Just Why Is Mission Bay Being Dredged?

by on January 23, 2018 · 8 comments

in Ocean Beach

A project to dredge sections of Mission Bay began last week by the City of San Diego. A large crane mounted on a barge has begun to excavate about a total of 64 acres of the bay as part of the plan.

Why is the Bay being dredged?

It’s all about the boats. Apparently over the last 50 years storms and currents – as well as boats themselves – have moved the floor of the Bay around and now it’s uneven and unsafe for boating. The dredging will make it easier and safer for boats to navigate around the Bay, the largest aquatic park on the West Coast.

As the material on the bay floor is pulled up by the crane, it’s deposited onto boats, which then transport the sand, mud and organic material to a designated reuse area. From there it will be deposited back to the bottom of the bay. A majority of the extracted material will be placed at various other locations in the bay, and the remaining materials will be used to restore beaches along Crown Point and Vacation Island.

To mitigate potential impacts to marine wildlife, up to 70 acres of eelgrass will be replanted in various locations using a team of scuba divers.

Faulconer’s office estimates the dredging will yield 122,000 to 220,850 cubic yards of material. The mayor ought to know – he once sat on the powerful Mission Bay Park Committee. (See here for the City’s project description.)

This and other images are screen grabs from KUSI TV

It’s the first major dredging of Mission Bay in 5 decades.  During the work, which is expected to end in October, some beaches and sections of the bay will be closed.

Some of the media accounts of the dredging emphasis that the project will replenish – even “restore” – sands onto the bay’s beaches. Even Faulconer said:

“Preserving and protecting our environment is part of San Diego’s DNA and projects like this will help conserve our beaches and bays for the next generation.”

One media outlet reported: “The dredging will restore the floor to its original elevation, according to the city.”

But, listen, any talk of Mission Bay’s “original elevation” is meaningless. Originally, what we now call Mission Bay was once a huge lagoon, fed by natural creeks and the San Diego River. It wasn’t very deep – in fact, the Spanish first called it “Bahia Falsa” – False Bay.

Okay, so maybe, we’re talking about the original elevation of the human-made bay. Here’s a bit of history from the City website:

In 1944, a Chamber of Commerce committee recommended development of Mission Bay into a tourist and recreational center to help diversify the City’s economy, which was largely military. In the late 1940s, dredging and filling operations began converting the marsh into the jewel that is today Mission Bay Park. Twenty-five millions cubic yards of sand and silt were dredged to create the land forms of the park, which now is almost entirely man-made.

So, it’s not news that the priorities of the city vis a vis Mission Bay are all about boats and visitors. This has been going on for a long time. Up to the early 1950s, a bridge connected north Ocean Beach to south Mission Beach – a bridge that held a trolley track and from where hundreds of fishermen fished from. But it was demolished for the boats – as the bridge wasn’t tall enough for sail boats;  the people of OB were promised a pier in return, which was built and opened in 1966, about 15 years later.

Won’t the dredging disrupt those parts of Mission Bay being worked upon? Faulconer said we’re supposed to be “preserving and protecting” the environment. This is an unanswered question.

The city says some 15 million people each year visit Mission Bay Park, which is the largest aquatic park of its kind in the U.S. How many of those millions are on boats?

As a layperson, I have not heard of boats running into each other, had no idea that navigation was so bad for them in Mission Bay; I have friends who sail in Mission Bay and I’ve never heard them complain of the unevenness of the bay floor. I wonder if the city has a list of accidents or near-accidents or other boating mishaps to warrant such expense and such a project. (What is the expense? Each time I click on the budget for the project on the website – it times out.)

Plus I didn’t know the beaches at Vacation Island – a tourist attraction – and those at Crown Point were losing sand.

Oh well, I’d feel more assured if there was a bevy of environmental scientists telling us we need to dredge the floor of Mission Bay to make it more even for the boats. But there isn’t.

