Carol Bach, who oversaw the restoration of a sliver of tidal wetlands on San Francisco’s industrialized shore in 1999, was alarmed to see her work eroding away decades later. Waves crossing the Bay from Hayward to Heron’s Head steadily carved away at this small peninsula of tidal habitat and public park favored by locals with few other options for waterfront recreation. The erosion was hard to miss: steep escarpments developed along the shore; the size of the marsh shrank; a tidal pool favored by shorebirds breached and became an embayment.
“We wanted to stop the erosion, restore the tidal pond, and protect the whole landscape using natural infrastructure,” says Bach, who stuck around long enough at the Port to fix the problem 20 years later. “But we couldn’t go with a green-only, vegetation-only shoreline resilience solution; the erosive forces at the site were too strong.”
Adds Eddie Divita, an engineer with Environmental Science Associates who helped design the project, “The landscape at Heron’s Head is strange, it’s not a natural form but a peninsula constructed out into the Bay with no local sediment supply. Our design goal was shoreline protection that would last 30 years.”
Map of construction project. Map: ESA
Their solution—incorporating coarse beach, two groins, three headlands perpendicular to the shore, 60 subtidal oyster reef balls, and a resilient coastal plant species called seablite—is a grey-green mix of infrastructure that showcases critical options for many eroding sites along the bayshore as sea level rises. “The idea is a vegetated beach protecting interior wetlands,” says Bach.
A centerpiece of the design is a two-part beach. On the east end farthest out in the Bay, where the waves roll in, lies a “feeder beach.” This beach offers a long-term local supply of coarse gravel to the second beach farther inland. (Managers even sourced the material from adjacent Martin Marietta, a sand-mining operation.)
“With constructed beaches, there’s often a maintenance problem,” says Divita. “If there is no natural sediment supply the beach washes away, especially if it’s at an angle relative to incoming waves like this one.”
Special walkway for construction over sensitive beach habitat. Photo: Port of SF
The port completed construction of the project in December 2022, just before the first round of atmospheric river storms over the holidays. “When that storm train arrived, I had many sleepless nights worrying it would wash all our work away,” says Bach. But to her delight, the project elements—beach, groins (barriers made of bigger rocks), headlands (barriers made of smaller rocks), a fortified tidal pool—performed exactly as designed.
“In early pictures, the groins look like big ugly scars, but after the first heavy-duty storms the coarse beach material washed east to west over them and now they look more natural. It held up really well in extreme weather,” says Bach.
“We wanted to make sure that we had enough speed bumps to keep the gravel on the beach during storms and for a longer period of time,” says Divita. Subsequent storms and large waves proved how dynamic their nature-based design could be: “The waves pushed the gravel up the beach slope, actually helping to build up the beach, instead of eroding the tidal marsh.”
The original design included five groins made of rip rap and football-size cobbles, and 100 oyster reef balls. But the San Francisco Bay Conservation and Development Commission, which regulates fill of the Bay, didn’t like the footprint. As the project made its way through the regulatory approvals process—the third to use the newly improved and more coordinated process called BRITT—three of the groins became smaller “headlands” and the number of reef balls shrank to 60.
“As built there are not enough oyster reef balls to act as offshore erosion control, but enough to serve as habitat for oysters,” says Bach. One promising aspect, however, is that the Heron’s Head oyster population is expected to be less susceptible to die-offs from excessive freshwater outflows from the upper Estuary. As such it can provide a more resilient source of seed oysters for the Bay in general.
Oyster reef balls on barge. Photo: Port of SF
Though the regulatory approvals took 1.5 years to acquire, crews from contractor Dixon Marine built the project itself in just under four months. Bach calls this “miraculous,” given the limitations on which months and times of day and tidal windows in which they could work, driven by endangered species protections and access requirements for big equipment.
“Heron’s Head is a unique example of nature-based solutions to sea-level rise, including both habitat and rip rap,” says Bach. “We need a lot of tools in our adaptation tool box. Not every tool will work in every shoreline.”
