Biologist  Trevor Hare and mining executive  Jamie Sturgess both have been studying wildlife corridors southeast of Tucson.

When Hare, who works for two local conservation groups, looks at a two-lane bridge on Arizona 83 that spans a mesquite-lined canyon, he worries that its future value will be jeopardized by plans for a neighboring copper mine.

And when Sturgess, a senior vice president for Rosemont Copper, looks at a hilly expanse of Sonoran Desert along Santa Rita Road east of Sahuarita, he believes its future will be helped by that same mine.

There is no debate that the $1.2 billion Rosemont Mine would have major environmental impact on nearby water, land and wildlife corridors. The latest draft of the U.S. Forest Service’s environmental impact statements foretells washes buried in waste rock; trees, shrubs, vines and cacti bulldozed; noise from mine blasting; and a constant glow of mine lighting.

As a final decision over whether the mine can be built nears, the main disagreement is over how severe the impacts might be. Rosemont is trying to compensate for the mine’s effects by spending $25 million on land and development rights to 4,500 undeveloped acres as well as more than 1,700 acre feet of water rights.

That’s almost $5 million more, Sturgess pointed out, than the $20.8 million Rosemont Copper’s parent company, Augusta Resource Corp., paid for the 900-plus-acre, privately owned portion of the mine site from a developer back in 2005.

The four prime land purchase areas are spread over Pima and Santa Cruz counties:

Fullerton Ranch, 1,780 acres of high desert near the Marley Ranch south and southwest of Tucson.

Helvetia Ranch North, 940 acres of lower-desert grasslands near the Santa Rita experimental range north of the Santa Rita Mountains.

Sonoita Creek Ranch, 1,200 acres where farm fields and ponds are irrigated by a neighboring spring about halfway between Sonoita and Patagonia.

Davidson Canyon and Mulberry Canyon, 383 acres southeast of Tucson and east of the mine site.

If those land holdings were to stay on the open market, they could be sold off and bladed for subdivisions, Sturgess said. Instead, they’ll be preserved — and the land used by the mine would be used for 20 to 25 years, then reclaimed, or returned to its natural state, over the next 25 years, he said. Half of the mine site would be reclaimed after 15 years of use because the company plans to start reclamation in its first year of operations.

“Will the land be exactly the same as it is now? No,” said Sturgess, Rosemont Copper’s senior vice president for corporate and government affairs. “Will it be functional and useful? Yes.”

But environmentalists, Pima County and the Arizona Game and Fish Department say Rosemont’s mitigation efforts on 4,500 acres outside the mine site don’t make up for the damage done to up to 5,400 acres that would be disturbed for the mine site in the Santa Rita Mountains southeast of Tucson.

Hare, for instance, disagrees with Sturgess on the development risk to several key mitigation parcels. Even if they were to be sold for development, he said, the vast majority are inside Pima County and subject to its land protection rules and guidelines, so a large percentage of the sites would stay undeveloped anyway.

For Pima County and Game and Fish, the Forest Service’s projections of the mine’s environmental damage to the land and wildlife are inadequate. Coronado National Forest Supervisor Jim Upchurch is meeting regularly with agencies that commented on the draft environmental report, trying to work out the differences in time to publish the final report and decide on the mine by Sept. 27.

The impacts

The Forest Service environmental report lays out the mine’s likely impacts:

It could damage 1 to 1,295 acres — .004 percent to 100 percent – of wildlife habitat in six corridors connecting the Santa Ritas with six other mountain ranges. The Santa Ritas today represent a fairly large, intact block of mountain habitat for native species, with only two paved roads within the national forest.

It could disturb species not listed as endangered or threatened, but uncommon enough to trigger concerns for their future among biologists. But it isn’t likely to push most of them toward a federal endangered or threatened listing, the Forest Service said. Ten endangered and threatened species could suffer some negative impacts as well, but not enough to jeopardize the species or their critical habitat. The Forest Service based its findings on the U.S. Fish and Wildlife Service’s Rosemont biological opinion.