In fact, the San Diego Audubon Society has learned that possibly the city is not the best organization to manage the environment around the bay. And just recently, bay committees and park and rec boards are telling us that a land-grab by a huge hotelier is really just consistent with the Mission Bay Master Plan.

Sources:

NBCSanDiego

KPBS

KUSI

San Diego County News

From the City:

For questions or concerns about the project, please contact the project community liaison Alli Berry at 619-538-0777 or aberry@curtinmaritime.com. You may also call the Public Works Department construction project information line at 619-533-4207, email engineering@sandiego.gov, or submit your inquiry online. Please reference the “Mission Bay Navigational Safety Dredging Project” in your inquiry.

{ 8 comments… read them below or add one }

stu January 23, 2018 at 2:48 pm

Don’t know how deep Mission bay is but I did stick the mast of a sailboat in the mud once in that bay and I was in the middle. I was in a laser, I’ll guess and say the mast was 16′ tall so the bay is not very deep. but the dreged sand will be good for the beachs as will the eel grass for bay life. I did run aground in a bigger boat in east bay but I should not have been there anyway. The life guards pulled me off.
The areas for dredging per your map are areas of bigger tidal flows and lots of boat transit
So I guess it is needed Be curious to see topography of the bottom in relation to mean low tide

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Frank Gormlie Frank Gormlie January 23, 2018 at 7:36 pm

Thanks Stu; we needed the views of a sailing enthusiast to help understand all of this.

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bodysurferbob January 23, 2018 at 8:49 pm

couldn’t get me to swim in mission bay, it’s so pollutted.

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Ol OB Hippie January 23, 2018 at 8:54 pm

I think the point you’re trying to make is, why all this expense without any scientific backup saying we need to dredge the bay.

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OB Joe OB Joe January 23, 2018 at 8:56 pm

I don’t want to say this, but maybe this is muchado about nothing. Ok, I said it. Maybe thee is nothing here, really.

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ToolPusher January 26, 2018 at 5:18 am

Dredging certainly has an impact on the environment. Of course it alters the sea floor, can release toxic substances when disturbing the bottom and the dredge spoils can be problematic when not disposed of properly. Nevertheless, dredging is a necessary activity to maintain most waterways to prevent vessel accidents and even flooding on rivers. Dredge spoils can be used for land restoration or reclamation and even new habit for species. If done correctly it can have a minimal environmental impact but greatly improves the waterway for human use or new habitat. If you want to find out more about dredging and its impacts the Dredge Research Collaborative is a good source: http://dredgeresearchcollaborative.org/. Maybe they can put on a dredgefest in Southern California like the recent one for San Francisco Bay.

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Elite Aerials January 26, 2018 at 3:09 pm

If you are interested in seeing what this looks like, take a look at the video that was shot today. https://youtu.be/0mJtDD7SYzw

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Frank Gormlie Frank Gormlie February 5, 2018 at 9:45 pm

Here is our report from Feb 2010: Stimulus Money Used to Hire Seattle Company to Dredge Mission Bay

The U.S. Army Corps of Engineers has awarded a $5.3 million stimulus contract to Manson Construction Co. of Seattle, Wash., to dredge Mission Bay. The company will dredge approximately 500,000 cubic yards of sand from the federal channels. Once dredged, the material will be placed on Mission Beach, where it will mix with the sand already there.

Mission Bay was last dredged in 1984. The Beacon reported:

The project is funded by the American Recovery and Reinvestment Act (ARRA) which President Barack Obama signed into law in February 2009 to help in the recovery of the U.S. economy.

“This project will vastly improve navigation in and around Mission Bay by clearing out sand that has shoaled into the channel over the years,” said Scott John, of the Corps’ Los Angeles District, who is managing the project. “We have been working closely with the City of San Diego as well as the San Diego Lifeguard Service on this project to make sure that we dredge the areas that need it most, protect important environmental resources and enhance the recreational resources at Mission Beach.”

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