This shoreline has another special asset: youth from Bayview-Hunter’s Point worked as eco-apprentices to grow the seablite in a nursery and plant it on the high beach elevations. “Unlike many wetlands, Heron’s Head is very visible to people,” Bach says. “It’s a place where lots of people can do hands-on restoration.”
Top Photo: Construction of groins and headlands at Heron’s Head in November 2022. Photo: Port of SF
Ariel Rubissow Okamoto is both today’s editor-in-chief and the founding editor of ESTUARY magazine (1992-2001). She enjoys writing in-depth, silo-crossing stories about water, restoration, and science. She’s a co-author of a Natural History of San Francisco Bay (UC Press 2011), frequent contributor of climate change stories to Bay Nature magazine, and occasional essayist for publications like the San Francisco Chronicle (see her Portfolio here). In other lives, she has been a vintner, soccer mom, and waitress. She lives in San Francisco close to the Bay with her architect husband Paul Okamoto.
Our magazine’s media motto for many years has been “Where there’s an estuary, there’s a crowd.” The San Francisco Estuary is a place where people, wildlife, and commerce congregate, and where watersheds, rivers and the ocean meet and mix, creating a place of unusual diversity. In choosing to tell the...
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Though the Clean Water Act did an amazing job of reducing wastewater and stormwater pollution of the San Francisco Estuary, some contaminants remain thorny problems. Legacy pollutants like mercury washed into the watershed from upstream gold mining, PCBs from old industrial sites, and selenium from agricultural drainage in the San...
Hothouse Earth
By Ariel Rubissow Okamoto
Photo by Megan Nguyen
Nothing could be stranger than sitting in the dark with thousands of suits and heels, watching a parade of promises to decarbonize from companies and countries large and small, reeling from the beauties of big screen rainforests and indigenous necklaces, and getting all choked up.
It was day two of the September 2018 Global Climate Action Summit in San Francisco when I felt it.
At first I wondered if I was simply starstruck. Most of us labor away trying to fix one small corner of the planet or another without seeing the likes of Harrison Ford, Al Gore, Michael Bloomberg, Van Jones, Jerry Brown – or the ministers or mayors of dozens of cities and countries – in person, on stage and at times angry enough to spit. And between these luminaries a steady stream of CEOs, corporate sustainability officers, and pension fund managers promising percentages of renewables and profits in their portfolios dedicated to the climate cause by 2020-2050.
I tried to give every speaker my full attention: the young man of Vuntut Gwichin heritage from the edge of the Yukon’s Arctic National Wildlife Refuge who pleaded with us not to enter his sacred lands with our drills and dependencies; all the women – swathed in bright patterns and head-scarfs – who kept punching their hearts. “My uncle in Uganda would take 129 years to emit the same amount of carbon as an American would in one year,” said Oxfam’s Winnie Byanyima.
“Our janitors are shutting off the lights you leave on,” said Aida Cardenas, speaking about the frontline workers she trains, mostly immigrants, who are excited to be part of climate change solutions in their new country.
The men on the stage, strutting about in feathers and pinstripes, spoke of hopes and dreams, money and power. “The notion that you can either do good or do well is a myth we have to collectively bust,” said New Jersey Governor Phil Murphy whose state is investing heavily in offshore wind farms.
“Climate change isn’t just about risks, it’s about opportunities,” said Blackrock sustainable investment manager Brian Deese.
But it wasn’t all these fine speeches that started the butterflies. Halfway through the second day of testimonials, it was a slight white-haired woman wrapped in an azure pashmina that pricked my tears. One minute she was on the silver screen with Alec Baldwin and the next she taking a seat on stage. She talked about trees. How trees can solve 30% of our carbon reduction problem. How we have to stop whacking them back in the Amazon and start planting them everywhere else. I couldn’t help thinking of Dr. Seuss and his truffala trees. Jane Goodall, over 80, is as fierce as my Lorax. Or my daughter’s Avatar.
Analyzing my take home feeling from the event I realized it wasn’t the usual fear – killer storms, tidal waves, no food for my kids to eat on a half-baked planet – nor a newfound sense of hope – I’ve always thought nature will get along just fine without us. What I felt was relief. People were actually doing something. Doing a lot. And there was so much more we could do.
