3.8.2.2 Study Methods

Study methods used to evaluate the visual resources which may be affected by the Proposed Action or alternatives to the Proposed Action include review of the Modoc National Forest LRMP to evaluate the Forest VQO applicable to the study area. This information was supplemented with a visual inspection of the study area conducted on July 2, 1997, which was conducted to identify potential vantage points from which facilities of the Proposed Action and/or alternatives might be visible.

3.8.2.3 Description of the Study Area

The study area is situated within the Medicine Lake Highlands. This area is visually distinctive topographically and geologically due to the many peaks and craters of volcanic origin which are in contrast to the surrounding broad valleys and level plateaus. Medicine Lake itself is the geologic and visual center of the area. Vistas from the lake show changes from an untouched landscape, including a boat ramp at the east end of the lake, private residences on the south shores, and campgrounds on the north shores. Although these changes are noticeable, they do not attract attention, and a high level of scenic integrity persists. Due to the lake’s geologic situation in a crater at a lower elevation (6,676 feet amsl) than the surrounding terrain, views from Medicine Lake are limited to the foreground and the peaks and higher ridges of the crater rim in the background. Prominent area peaks include Little Mount Hoffman to the west; Mount Hoffman, the tallest peak of the surrounding crater rim at 7,913 feet elevation, to the north; Glass Mountain to the northeast; Red Shale Butte to the east; and Medicine Mountain to the southwest (see Figure 3.8.1). The area has the landscape character of a gentle-sloped basin with a full forest canopy of lodgepole pine, Shasta red fir, white pine and white fir. The open flats of Arnica Sink, the unvegetated Medicine Lake and Glass Mountain Lava Flows, scattered mountain meadows, and the waters of Medicine Lake provide visual contrast and variety to the otherwise forested landscape. With the exception of these described open areas and a few elevated locations, the forested nature of the landscape, and the generally gentle grade of the area, limits most ground level views to the immediate foreground. This forest cover enhances the strong sense of scenic integrity and intactness of the area. The VQO’s for the study area, including the geothermal wellfield and power plant sites for the Proposed Action and all alternatives, are shown on Figure 3.8.2. Based on the LRMP, the power plant sites of the Proposed Action and Alternative A are being managed for partial retention. The power plant site for Alternative B is managed for modification. The areas immediately surrounding Primary Forest Route 97, located south of the power plant sites, and the section of Primary Forest Route 49 located in the vicinity of Medicine Lake, are each managed for retention. The lands immediately surrounding secondary Forest Roads 43N21 and 43N53 are each managed either for partial retention or modification.

3.8.3 Environmental Consequences

3.8.3.1 Significance Criteria

Appendix G of the CEQA Guidelines indicates either of the following adverse effects would normally be considered a significant effect: Conflict with adopted environmental plans and goals of the community where it is located (e.g., visual plans or goals); or A substantial, demonstrable negative aesthetic effect. For the purposes of this assessment, a visual effect would be considered significant if any of the following would occur: A long-term inconsistency with established USFS Visual Quality Objectives (VQOs) when viewed from one (1) or more key observation points (KOPs), other inventoried, visually sensitive locations, or other locations determined to be visually sensitive; Elimination or substantial alteration of significant visual features, view corridors, or public vista points; Substantial alteration of natural landforms; Incompatibility with the scale or visual character of the surrounding area; or Creation of significant new sources of light or glare visible from routinely occupied areas.

