David Moore, PacifiCorp Cultural Resources Coordinator Denise DeJoseph, Project Archaeologist

Transcription

1 References DeJoseph, Denise 2011 Lewis River HPMP: Swift Camp FSC Survey Negative Results. Memo report submitted by Historical Research Associates to PacifiCorp, Portland, Oregon. Copies available at PacifiCorp, Portland, Oregon. Emmons, Ann, Michelle O'Doherty, Marcia Montgomery, Gail Thompson, Melissa Darby, Caroline Swope, and Simon Geerlofs 2002 Historic Resources Inventory and Assessment for the Federal Energy Regulatory Commission Relicensing of the Merwin Hydroelectric Project (FERC No. 935) Swift No. 1 Hydroelectric Project (FERC No. 2111) and Swift No. 2 Hydroelectric Project (FERC No. 2213), Clark, Cowlitz, and Skamania Counties, Washington. Prepared by Historical Research Associates, Seattle, Washington for PacifiCorp, Portland, Oregon. Copies available at PacifiCorp, Portland, Oregon. General Land Office 1901 Cadastral Survey Plat Map and Notes, Township 7 North, Range 6 East, Willamette Meridian. Electronic document, accessed June 28, Thompson, Gail, and Tom Becker 2004 Historic Properties Management Plan (HPMP) Swift No. 1 Hydroelectric Project (FERC No. 2111),Yale Hydroelectric Project (FERC No. 2071), and Merwin Hydroelectric Project (FERC No. 935) Clark, Cowlitz, and Skamania Counties, Washington. Historical Research Associates, Seattle, Washington. Submitted to PacifiCorp, Portland, Oregon. Copies available at PacifiCorp, Portland, Oregon. United States Forest Service 1917 Columbia National Forest. United States Department of Agriculture, Washington Map C-9 in Forest Atlas of the National Forests of the United States, Columbia Folio, Washington (District 6). Map compiled by USDA, Forest Service from U.S.G.S., G.L.O., Forest Service and other surveys by H.S. Meekham. U.S. Geological Survey, Washington Columbia National Forest, Washington. U.S. Forest Service, Portland, Oregon. 7

2 909 N. Beech St., Suite 210 Portland, OR Phone: MEMO REPORT TO: FROM: SUBJECT: DATE: May 19, 2011 David Moore, PacifiCorp Cultural Resources Coordinator Denise DeJoseph, Project Archaeologist Lewis River HPMP: Swift Camp FSC Survey Negative Results In May 2010, HRA reviewed the proposed Swift Forest Camp Fish Surface Collector Project pursuant to the Lewis River Historic Properties Management Plan (HPMP) and determined that the project had the potential to affect archaeological resources, should they be present. HRA submitted a Cultural Review Checklist and survey review memo on 5/10/2010, recommending a survey and shovel testing in specific areas that had not been previously tested during the Swift No. 1 FERC relicensing studies in 2002 (HRA 2002). In particular, a proposed launch channel for the fish surface collector (FSC) unit that would be dredged from the swimming beach area into the reservoir to approximately 984 feet (ft) elevation was of concern, as this area had not been shovel tested during the 2002 FERC relicensing studies. Since the 2010 cultural review of the project, the design has changed and the swim area launch channel has been deleted. The FSC unit will now be launched by rolling the unit onto a barge in the reservoir from the construction area. The unit is being built on piers in a graveled public parking area adjacent to the Swift Forest Camp boat launch. Construction and staging of the FSC unit which was underway as of April 2010 is currently and causing no ground disturbance (Figure 1). The location of the work area is shown in the attached project map. 1

3 Figure 1. FSC under construction. During the 2002 FERC relicensing studies, at which time the reservoir had been drawn down to 950 ft elevation, approximately 30 m (100 feet) of the exposed drawdown zone was surveyed, but no subsurface probes were excavated in the vicinity of the Swift Forest Camp boat launch (HRA 2002:21). During the fieldwork, HRA s survey team mapped a lahar layer 0.5 to 2.5 m (2 to 8 ft) thick in the eastern end of the reservoir from the 1980 Mount St. Helens eruption (HRA 2002:6). The Swift Forest Camp boat launch area was mapped on terrace T2, above the lahar deposits, and was assessed as having a high probability of containing prehistoric archaeological deposits (HRA 2002:25-27). On April 28, 2011, HRA Project Archaeologist Denise DeJoseph, M.Sc., (HRA) conducted a survey of the FSC launch area and the location where an anchor for the launch barge will be buried on the north bank of the reservoir northwest of the FSC construction area (the anchor will stabilize the barge on which the FSC will be launched, and will consist of an 8,000 lb boat anchor buried to a depth of 7 ft). One shovel probe was excavated at the anchor location 2 m (6.5 ft) south of the reservoir cut bank (Figure 2). The probe (SP1) was excavated to 50 centimeters (cm) (20 inches [in]) below the surface, and exhibited typical forest stratigraphy observed elsewhere on the Lewis River: surface sediments were brown sandy loam and sand with few gravels, transitioning to a lighter grey sand with few gravels at approximately 40 cmbs with a layer of reddish mottling at approximately cm (Figure 3). Below cm the soil was very compact and greater depth could not be achieved. Some light tan, compact mottling and gravels were evident at 50 cm and were assessed as possible lahar sediments. Sediments were screened through ¼-in hardware cloth. No archaeological materials were observed on the surface or in probe sediments. Figure 2. Location of FSC anchor on north shore of reservoir. 2

4 Figure 3. SP1 at boat anchor location. The FSC launch channel is an area approximately 30 m (100 ft) wide extending from the graveled construction area into the reservoir to approximately 980 ft elevation. HRA excavated three shovel probes along the centerline of the launch channel at 20 m (65 ft) intervals off-set by 10 m (30 ft) (Figure 4). The probes were excavated to a depth of cm (20 in), and consisted of dark brown sand transitioning to tan/grey sand with depth and few gravels. In SP 2, possible lahar deposits were observed at approximately 50 cm (Figure 5). In SP 3, excavated approximately 80 m (262 ft) from the edge of the construction area, water percolated into the probe at 40 cm. All three probes and a surface survey of the launch channel were negative for archaeological materials. Figure 4. Centerline of FSC launch channel. 3

5 Figure 5. Possible lahar sediments in SP2. Results and Recommendations Results of survey and testing were negative for archaeological resources. HRA s field observations confirmed that project design plans have been changed to limit ground disturbance to already graded and graveled areas in the parking and boat launch areas. PacifiCorp s contractor MacKay & Sposito informed HRA that the anchor location may be abandoned and the barge would be anchored to the concrete boat launch instead (N. Hastings personal communication 2010). If the anchor is installed on the reservoir shoreline, HRA anticipates that no buried archaeological deposits are present below the depth of subsurface testing in this location given its distance from a stream channel and the original river channel. Construction monitoring is not recommended. HRA concludes that the project as currently designed would have no impacts to historic properties. HRA recommends that contractor personnel working be briefed on the Lewis River HPMP Inadvertent Discovery Plan in the unlikely event of a post-review discovery. Attachment: Map of project area. References Historical Research Associates, Inc. (HRA) 2002 Archaeological Resource Inventory of the Swift No. 1 Reservoir (FERC No. 2111), Skamania County, Washington. By Goetz, Linda Naoi with contributions by Dr. D. Craig Young, Jr. and R. Wayne Thompson. Report prepared for PacifiCorp by Historical Research Associates, Inc., Portland. 4