The Pima County Board of Supervisors delayed a decision to accept money from Rosemont Copper to compensate for what the company says is the impossibility of mitigating damage from putting water and electric lines through a sensitive riparian area.

Rosemont proposed paying a $145,230 mitigation fee in lieu of developing a mitigation plan for the area flanking Santa Rita Road, which runs from Sahuarita to Helvetia Road on the west side of the Santa Rita Mountains.

The board decided to wait 90 days to let county officials research how the mitigation cost was calculated.

According to county documents, Rosemont wants to build a proposed waterline and electrical distribution line that would run through more than 7 acres of riparian area.

Rosemont hired Westland Resources to assess the area, but the company found no suitable way to mitigate any potential disturbance to the habitat, in which case Rosemont has to pay a fee in order to build the water and electrical lines.

Supervisor Richard Elías wondered whether $145,230 would be enough to “make up for the damage being done.”

“I don’t see anything that really explains in any detail ... the calculations of how this dollar amount was come to,” he said.

The formula for calculating mitigation fees is based on the type of habitat and how many acres will be disturbed, said Bill Zimmerman, deputy director of the Pima County Flood Control District, in an email.

Elías also wanted to know if the supervisors could withhold a decision or give conditional approval of the fee until Rosemont receives the final permits it needs to begin construction.

Rosemont is waiting for two remaining federal approvals, including a permit to dredge and fill washes and streams, before it can begin construction on the east side of the Santa Rita Mountains, southeast of Tucson.

The county will have to consult its attorneys to find out if it can issue a conditional or delayed approval until the mine receives its permits, said County Administrator Chuck Huckelberry.

The county will also consult the Arizona Corporation Commission, which conditionally approved an electrical line to the mine, but required Rosemont to acquire a series of permits.

Huckelberry said the item was presented to the board Tuesday because the county had a deadline to respond to Rosemont after the company submitted its plans.

Rosemont CEO and President Rod Pace issued a statement Tuesday afternoon saying the company understands the board’s decision to delay approval, but questions whether the board is following proper rules and statutes.

“We think it is understandable they have this view given their past positions on Rosemont county permits. And we acknowledge it makes no material difference to us with respect to project timing,” Pace said. “However, we strongly believe that rules and statutes are just that, and they should be applied consistently and without prejudice.”

Contact reporter Jamar Younger at or 573-4242. On Twitter @JamarYounger