B O N N E V I L L E P O W E R A D M I N I S T R A T I O N UNITED STATES FOREST SERVICE Eightmile Ranch Coho Acclimation Site Draft Environmental Assessment December 2014 DOE/EA-1959 Eightmile Ranch Coho Acclimation Site Draft Environmental Assessment DOE/EA-1959 Bonneville Power Administration U.S. Forest Service, Okanogan-Wenatchee National Forest Methow Valley Ranger District December 2014 This page intentionally left blank Eightmile Ranch Coho Acclimation Site Draft Environmental Assessment TABLE OF CONTENTS Table of Contents ............................................................................................................................................ i CHAPTER 1. PURPOSE OF AND NEED FOR ACTION ..................................................................... 1-1 1.1. Introduction .................................................................................................................................................. 1-1 1.2 Underlying Need for Action .......................................................................................................................... 1-1 1.3 Purposes ......................................................................................................................................................... 1-3 1.4 Background Information ................................................................................................................................ 1-3 1.5 Management Direction .................................................................................................................................. 1-4 1.6 Public Involvement ........................................................................................................................................ 1-5 1.6.1 Scoping Summary ................................................................................................................................................... 1-5 1.6.2 Public Review Process ............................................................................................................................................ 1-8 CHAPTER 2. ALTERNATIVES INCLUDING THE PROPOSED ACTION ........................................ 2-1 2.1 Elements Common to Both Locations ........................................................................................................... 2-1 2.1.1 Acclimation Pond .................................................................................................................................................... 2-1 2.1.2 Fencing .................................................................................................................................................................... 2-3 2.1.3 Surface Water Supply ............................................................................................................................................. 2-3 2.1.4 Groundwater Supply ............................................................................................................................................... 2-6 2.1.5 PIT tag Detector ...................................................................................................................................................... 2-7 2.1.6 Emergency Aeration System ................................................................................................................................... 2-7 2.1.7 Electrical System ..................................................................................................................................................... 2-7 2.1.8 Access ..................................................................................................................................................................... 2-7 2.1.9 Forest Plan Amendment .......................................................................................................................................... 2-8 2.2 Location 1 ...................................................................................................................................................... 2-8 2.2.1 Design Details ......................................................................................................................................................... 2-8 2.2.2 Site-Specific Mitigation Measures .......................................................................................................................... 2-9 2.3 Location 2 ...................................................................................................................................................... 2-9 2.3.1 Design Details ......................................................................................................................................................... 2-9 2.3.2 Mitigation Measures .............................................................................................................................................. 2-10 2.4 Construction and Operations Activities ....................................................................................................... 2-10 2.4.1 Duration and Season of Construction Activities ................................................................................................... 2-10 2.4.2 Activities During Acclimation .............................................................................................................................. 2-10 2.5 Design Criteria ............................................................................................................................................. 2-10 2.5.1 General Design Criteria ......................................................................................................................................... 2-10 2.5.2 General Construction Criteria ............................................................................................................................... 2-11 2.5.3 Erosion Control ..................................................................................................................................................... 2-12 2.5.4 Dewatering ............................................................................................................................................................ 2-12 i Eightmile Ranch Coho Acclimation Site Draft Environmental Assessment 2.5.5 Bank Stabilization ................................................................................................................................................. 2-13 2.5.6 Water Quality Protection ....................................................................................................................................... 2-13 2.5.7 Air Quality ............................................................................................................................................................ 2-14 2.5.8 Vegetation Protection ............................................................................................................................................ 2-14 2.5.9 Re-vegetation ........................................................................................................................................................ 2-15 2.5.10 Operations and Maintenance ............................................................................................................................... 2-16 2.5.11 Site Reclamation .................................................................................................................................................. 2-16 2.6 Costs of the Proposed Action ...................................................................................................................... 2-17 2.7 No Action Alternative ................................................................................................................................. 2-17 2.8 Alternative Considered and Eliminated from Detailed Evaluation ............................................................. 2-18 2.9 Comparison of Alternatives ......................................................................................................................... 2-19 CHAPTER 3. AFFECTED ENVIRONMENT AND ENVIRONMENTAL EFFECTS .......................... 3-1 3.1 Land Use ........................................................................................................................................................ 3-1 3.1.1 Information Sources ................................................................................................................................................ 3-1 3.1.2 Analysis Area .......................................................................................................................................................... 3-1 3.1.3 Affected Environment ............................................................................................................................................. 3-1 3.1.4 Environmental Effects and Mitigation .................................................................................................................... 3-3 3.1.5 Cumulative Effects .................................................................................................................................................. 3-5 3.2 Soils ............................................................................................................................................................... 3-6 3.2.1 Information Sources ...............................................................................................................................................