Botany and Wetlands Study Report - McMillen, LLC

Botany and Wetlands Study ReportSoutheast Alaska Power AgencyApproximately 10.5 acres (7.5 percent) of the analysis area was mapped as forested muskeg.Although forested muskeg is considered a wetland type; they are not considered a wetland typeas described in Section 3.7. Wetland resources in the analysis area, as described in Section 2.3.2,were mapped using a combination of the Tongass NF wetland layers, the hydric soils layers fromthe Ketchikan area soil survey for the Tongass NF, and wetland boundaries delineated duringfield surveys of the analysis area in August 2012. The majority of the areas delineated asforested muskeg by the Size and Density Mapping Model (Figure 3) were delineated as adifferent wetland category based on mapped wetlands described in Section 3.7 and shown onFigure 4. The small remaining areas mapped as forested muskeg based on the SD7 model werenot mapped as wetlands using the methods described above and in Section 2.3.2; therefore, theforested muskeg vegetation type is not further discussed in this report.3.6 Invasive PlantsSurveys for Invasive plants were conducted for this project in conjunction with surveys forSensitive and Rare plants (August 6 to August 10, 2012). Prevention measures for invasive plantswould follow the Tongass NF protocols specified in Forest Service Manual (FSM) 2000‐NationalForest Resource Management, Chapter 2080‐Noxious Weed Management, Tongass NationlForest Supplement–R10‐TNF‐2000‐20007‐1.3.7 Wetland ResourcesApproximately 55% or 77.4 acres of the analysis area consists of wetlands. Several types ofwetland communities, including forested wetlands, emergent wetlands, and moss muskegs arefound in the analysis area (Figure 4; Table 4; Appendix C). The different wetland types found inthe analysis area are briefly described below.Table 4. Acres of Wetland Resources in the Analysis Area 1/Wetland Type Acres Percent of Analysis Area 1/Forested Wetlands 60.9 43.4Emergent Wetlands 2/ 15.0 10.7Moss Muskegs 3/ 1.5 1.1Total 77.4 55.21/ Analysis area is approximately 140.3 acres.2/ Includes areas mapped as tall sedge fens in the Tongass National Forest wetland mapping layer.3/ As stated above in Section 3.5, forested muskegs mapped using the Forest Service’s Size Density Model OutputLayer are not included in the discussion of wetland resources.Swan Lake Hydroelectric Project January 2013FERC Project No. 2911 Page 14 Version: Agency Review