Mattole River Watershed Analysis Cumulative Watershed Effects Public Review Draft September 2011 Cumulative Watershed Effects TABLE OF CONTENTS LIST OF TABLES ...................................................................................................................... iii LIST OF FIGURES .................................................................................................................... iv LIST OF PHOTOGRAPHS ........................................................................................................ vi LIST OF APPENDICES ............................................................................................................ vii LIST OF MAPS ........................................................................................................................ viii LIST OF ATTACHMENTS .......................................................................................................... x LIST OF ACRONYMS ............................................................................................................... xi 1.0 ABSTRACT .......................................................................................................................... 1 2.0 INTRODUCTION ................................................................................................................... 5 2.1 OVERVIEW OF WATERSHED ANALYSIS PROCESS .................................................................. 6 2.2 PURPOSE AND ORGANIZATION OF REPORT ........................................................................ 11 2.3 ISSUES IDENTIFICATION ..................................................................................................... 11 2.4 DEFINITIONS ..................................................................................................................... 16 3.0 WATERSHED SUMMARY ................................................................................................. 17 3.1 GEOGRAPHIC SETTING AND STUDY AREA DELINEATION ..................................................... 17 3.2 GEOLOGY AND SEISMIC REGIME ........................................................................................ 22 3.3 SOILS ............................................................................................................................... 24 3.4 TOPOGRAPHY ................................................................................................................... 24 3.5 STREAM CLASS ................................................................................................................. 28 3.6 CLIMATE ........................................................................................................................... 29 3.7 STREAMFLOW RECORDS AND FLOOD HISTORY .................................................................. 29 3.8 HYDROLOGY ..................................................................................................................... 34 3.8.1 North Fork Mattole Area ......................................................................................... 37 3.8.2 Upper North Fork Mattole Area .............................................................................. 40 3.8.3 McGinnis/Pritchard Creeks .................................................................................... 45 3.9 FOREST ECOLOGY ............................................................................................................ 47 3.9.1 Riparian Forest ....................................................................................................... 47 3.9.2 The Role of Fire ..................................................................................................... 48 3.10 FISH SPECIES COMPOSITION AND DISTRIBUTION .............................................................. 49 3.11 AMPHIBIAN AND REPTILE SPECIES COMPOSITION AND DISTRIBUTION ................................ 51 4.0 LAND USE .......................................................................................................................... 52 4.1 PREHISTORIC LAND USE .................................................................................................... 52 4.2 HARVEST HISTORY (1900-1988) ....................................................................................... 56 4.3 HARVEST HISTORY (1988-2003) ....................................................................................... 57 Mattole River Watershed Analysis Page i Cumulative Watershed Effects 5.0 CUMULATIVE EFFECTS OF TIMBER OPERATIONS AND WATERSHED PROCESSES ON AQUATIC HABITAT CONDITIONS.............................................................................. 65 5.1 OVERVIEW ........................................................................................................................ 65 5.2 SALMONID DISTRIBUTION .................................................................................................. 67 5.3 HABITAT CONDITIONS FOR STREAMS ON HRC PROPERTY .................................................. 68 5.3.1 Spawning Habitat ................................................................................................... 70 5.3.2 Rearing Habitat – Pools ......................................................................................... 73 5.3.3 Rearing Habitat – Temperature .............................................................................. 82 5.4 RIPARIAN CONDITIONS AND FUTURE MANAGEMENT ............................................................ 85 5.5 HILLSLOPE CONDITIONS AND FUTURE MANAGEMENT ......................................................... 92 5.5.1 Overview of Mass Wasting Sediment Input Analysis ............................................. 93 5.5.2 Sediment Budget – 1988-2003 .............................................................................. 98 5.5.3 Channel and Fish Habitat Condition Trends ........................................................ 103 5.6 AMPHIBIAN AND REPTILE HABITAT ................................................................................... 107 6.0 MANAGEMENT RECOMMENDATIONS ......................................................................... 109 6.1 HILLSLOPE ...................................................................................................................... 109 6.2 RIPARIAN ........................................................................................................................ 111 6.3 CONCLUSION .................................................................................................................. 112 7.0 REFERENCES .................................................................................................................. 115 Mattole River Watershed Analysis Page ii Cumulative Watershed Effects LIST OF TABLES Table 2-1. Analysis and data collection for the Mattole River watershed analysis. .................................... 9 Table 3-1. Watershed areas for the Mattole River basin. ........................................................................... 17 Table 3-2. HRC ownership and non-HRC ownership by sub-basin. ......................................................... 20 Table 3-3. Distribution of lithologic units in HCP area. ............................................................................ 22 Table 3-4. Properties of soils for HCP lands in the Mattole River Watershed Analysis Unit. .................. 25 Table 3-5. Summary of acres in major slope gradient classes in HCP area. .............................................. 26 Table 3-6. Summary of stream channel lengths in HCP area. ................................................................... 28 Table 3-7. Existing and discontinued long-term precipitation gauges located within or near the Mattole River basin. ......................................................................................................................................... 30 Table 3-8. Life history patterns of salmon and steelhead in the Mattole River. ........................................ 50 Table 4-1. Timber stand acres by type and age (2011 data) for HCP area of the Mattole River WAU. ... 53 Table 4-2. First harvest entry acres in HCP area (2006 data). ................................................................... 55 Table 4-3. Roads by sub-basin in HCP area (based on 2006 GIS data). .................................................... 63 Table 5-1. LWD recruitment potential categories (H = High; M = Moderate; L = Low) as defined by RCU stand type, tree size class, and canopy closure. ......................................................................... 89 Table 5-2. Number of Class I and Class II stream RCU acres by LWD recruitment potential category, Mattole River HCP lands. ................................................................................................................... 91 Table 5-3. Landslides in project area by time period. ................................................................................ 94 Table 5-4. Landslide delivery (cubic yards) in project area by geomorphic association. .......................... 95 Table 5-5. Sediment sources included in each land use association category. ........................................... 99 Mattole River Watershed Analysis Page iii Cumulative Watershed Effects LIST OF FIGURES Figure 2-1. Schematic illustration of the role of surface processes on shaping habitat characteristics and variability and the potential for ecological systems to influence surface processes