A RARE PLANT SURVEY OF THE LAKE CHELAN PROJECT AREA Final LAKE CHELAN HYDROELECTRIC PROJECT FERC Project No. 637 September 26, 2000 Public Utility District No. 1 of Chelan County Wenatchee, Washington Rare Plant Survey TABLE OF CONTENTS SECTION 1: INTRODUCTION........................................................................................1 SECTION 2: PROJECT AREA .......................................................................................1 SECTION 3: METHODS .................................................................................................2 SECTION 4: RESULTS.................................................................................................11 SECTION 5: SUMMARY AND DISCUSSION ...............................................................16 SECTION 6: ENHANCEMENT, PROTECTION AND MITIGATION MEASURES.........17 SECTION 7: REFERENCES.........................................................................................19 APPENDIX A APPENDIX B APPENDIX C APPENDIX D Final Lake Chelan Project No. 637 September 26, 2000 Page i SS/4395_2 Rare Plant Survey LIST OF TABLES Table 3-1: Rare plant taxa potentially present in the Lake Chelan Project Area pre-1998. .......................................... 4 Table 4-1: Known Rare Plant Populations for Lake Chelan, Pre-1998*..................................................................... 15 Table 4-2: Rare Plant Populations for the Lake Chelan Project.................................................................................. 15 Table A 1: Botanical Sub-Units for the Lake Chelan Project area used for species lists. ........................................... 23 Table A 2: Vascular plant species of the Lake Chelan Project area, 1998-1999......................................................... 24 LIST OF FIGURES Figure 3-1: Sheet 1 - Lower Lake.................................................................................................................................. 5 Figure 3-1: Sheet 2 - Middle Lake ................................................................................................................................ 7 Figure 3-1: Sheet 3 - Upper Lake.................................................................................................................................. 9 Lake Chelan Project No. 637 Final SS/4395_2 Page ii September 26, 2000 Rare Plant Survey SECTION 1: INTRODUCTION This document summarizes two years of rare plant surveys of the shoreline of Lake Chelan which were undertaken as part of relicensing of the Lake Chelan Hydroelectric Project, FERC No. 637 (Lake Chelan Project). For the purposes of this document, a "rare plant" is defined as any plant species or variety of a species which is designated by the U.S. Fish and Wildlife Service (USFWS), the U.S. Forest Service (USFS), or by the state of Washington as Endangered, Threatened, or Sensitive (WNHP 1997a). Species or varieties which are on the Washington "Monitor Group 1" and "Monitor Group 2" lists are also included. Federal and state status designations may change over time. SECTION 2: PROJECT AREA The Project area as identified in the final Botanical Study Plan dated July 16, 1999, for the Lake Chelan Project included the entire shoreline of Lake Chelan from the existing water level to an elevation approximately 30 feet above the high water level (1,100 – 1,130 feet m.s.l.). Selected creek drainages along the lake were searched to 30 vertical feet above the level of the lake or to the lowest fish barrier. These included: Mitchell Creek, Grade Creek, Safety Harbor Creek, and Prince Creek on the north shore, and First Creek, 25-Mile Creek, and Railroad Creek on the south shore. The Project area also included the Chelan River Gorge, from the Chelan Dam downstream to the confluence with the Columbia River. In general, the Project Area lies across an ecotone between eastern Washington shrub-steppe habitat and the cooler montane forests of the North Cascades. The north shore (south facing) portion of the lake supports open, dry-site vegetation, while the south shore (north facing) supports denser forests. Similarly, as one travels uplake and deeper into the Cascades, the montane and marine influence becomes more pronounced and a number of species which are more characteristic of western Washington become common. The Project area includes a number of plant community types. Based on the Chelan Basin Watershed Assessment (USFS 1995), the following plant community types are found within the Project area: two forested climax plant series (a grouping of a number of forested plant community types and plant associations), five shrub community types, one deciduous community type, and "bare ground and rock". The Lake Chelan Project area