The damaged Fennica icebreaker, shortly before leaving Dutch Harbor for Oregon. KUCB/John Ryan photo.

The Obama administration approved Shell Oil’s plan for drilling in the Arctic Ocean Wednesday. But for now at least, Shell is restricted on how deep it can drill.

With a key piece of Shell’s oil-spill equipment currently heading away from the Arctic, the Interior Department told the company it cannot drill into any oil-bearing rock layers.

Shell’s “capping stack” is on board an icebreaker, the Fennica, that apparently hit an uncharted rock and tore a three-foot hole in its hull in Dutch Harbor on July 3.

The Fennica is now about halfway through its weeklong journey from Dutch Harbor, 1000 miles south of the drilling site, to a shipyard in Portland, Oregon, for repairs.

“Fennica’s going the opposite direction,” Brian Salerno, head of the Interior Department’s Bureau of Safety and Environmental Enforcement, said. “Until such time as the Fennica makes hull repairs and then is able to return to Arctic with the capping stack, the restriction will remain in place.”

Even with the restriction, Shell spokeswoman Megan Baldino called the permit an important approval.

“Based on the current ice forecast, we could begin drilling as soon as next week,” Baldino said.

She said Shell still fully expects the Fennica to return to the Arctic in time to support drilling into the deeper, oil-bearing rocks beneath the Chukchi Sea floor.

Environmental groups called the decision a “dangerous mistake,” given the twin hazards of Arctic oil spills and global warming.

“The Arctic Ocean is too important to trust to Shell, and our government must stop bending rules to accommodate the company,” Andrew Sharpless, head of the group Oceana said in an emailed statement. “This perilous treasure hunt for oil is not the solution to our nation’s long-term energy needs.”

“We’re not bending any rules whatsoever,” Brian Salerno with BSEE said. “We’re actually holding Shell to a very high standard.”

The federal permits also prevent Shell from drilling its two planned wells, which are about 9 miles away from each other some 70 miles off the northwest Alaskan coast, at once. That rule aims to protect walruses in the area from drilling noise.