The Villages at Vigneto will cover some 12,000 acres along Arizona 90 near Kartchner Caverns State Park.

Ron Medvescek / Arizona Daily Star /File

A move by the U.S. Fish and Wildlife Service could delay or change plans for a 28,000-home development near Benson.

But that could depend on how much legal weight is given to an unsigned recommendation from the federal agency.

A draft letter from the service’s Phoenix office says officials recommend that the Army Corps of Engineers consult with it to determine the Villages at Vigneto’s potential impacts on two federally protected species: the Western yellow-billed cuckoo and Northern Mexican garter snake.

Fish and Wildlife mailed the letter to the Corps in mid-July. The Star recently obtained a copy through the federal Freedom of Information Act.

The service’s request puts it clearly on the side of environmentalists, who already have asked the Corps to analyze the Villages at Vigneto’s impacts on endangered species and habitat. The recommendation also joins with a Tucson Audubon Society letter, written in May, seeking a re-evaluation of the Corps’ decision in favor of an earlier version of the Vigneto project. In 2006 the Corps granted a Clean Water Act permit to Whetstone Ranch to start construction, but that project never got far off the ground. It has since been taken over by Vigneto’s developer, Phoenix-based El Dorado Holdings Inc.

As Audubon did, the wildlife service noted that the cuckoo and garter snake have been listed as threatened species since that permit was issued.

The Corps still hasn’t decided whether to review that permit, a spokesman said.

Letter’s force at issue

The nature of the service’s request — an unsigned, draft letter — makes it unclear how much legal force it has. Three legal experts on the Endangered Species Act said they didn’t think the letter’s draft status would make a difference to a judge if the controversial development ends up in court over the endangered-species issue. But a fourth said a judge might give less weight to a draft letter, since it would be impossible to know why it wasn’t finalized.

In a brief statement emailed to the Star last week, Corps spokesman Dave Palmer said the agency has no basis to formally respond to the draft wildlife service letter. But he said the agency is gathering information on threatened and endangered species and will start a formal review if necessary.

Regardless, it seems likely that the project — which many Benson officials and business leaders view as an economic savior — will become part of one of the most divisive endangered-species issues in the U.S. The controversy centers on Section 7 of the Endangered Species Act, which requires federal agencies to consult with the wildlife service before issuing a permit for a private construction project that may affect an endangered species.

Developers have tried unsuccessfully to get that requirement weakened in Congress. They dislike it because such reviews last at least four months and often lead to the developers having to pony up significant amounts of money for land acquisition or other means of compensation. Environmentalists and wildlife service officials say the required consultations are integral to the act’s goals of preserving imperiled plant and animal species.

Vigneto developer El Dorado Holdings Inc. has said it hopes to start construction on the project by next year. That might not be possible if an endangered-species review is lengthy.

Places to nest

When the Corps issued its 2006 permit, it concluded that the development, at the time slated for 20,000 homes, wasn’t likely to impact endangered or threatened species. That was in part because no such species were known to live on the site.

The Corps also didn’t look closely at the project’s impact on imperiled species along the neighboring San Pedro River. It concluded that consultants on the project had raised a reasonable possibility that the development’s groundwater pumping wouldn’t dry up the San Pedro — and that the Corps lacked power to prevent the river from drying up in any case. That came despite written requests from the wildlife service and the EPA to consider impacts to the river’s much-treasured ecosystem.

But in its July letter, the service said there’s a reasonable chance that both the garter snake and the cuckoo exist on the Vigneto site:

• The site, as close as 2 miles from the Lower San Pedro, contains washes with trees and shrubs that have cuckoo nesting and foraging habitat similar to that near the Upper San Pedro River northeast of Sierra Vista, where those birds nest.

• Cuckoos breed in evergreen woodlands in the Patagonia Mountains similar to those in the Whetstone Mountains adjoining the Vigneto site. That makes it likely that cuckoos live in the project area between the mountains and the San Pedro.

• Proposed critical habitat for the garter snake exists along the river adjacent to the project site.

The service is also concerned about the development’s potential indirect impacts on the species. The federal species act says “all areas to be affected directly or indirectly” by a proposed project should be studied.

One indirect impact would occur if groundwater pumping for the project lowers the water table and reduces both above-ground and underground water flows, the service wrote. That could hurt the cuckoo and the Southwestern willow flycatcher, which has been listed as endangered since 1995, the service said.

Also, the service said, because the 12,000-acre Vigneto project is much larger than the 8,200-acre Whetstone site, the Corps needs to look again at impacts to the endangered jaguar and the lesser long-nosed bat that it considered unlikely back in 2006. Since then, the feds have designated land in and adjacent to the Vigneto site as critical jaguar habitat.

Officials with Vigneto developer El Dorado Holdings Inc., have said they don’t believe the Corps should have to review impacts of the additional 4,100 acres until the developer is ready to build upon them — and there’s no telling when that will be.

Other potential indirect impacts include degraded water quality, erosion, habitat destruction, flooding and alteration of stream channels due to paving of the development site, the service said. If these impacts spread downstream, they could also affect the Southwestern willow flycatchers and their critical habitat along the Middle and Lower San Pedro, the service said.

“A CAUTION FLAG”?

Wildlife field service supervisor Steve Spangle, who sent the Vigneto letter to the Army Corps on July 15, said sending such letters in draft form “is the way I do business.” It’s a way to make sure it’s factually correct, Spangle said.

But in this case, Spangle said, he decided they didn’t need to finalize or sign the draft because in late July Sallie Diebolt, an Army Corps official, told him she would respond to the service’s questions when she responded to the earlier letter from Tucson Audubon.

Vermont Law School professor Pat Parenteau and law professors Fred Cheever at the University of Denver and J.B. Ruhl of Vanderbilt University agreed that whether the letter is draft or final won’t make much difference if the question of endangered-species reviews goes before a judge.

Without a follow-up letter from the wildlife service agreeing that the project won’t hurt the threatened species, the Corps’ obligation to consult is clear, Parenteau said.

Because the letter says a review is Fish and Wildlife’s official recommendation, “Fish and Wildlife has a good reason to be contacting the Corps,” Cheever said.

But law professor Dan Rolhf, of Lewis and Clark Law School in Portland, said he thinks a judge will consider the letter’s form because he will have no way of knowing the service’s intent when it sent the letter.

“If I were a judge,” Rohlf said, “an unofficial letter would be a caution flag.”

Contact reporter Tony Davis at tdavis@tucson.com or 806-7746. On Twitter: tonydavis987.