Home News ACHP Issue Spotlight: Transmission Lines in the West

ACHP Issue Spotlight: Transmission Lines in the West

Traversing land owned by federal and state agencies as well as by individuals, construction of transmission lines is usually a federal undertaking subject to the Section 106 process. The Bureau of Land Management (BLM) is currently the lead federal agency on a number of these projects. The ACHP is formally participating in four cases and monitoring developments on two others. 

Transmission lines generally involve a variety of developments. The towers supporting overhead cable can be 80-200 feet tall and come in a variety of styles, although most are steel lattice. In addition, construction includes new substations, connections to existing substations, new or improved roads, communication sites, and temporary work areas associated with construction activities. The federal undertaking occurs commonly when the project proponents ask a federal land-managing agency to permit a right-of-way across federal land.

All of these cases involve government-to-government consultation by the BLM with Indian tribes regarding the proposed projects. Other parties consulting on the projects include the State Historic Preservation Offices (SHPOs), Tribal Historic Preservation Offices (THPOs), land owners (i.e. federal agencies, private citizens), state and local governments and agencies with oversight or interest (i.e. Utah Public Lands Policy Coordination Office, Chaffee County Heritage Area Advisory Board), and proponents. When a national park or national historic landmark (NHL) will be affected, the National Park Service (NPS) is invited to participate. In addition, the BLM invites other groups to consult, such as the National Trust for Historic Preservation, state and local preservation groups (i.e. Montana Preservation Alliance, Fremont Custer Historical Society), and historic trail groups (i.e. Old Spanish Trail Association, Oregon-California Trails Association). On many of these projects, BLM grants interested citizens consulting party status.

As a group these cases tend to be challenging because of the length of the project lines, multiple jurisdictions, and the large areas of potential effect (APEs) that ensue. This is complicated by the fact that there are ordinarily several major routes under consideration with many local variations that may require consultation on thousands of miles of potential corridor. Indian tribes may be reluctant to provide sensitive information on such broad swathes of land until the route is refined or even chosen, and at that point it is difficult to take landscape-scale resources and visual impacts into account. Tribes, THPOs, SHPOs, and even federal agencies find their staff resources are strained to consult on such large-scale projects, and often on multiple large projects at one time.

Another challenge is effectively addressing cumulative effects. Some historic properties are affected by several of these lines, and some lines have multiple phases, with National Environmental Policy Act (NEPA) and Section 106 done separately for each phase because they may be developed years apart and have independent funding sources. As a result of all these challenges, project-specific Programmatic Agreements (PAs) are being formulated in many cases that take a phased approach to identification and evaluation to fulfill Section 106.

The Gateway West Transmission Line, an interstate, interagency project, which would construct a new transmission line from Glenrock, Wyoming, to the Hemingway substation southwest of Boise, Idaho. The line will be approximately 1,100 miles long with a 300 foot wide right-of-way and may involve lands or permits administered by the BLM, Forest Service (FS), Bureau of Reclamation (BOR), U.S. Army Corps of Engineers, Idaho National Guard, and NPS. It may also cross lands on the Fort Hall Indian Reservation, for which the Bureau of Indian Affairs has trust responsibilities. After a false start at developing a PA, the BLM and consulting parties agreed to form a work group to write the PA. Twelve of the 29 consulting parties, including one Indian tribe, opted to participate in the actual writing—including the ACHP and the Wyoming and Idaho SHPOs—but all consulting parties will have opportunities to review and discuss the drafts.

The Mountain States Transmission Intertie project proposes construction of a 400-430 mile long, 500 kilovolt (kV) transmission line crossing parts of Idaho and Montana. There are potential effects to a number of important historic properties, including the Butte-Anaconda NHL, Three Forks of the Missouri NHL, Lewis and Clark National Historic Trail (NHT), Nez Perce NHT, Oregon NHT, and a traditional cultural property at Big Southern Butte. As a result, the BLM is currently consulting with 25 consulting parties and nine Indian tribes. Progress on this project has been slowed by a state lawsuit over the adequacy of environmental consultation with a county government, which has provided additional time for the Section 106 consultations. One important impact, visual effects of this transmission line, will be approximated through “backsighted analysis.” This process will use viewsheds of 5-10 miles to identify areas, based on terrain and distance, from which the transmission line could possibly be seen (without taking vegetation into account).

The Sigurd to Red Butte Transmission Line is proposed to be a 160 mile long, 345 kV line with associated facilities within Utah. One alternative route may affect the Mountain Meadows Massacre Site Historic District, which plays an important role in Mormon history and has been nominated as an NHL, in addition to several other sites of significance to Mormons. As a result, this consultation includes parties such as the Church of Jesus Christ of Latter-day Saints, Mountain Meadows Association, Mountain Meadows Monument Foundation, and Mountain Meadows Massacre Descendants, along with 14 Indian tribes, an Indian organization, two trail associations, an archaeological institute, a rock art association, and other parties. The PA for this proposed line calls for the development of a visual effects study, monitoring plan, discovery plan, and historic properties treatment plan.

The Boardman to Hemingway Transmission Line—from Boardman, Oregon, to the Hemingway substation southwest of Boise, Idaho—would be approximately 300 miles long and cross land administered by the BLM and FS, and possibly by BOR and the Navy, as well as private lands. The BLM is consulting with the Oregon and Idaho SHPOs, Tribal Historic Preservation Office for Confederated Tribes of the Umatilla Indian Reservation, NPS, National Trust for Historic Preservation, Oregon-California Trail Association, Oregon Department of Energy, Oregon Historic Trails Advisory Council, and Malheur County Historical Society. They have also initiated consultation with nine Indian tribes. Assessment of visual effects to historic properties is a challenge on this project, as with most transmission lines. However with a goal of completing the Section 106 consultations by 2013, there should be time to work through this and other cultural resource issues.

The ACHP is monitoring developments on the TransWest Express and Gateway South Transmission Line projects pending receipt of additional information on historic properties. TransWest Express is proposed to be a 600 kV transmission line approximately 765 miles long, with an additional 3,000 miles of alternative routes being studied. Gateway South would be a 500 kV transmission line approximately 400 miles long, from Rawlins, Wyoming, to south of Salt Lake City, Utah. These proposals illustrate challenges presented by the scale of the undertakings. The regulations at 36 CFR Part 800 instruct agencies to include documentation, when inviting the ACHP to participate, such as a description of the affected historic properties (800.11(e)(3)). Yet because of the huge scale, the Section 106 process for these projects is often resolved through a PA that allows for phased identification and evaluation of historic properties over time.

As a group, these projects are large-scale and time-consuming for the agencies and all consulting parties. They challenge federal agencies and the ACHP to look for efficiencies in the Section 106 process and consider how to take adverse effects, including visual effects, into account over long distances and in landscape-scale historic properties. Transmission lines represent a component of renewable energy development that is often unacknowledged but has potential for significant impacts to historic properties.

Posted May 3, 2011