Humboldt Bay Shipping Impacted by Shallow Depth

Sediment from the Eel River does not always move north, as seen in this photo from NASA satellite in December 2012 .
Sediment from the Eel River does not always move north, as seen in this photo from NASA in December 2012 .

Abnormally large waves at the entrance of Humboldt Bay caused by its shallow depth are creating treacherous conditions for boaters and barges as well as impacting shipments in and out of the bay, local officials state.

While the bay is set to be dredged next month due to the hazardous conditions, local and federal entities are now discussing long-term solutions to the issue.

Fortunately for the U.S. Coast Guard Humboldt Bay Sector, nobody has been injured or required rescue from the rocky waters so far this year.

“With the closure of the crab fishing season, I think we’ve gotten lucky that nobody has been transiting on the bar,” U.S. Coast Guard Humboldt Bay Sector petty officer Garrett Hamilton said, while also acknowledging the alertness of the local fishing fleet to ocean conditions.

Waves broke at around 20 feet in the bay entrance and shipping channel near the south jetty last week, which local officials say was the result of sediment filling in bay after recent winter storms.

Known as shoaling, this sediment buildup has caused some areas of the bay entrance to have only a 15-foot depth, when it should be closer to 48 feet, Humboldt Bay Harbor, Recreation and Conservation District Deputy Director Adam Wagschal said.

“(Shoaling) causes waves to break in the entrance and at the bar, which is a safety hazard for boats of all sizes,” Wagschal said. “It also prevents ships from entering the bay. Depending on their draft, which is how much water a ship needs below it, it might not be able to enter the bay.”

Timber shipments have recently been resigned to head ship out with lighter cargo loads. The rough conditions have led to some discussions within the Coast Guard about whether to temporarily close off the bay entrance to commercial ships during these rough water periods.

Humboldt Bay Bar Pilot John Powell said ships are now required to leave only at high tides, and those ships must have at least a 25-foot draft.

“That doesn’t give them much of a load they can put on a cargo ship,” he said. “They like to leave with heaver loads.”

Since Green Diamond Resource Company finished rebuilding its chip dock in 2013 and its first cargo ship sailed out in July 2014, shoaling on the bay has impacted half of the company’s shipping operations, Green Diamond Forest Policy and Sustainability Manager Gary Rynearson wrote in an email to the Times-Standard.

“To date we have shipped four cargos of wood chips, but unfortunately have cancelled four ships due to shoaling,” Rynearson wrote.

Wagschal said the waves also create a potential problem for the Chevron fuel barges which provide most of the county’s fuel supply.

Last week, the harbor district announced that the bay entrance is set to be dredged to around 48 feet by the U.S. Army Corps of Engineers in May. The announcement came after the harbor district and 2nd District California Congressman Jared Huffman (D-San Rafael) urged the federal government to provide dredge funding due to the hazardous conditions. The Army Corps of Engineers allocated $7.5 million for the project last week. The bay’s bar and interior channels are set to be dredged in June.

National Weather Service Eureka station meteorologist Matthew Kidwell said shoaling occurs every year on Humboldt Bay as sediment from the Eel River flows into the bay entrance.

However, this year was different, with Hamilton noting that the more recent waves were the largest he’s seen along the jetty during the last four years he has been stationed in Eureka.

“It’s breaking a lot closer and it’s directly in the channel and in the entrance,” he said on Monday. “Even with smaller weather like today, being out there, the north spit buoy is reading at six or seven feet.”

Kidwell said more sediment was transported from the Eel River out into the bay due to the large amount of recent rainfall.

“We had a lot of high flows on the Eel this winter,” Kidwell said.

Wind patterns also helped drive a northbound current which carried the sediment toward the mouth of the bay.

Humboldt Saltwater Anglers Association Director Casey Allen said crossing the bar on Humboldt Bay can be a dangerous endeavor even without shoaling.

“When the outgoing tide meets the ocean swell is the most dangerous time,” he wrote in an email to the Times-Standard. “The two colliding forces can create steep breaking waves that can capsize a boat. The incoming tide is the safest because all the force of swell and tide are traveling in the same direction.”

But with the recent shoaling, Allen said that the waves can break at any tide.

“An angler leaving the bay today might see breaking waves at the end of the south jetty, but calmer water in the middle ground,” he wrote. “It will take some time for boaters to get used to where the dangers are at each tide and how to maneuver around them. Hopefully, folks are smart enough to not take chances.”

Powell, who is also a sport fisherman, said it is important for the fishing community to know how dangerous the south jetty can be even on a seemingly calm day, especially with the salmon season opener fast approaching.

“A lot of the sport fishing boats go off the south jetty there and this is right in their path if they’re gong south to Cape Mendocino,” Powell said.

Allen said that the shoaling issue prompted a meeting with the Harbor District on April 15 where it was agreed by multiple entities to look into creating a long-term sediment control plan, with one option proposing to build an artificial reef south of the south jetty to trap and divert the sediment farther off into the ocean.

Rynearson said Green Diamond has also been working with the county, federal entities, and the harbor district to address the shoaling issue.

“A predictable shipping schedule is critical to our customers,” he said. “We plan to work closely with all of the parties to develop a plan for a safe and predictable entrance channel.”

While the large waves have mostly been a detriment to the bay’s operations, Hamilton said they’ve been put to some good use.

“We’ve had more consistent waves out there and better weather in our eyes,” he said. “We get a lot of training in those bad conditions.”


Article by: Will Houston

Published by: Eureka Times Standard

Read original article here.

Will Houston can be reached at 707-441-0504.