SunZia Transmission Project: Balancing Renewable Energy with Tribal and Environmental Concerns

By Cathryn Newman. 

The SunZia Transmission Project 

In May 2023, the Department of the Interior’s Bureau of Land Management (BLM) approved the largest wind project in the Western Hemisphere and in U.S. History, the SunZia Transmission Project (SunZia). SunZia is a privately funded project comprising a 3.5-gigawatt wind farm in New Mexico and two 500-kilovolt above-ground transmission lines across approximately 550 miles of federal, state, and private lands between central New Mexico and Arizona. The goal of this project is to transport up to 4,500 megawatts of renewable energy generated by the wind farm to more than three million Americans in New Mexico, Arizona, and California. Secretary of the Interior Deb Haaland stated, “[t]he SunZia Transmission Project will accelerate our nation’s transition to a clean energy economy by unlocking renewable resources, creating jobs, lowering costs, and boosting local economies.” SunZia is one of over two dozen planned transmission lines, which are all vital to the Biden-Harris administration’s climate goal of reaching net zero greenhouse gas emissions from the power sector by 2035.

Southwestern Power Group, a Phoenix-based developer, conceived the idea for SunZia in 2006. As the first project of its kind and size, it has overcome significant hurdles in the past 17 years before receiving final approval. BLM evaluated the project through the National Environmental Policy Act (NEPA) from 2009 to 2015 and issued a right-of-way grant (ROW) for the project’s construction route on federal lands in 2016. However, numerous setbacks, including challenges by environmental groups, local communities, and tribes and subsequent amendments requested by SunZia developers, halted BLM’s issuance of a Final Environmental Impact Statement (FEIS) and ROW until February of 2023. 

SunZia began construction in 2023 after Pattern Energy Group LP, the developer behind the project, secured over 11 billion dollars in funding. The transmission lines are supposed to be available for commercial operation by 2026.  

Tohono O’odham Nation et. al. v. United States Department of Interior et. al.

Despite approval by BLM, SunZia ran into yet another hurdle. Last month, part of SunZia came to a standstill in Arizona when two tribes, the Tohono O’odham Nation and San Carlos Apache Tribe, joined by the Center for Biological Diversity and Archaeology Southwest, filed suit against the Department of the Interior, BLM, and Secretary Haaland in the United States District Court for the District of Arizona. At issue is a 50-mile segment of private and state land in the San Pedro Valley. This area is of profound cultural and ancestral significance to many tribal nations, including the plaintiffs in this case, the Hopi Tribe, and Pueblo of Zuni. The groups argue that BLM did not properly comply with the National Historic Preservation Act (NHPA) and the Administrative Procedure Act (APA) when it issued the Limited Notices to Proceed (LNTPs), which authorized the partial construction of the SunZia transmission lines in the San Pedro Valley.

In their complaint filed on January 17, 2024, the tribes state that the construction of the transmission lines has and will negatively impact plants, animals, human remains, and water resources, which are sacred to the tribes. Further, they allege that BLM’s compliance with Section 106 of NHPA was “deeply flawed” as it failed to consider evidence submitted by the tribes of the Valley’s cultural significance. BLM found that there were “no historic properties present” in the construction area, and failed to recognize the area as “traditional cultural property” until March of 2023. Finally, the tribes claim that the agency did not “meaningfully consult” with the tribes as required by Section 106 of NHPA and restricted alternatives that would minimize the adverse effects on the historical land, namely rerouting the transmission lines.

The Plaintiffs seek relief in two forms: (1) they want the court to vacate the LNTPs and remand to BLM and (2) they want the court to halt construction of the transmission lines until BLM implements a process that complies with the NHPA. This would require BLM to meaningfully consult with the tribes by identifying all historic properties, fully consider the direct, indirect, and cumulative effects of SunZia’s construction on these properties, and complete a Historic Properties Treatment Plan (HPTP) to address and resolve all of the adverse effects.

Impact of Litigation on SunZia & Renewable Energy

According to SunZia’s motion to intervene as a defendant in the action, the delay in construction caused by this suit will have a severe impact. First, any delay in constructing the transmission lines impacts the wind farm under construction in New Mexico as they are interdependent. Additionally, the suit puts at risk “a renewable power supply for up to three million people, fulfillment of state and federal renewable energy targets, approximately 2,000 construction jobs, and over three billion dollars of existing investments out of a planned $11 billion worth of transmission and wind energy projects.” Furthermore, they call attention to the fact that the construction at issue is on private and state land, not federal or federally recognized tribal land. 

What’s Next?

Concerns and subsequent legal challenges will only become more prevalent as the renewable energy industry develops. On one hand, experts state that to meet our renewable energy goals, constructing more transmission lines is necessary to deliver wind and solar energy. Without transmission lines, we are stuck in “intermittent renewable” land and must continue to rely on traditional energy sources when the wind isn’t blowing or the sun isn’t shining. However, a 17-year timeline for approval is hardly sustainable if we want to build the requisite number of transmission lines. This timeline is further frustrated by regulatory agencies, environmental groups, and local communities who can slow or even stop development by bringing suit.

On the other hand, these transmission lines will damage sacred tribal lands and the environment severely and irreversibly. While the developers decided to avoid building on federally recognized tribal lands, the San Pedro Valley is a deeply sacred area to the tribes in the surrounding area and in New Mexico. Their presence is documented as early as the 1500s. Clearing, grading, road construction, and other ground-disturbing activities necessary to construct transmission lines will also impact plants, animals, and the natural desert landscape.   

While we wait for the court to issue its verdict on this matter, this case and SunZia generally can shed light on the need to balance the country’s renewable energy goals, which are necessary to combat climate change and support our growing infrastructure, with sacred tribal rights, economic interests, and the preservation of the environment.

"San Pedro River Valley Sunset" by treegrow is licensed under CC BY 2.0.

By Cathryn Newman

J.D. Candidate, 2025

Cathryn Newman is a 2L Staff Writer for the Arizona State Law Journal. Before law school, she attended Arizona State University, where she earned a B.S. in Political Science with an emphasis in International Studies and Socio-Legal Studies. Cathryn’s legal interests include trusts and estates, corporate law, and real estate law. In her free time, she enjoys reading and listening to music.