Page 18 of 20riparian community on the slopes of the east side of the Wood Gulch canyon should be avoideddue to the hydrological contribution of these streams to Wood Creek <strong>and</strong> density of juniper trees<strong>and</strong> other woody vegetation in these draws. In addition, impacts to the spring-fedintermittent/perennial stream <strong>and</strong> perennial stream (instream habitat) <strong>and</strong> associated wetl<strong>and</strong>habitat (critical areas) <strong>and</strong> their buffers situated on the east slope of Wood Gulch should beflagged for avoidance.Rare plant species observed within the OH collector line study corridor includes only the ribseeddesert-parsley. Impacts to the mapped colonies (Figure 4C) should be avoided or gradingshould be minimized under the proposed line where mapped colonies occur. WDFW PriorityHabitats within the corridor include juniper savannah, wetl<strong>and</strong>s, oak woodl<strong>and</strong>, <strong>and</strong> riparian.Impacts to these habitats should be avoided to the extent possible or minimized if avoidance isimpractical. The Riparian vegetation in Big Horn Canyon <strong>and</strong> the Oregon white oak in WoodGulch can be avoided by spanning of the OH collector line over the streams. As noted above inthe Wetl<strong>and</strong>s section, it would be difficult to avoid impacting other Priority Habitats (i.e., aspenst<strong>and</strong>, Wetl<strong>and</strong> B, Oregon white oak woodl<strong>and</strong>s) by going around Wetl<strong>and</strong> A. This wetl<strong>and</strong> canbe protected from construction impacts, however, by the use of Mabey® or other crane mats(temporary hardwood surface) placed across the wetl<strong>and</strong>s. The mats allow for flow, whileminimizing soil disturbance, compaction, erosion, <strong>and</strong> sedimentation.OTHER RESOURCES AND CRITICAL AREASAffected Environment <strong>and</strong> Updated StudiesThe Klickitat County CAO was adopted pursuant to the critical areas requirements of the State ofWashington’s Growth Management Act, RCW 36.70A, that are applicable to all counties. Acritical areas review is required for permits or l<strong>and</strong> use approvals issued by the County <strong>and</strong> forcertain grading/clearing activities. Critical areas include: wetl<strong>and</strong>s <strong>and</strong> other waters; areas with acritical recharging effect on aquifers used for potable water; critical fish <strong>and</strong> wildlife habitatconservation areas; frequently flooded areas; <strong>and</strong> geologically hazardous areas. Impacts to keycritical areas have been addressed above; other resource areas are discussed below in associationwith the proposed Project micrositing revisions.A review of l<strong>and</strong> use, socioeconomic <strong>and</strong> aesthetic resources has indicated that there are no newor significant impacts associated with the proposed Project micrositing revisions.A review of traffic <strong>and</strong> transportation has been completed for <strong>Miller</strong> SW. The Project will useaggregate from the two western-most on-site borrow areas noted in Figure 7 of the <strong>Miller</strong> <strong>Ranch</strong>Project SEPA Checklist, or the existing, permitted aggregate borrow area located near Dot <strong>and</strong>Newell roads. As the <strong>Miller</strong> <strong>Ranch</strong> SEPA Checklist accounted for the possibility of truck trafficassociated with transport of aggregate rock materials from off-site, no additional truck trips arenoted here. Water will be brought onto the Project site from a nearby privately owned, permittedwell located near Schrantz Road, approximately one-half mile north the Project. A temporarypipeline will extend from the well to a temporary pond excavated in an upl<strong>and</strong> area near thesubstation. As the pond will be dewatered <strong>and</strong> deconstructed to the original contours <strong>and</strong>characteristics of the upl<strong>and</strong> area immediately upon completion of construction, it will not bepermanent; therefore, no wetl<strong>and</strong> or other waters will have been created. As a result of thisapproach, there will be no requirement for trucking of water to the site.
Page 19 of 20Placement of OH collector line poles <strong>and</strong> other facilities in geologically hazardous areas will beavoided to the greatest extent possible. Any project facilities located in geologically hazardousareas will be constructed <strong>and</strong> operated in compliance with the <strong>Miller</strong> <strong>Ranch</strong> <strong>Wind</strong> Project EOZPermit <strong>and</strong> the Klickitat County CAO.Conclusions <strong>and</strong> RecommendationsThere are no new impacts to l<strong>and</strong> use, socioeconomic <strong>and</strong> aesthetic resources associated with themicrositing revisions. The <strong>Miller</strong> SW facilities will not result in direct impacts to jurisdictionalwetl<strong>and</strong>s or surface waters. Impacts to wetl<strong>and</strong> stream buffers resulting from Projectconstruction or operation will be addressed through on-site or off-site mitigation. Mitigationmeasures will be determined in coordination with Klickitat County <strong>and</strong> WDFW, in accordancewith the Project EOZ Permit conditions. There are no wetl<strong>and</strong>s <strong>and</strong> other waters, criticalrecharge areas, fish <strong>and</strong> wildlife habitat conservation areas, frequently flooded areas orgeologically hazardous areas significantly impacted by the construction or operation of therevised layout in the <strong>Miller</strong> SW area.As there are no new impacts to l<strong>and</strong> use, socioeconomic <strong>and</strong> aesthetic resources, no mitigationmeasures have been recommended. Road requirements associated with the Road HaulAgreement are adequate to address truck traffic associated with use of an off–site aggregatesource. Mitigation associated with <strong>Miller</strong> SW will be consistent with the Project EOZ Permitdated June 6, 2008.If you have any questions or comments on the information provided herein, please call me at425-482-7706Sincerely,TETRA TECH EC, INC.Virginia HowellEnclosures:Attachment 1, Cultural Resource Memor<strong>and</strong>um (Confidential)Attachment 2, <strong>Miller</strong> SW Habitat Management Plancc: Collin Whitehead, enXco Development Corporation
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