Dredging Cycle Volume Limits Impact SoCal Harbors

Harbors along the California coastline are attempting to convince the U.S. Army Corps of Engineers to increase the amount of sediment that can be dredged from their waterways as decreased dredging cycle limits have left more sand in federal and navigational channels. The limits may create difficulties for boater traffic if the sand is not removed during routine maintenance projects.

A national problem, harbors in Southern California are working to secure funding for future dredging projects and get the amount of allowable dredged sediment increased before shoaling becomes a problem for boaters.

Santa Barbara

Boaters navigating Santa Barbara Harbor were close to having their cruises impeded when the Corps had to negotiate a balanced bid with the lone company that submitted an offer to conduct the annual maintenance dredge work.

“They usually dredge twice a year but we missed the fall cycle this year because of the Corps award process,” said Karl Treiberg, waterfront facilities manager for the Santa Barbara Waterfront Department.

The Corps is responsible for the routine maintenance dredging of Santa Barbara Harbor under the Rivers and Harbors Act. Since 1972, Corps engineers have pulled approximately 300,000 cubic yards of sediment from the harbor’s federal channel.

The city is financially responsible for all dredging outside the federal channel.

The Corps awards a construction contract with a private contractor every three years for dredging. The previous three-year contract was completed in April, 2013 and a new three-year contract went out to bid this summer with only one bid submitted from AIS Construction Company.  AIS’s low bid of $6,300,000 was slightly less than their 2010 bid but unacceptable to the Corps due to an imbalance in annual dredging costs for the three-year contract, Treiberg explained.

U.S. President Barack Obama’s budget includes $2,665,000 for dredging Santa Barbara Harbor but AIS’s bid included approximately $3,650,000 for the first year of dredging and $1,325,000 for each of the remaining two years.

Since the first year of AIS’s bid exceeds the Corps’ funding for Fiscal Year 2014, the bid was rejected with the expectation that AIS could resubmit a balanced bid over the three-year contract, he said.

A revised bid was submitted by AIS and the Corps of Engineers’ Dredging Contract Corps went through a lengthy review process resulting in a “balanced” and acceptable bid. In order to achieve the balanced bid, the Corps made two significant changes to their dredging program for this year: combining the fall and spring dredge cycles into a single cycle and reducing the volume of contractually obliged dredge material to offset the mobilization costs.

The amount of sediment that needs to be removed from the harbor will be higher than past cycles since the Corps missed the fall maintenance dredge, he said, which is a little bit of concern for the waterfront department since the Corps has decided to reduce the dredging cycle limits from 150,000 cubic yards per cycle to 120,000 cubic yards per cycle, and a total of 180,000 cubic yard annually. The Corps dredging contract formerly allowed for a total of 300,000 cubic yards on an annual basis.

The remaining two years in the new three-year contract includes 240,000 cubic yards for each year.

Skipping the fall cycle and getting off to a late start means there will be more to dredge during this cycle, he explained.

“That number doesn’t capture all the necessary dredging,” he said. “We only had one year when we dredged less than 180,000.
“We are somewhat vulnerable right now,” Treiberg added.

Sand rolls off nearby beaches into the federal channel very rapidly during the winter months, making for potential problem areas in the navigation channel.

AIS is also the only electric dredge in the region that can work in Santa Barbara since a no diesel dredging policy limits contracts for dredging in the harbor.

“The Corps and AIS successfully negotiated a revised bid with contract documents and a Notice to Proceed tentatively scheduled to be issued Feb. 14,” he said. “We expect AIS to possibly start dredging by the end of February.”

Ventura Harbor   

In Ventura, Port District officials hope the Corps increase the dredging cycle limits to allow the harbor to be cleared of accumulated sand in the navigation channel.

“The quantity dredge that Ventura and most other harbors has been allowed is way below what  is needed to keep up with the annual rate of infill,” said Richard Parsons, dredging program manager for the Ventura Port District. “So in recent years the Corps is falling short of what is needed.”