As we all pumped fists in the dark, as the presentations went on and on and on because so many people and businesses and countries wanted to STEP UP, I realized how swayed I had let myself be by the doomsday news mill.
“We must be like the river, “ said a boy from Bangladesh named Risalat Khan, who had noticed our Sierra watersheds from the plane. “We must cut through the mountain of obstacles. Let’s be the river!”
Or as Harrison Ford less poetically put it: “Let’s turn off our phones and roll up our sleeves and kick this monster’s ass.”
4th California Climate Change Assessment Blues
by Isaac Pearlman
Since California’s last state-led climate change assessment in 2012, the Golden State has experienced a litany of natural disasters. This includes four years of severe drought from 2012 to 2016, an almost non-existent Sierra Nevada snowpack in 2014-2015 costing $2.1 billion in economic losses, widespread Bay Area flooding from winter 2017 storms, and extremely large and damaging wildfires culminating with this year’s Mendocino Complex fire achieving the dubious distinction of the largest in state history. California’s most recent climate assessment, released August 27th, predicts that for the state and the Bay Area, we can expect even more in the future.
The California state government first began assessing climate impacts formally in 2006, due to an executive order by Governor Schwarzenegger. California’s latest iteration and its fourth overall, includes a dizzying array of 44 technical reports; three topical studies on climate justice, tribal and indigenous communities, and the coast and ocean; as well as nine region-specific analyses.
The results are alarming for our state’s future: an estimated four to five feet of sea level rise and loss of one to two-thirds of Southern California beaches by 2100, a 50 percent increase in wildfires over 25,000 acres, stronger and longer heat waves, and infrastructure like airports, wastewater treatment plants, rail and roadways increasingly likely to suffer flooding.
For the first time, California’s latest assessment dives into climate consequences on a regional level. Academics representing nine California regions spearheaded research and summarized the best available science on the variable heat, rain, flooding and extreme event consequences for their areas. For example, the highest local rate of sea level rise in the state is at the rapidly subsiding Humboldt Bay. In San Diego county, the most biodiverse in all of California, preserving its many fragile and endangered species is an urgent priority. Francesca Hopkins from UC Riverside found that the highest rate of childhood asthma in the state isn’t an urban smog-filled city but in the Imperial Valley, where toxic dust from Salton Sea disaster chokes communities – and will only become worse as higher temperatures and less water due to climate change dry and brittle the area.
According to the Bay Area Regional Report, since 1950 the Bay Area has already increased in temperature by 1.7 degrees Fahrenheit and local sea level is eight inches higher than it was one hundred years ago. Future climate will render the Bay Area less suitable for our evergreen redwood and fir forests, and more favorable for tolerant chaparral shrub land. The region’s seven million people and $750 billion economy (almost one-third of California’s total) is predicted to be increasingly beset by more “boom and bust” irregular wet and very dry years, punctuated by increasingly intense and damaging storms.
Unsurprisingly, according to the report the Bay Area’s intensifying housing and equity problems have a multiplier affect with climate change. As Bay Area housing spreads further north, south, and inland the result is higher transportation and energy needs for those with the fewest resources available to afford them; and acute disparity in climate vulnerability across Bay Area communities and populations.
“All Californians will likely endure more illness and be at greater risk of early death because of climate change,” bluntly states the statewide summary brochure for California’s climate assessment. “[However] vulnerable populations that already experience the greatest adverse health impacts will be disproportionately affected.”
“We’re much better at being reactive to a disaster than planning ahead,” said UC Berkeley professor and contributing author David Ackerly at a California Adaptation Forum panel in Sacramento on August 27th. “And it is vulnerable communities that suffer from those disasters. How much human suffering has to happen before it triggers the next round of activity?”
The assessment’s data is publicly available online at “Cal-adapt,” where Californians can explore projected impacts for their neighborhoods, towns, and regions.
The results are alarming for our state’s future: an estimated four to five feet of sea level rise and loss of one to two-thirds of Southern California beaches by 2100, a 50 percent increase in wildfires over 25,000 acres, stronger and longer heat waves, and infrastructure like airports, wastewater treatment plants, rail and roadways increasingly likely to suffer flooding.