3.8.3.2 Assessment Methodology

As discussed in Section 3.8.2.2, the Modoc National Forest LRMP prescribes VQOs for all areas of the Forest, including the area of the Proposed Action and Alternatives. The visual effects of the facilities and operations of the Proposed Action and Alternatives were evaluated with respect to conformance with the established VQO. This analysis was initiated through a review of USGS topographic maps and USFS maps to identify line-of-sight points of Project visibility and potential key observation points (KOPs) from which the Project facilities may be visible from routinely accessible vantage points. Potential KOPs were also identified through: Consultation with representatives of the USFS; Public scoping conducted as part of the EIS/EIR process; and Review of the Fourmile Hill Geothermal Development Project EIS/EIR. Potential KOPs were also considered based on their proximity to the proposed Project facilities or their elevated location relative to the surrounding terrain. The potential KOPs identified included stretches of Forest Route 49 west of the Project wellfield area, Forest Route 97 south of the Project wellfield area, Forest Road 43N21 west of the power plant sites proposed for the Proposed Action and for the Project Alternatives, and Forest Road 43N53 east of these same power plant sites (see Figure 3.8.3). The alternative power plant sites are also visible from the surrounding mountain peaks. However, these mountain peaks, with the exception of Little Mount Hoffman, do not have public vehicular access. Visibility from Little Mount Hoffman is obscured due to its distance (approximately 5.5 miles) and the intervening 7,122-foot elevation unnamed hill located approximately ¼-mile west of the Proposed Action power plant site (see Figure 3.8.3). On September 29-30, 1997, a field assessment was conducted to evaluate the visibility of the principal Project facilities from all of the potential KOPs identified on Figure 3.8.3 based on line-of-sight. The power plant site locations and transmission line segments were first verified in the field by the USFS. Two, 7’ × 4½’, aluminum blankets were then placed at a measured height of 80 feet in each of two (2) trees on each of the power plant sites (Proposed Action, Alternative Site A and Alternative Site B) by tree climbers to represent the maximum height of the power plant at each location (see Figure 2.2.15). The trees selected at each site were located approximately 300 feet apart on a north-south axis to represent the approximate length of the largest power plant structure, and to provide backup in case one end of the site was not visible. The reflective surfaces were oriented both east/west and north/south. The lengths of Primary Forest Route 49 and Primary Forest Route 97 selected as potential KOPs were then slowly driven in a car with an observer looking for the marked trees. While still in the trees at an elevation of 80 feet above the ground, the tree climbers noted all of the roads and major natural features visible. Because of the proximity of Forest Road 43N21 to the power plant site for the Proposed Action, an additional technique was also used to evaluate visibility of the primary power plant facilities. For this technique, a vehicle was driven back and forth on Forest Road 43N21 as fast as could be safely traveled with the horn honking. The tree climbers located 80 feet above the ground then watched in the direction of the honking horn for dust from the vehicle traveling on the road. Helium balloons and smoke bombs were also used as visual markers of the power plant sites, but were found to be ineffective site locators due to the high winds experienced over the dates of the field studies, the full-to-partial tree canopy of 80 to 120 feet in height, and the distance of the alternative power plant sites from the potential KOPs. The field visibility assessment described above determined that the only point within any of the potential KOPs from which any of the primary power plant facilities located on any of the power plant sites may be visible was from Primary Forest Route 49, north of Medicine Lake, approximately ¼-mile east of its intersection with Forest Road 44N50 (see Figure 3.8.3). This point was selected as the only KOP for the Proposed Action or the power plant site Project Alternatives. Only facilities located on the Proposed Action power plant site and Alternative Site A power plant site would be potentially visible from this KOP. Facilities located on Alternative Site B power plant site would not be visible, but the cooling tower condensate plume that would rise above the proposed power plant facilities under some atmospheric conditions would be visible from the KOP for each of the alternative power plant sites. Photographs were taken from this KOP in the direction of the visible marked trees with a 28 mm lens to obtain a panoramic views (see Figure 3.8.4). This photograph was then used to create photosimulations of the facilities on the power plant sites which may be visible. To obtain approximations of actual size and scale of the Project facilities on the visible power plant sites, an 80-foot high tower was visually scaled from a distance of about four (4) miles, then used as a scale guide for estimating the actual size of the simulated power plants, as viewed from the four (4) mile distant Primary Forest Route 49 KOP. Similarly, the height of the power plant facilities on the photosimulations were compared to the height of the adjacent tree canopy, and individual trees on the skyline which appeared on the photographs. The photosimulations were constructed to simulate the power plant facilities as seen during daylight hours during the summer, the most frequently viewed time. The transmission line utility corridors to which the initial line segments from the Telephone Flat Project would connect were analyzed in the Fourmile Hill Geothermal Development Project EIS/EIR (BLM et al. 1998). The visual assessment of the impacts of those transmission line segments are incorporated by reference into this EIS/EIR and are summarized in Exhibit 4 to this EIS/EIR (see selected pages 4-141 to 4-176 in Exhibit 4).

3.8.3.3 Proposed Action

3.8.3.3.1 Consequences of the Proposed Action

Field observations relevant to the visibility of the Proposed Action power plant site are summarized in Table 3.8.2. This field visibility assessment determined that the only point where the primary power plant facilities located on the Proposed Action power plant site may be visible was from the Primary Forest Route 49 KOP, located north of Medicine Lake, approximately ¼-mile east of its intersection with Forest Road 44N50 (see Figure 3.8.3). Along this section of road, the upper portions of the power plant facilities located on the Proposed Action power plant site would likely be visible for approximately 500 feet while traveling east (i.e., for about 14 seconds for vehicles traveling at 25 miles per hour). Above this section of road (to the west), the view of facilities located on the Proposed Action power plant site is blocked by the elevated terrain which forms the rim of the Medicine Lake basin. As the road descends below this section, the view is first blocked by the Medicine Lake Lava Flow, then, as the road descends further into lower terrain, the forested foreground obstructs the views in the direction of the Proposed Action power plant site. The prominence of the Primary Forest Route 49 KOP is magnified by the contrast with the visual terrain encountered before reaching this location as one travels south on Primary Forest Route 49. The lead-up to this KOP is through land with forest on both sides of the road and with opportunities for viewing limited to the foreground. As one crests the ridge to enter the Medicine Lake basin, the road turns to the east-southeast, and a panoramic vista, including Glass Mountain, Red Shale Butte, and Medicine Mountain, comes into view (see Figure 3.8.4). The foreground includes mountain meadows, and scattered groupings of trees. The middleground includes Medicine Lake Volcanic Flow, Medicine Lake, and a visually intact forest cover. Figure 3.8.5 is a photosimulation of the view of the facilities on the Proposed Action power plant site which would be expected to be visible from the Primary Forest Route 49 KOP. In this view, the visible portions of the Proposed Action power plant facilities have been simulated in white (not the color proposed in the Proposed Action) to facilitate identification by the viewer. Although the tallest trees immediately adjacent to the visible side of the power plant facilities are approximately the same height as the turbine-generator building, the tree density is not high. Thus, as seen in Figure 3.8.5, approximately the upper third of the turbine-generator building (see Figure 2.2.15) would likely be visible through the upper portions of the tree canopy. Of the other structures located on the power plant site, only the cooling tower fan shroud and the very top of the H2S abatement enclosure may be visible through the trees. Views of the otherwise visible portions of the facilities, including the wellfield facilities, would be blocked by the forest.