CASCABEL — Drive through the Lower San Pedro River Valley, and a well-graded dirt road will take you past homes, organic farms, ranches and other structures where fewer than 200 people live. The only other signs of human presence are a handful of lesser dirt roads and an underground natural-gas power line.
They coexist with prickly pear, agave, saguaro and other cacti, and Sonoran desert trees and shrubs. Cows graze on leased, state-owned or Pima County-owned property.
Now this tranquil valley is the final battleground in a decade-old conflict over a two-state power line.
When the proposed, 515-mile SunZia power line goes before the Arizona Corporation Commission in early February, opponents hope to prove it would irretrievably alter the river valley’s character and fragment its landscape.
The transmission company that has nurtured this $1.2 billion to $1.7 billion proposal hopes to show the impacts can be eased through a long list of mitigation measures it says are more advanced than those related to any other Arizona power line. But opponents criticize them as little more than standard best-management practices.
SunZia would include two high-voltage power lines from central New Mexico through southern New Mexico into Southern Arizona. Its 200 miles in Arizona would first cut through rural areas north of Willcox and Bowie, head north through the San Pedro Valley for close to 35 miles and end at an existing substation near Coolidge.
Its goal is to bring wind and other renewable energy produced in New Mexico into Arizona for sale here or in California.
Panel OK’d line 8-0
The most recent round of public hearings regarding SunZia lasted a month and filled more than 2,700 pages of transcripts. The hearings came before the ACC’s Line Siting Committee, a quasi-judicial body that voted 8-0 with one abstention on Nov. 19 to certify that the line will be environmentally compatible. Its vote must be upheld by the five-member, all-Republican commission.
The two sides are debating the line’s need and benefits. Backers promote it as a boon for renewable energy, particularly wind energy they say is now “stranded” in lesser-populated New Mexico, that can help Arizona meet increasingly tough federal clean-air and clean-power mandates. They also say it will make the existing electrical grid in Southern Arizona more reliable.
Opponents denounce SunZia as a highly speculative plan built on “smoke and mirrors.” They argue that the project is not likely to transmit much renewable energy due to the high costs of burying five miles of the line in southern New Mexico and to what they see is a limited market for it in Arizona and California.
But the San Pedro is the centerpiece of the project’s environmental debate:
- The Lower San Pedro is an internationally important bird corridor that draws about 345 species, says the Arizona Audubon Society. It’s made Audubon’s list of Important Bird Areas, and its bird-species diversity is at least as good as the better-known Upper San Pedro near Sierra Vista, Audubon says.
- The entire San Pedro Valley contains the highest bird diversity in five Southwestern states and ranks high on other major biological indicators, said a study done by researchers for the Environmental Protection Agency and New Mexico State University.
- Agencies and nonprofit groups have spent more than $42 million to protect 193,000 acres in the Lower San Pedro to compensate for environmental impacts from projects around the state, the Nature Conservancy has said.
Project opponents fear that if SunZia, with more than 30 miles of 500 KV transmission lines and with towers standing about 135 feet tall, will set a precedent for future industrial intrusion. Led by Christina McVie, the Tucson Audubon Society’s conservation chair, opponents cite a state law requiring special consideration when power lines are considered for areas such as the San Pedro that have unique biological wealth or that have habitat for endangered or threatened species.
“You will be irreversibly impacting the one valley where all of Arizona’s water issues are mitigated, and where the last remnant of an intact riparian watershed provides home for numerous candidate, threatened and endangered species,” McVie told the siting committee. “You will be threatening a sustainable economic engine that is supporting rural economies throughout the valley and that exceeds the contribution economically of golf in the state of Arizona.”
Builders promise care
Project proponents say they recognize the valley’s importance and will treat it with the utmost care if allowed to build there. The committee approved 37 conditions to make the project more sensitive to the environment and cultural resources, on top of more than two dozen mitigation measures approved by the U.S. Bureau of Land Management when it selected the route in early 2015.
“Biological resources of the San Pedro were studied extensively. And what were the results? The project would not jeopardize the continued existence of any endangered species and would not destroy or adversely modify critical habitat,” testified Albert Acken, an attorney representing SunZia, referring to a biological opinion by the U.S. Fish and Wildlife Service. “It already today, as proposed, sets a new standard for transmission lines in Arizona.”
While the project is opposed by numerous other environmental groups, it’s supported by officials of all five counties through which it would pass — except Pima County. County Administrator Chuck Huckelberry is concerned about impacts on land in the San Pedro Valley that the county owns and leases from the State Land Department. That land is part of his proposed federal habitat-conservation plan.
The other counties’ officials favor the project in part because of its promise of new construction jobs and other jobs. Economic development groups in Benson and Sierra Vista support SunZia, while the Tohono O’Odham Tribe and activist groups in Cascabel such as the Cascabel Working Group oppose it.
Fish and Wildlife and the Nature Conservancy, which rarely opposes major Arizona development projects, have opposed routing SunZia through the San Pedro. The Arizona State Land Department, the Arizona Department of Transportation and the Arizona Game and Fish Department signed a letter saying the San Pedro route has less environmental impact than other routes studied, and that mitigation measures will minimize impacts to sensitive resources. The letter didn’t formally endorse the project.