Increased mine truck traffic on Highway 83 and other roads would jeopardize wildlife that are attracted to roads, move over a wide range, and have low reproductive rates or low natural population densities. Most hurt would be large mammals, amphibians and reptiles, followed by birds, then mid-sized mammals and small mammals.

Increased night lighting would hurt some species and help others. For example, it could change the orientation or confuse some birds, insects, reptiles and amphibians. It could make some wildlife more vulnerable to prey and could disrupt their biological clocks.

Each of these things may not have a major effect on a species, but adding them together may reduce an area’s suitability for certain species, “especially those that are rare, secretive and do not tolerate human activity, rely on high ecosystem integrity or are dependent on large blocks of fragmented habitat,” Game and Fish wrote in response to the Forest Service report.

The report says Rosemont will be required to conduct a $50,000 camera study to assess how mine trucks affect wildlife movements from the Santa Rita to the Whetstone Mountains. Game and Fish wants a $175,000 camera study, or preferably a $285,000 study that would include radio collaring of mountain lion, deer and javelina.

Pima County’s comments on the report focus on the Forest Service’s failure to examine the mine’s impacts on numerous individual species, including the once-endangered peregrine falcon, still a state species of concern, as well as the Arizona ridge-nosed rattlesnake, the lowland leopard frog, the Sonoran Desert tortoise, the Bell’s vireo, the desert box turtle, Merriam’s mouse, the southern yellow bat and the California leaf-nosed bat. County officials fear the mine could wipe out Coleman’s coral root, a rare orchid, of which 40 percent of known plants are inside the project area, but the report said the mine would not affect the viability of a species.

“This shows that the Forest Service is not taking an objective view of those impacts,” the county wrote in its comments.

Disagreement ongoing

As Sturgess drove around the Helvetia Ranch recently, he said he didn’t object to the Game and Fish comments.

“They were in a neutral category,” he said. “They didn’t say this project sucks and can’t go forward because of unanswered questions. In their role as a cooperating agency, I believe it was their duty to answer some of the questions raised in there.”

But the county’s comments were a different story, he said. Officials hammered at each individual plant and animal, he said.

“There was way too much information. That’s not what an environmental impact statement is supposed to do. They’re supposed to declare the impacts to the broader human and natural environment to help with decision-making.”

The Helvetia Ranch, he said, assures long-term connections between that area and the experimental range and prevents fragmentation of the habitat. It’s got semi-desert grasslands, Sonoran Desert and mesquite flats. It is remote, with plenty of room for wildlife.

In the Mulberry Canyon area — one of the Davidson-area parcels — there’s mesquite, catclaw, grass, stool, yucca, bear grass and ocotillo, along with walnut, ash and hackberry trees. Fullerton Ranch has rolling hills on its south side and steep, mountainous terrain to the north, making much of it excellent wildlife habitat.

The Forest Service says most or all of these parcels will compensate for impacts to endangered species closer to the mine, as well as more general impacts to wildlife. But the final draft report also says these parcels and other biological mitigation measures – it spells out 10 pages’ worth – won’t compensate for all the mine’s impacts.

“The proposed mine is a large project that would result in 5,401 acres of direct, or long-term or permanent impacts and 146,153 acres of indirect impacts to biological resources,” the report says.

Considering that, Rosemont’s proposed mitigation efforts just aren’t enough, Pima County officials contend. Besides that, several parcels that are part of the mitigation plan are too far from the mine site to make up for the damage it will do. And some, like Davidson parcels, are likely to be affected by the mine so their mitigation benefits are highly uncertain.

Helvetia Ranch is an exception, said  Julia Fonseca , a Pima County geologist. It’s close to the mine but shouldn’t be affected by it.

And so, as a decision over Rosemont Mine draws closer, the disagreements continue. The company contends that 4,500 acres adequately compensate for the damage the mine will cause. And Pima County wants almost double that amount protected: 8,800 acres.

NOTE: This is the second of two parts on Rosemont’s mitigation plans. The water mitigation plan appeared in the Sept. 8 edition of the Star.