National Wildlife Refuge

Hydrogeomorphic Evaluation of Ecosystem Restoration and Management Options for CAMAS National Wildlife Refuge Prepared For: U. S. Fish and Wildlife Service Region 1 Hamer, Idaho Greenbrier Wetland Services Report 14-04 Adonia R. Henry Mickey E. Heitmeyer March 2014 HYDROGEOMORPHIC EVALUATION OF ECOSYSTEM RESTORATION AND MANAGEMENT OPTIONS FOR CAMAS NATIONAL WILDLIFE REFUGE Prepared For: U. S. Fish and Wildlife Service Region 1 Camas National Wildlife Refuge Hamer, Idaho By: Adonia R. Henry Scaup & Willet LLC 70 Grays Lake Rd. Wayan, ID 83285 and Mickey E. Heitmeyer Greenbrier Wetland Services Rt. 2, Box 2735 Advance, MO 63730 March 2014 Greenbrier Wetland Services Report No. 14-04 Mickey E. Heitmeyer, PhD Greenbrier Wetland Services Route 2, Box 2735 Advance, MO 63730 www.GreenbrierWetland.com Publication No. 14-04 Suggested citation: Henry, A. R., and M. E. Heitmeyer. 2014. Hy- drogeomorphic evaluation of ecosystem restoration and management options for Camas National Wildlife Refuge. Prepared for U. S. Fish and Wildlife Service, Region 1, Camas NWR, Hamer, ID. Greenbrier Wetland Services Report 14-04, Blue Heron Conservation Design and Printing LLC, Bloomfield, MO. Photo credits: COVER: Adonia Henry Adonia Henry; Andy Vernon; Cary Aloia, www.Gardners- Gallery.com; Karen Kyle This publication printed on recycled paper by ii Contents EXECUTIVE SUMMARY ...................................................................................... v INTRODUCTION ................................................................................................ 1 THE HISTORICAL EASTERN SNAKE RIVER ECOSYSTEM ......................... 3 Geology, Geohydrology, Geomorphology ..................................................... 3 Pre-Quaternary Volcanism................................................................ 3 Quaternary Processes, Geohydrology, and Geomorphology .............. 4 Soils ......................................................................................................... 7 Topography ................................................................................................ 11 Climate and Hydrology .............................................................................. 11 Climate .......................................................................................... 11 Surface water .................................................................................. 14 Groundwater .................................................................................. 16 Historical Flora and Fauna ......................................................................... 19 Overview ........................................................................................ 19 Historical Vegetation Communities ................................................ 19 Key Animal Communities .............................................................. 29 CHANGES TO THE CAMAS ECOSYSTEM .................................................... 31 Overview .................................................................................................... 31 Early Settlement and Land Use Changes .................................................... 31 Regional Land Use and Hydrologic Changes Since 1880 ............................ 32 Refuge Establishment and Management History ............................ 34 Changes in Plant and Animal Populations .................................................. 42 Predicted Impacts of Future Climate Change ............................................. 47 iii 1 CONTENTS, cont’d. OPTIONS FOR ECOSYSTEM RESTORATION AND MANAGEMENT ..... 49 Synthesis of HGM Information ................................................................. 49 Recommendations for Ecosystem Restoration and Management ................ 50 MONITORING AND SCIENTIFIC INFORMATION NEEDS ..................... 61 Key Baseline Ecosystem Data ..................................................................... 61 Restoring or Managing for Natural Water Regimes and Flow Patterns ........ 62 Long-term Changes in Vegetation and Animal Communities ..................... 62 ACKNOWLEDGEMENTS ................................................................................. 65 LITERATURE CITED ......................................................................................... 67 APPENDICES ....................................................................................................... 