Incorporating holistic methodologies in determining wind resource availability for the Confederated Salish and Kootenai Tribes

Abstract

We have carried out site feasibility and desirability assessments for wind development on the reservation of the Confederated Salish and Kootenai Tribes (CSKT), located in Western Montana, USA working in collaboration with tribal experts and leaders. Holistic review of siting options includes technical, economic, environmental, and aesthetic factors. We have combined publically available GIS data for wind power classifications, digital elevation maps, and built infrastructure, with input from tribal planners to identify Seepay Ridge as a key technically and economically favored site. Preliminary go/no-go environmental assessments have been carried out by others. A major goal for this work was to provide new geospatial mapping methods and site indexing tools to enable individual communities and the reservation as a whole to assess the perceived visual impacts of specific wind development sites. The visual impact of wind development site j on any given location i was computed using a model from the literature, combined with line-of-sight viewshed modeling. We map the expected visual impact of a Seepay Ridge wind farm with either 10 or 50 turbines on locations across the reservation. The aggregated visual impact from towns on the reservation was also computed based on a population weighting. We found that a 50-turbine Seepay Ridge development has an Aggregated Urban Index (AUI) of 0.05. This means the development has about 5% of the visual impact of building a 50-turbine farm adjacent to each town on the reservation. We also conjecture that situational visual impact is an important, but as of yet unmeasured, viewshed impact variable. The perceived impact of a wind development is likely to be situation-dependent, since the perception of impact by an observer in an urban area vs. a cultural, wilderness, or primitive area is likely to be different for the same observer.