightmile Lake dam.

At a recent meeting of environmentalists, officials, and Icicle work group members, a Forest Service official explained his agency's position on current plans by the Icicle-Peshastin Irrigation District to rebuild the Eightmile Lake dam. He stated that the Forest Service foresees a need for two federal permits, a NEPA process, and two presidential exceptions before the dam can be rebuilt under any of the current proposed designs.

One permit and presidential exception would be required, he explained, because the level of Eightmile Lake would drop below the lowest lake level when Congress created the Alpine Lakes Wilderness in 1976.

A second permit and presidential exception would be required, he says, because all current designs for the dam propose that the siphon outlet would be at a lower elevation than the current one, extending farther into the wilderness than before.

The lower lake level and lower siphon outlet are obviously related and the main source of controversy. This lower siphon outlet, coupled with the siphon intake extending deeper into the lake, would allow the irrigation district to withdraw approximately 2,500 acre-feet of water, the maximum allowed under its 1920s water right. The irrigation district has never withdrawn more than about 1,700 acre-feet of water from Eightmile Lake, leading some to argue that the irrigation district has forfeited its right under state law to withdraw more. This remains the major point of contention.

The Forest Service and state Department of Ecology plan to prepare a joint EIS (environmental impact statement) to comply with both NEPA and SEPA (the federal and state environmental policy acts). The Department of Ecology predicts it will select environmental consultants within the next month to start preparing this EIS. The EIS apparently will address whether to grant the foregoing permits and whether to approve the proposed new dam. The latter requires approval from Ecology's Office of Dam Safety.