75 Adonia Henry iv EXECUTIVE SUMMARY Camas National Wildlife Refuge (CNWR) includes 10,578 acres of diverse wetland and upland habitats in the Eastern Snake River Plain (ESRP) along eight miles of Camas Creek in Jefferson County, Idaho. Dominant landform characteristic of the refuge is the shallow Mud Lake alluvial aquifer formed from lacustrine deposits of pluvial Lake Terreton and its juxtaposition with basalt lava flows and alluvial processes on Camas Creek. Surface water from Beaver, Camas, and Warm Creek flows through CNWR to Mud Lake, a topographically closed terminal basin with no surface water outflow to the Snake River. CNWR was established in 1937; then existing agricul- tural “improvements” were modified and expanded to develop infrastructure to manage wetland habitats for migratory birds. Prior to developments at and surrounding CNWR, water levels in the lower Beaver-Camas subbasin (including Mud Lake and CNWR) were characterized by seasonal, annual, and long-term multi-decadal fluctuations in the depth, duration and extent of flooded habitats. During wet years, Camas Creek overflowed its banks and Mud Lake and the surrounding herbaceous wetlands contained extensive surface water area that supported large numbers of migrating and breeding waterbirds. In contrast, during dry years, less water was present and although the area could not support as many waterbirds, these dry conditions sustained important wetland processes. During 2010, the USFWS started a Comprehensive Conservation Plan (CCP) for CNWR. Most of the CCP’s completed for NWR’s to date have highlighted ecological restoration as a primary goal. However, limited information typically is provided in the CCPs on how restoration will be accomplished in the existing and often highly modified Adonia Henry regional landscape. Historical conditions (those prior to sub- v stantial human-related changes to the landscape) are often selected as the benchmark condition (Meretsky et al. 2006), but restoration to these historical conditions may not be well understood, feasible, or cost-effective, thereby compromising success of restoration actions. This report provides a hydrogeomorphic (HGM) evaluation to help identify future options for ecosystem restoration and management of CNWR. The HGM approach objectively seeks to understand: 1) how this ecosystem was created, 2) the fundamental physical and biological processes that histori- cally “drove” and “sustained” the structure and functions of the system and its communities, and 3) what changes have occurred that have caused degradations and that might be reversed and restored to historical and functional conditions within a changing environment. This HGM approach also provides a basis to help future efforts evaluate the NWR within the context of the larger ecoregion. The HGM approach obtains and analyzes available historical and current information about: 1) geology and geomorphology; 2) soils; 3) topography and elevation; 4) hydrology and climate; 5) land cover and vegetation communities; 6) key plant and animal species; and 7) physical anthropogenic features of the CNWR and surrounding lands. Objectives for this HGM evaluation were: 1. Identify the Presettlement (pre-European contact) ecosystem conditions and the ecological processes sup- porting them at CNWR. 2. Evaluate changes in the CNWR ecosystem from the Presettlement period with specific reference to altera- tions in hydrology, topography, vegetation community structure and distribution, and resource availability for priority fish and wildlife species. 3. Identify restoration and management options plus ecological attributes needed to successfully restore and/or manage specific habitats and conditions at CNWR. The Mud Lake basin, including CNWR, was formed by the complex succession of geologic processes throughout the Pleistocene and Holocene, including volcanism associated with the Yellowstone Hotspot, outwash from montane glaciers, the vi rise and fall of pluvial lakes, alluvial transport of sediments, and eolian processes. Alluvium from adjacent mountains and sediments transported by glacial, lacustrine, fluvial, and eolian processes created sedimentary interbeds and surface soils within volcanic basalts that contribute to confined and perched groundwater conditions that affect local groundwater movement and supply. Soils at CNWR range from somewhat excessively drained sands on lava plains to very poorly drained silty clays on relict lakebed features. The climate at CNWR is semi-arid with annual precipitation averaging about 9 inches/year. Annual precipitation is highly variable, ranging from 43 to 171% of the mean. Snowpack in the headwaters of the Beaver-Camas subbasin is also highly variable, with annual peak snow water equivalent ranging from 9 to 31 inches. Historical water levels at CNWR peak during the spring as a result of snowmelt runoff and decline throughout the summer. In addition to seasonal patterns of flooding, CNWR and Mud Lake have evidence of long recurring 15-20 year patterns of peaks and lows in regional precipitation, runoff, and water levels,

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