Environmental Assessment for Watershed Enhancements at Joint Base Elmendorf-Richardson
MWH AMERICAS INC ANCHORAGE AK
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DESCRIPTION OF THE PROPOSED ACTION AND ALTERNATIVES The U.S. Air Force s USAF 673d Civil Engineering Squadron CES is proposing to conduct watershed and fishery enhancement activities in the Otter Creek and Sixmile Creek watersheds at JBER. The Proposed Action in the Otter Creek watershed includes 1 eliminating northern pike Esox Lucius from Otter Lake via gill netting and application of the piscicide rotenone and 2 restocking the lake with rainbow trout Oncorhynchus mykiss. Alternatives considered for achieving the desired objectives at Otter Lake include limitless pike angling, gill netting andor electrofishing in combination with restocking Otter Lake with anadromous fish. The No Action Alternative would allow invasive northern pike to continue to inhabit Otter Lake. The Proposed Action in the Sixmile Creek watershed includes removing the existing fish ladder at the Lower Sixmile Lake outlet and replacing it with a modified stream channel design to facilitate fish passage. Alternative fish ladder designs were considered for achieving the desired objectives at Lower Sixmile Lake, but all were considered inferior to a natural roughened channel design for longevity, aesthetic value, and effectiveness in passing salmon species of all age classes. The No Action Alternative would leave the current Lower Sixmile Lake fish ladder in place and unchanged. The Phase II Option includes additional enhancements in the Otter Creek watershed, based on the efficacy of pike eradication efforts under the Proposed Action at Otter Lake. Phase II activities include stocking Otter Lake with coho salmon Oncorhynchus kisutch, removingmodifying physical barriers impeding anadromous fish passage between Eagle River and Otter Lake. The design of the step-pools would be determined at a later time, but prior to implementation of the Phase II Option.
- Civil Engineering