primarily supports two forested climax plant series: the Ponderosa pine series and the Douglas fir series. Shrub communities dominate the vegetated areas of the north shore of Lake Chelan downlake of Prince Creek, and occur on exposed and/or rocky sites within forested areas throughout the Project area. There are four shrub community types (as recognized by the USFS) within the Lake Chelan Project area: low elevation lush shrub communities, shrub- steppe/herbaceous communities, shrub-steppe/bitterbrush communities, and shrub-steppe/sagebrush Final Lake Chelan Project No. 637 September 26, 2000 Page 1 SS/4395_2 Rare Plant Survey communities. These classifications are very general, and each could be subdivided into a number of plant communities based on the actual dominant species within the community. The open grasslands on the north side of Lake Chelan are considered shrub-steppe/herbaceous communities. A large portion of the shoreline of Lake Chelan between Manson and Prince Creek, and scattered in other areas are made up of nearly bare rock and talus. Common plant species in these habitats include: selaginella, lichens, ferns, serviceberry, squaw currant, rose, alumroot, penstemon, and wild buckwheat. Plant community types have not been described for these habitats. In general, there is considerable intergradation between plant community types. Wetland and riparian areas associated with Lake Chelan are of several types. The mouth of the Stehekin River supports a large emergent wetland. However, the wetland vegetation at the mouth of the river has been altered from pre-settlement times, mostly by the invasion of non-native plants, particularly reed canary-grass and other non-native pasture grasses. There may have been wetlands in the Manson area at one time, but these wetlands are no longer in existence. With the exception of the Stehekin River, riparian areas are typically very narrow, steep, and rocky. There are also numerous small (less than ½ acre) seeps adjacent the lake between Prince Creek and Stehekin on the north shore and near Lucerne on the south shore, which support a high diversity of native plants. Based on the current vegetation adjacent to the lake and the steep, rocky nature of most of the lakeshore, large areas of pre-settlement or pre-project riparian or wetland vegetation associated with the lakeshore seem unlikely. SECTION 3: METHODS Survey methods were as follows: for initial planning purposes a list of the known and potential rare plant species for the Lake Chelan Project area was developed based on current Washington Natural Heritage Program (WNHP) and USFS information (WNHP 1997b). Table 3-1 summarizes this information. The timing for field surveys was based on flowering times of potential rare plant species. Some areas were visited more than one time to search for both early and late blooming rare plant species. The Project area was divided into six subunits in consultation with the USFS (Appendix A, Table A 1) and a full vascular plant species list was compiled for each subunit. A total of 452 plant taxa were identified in the Project area (Appendix A). The entire study area was searched, though at varying intensities depending on the potential for rare plant populations (Figure 3-1, Sheets 1-3). Two primary survey intensities were utilized. In “walking surveys” multiple transects were walked across the 30 vertical feet of the Project area through habitats with a high potential for rare plants. In “boat/binocular surveys” steep areas or areas with a low potential for rare plants were surveyed by boat and binoculars. Due to the water depth, boats can get very close to the bank, and whenever higher potential habitat or unknown plants were encountered, we would switch to a “walking survey.” Areas also varied in the number of repeated surveys that took place. Areas with high potential for rare species were surveyed several times over a two year period; other areas were only surveyed once. Particular attention was given to campgrounds and state parks within the study area. Of the approximately 118 miles of Lake Chelan Project No. 637 Final SS/4395_2 Page 2 September 26, 2000 Rare Plant Survey shoreline in Lake Chelan, the entirety was surveyed by binocular at least once during the two field seasons, and approximately 43 miles were surveyed on foot. A GPS unit (Trimble GeoExplorer II) was used to map rare plant populations more accurately, though populations were also mapped on USGS 7.5’ topographic maps in the field. Photographs were taken of all rare plant species. Plant collections were made when it was deemed necessary to identify a plant. A collection permit was obtained from the National Park Service (NPS). Collections from within the National Recreation Area and/or Forest Service areas