BUTTE – Local government officials and members of the community gathered at Montana Tech in Butte on Friday for the release of detailed reports from the Mountain States Transmission Intertie Review Project, which has conducted an independent analysis of the potential impacts of a proposed 500-kilovolt transmission line stretching from Townsend to Jerome, Idaho.
The research findings of the project, which began over a year ago, focus on data related to impact on property values and taxes, who will pay for the transmission line and what the need for and purpose of the line is. Through this process, the review project team also developed an what they called an objective, quantitative and transparent spatial analysis and alternative corridors for the MSTI line with the help of locally appointed officials to reflect economic, cultural and environmental values and concerns.
The project also used community workshops to gather information from local community members and elected officials about how variables such as private property, recreation and agriculture as well as population density and existing infrastructures should be ranked in order of importance. The information was then used by project members to identify potential corridors for the MSTI line that incorporates the values related to these themes.
Cameron Ellis of the Sonoran Institute was responsible for the community route analysis portion of the MSTI Review Project. In his summary of his research, Ellis said the goal of the community model was utilize community input to create maps to identify corridors and routing options for the line. In doing so, the model produced a values surface that assigns locally scored community values to a map of the area in 90 meter intervals as well as a community values corridor that represents the route of least possible impact to locally assigned community values.
The results of the community model indicate that the top priorities in determining a potential corridor are protecting private property, agricultural and residential land uses and collocating with major existing infrastructure. The community model also determined that the least impact/most suitable corridor for the line would be on public land. While the community map attempts to collocate with existing infrastructure and land uses, it is comprised of approximately 70 percent public land and 30 percent private land because there is no continuous stretch of public land between Townsend and Jerome.
Northwestern Energy and the Bureau of Land Management have identified engineering constraints and special management areas that represent “no go” areas on the map where transmission lines are prohibited, discouraged or difficult to build due to terrain features or existing physical structures.
Brent Brock of the Craighead Institute was responsible for the wildlife route analysis portion of the MSTI Review Project. In his summary of his research, Brock said the goal of the wildlife model was to explore alternative routes for the proposed line that would minimize potential impacts to wildlife. This model produced a Wildlife Cost Surface and assigns values to a map of relative affects on wildlife based on published research and input from qualified professional biologists over the entire area. The wildlife model also produced a least cost wildlife corridor that represents the relative accumulated impacts to wildlife and habitats throughout the length of the transmission line. As a result of the wildlife model, a quantitative comparison of three corridor options connecting the Townsend substation to the Interstate 15 corridor.
The wildlife model indicates that the importance of collocating near existing infrastructure in order to protect clusters of relatively undisturbed habitat in the throughout the project area. Because this habitat exists on both private and public lands, the wildlife map is made up of 50 percent private and 50 percent public lands.
As indicated by the wildlife model, the three potential corridors to connect the MSTI line between the Townsend substation and the I-15 corridor run from Townsend to Mill Creek via either the existing Bonneville Power Administration line or the I-90 corridor, or from Townsend to I-15 through the Jefferson Valley. Cost distance analysis suggests that the Townsend to Mill Creek via I-90 route would produce the least cumulative impacts to wildlife habitat, while the route from Townsend to I-15 via the Jefferson Valley would produce greater cumulative impacts despite being shorter in length.
In a press release issued by project coordinator Monique DiGiorgio, officials from both Madison and Jefferson County reflected on the MSTI Review Project. Jefferson County commissioner Leonard Wortman said that the community mapping workshops he participated in provided a valuable opportunity for meaningful input into the MSTI Review process.
“We have proven the value of this type of stakeholder process with county commissioners, and hope it will serve as a model for other projects across the West, early in project planning and with other stakeholders,” Wortman said in the press release.
Dennis Glick of Future West was involved in county and stakeholder outreach for the MSTI Review Project, and offered insight into the projects’ results on Friday.
“There is a lot of information that was collected from a lot of different sources and displayed in a way that we think people can understand, and if they want to look at all those sources that resulted in that least cost route, they can dig in to that on the website,” Glick said.
Finalized reports from the MSTI review project will be available at the end of this month. For more information visit the review project website.