Adam Spencer, The Triplicate

After two weeks of operating under short-term, emergency permit extensions, construction in Crescent City Harbor can now forge ahead without a days-away deadline looming over.

Well, sort of.

Dutra Construction, the lead project contractor, has until Dec. 15 to install 88 hollow steel pilings and accompanying docks to accommodate commercial crab fishermen for this winter's fishing season. The harbor district received a notice of the work extension from the California Coastal Commission on Friday.

"We hope it's enough time to get the pilings in, because the reality is that it's unlikely we'll get an extension beyond that," said CEO/Harbormaster Richard Young.

Dutra will start operating two shifts Monday, Young said, in order to complete the work on time.

The deadline for in-water construction work is a result of the Endangered Species Act. Three federally threatened species are known to sometimes be present in the harbor vicinity: coho salmon, North American green sturgeon and Steller sea lions.

The threat to sea lions was mitigated by a field observer who has been stationed at the entrance to the inner boat basin watching for marine mammals and halting construction work when any are present.But coho salmon known to occasionally spawn in Elk Creek, which dumps into the harbor's outer basin, were still a concern.

To protect coho, in-water work was confined to June 1 to Nov. 15, avoiding the time when salmon spawn in Elk Creek. But as of Nov. 15, Dutra had only installed 13 pilings to design specifications' depth.

The harbor district and Dutra hired consultants and contacted state and federal agencies to get more time.

On Thursday, National Marine Fisheries Service sent a letter to harbor officials stating: "the Harbor District's project, with the extended work window to December 15, is unlikely to cause effects to listed species or their designated critical habitats ..."

Zack Larson, a local fisheries biologist hired as a consultant by Dutra, said that the salmon that spawn in Elk Creek are not likely to be affected by the pile driving in the inner boat basin if it's done before Dec. 15, because Elk Creek coho have typically only been observed in January.

"It's possible that fish would be coming in (the harbor) because they would be homing in on the fresh water, but there are no freshwater sources in the inner boat basin so that isolates them somewhat," Larson said.

Acoustic tests commissioned by Dutra show that only the area near the entrance to the inner boat basin would have sufficient noise from pile driving to adversely affect fish, according to the NMFS letter to the harbor, and the mouth of Elk Creek is about 2,000 feet from the inner boat basin entrance.

Additionally, Dutra plans to use a "bubble curtain" when driving pilings near the basin entrance. A bubble curtain is a mechanism that dampens sound energy throughs a series of air-pockets that will surround the pile-driving equipment.

Juvenile salmon emigrating from the creek to the ocean also would be isolated from the construction since that swim typically occurs in the spring, Larson said, and the fish characteristically make a bee-line for the open sea.

Now that all threatened species concerns are wrapped up, harbor officials are putting the onus on Dutra to finish the job they promised to complete before crab season.

"We're dependent on Dutra to come through for us so we're hoping they get it done," Young said. "Dutra has the opportunity."

Reach Adam Spencer at