It's on us. Share your news here.

Dredging critical to Bay Area economy, and as potential solution to wetlands restoration in response to climate change effects

Posted on April 12, 2023

In the Port of Oakland on a weekday, trucks, cranes and ships laden with containers moved goods across the sprawling 1,300-acre complex with the precarious precision of a Rube Goldberg machine.

Just blocks from downtown Oakland, the port essentially functions as a city within a city. It is the nation’s ninth busiest port and the first port of call for 99% of containerized goods shipped through Northern California.

A large container ship docks at the Port of Oakland in Oakland, California on April 4, 2023. (Dai Sugano/Bay Area News Group)

In the hubbub of logistics and machinery, it’s easy to forget that everything that happens here is made possible by an unsung, lackluster, and Sisyphean task: hauling mud out of San Francisco Bay.

This dredging process has huge implications for the future of shipping and transportation in the Bay Area and could be key to protecting local shores.

“The bottom line is that none of this happens if we don’t dredge,” said port spokesman Robert Bernardo, looking at container stacks. “Period.”

San Francisco Bay has long been known as one of the best managed and largest natural harbors in the world. This is one of the main reasons the Bay Area has become the metropolitan area it is today. But in the age of modern navigation, one of the bay’s natural features poses an increasing challenge – despite being a vast sheltered harbour, it is mostly flat. Its average depth is about 12 feet, only slightly deeper than a swimming pool. Container ships require a water depth of at least 30 feet, if not more.

Dredging solves this problem.

A crane dredges the Oakland Estuary as it meets San Francisco Bay on Thursday, December 6, 2018, in Oakland, Calif. (AP Photo/Ben Margot)

Every summer and autumn 3 to 6 million cubic meters of sediment are removed from the bottom of the bay to make room for ships. Huge dredgers suspended from the side of dredger boats haul silt up from the bottom of the bay to create underwater paths for our pelotons, sofas and TVs.

For the last 20 years, the process of disposing of all this extra sludge has been governed by what the authorities call the “40-40-20” split. Over the course of five years, 40% of the mud dredged from the bay is dumped into the Pacific Ocean, 40% is destined for “beneficial reuse” such as wetland restoration, and 20% is disposed of elsewhere in the bay.

In recent years, agencies have started rethinking the math.

“It was an old paradigm. It has served us well,” said John Coleman, CEO of the Bay Area Planning Coalition, a local nonprofit focused on sustainable industry. “But when they developed it years ago, no one thought about climate change.”

The Pacific was a simple dumping ground. Dumping sediment into the bay has long been the cheapest and safest way to get rid of it. In the 1980s, a hundred years of industry filled the ground with toxins.

Howard Terminal and the Oakland Estuary are visible in this drone view over Oakland in November 2018. (Jane Tyska/Bay Area News Group)

But as climate change accelerates sea-level rise, erosion, and flooding, there’s growing recognition that the Bay Area needs as much sediment as it can get.

A recent report from the San Francisco Estuary Institute and Aquatic Science Center estimates that the bay’s wetlands, which serve as the region’s first line of defense against flooding, will need more than 1,500 million cubic feet of sediment by the year 2100 “just to sustain them.” what we have right now.” That’s like filling the Salesforce Tower with mud six hundred times.

The same study estimates that over $100 billion worth of assets are at risk of flooding over the same period.

With such a shortage of sediment and such a high risk, experts have turned to an obvious candidate to protect our coasts: dredged sediments. It is estimated that changing the dredger disposal paradigm could account for up to 60% of this deficit. Dredged sediments are already being used to restore natural habitats such as the Montezuma Wetlands near the city of Suisun.

Still, repurposing the mud for coastal protection is easier said than done. The 40-40-20 split was established in a long-term management plan in 2001. The Army Corps of Engineers, a federal agency that manages most of the dredging work in the bay, prioritizes minimizing its costs above all else. Federal agencies are notoriously slow.

“We’re in a scenario where there’s a desire to do more beneficial reuse, but a lot of the material is still dumped in the ocean because it’s cheaper,” said Ian Wren, a staff scientist at San Francisco Bay Keeper , a local non-profit environmental organization.

Literally, an even bigger problem looms for regional ports. Every year ships get bigger and bigger. Part of a new generation of megaships, the MSC Arina is a quarter mile long and requires a water depth of at least 52 feet. Turning in a narrow channel like the Port of Oakland requires larger and deeper turning basins.

  • The MSC Anna, the largest ship in North American history to dock in the Port of Oakland, sails along San Francisco Bay in San Francisco on April 16, 2020 toward the San Francisco-Oakland Bay Bridge Western Span. The 1,312-foot cargo ship is longer than the Salesforce Tower is tall. (Anda Chu/Bay Area News Group)

  • The MSC Anna sails towards the Port of Oakland on April 16, 2020. The 1,312-foot MSC Anna is the largest ship in North American history to dock at the Port of Oakland. (Aric Crabb/Bay Area News Group)

“Ships are getting longer, wider and bigger,” said Edwin Draper, a port supervising engineer at the Port of Oakland. “It’s definitely more difficult to maneuver in tight spaces. These turning spots are almost like a dead end.”

In preparation for these larger ships, the port has begun investigating how its turning basins can be deepened and widened to accommodate larger and larger vessels. They are currently in the feasibility phase of the project, but it is unclear if the project will ever come to fruition. Nearby residents have raised concerns about air quality and safety with additional trucks and traffic. It is unclear where the funding for the project will come from.

“We need to do a reality check,” Coleman said. “If we don’t dredge to the appropriate depth and width for wider ships to arrive, those ships will go elsewhere. With that comes thousands of jobs, millions of dollars in taxable income.”

For both Oakland’s harbor and shoreline restoration, finance, rather than political will, serves as the primary obstacle. While other coastal states provide an annual allocation for dredging, the state of California contributes no such money — instead, it relies solely on federal funds to dredge shipping channels.

No money is provided for restoration work either. It’s hard to get people interested in mud.

“We’d like to see the state of California have a budget line that says because we care about wetlands, we will have money for useful reuse,” said Brenda Goeden, sediment program manager at San Francisco Bay Conservation and Development Commission. “But we are not there yet.”

For now, both the Bay Area’s ports and shorelines are coping. But if the Rube Goldberg machine is to keep working, Coleman believes that may need to change.

“We tend to work in contingency mode,” Coleman said. “But we need to fix this before it’s too late.”


It's on us. Share your news here.
Submit Your News Today

Join Our
Click to Subscribe