Little Salmon River Subbasin Assessment and TMDL Department of Environmental Quality February 2006 Little Salmon River Subbasin Assessment and TMDL February 2006 This space intentionally left blank for correct double-sided printing. ii Little Salmon River Subbasin Assessment and TMDL February 2006 Little Salmon River TMDL February 2006 Prepared by: Boise Regional Office Department of Environmental Quality 1445 N. Orchard St. Boise ID 83706 iii Little Salmon River Subbasin Assessment and TMDL February 2006 This space intentionally left blank for correct double-sided printing. iv Little Salmon River Subbasin Assessment and TMDL February 2006 Table of Contents Table of Contents ................................................................................................................................. v List of Tables........................................................................................................................................ix List of Figures......................................................................................................................................xi Abbreviations, Acronyms, and Symbols ........................................................................................xiii Executive Summary .........................................................................................................................xvii Subbasin at a Glance......................................................................................................................xvii Key Findings..................................................................................................................................... xx TMDLs.............................................................................................................................................. xx Public Participation..........................................................................................................................xxii 1. Subbasin Assessment – Watershed Characterization .................................................................1 1.1 Introduction ..................................................................................................................................1 Background....................................................................................................................................1 Idaho’s Role ...................................................................................................................................2 1.2 Physical and Biological Characteristics .......................................................................................3 Climate...........................................................................................................................................5 Geology..........................................................................................................................................7 Fisheries.......................................................................................................................................14 Subwatershed Characteristics .....................................................................................................21 Stream Characteristics.................................................................................................................24 1.3 Cultural Characteristics..............................................................................................................27 Land Ownership, Cultural Features, and Population...................................................................27 Land Use......................................................................................................................................31 History..........................................................................................................................................33 Economics ...................................................................................................................................34 Recreation....................................................................................................................................35 2. Subbasin Assessment – Water Quality Concerns and Status...................................................37 2.1 Water Quality Limited Assessment Units Occurring in the Subbasin ........................................39 About Assessment Units..............................................................................................................39 Listed Waters ...............................................................................................................................40 2.2 Applicable Water Quality Standards ..........................................................................................40 Beneficial Uses ............................................................................................................................41 Criteria to Support Beneficial Uses..............................................................................................43 2.3 Pollutant/Beneficial Use Support Status Relationships .............................................................46 Temperature ................................................................................................................................46 Dissolved Oxygen ........................................................................................................................46 Sediment......................................................................................................................................47 Bacteria........................................................................................................................................48 Nutrients.......................................................................................................................................49 Sediment – Nutrient Relationship ................................................................................................50 Floating, Suspended, or Submerged Matter (Nuisance Algae)...................................................50 2.4 Summary and Analysis of Existing Water Quality Data ............................................................51 Data Assessment Methods..........................................................................................................51 v Little Salmon River Subbasin Assessment and TMDL February 2006 StreamStat................................................................................................................................... 54 Little Salmon River ...................................................................................................................... 55 Mud Creek ................................................................................................................................... 67 Big Creek..................................................................................................................................... 73 Goose Creek ............................................................................................................................... 80 Brundage Reservoir..................................................................................................................... 87 Geology ....................................................................................................................................... 87 Six Mile Creek/ Four Mile Creek/ Three Mile Creek.................................................................... 88 Round Valley Creek..................................................................................................................... 94 Hazard Creek .............................................................................................................................. 97 Boulder Creek............................................................................................................................ 105 Elk Creek ................................................................................................................................... 113 Indian Creek .............................................................................................................................. 119 First and Second Order Tributaries to the Little Salmon River below Round Valley Creek...... 123 Sheep Creek.............................................................................................................................. 125 Hat Creek .................................................................................................................................. 126 Denny Creek.............................................................................................................................. 128 Lockwood Creek........................................................................................................................ 129 Rattlesnake Creek..................................................................................................................... 130 Fall Creek .................................................................................................................................. 132 Rapid River................................................................................................................................ 133 Shingle Creek...........................................................................................................................