Game and Fish is negotiating with SunZia’s management for a more detailed mitigation agreement. Assistant Game and Fish Director Jim DeVos said last week that “one key issue,” which he wouldn’t discuss, remains unresolved.
Another route sought
SunZia itself has recognized the route’s controversial nature.
When BLM proposed routing the power line through the San Pedro Valley in the early 2010s, SunZia project manager Tom Wray wrote the bureau two letters urging another route, through Aravaipa Canyon farther east.
One reason was that the San Pedro route would be 43 miles longer and cost more. Wray also laid out environmental concerns similar to those environmentalists are raising now. He wrote that the line would cut across several feeder tributaries to the river, likely harming water resources and riparian habitat, and increasing erosion risks.
“SunZia believes such damage will be very difficult to mitigate,” Wray wrote the BLM in June 2012.
Today, Wray no longer stands by those letters — he says the mitigation measures approved by the BLM and the ACC committee, along with the wildlife service’s biological opinion, address the concerns he raised. The mitigation measures will reduce impacts from tower and temporary road construction, among other things, he said.
But when it came time to decide on the power line last fall, some members of the line-siting committee, including chairman Thomas Chenal, said they were voting for it because they felt no acceptable alternative routes existed. Routes through Tucson and the Aravaipa Canyon area east of the San Pedro Valley were rejected by the BLM after it prepared a final environmental impact statement.
“The decision is very difficult. I have been very torn by it,” Chenal said on Nov. 19. “The solace in my decision is that I hope there will be some mitigation factors that will assist.
“I think this is a perfect example of the effort to find the least worst decision. ... The jewel, the San Pedro River Valley, is pristine. ... And my heart just breaks that, you know, there’s going to be a transmission line through there. ... But the alternatives seem worse to me.”
Danger to birds
At a power line hearing last November, Tice Supplee, a top Arizona Audubon Society official with decades of wildlife management experience, testified at length about the potential for Sun Zia to damage the valley’s ecology through habitat fragmentation, bird-line collisions and electrocution.
She expressed concern that cranes flying north of the Willcox Playa area to forage for food could collide with the power line. She spoke of major issues with bird-power line collisions in southern Colorado’s San Luis Valley and the Platte River in Nebraska, the latter a major sandhill crane flyway.
While the San Pedro Important Bird Area covers mainly riparian zones along the river, Supplee testified that birds are likely to use the entire valley to migrate. The power lines would be built two to six miles from the river and cross it once.
“There is constant movement up and down and across these corridors by these bird species seasonally,” said Supplee, a former top Arizona Game and Fish Department official who is now Arizona Audubon’s bird conservation director and interim executive director.
Generally, “linear disruptions” such as power lines can be the most difficult to mitigate because their impacts are spread over hundreds of miles, she testified.
Birds’ susceptibility to power-line collisions depends on individual species’ biological characteristics, an area’s topography and weather, and the line’s design, she said.
To reduce the project’s risks to bird life, lines should be designed with towers high enough to minimize tree clearing, she said. Also, SunZia should avoid use of guy lines to support transmission towers because they add another point of potential contact, she said.
Bird diverters a must
One mitigation technique the BLM will require for this project is the use of bird diverters, devices intended to help birds avoid power lines. Described by Supplee as an emerging technology, they’re planned for the Southline transmission project, another power line to run near the Willcox Playa.
Bird diverters can be six-inch square pieces of reflective plastic or metal, clamped to a power line, that are supposed to catch a bird’s attention, testified David Kahrs, a biologist employed by EPG, a Phoenix-headquartered, six-state consulting firm hired by SunZia’s owners.
“Bird diverters can be effective. They do reduce collisions,” testified Kahrs.
In general, putting two transmission lines such as these close together can reduce the risk to migratory birds by making the lines more visible and easier to avoid, Kahrs said. The project is not likely to substantially threaten cranes in the Willcox area because it will be next to two existing TEP lines in a corridor not heavily used by cranes, he said.
In her testimony, Supplee struck a cautionary note about diverters, saying their effectiveness is still being scientifically evaluated.
Some conditions OK’d
One condition approved by the line-siting committee was for SunZia to comply with a still-unwritten bird-protection plan. Another required step is to detail mitigation efforts in a plan of development in cooperation with all interest groups.
The plan is supposed to avoid building new roads when possible, since roads can cause erosion, fragment habitat and allow invasive species to enter. The conditions also require the use of helicopters to install transmission structures through an 8-mile area of a highly sensitive canyon. Opponents have asked ACC to require aerial construction through the entire San Pedro Valley.
Finally, the BLM is requiring developers to minimize tree clearing to the amount necessary to meet standards that kick in after 10 years of timber growth, and to remove vegetation selectively.
But opponent McVie denounced that condition, saying it will only mean that trees that reach a certain height will be cut down to the point they lose value as canopy cover. She prefers a requirement to build the towers high enough in all riparian crossings to avoid trees altogether.