Condit Dam Removal Condit Dam Removal - Access Washington

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Condit Dam Hydroelectric Project Final Supplemental EIS 4.4.3 Mitigation Measures This is a project with very little opportunity to avoid wetland impacts. There may be an opportunity to route the access road from the dam to the concrete storage/disposal area to minimize impacts to Wetland 21, but that will depend on engineering feasibility and impact trade-offs with forest clearing. Wetlands directly associated with the reservoir or the river cannot be avoided nor impacts minimized. On the other hand, the changes associated with removing the dam and reservoir provide the natural regeneration of wetlands that will be worthy of consideration as compensation for the unavoidable losses of wetlands. In addition, other benefits of dam removal tend to offset impacts on lake-associated wetlands. The wetland impacts and expected new wetlands are summarized below. While these totals (both impacts and mitigation) differ somewhat from those in the Wetland Mitigation Plan (PacifiCorp 2004), it appears that the total area of currently existing wetland would be very similar to that after the Condit Project is gone and the system has stabilized (1 to 5 years). The specific functions would be different for some wetlands and the same for others. Overall, the wetlands being lost are category III or IV lake-fringe wetlands. These wetlands would probably be replaced with Category III wetlands, with potential for some to become Category II over time. If monitoring as proposed by PacifiCorp (2004) shows that a smaller amount of wetlands develop than shown in Table 4.4-2, it would be necessary to determine whether manipulation of residual reservoir sediment may be possible to increase the amount of wetland in certain areas. Table 4.4-2 Summary of Impacted Wetland Areas and Expected New Area Wetland Type Impact Area (acres) Expected New Area (acres) Lake-fringe wetlands 2.8 — Slope wetlands 0.024 0.75 Tributary riverine wetlands 0.5 0.5 or more Mainstem riverine wetlands 1.0 temporary impact 2 downstream, 1 upstream Totals 3.324 permanent, 1 temporary 4.25 or more 4.4.4 Significant Unavoidable Adverse Impacts Unavoidable adverse wetland impacts include the loss of approximately 2.8 acres of lakefringe wetlands. These impacts are expected to be mitigated by the establishment of riverine and slope wetlands within 1 to 5 years of dam removal. 4.4-10
Condit Dam Hydroelectric Project Final Supplemental EIS 4.5 TERRESTRIAL RESOURCES 4.5.1 Affected Environment The vegetation cover was well described in the 1996 FERC FEIS (FERC 1996). The FEIS described 13 upland plant community types in the study area. About two-thirds of the upland area was occupied by relatively undisturbed plant communities, primarily forests and woodlands. About a third of the study area was occupied by modified cover including pastures, orchards, and residential areas. Those cover types are essentially the same in 2005. The 1996 FEIS described six habitats of special concern. The Oregon White Oak Forest is found on slopes above the lower part of the White Salmon River and will not be affected by removal of the Condit Project. Wetlands are discussed in Section 4.4 of this SEPA SEIS. Old-growth forests do not occur in the immediate vicinity of the project. Some patches of mature second-growth forest do occur, and one of these mature stands will be affected by the access road from the dam to the concrete storage/disposal site. Riparian areas occur along tributaries that enter the reservoir and along the river downstream from the dam. The lake fringe has some areas of vegetation that are riparian in nature and that will be far from the water after the dam and reservoir are gone. Cliffs were noted as a prevalent habitat occupying two percent or about 59 acres. The 1996 FEIS concluded that the project lands do not provide suitable deer wintering habitat. The 1996 FEIS adequately described most of the wildlife resources of the project area, potentially including 84 species. Additional language covering the northwestern pond turtle (Clemmys marmmorata) and Canada lynx (Lynx canadensis) was added to the FSFEIS (FERC 2002). Neither the 1996 FEIS nor 2002 FSFEIS addressed insects. There is some potential that the Columbia River tiger beetle (Cicindela columbica) may use sand shores of the Bonneville pool and lower reaches of the White Salmon River (Leffler 1976 and 1979). This species depends on sandy, unvegetated habitats, in which they lay eggs and burrow. Larvae dig tunnels as deep as 12 inches where they prey on other insect species. The Columbia River tiger beetle is a Washington State candidate species (WDFW 2005). The threatened and endangered species potentially in the project area were discussed in the 1996 FEIS and in the 2002 FSFEIS. The 1996 FEIS discussed five plant species listed by the state of Washington as sensitive or monitor species. Based on 2005 information, the greenfruited sedge and the yellow sedge are either no longer considered sensitive species or are not reported from Klickitat County. 4.5.2 Impacts Pre-Dam Removal Activities Site inspections of 1) the areas to be cleared of vegetation and graded at the staging areas and disposal sites, 2) the Mt. Adams Orchard diversion structure replacement area, 3) the work areas for the temporary water supply pipeline, and 4) the access roads showed that none of the priority species or habitats occur in those locations. Therefore, there will be no impacts on the protected plant or animal species. 4.5-1
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Condit Dam Removal Final SEPA Suppl
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March 23, 2007 Dear interested part
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Appendix A Memorandum of Agreement
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Appendix C Supplemental Aquatic Res
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Agency and Organization Letters and
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Contents Public Meetings Response P
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Contents Individuals Individuals A-
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