Botany and Wetlands Study Report - McMillen, LLC

Botany and Wetlands Study ReportSoutheast Alaska Power Agency2 PROCEDURES2.1 Analysis AreaThe study area for direct and indirect effects to sensitive and rare plants, general vegetationcommunities, and wetland resources includes the “activity area” (FSM 2554). For this project,the “activity area” is between the current spillway crest elevation (330 feet) and the proposednew dam crest elevation of350 feet (3 feet of freeboard above the PMF of 347 feet). It isestimated that there are about 14 miles of the Swan Lake reservoir shoreline at the 350‐footelevation contour; including portions of Lost Creek, Track Creek, Mint Creek, and Fry Creek. Theanalysis area is approximately 140.3 acres.Additional surveys for sensitive and rare plants, general vegetation communities, and wetlandresources were conducted outside of the activity area. This area included a 150‐foot bufferaround areas where temporary and permanent construction activities (e.g., laydown yards,existing road improvements) associated with the proposed project would likely occur. This areais located below the dam and near existing facilities.2.2 Pre‐Field Contact with Forest Service and Review of ExistingInformationPrior to field surveys, a pre‐field review of the analysis area was conducted (Tetra Tech 2012a)and approved by Rick Turner, USDA Forest Service Ecologist. No species on the Alaska RegionSensitive Plant List have previously been documented in the analysis area although severalspecies have previously been documented in the Ketchikan‐Misty Fiords Ranger District.Habitat information in the analysis area was assessed based on information obtained from GIS,reviews of aerial photographs, and discussions with resource specialists. Habitat types likely tooccur in the analysis area include forest edge, coniferous forest, rocky areas, rock outcrops,ridgetops, cliffs, gravel, seeps, wet areas, riparian areas, streambanks, ponds, shallow freshwatermarshes, muskeg, waterfalls, lake margins, fens, and sandy areas. Based on the variety ofhabitats present, it was determined that eight of the sensitive species on the Alaska RegionSensitive Plant List (Appendix A) have a reasonable potential to occur in the analysis area.The data reviewed for wetland resources in the analysis area was based on the Tongass NationalForest wetland mapping layer. This GIS mapping layer has been modified from the NationalWetland Inventory (NWI) maps, through the inclusion of the common wetland types present inSoutheast Alaska. Additionally, the Ketchikan Area soil survey for the Tongass NF area wasreviewed to determine the potential location of hydric soils within the analysis area.Swan Lake Hydroelectric Project January 2013FERC Project No. 2911 Page 6 Version: Agency Review