Stretching more than 550 miles across two states, the SunZia Wind and Transmission project is a massive endeavor aimed at modernizing the southwest’s power grid. But its very size – particularly an extensive High Voltage Direct Current transmission line route – triggered a regulatory stalemate that took nearly two decades to resolve.
Although construction of the transmission line took only six years, permitting at the state, county and federal levels resulted in a 17-year regulatory bottleneck. The $10 billion energy initiative spans New Mexico and Arizona, meaning it crosses an excess of federal property and tribal lands, as well as stretches of private parcels.
“This is 550 miles of linear infrastructure where we don’t always know what’s there,” said
Justin Pidot, co-director of the environmental law program at University of Arizona Law. “Part of the challenge is that we know there are endangered species and water implications (in these areas), but you have to figure out what’s there so you can make a good decision.”
SunZia underwent a seven-year review process for its first major route approval, a gauntlet encompassing the Bureau of Land Management (BLM), the Department of Defense and numerous local municipalities.
In all, more than 80 firms, utilities, contractors and regulatory agencies consulted on SunZia for final HVDC design and construction. In 2022, SouthWestern Power Group transferred ownership of the project to Pattern Energy, which is now overseeing its final stretch. Billed as a "clean power superhighway," SunZia is slated to bring 3,500 megawatts of wind-generated electricity from New Mexico to customers as far away as California, according to Pattern.
While Pattern declined comment for this story, company filings indicate the wind farm will feature 916 turbines, ten collection substations and 115 miles of overhead collection lines. The long-deferred transmission line, meanwhile, runs west from Corona, New Mexico, to a converter station near Casa Grande, Arizona.
Among other specifications, the transmission route bypasses the restricted airspace of New Mexico’s White Sands Missile Range. Securing a right of way (ROW) is a must for anyone building on federal property, according to the BLM, which also declined comment for this article. Even with the BLM’s blessing, developers still needed clearance for any remaining public parcels affected by the route.
“Individuals and businesses may apply to obtain a right-of-way grant to use specific pieces of public land for projects such as electric power or fiber optic lines, or wind or solar energy generation,” said a note on BLM’s website. “You need a ROW whenever you wish to build on public land or conduct any activity that would involve appreciable disturbance, alteration or damage to public lands.”
Permitting problems tend to multiply with a project of SunZia’s scope, noted Pidot.
“You could be dealing with one federal land management agency, but you’ll also see multiple rights of way when you’re dealing with Wildlife Services or other groups,” Pidot said. “It depends on whose property is being crossed. Each agency has its own decision-making process and statutes.”
Engagement is key
SunZia and similar efforts often involve Clean Water Act permits under Section 404, which regulates “the discharge of dredged or fill material into waters of the United States.” Citing the century-old Rivers and Harbors Act, the U.S. Army Corps of Engineers mandates separate permitting for river-based initiatives.
Construction of SunZia was temporarily suspended in late 2023 to address tribal concerns regarding ancestral lands and local wildlife. Last May, a federal appeals court ruled that developers failed to “adequately consult” local tribes on historic designations within the San Pedro Valley, which represents a 50-mile segment of the transmission conduit.
“SunZia isn’t crossing reservation land, but these are cultural and religious sites for tribal governments,” said Pidot. “You have a large Department of Defense footprint with the project as well, so depending on the transmission route, that can create additional challenges.”
Pidot previously worked as general counsel for the Biden administration’s White House Council on Environmental Quality, which touted a carbon pollution-free power sector by 2035. Current President Donald Trump has prioritized a surge in domestic energy production, citing the power requirements of AI development and new data centers.
This ongoing infrastructure surge will continue to stretch federal and state oversight to its limits. However, establishing early consensus with residents and municipalities can smooth even the most contentious permitting path, said Pidot.
“If you build goodwill with stakeholders, that can get you a long way,” Pidot said. “You’ll sometimes see the federal government reaching out to the public, while the developer is doing nothing. By the time public comment begins, those people are upset and don’t think they’re getting a fair hearing. There’s always someone who cares about a parcel. A (developer) should do their due diligence on the front end, where the conflicts are lowest, and engage with folks about their concerns.”