WETLAND CONSERVATION STRATEGY FOR THE UPPER SNAKE RIVER, PORTNEUF DRAINAGE, AND ADJACENT VALLEYS Prepared by Mabel Jankovsky-Jones Idaho Conservation Data Center November 2001 Idaho Department of Fish and Game Natural Resource Policy Bureau 600 South Walnut, P.O. Box 25 Boise, ID 83707 Report prepared with funding from the United States Environmental Protection Agency through Section 104(b) (3) of the Clean Water Act Grant No. CD 980102-01-0 SUMMARY The Idaho Conservation Data Center has received wetland protection grant funding from the Environmental Protection Agency under the authority of Section 104 (b)(3) of the Clean Water Act to enhance existing wetland information systems. The goal is to identify the following: 1) Where are the wetlands? 2) What is the condition and management status of wetlands? 3) What kind of wetlands are they? This information can then be applied to state biodiversity, conservation, and water quality enhancement projects on a watershed basis. This builds on previous inventories in the state to create a consistent source of wetland information. Previous project areas included the Henrys Fork Basin, Big Wood River Basin, southeastern Idaho watersheds, the Idaho Panhandle, east-central basins, and Spokane River Basin. This document summarizes our findings on the main stem of the upper Snake River and its tributaries. The survey area includes the main Snake River and lower reaches of its major tributaries from the confluence with the Henrys Fork downstream to Milner. Tributaries surveyed include the Arbon, Portneuf, Rockland, and Curlew Valleys. We used the United States Fish and Wildlife Service National Wetlands Inventory (NWI) to gain a broad perspective on the extent and types of wetlands in the survey area. Landownership and management layers were overlaid on the NWI to determine ownership and the protected status of wetlands. Plant associations occurring in the survey area were placed into the hierarchical NWI classification and provide information relative to on-the-ground resource management. Assessment of the quality and condition of plant associations and the occurrence of rare plant and animal species allowed us to categorize 16 wetland sites based on conservation intent. Wetlands were surveyed using standard heritage program methods. The surveys were used to populate the Site Basic Record, Element Occurrene Record, and Community Characterization Abstract data bases of the Biological and Conservation Data System. Data base summaries are provided here and include information on the biological significance of the surveyed wetland sites, abstracts for selected plant associations, and summaries of plant and animal species of special concern. Land managers can apply the process presented here to categorize wetlands which were not surveyed. We identify conservation strategies for sites surveyed and for plant associations that are unprotected or under-protected. Seven percent of the wetlands and deepwater habitat in the survey area have protection beyond regulatory provisions of the Clean Water Act. Most of the habitat within special management areas is deepwater habitat within the Lacustrine system (88%). Only two percent of wetlands excluding deepwater habitat are within special management areas. Most of the wetlands (excluding deepwater habitat) in the special management areas are emergent habitat. However, this only represents 2 percent of the emergent wetlands in the survey area. Deciduous forested wetlands and scrub-shrub wetlands are also poorly represented in special management areas and should be of high priority for conservation activities. Only portions of the information from the NWI maps and data base records are summarized in this conservation strategy. All information contained in the data bases is available for public use except a limited amount of threatened and endangered species information considered sensitive by the U.S. Fish and Wildlife Service. Contacts for accessing digital and analog data are included at the end of this manuscript. ACKNOWLEDGMENTS This project could not have been completed with the assistance of the following individuals: Bart Butterfield, Idaho Department of Fish and Game Luana McCauley, Idaho Conservation Data Center Stephanie Mitchell, Idaho Conservation Data Center Bob Moseley, formerly with Idaho Conservation Data Center Chris Murphy, Idaho Conservation Data Center John Olson, Environmental Protection Agency George Stephens, Idaho Conservation Data Center Terry Vernholm, Idaho Department of Fish and Game Linda Williams, formerly with Idaho Conservation Data Center ii TABLE OF CONTENTS SUMMARY....................................................................................................................... i ACKNOWLEDGMENTS .................................................................................................. i TABLE OF CONTENTS................................................................................................. iii LIST OF FIGURES......................................................................................................... iv LIST OF TABLE............................................................................................................. iv LIST OF APPENDICES ................................................................................................. iv INTRODUCTION............................................................................................................. 1 SURVEY AREA............................................................................................................... 2 METHODS ...................................................................................................................... 3 FIELD METHODS............................................................................................................................ 3 Reference Areas and Sample Sites.................................................................................... 3 Field Data Collection...........................................................................................................3 OFFICE METHODS......................................................................................................................... 4 National Wetlands Inventory ............................................................................................... 4 Wetland Plant Associations................................................................................................. 4 Site and Community Data Bases........................................................................................ 5 Site Ranking........................................................................................................................ 6 RESULTS........................................................................................................................ 9 WETLAND ACREAGE AND TYPES............................................................................................... 9 WETLAND PROTECTION STATUS ............................................................................................. 15 WETLAND CONDITION................................................................................................................ 15 Wetland Losses................................................................................................................. 15 Functional Shifts................................................................................................................ 16 WETLAND DIVERSITY ................................................................................................................. 17 Wetland Plant Associations............................................................................................... 17 Rare Flora ......................................................................................................................... 20 Rare Animals..................................................................................................................... 20 CONSERVATION PRIORITIES FOR WETLANDS....................................................................... 22 Class I Sites ...................................................................................................................... 22 Class II Sites ..................................................................................................................... 22 Reference Sites ................................................................................................................ 23 Habitat Sites...................................................................................................................... 23 Other Sites and Priorities for Conservation ...................................................................... 24 How This Information Can be Used.................................................................................. 24 LITERATURE CITED .................................................................................................... 28 iii List of Figures Figure 1. Location of wetland and deepwater habitat in the survey area by system ................................................................................................................. 8 Figure 2. Acreage of wetland and deepwater habitat in Hydrologic Unit 16010204 (Lower Bear-Malad) ......................................................................... 11 Figure 3 Acreage of wetland and deepwater habitat in Hydrologic Unit 16010309 (Deep Creek Curlew Valley)