Parsons estimates 900,000 cubic yards of sediment needs to be dredged from the harbor’s channels. However, the Corps has only approved 450,000 cubic yards of dredged material for the winter cycle. “It’s still not really enough,” he added.                 Approximately 600,000 cubic yards of sands is dredged annually from the harbor

Dredging began on Feb. 10.

In 2011, the Corps dredging project was so minimal that the Ventura Port District funded additional dredge work. The $2.3 million federal dredging project cleared the entrance, but left the sand trap completely full. The Ventura Port District spent $1.5 million of its dredging reserve in 2012 – in addition to the $2.2 million the Corps spent that year on dredging work – to clear part of the sand trap.

When adequately dredged, the sand trap at Ventura Harbor captures the sand before it accumulates in the harbor entrance. However, without adequate annual dredging, the sand trap fills to capacity, the entrance fills with sand, and the waterway becomes impassable for commercial boats first, sailboats second, and eventually recreational power vessels, according to the port.

“This hasn’t been a problem for the boating community because we have been proactive about dredging,” Parsons explained.

The Corps dredged again in 2013, spending $2.3 million to remove about 240,000 cubic yards of material. A 2014 dredging project is long overdue and expected to remove only 450,000 cubic yards of sand. The Corps approved $3.7 million in funding toward the $6 million dredging project.

Ports up and down the coast are feeling the effects of limited dredging cycle limits and partial funding.

“This is a concern for ports,” Parsons said. “It is a constant battle to get additional dollars to get the work done.”

Federally maintained harbors and channels receive project funding from fees tied to imports and domestic cargo arrival at U.S. ports thought the Harbor Maintenance Tax. The fees are dumped into the Harbor Maintenance Trust Fund, which was established in 1986 to cover the maintenance and operation costs of federal ports and harbors.

Channel Islands Harbor     

Ventura and Santa Barbara harbor appear to be in a better position than their neighboring harbor. Channel Islands Harbor is not scheduled to be dredged this year which is fine for the navigation channel but has negatively affected Hueneme Beach, Parsons explained.

“The material dredged from the harbor is deposited on Hueneme Beach so there hasn’t been enough sand to put on the beach and it’s eroded,” he said.

According to Parsons, the city was able to get emergency funds from the state to install rocks around the beach to protect it from further erosion.

“This shows what happens down the coast when you don’t dredge on schedule,” Parsons said.

Channel Islands Harbor is dredged every year by the Corps, with the last project taking place in 2012-2013. At that time, a mere 600,000 cubic meters of sediment was removed for the harbor and 741,000 cubic meters was pulled during the 2011 cycle.

“One-year ago it was half of what we should normally be dredging and in 2011 it was 70 percent of what’s needed,” said Channel Islands Harbor Director Lyn Krieger.

Prior to the limit reductions, the Corps was removing larger quantities ranging from 1,093,000 cubic meters in 1991 to 1,230,000 cubic meters in 1997.

Although the harbor is not scheduled to be dredged until 2015, Kreiger is busily working to secure funding for the project.             “We are always thinking about dredging,” she said.

Harbor staff is working with Congresswoman Julie Brownley (D-Oxnard) to ensure Channel Islands Harbor is included in the budget and for more yardage to get the sand trap cleaned out. The harbor’s entrance acts as a sand trap for all beaches south of Channel Islands Harbor.

So far the lowered dredging limits have affected users of the harbor entrance. Kreiger said, as the entrance to the north is functional only for small recreational boaters. The northern entrance is now about 75 feet wide, but only 15 feet deep.  It is normally hundreds of feet wide and 35 feet deep.

“The other problem we have here is that the sand stays in the sand trap,” she said.  “If we do get more storms we worry that that sand will be pushed into our major entrance channel

Kreiger added, “As it is, you can walk to the breakwater at low tide.”

Share This:


Your email address will not be published. Required fields are marked *