Mt. Baker-Snoqualmie National Forest Miller-Foss Watershed Analysis Chapter 1 - Introduction..................................................................................................... i Purpose of the Analysis............................................................................................................. 1 Watershed Analysis Planning Basis ....................................................................................... 1 Analytical Process Used............................................................................................................ 2 Watershed Analysis Context................................................................................................... 3 Watershed Analysis Products and Outcomes ......................................................................... 4 Watershed Analysis Organization .......................................................................................... 4 Steps Utilized in Watershed Analysis..................................................................................... 4 Watershed Characterization.................................................................................................... 4 Management Direction ........................................................................................................... 6 Climate and Physiography.................................................................................................... 10 Watershed Resources............................................................................................................ 11 Chapter 2 - Issues and Key Questions............................................................................. 14 Human Domain ....................................................................................................................... 15 Silviculture............................................................................................................................ 15 Roads and Infrastructure....................................................................................................... 16 Recreation............................................................................................................................. 17 Terrestrial Domain ................................................................................................................. 18 Wildlife................................................................................................................................. 18 Botany................................................................................................................................... 19 Aquatic Domain....................................................................................................................... 21 Regional Scale Issues ........................................................................................................... 21 Past and Current Conditions, and Expected Future Trends.......................................... 25 Physical .................................................................................................................................... 25 Climate Change .................................................................................................................... 25 Hillslope Processes ............................................................................................................... 26 Soils ...................................................................................................................................... 35 Hydrologic Processes............................................................................................................ 37 Water Quality........................................................................................................................ 48 Aquatic Habitats and Species ............................................................................................... 58 Terrestrial Ecosystem ............................................................................................................. 71 Ecology and Vegetation........................................................................................................ 71 Wildland and Human-Caused Fires...................................................................................... 75 Timber and Vegetation ......................................................................................................... 77 Current Conditions................................................................................................................ 80 Climate Change .................................................................................................................... 81 Species of Interest................................................................................................................. 81 Wildlife................................................................................................................................. 83 Climate Change .................................................................................................................... 92 Human Uses and Influences ................................................................................................... 94 Heritage: Past Human Uses and Patterns.............................................................................. 94 Social/Economic................................................................................................................. 101 Population Trends............................................................................................................... 101 Town of Skykomish............................................................................................................ 102 Recreational Use................................................................................................................. 103 i Mt. Baker-Snoqualmie National Forest Miller-Foss Watershed Analysis Land and Minerals .............................................................................................................. 110 Infrastructure....................................................................................................................... 113 Chapter 3 - Findings and Recommendations ............................................................... 118 Introduction......................................................................................................................... 118 Figure 1. Miller-Foss watershed analysis area vegetative disturbance, year 1300 to present....................................................................................................................... 47 Figure 2. Miller-Foss watershed analysis area vegetative disturbance year 1300 to present ................................................................................................................................... 47 Figure 3. Wood density in the analysis area by subwatershed ......................................... 63 Figure 4. Wood density comparisons in Miller River, 1989 and 2003............................. 64 Figure 5. Wood density compared in Miller River mainstem and East Fork, 1989 and 2003........................................................................................................................... 64 Figure 6. Miller-Foss subwatershed major species composition of trees (MBS TRI data). ................................................................................................................................... 80 Figure 7. Big Huckleberry. Photo courtesy of Laura Potash, MBS................................ 100 Figure 8. Population Trends............................................................................................ 101 Figure 9 Median household income in King and Snohomish counties .......................... 102 Figure 10. Alpine Lakes Wilderness. Gary Paull, MBS................................................. 105 ii Mt. Baker-Snoqualmie National Forest Miller-Foss Watershed Analysis Table 1. Land Ownership in the Miller and Foss Subwatersheds....................................... 5 Table 2. Forest Plan Land Allocations in the Miller and Foss Subwatersheds................... 7 Table 3. High mass wasting potential rating summary..................................................... 32 Table 4. Key watershed characteristics among the 7th-field watersheds that comprise the Miller and Foss 6th-field watersheds........................................................................ 33 Table 5. Soil groups and corresponding soil mapping units found within the Miller and Foss subwatersheds according to the Forest Service Soil Resource Inventory. ....... 35 Table 6. Flood recurrence interval estimates for the mainstem Skykomish River at Gold Bar, WA .................................................................................................................... 41 Table 7 Miller-Foss Subwatershed distribution of lowland, rain dominated, rain-on-snow, and snow dominated zones ....................................................................................... 44 Table 8. Lakes in the Miller and Foss Subwatersheds with Surface areas of 10 acres or more .......................................................................................................................... 53 Table 9. 1990 Estimated critical ion deposition loads at three Washington Western Cascades Stations.....................................................................................................