For Will Travis, it began 12 years ago, with an eye-opening article in the New Yorker magazine about rising seas and the widespread flooding and dislocation that would bring. As the executive director of the San Francisco Bay Conservation and Development Commission, the region’s coastal management agency, he needed to know more.

Travis had his staff research the issue. In 2007 they handed him a report that foretold catastrophe. The agency produced maps with colorful, frightening flood projections and shared it with local policymakers. Trillions of dollars in public and private infrastructure were at risk, Travis told them. The time to prepare was now.

In some areas, residents needed to start retreating from the shoreline, he preached. The most resilient future structure might be “a little Winnebago trailer that you keep moving back into the hills.” Think of California’s cities as “very long-term campgrounds” that, he warned, would be forever on the move back, away from the rising tide.

Yet the region’s elected officials and Silicon Valley’s cluster of high-tech firms were deaf to the urgency of his message. No one was planning for higher seas. Their problems were more immediate.

“What I heard a lot was, ‘I’m trying to get my kid into a good college, my wife wants me to lose weight, the car transmission is making a funny noise and you want me to worry about sea level rise?’ ” Travis said. “ ‘Yeah, I’ll get to that when I prepare my earthquake supplies.’ ”

He crafted a policy response for his region anyway. In 2011, after four years of intense bickering, scientific analysis and legal fights, the commission issued what Travis described as the nation’s first enforceable requirement that all shoreline development address the rising sea.

Today, with the breadth and scale of the problem known, the entire state is grappling with how to respond. Every agency and most municipalities are busily crafting plans and prioritizing projects, totaling up what will ultimately be hundreds of billions of dollars in costs to build barriers, restore wetlands and—somehow—raise or relocate roads, bridges, railroads and power plants away from the onrushing Pacific.

Global climate change is warming oceans and melting glaciers, raising seas higher and threatening the people and things that crowd California’s 1,100-mile coastline. Beaches are shrinking and bluffs are being pulverized. And the water’s rise, which had been somewhat steady in the past 100 years, is now accelerating alarmingly, 30 to 40 times faster than in the last century.

In as few as three decades, scientists say, some areas that are now dry will be permanently under water. Other places, miles from the ocean, will flood more regularly and more deeply, as warmer waters spawn more intense storms and the already swollen sea pushes farther onshore, unimpeded.

This winter’s lashing storms that took out parts of Highway 1 are an example of collateral damage: Rising seas are making flood-related events worse because there’s more water available to do damage. Flooding along roads is more frequent and lingers longer. Erosion from more powerful waves works away at bridge footings, undermining spans that are critical to transportation corridors, which themselves are strung along the California coast.

A report by the Ocean Protection Council, the state agency that coordinates the government’s coastal programs, was released in April with the most dire projections yet: The Pacific could rise as much as 10 feet in California in the next 80 years, covering up 800 feet of existing beach and taking out anything in its path.

Preparing for this eventuality has been declared a top priority in California. By calling for extensive scientific studies and projections, the state has thrown its full power behind the problem. But its power is not absolute. Even though the effects of rising water will be felt comprehensively, bridging public and private property and interests, some of the state’s jurisdiction stops at local borders.

Under current law, the state and its agencies have limited authority to dictate to cities and counties where and how, for example, building and development may take place.

“In a lot of ways it’s a zoning issue,” said Hilary Papendick, the climate change and adaptation program manager for San Mateo County.

State planning began in 2008 with an executive order from then-Gov. Arnold Schwarzenegger. That was followed by Gov. Jerry Brown’s 2010 requirement that state agencies include an adaptation strategy in all planning and permitting documents. Most are still refining those plans.

The beleaguered Department of Transportation has inventoried its holdings, identified which highways will be moved back from the coast and which low-lying roads must be elevated. Highway 1, the meandering, coast-hugging byway famed more for windshield tourism than modern transportation, has been clawed at by erosion and appears often on the state’s flood maps. A section of the roadway at Gleason’s Beach in Sonoma County will be pushed back from the shore some 400 feet. Approvals for the project are expected next year.

Similar ground-level planning is under way in other agencies. The parks department, for instance, is considering relocating parking lots and restrooms away from the beach up and down the state—although in some areas there is no room to move facilities, even if the agency could afford to do it.

The Coastal Commission has assisted California’s 15 coastal counties in preparing vulnerability assessments, which identify structures to be moved and areas where it’s too dangerous to build. The commission, which approves permits for all development along the coast, has denied the siting of a wastewater treatment plant in Morro Bay and has deemed a power plant in Oxnard to be in harm’s way.

The senator would not hazard a guess at the overall cost of shoring up state-owned infrastructure: “That would be a scary number.”

But despite such efforts, some say officials need to be much more nimble.

“The pace at which government is allowed to move seems to be inadequate with what we see coming,” said Sam Schuchat, executive officer of the Coastal Conservancy, a state agency that works to preserve coastal environments. “But the sooner you take an action, the cheaper it is.”

Tackling such a profoundly complicated scientific and legal problem in a cohesive way has been, to say the least, challenging.

A just-released report from the University of California, Davis polled 50 policymakers in the Bay Area, and found that all took sea-level rise seriously, but concluded that decision-making was fragmented: “Everybody’s involved, but nobody is in charge.”

When it comes to responding to rising seas in California, the report concluded, there is a “governance gap.”

The public cost of armoring the coast with sea walls and breakwaters—not always the right response but sometimes the best short-term option—of lifting up highways and defending airports, railways and power plants surely will be staggering. No one knows what it is. The exhaustive scientific analyses commissioned by the state don’t address cost.

State Sen. Bob Wieckowski, a Democrat from Fremont who chairs the Senate’s Environmental Quality Committee, would not hazard a guess at the overall cost of shoring up state-owned infrastructure.

“That would be a scary number,” he said.

For all the state’s studies, the precise details for responding to sea rise are mostly local decisions involving zoning, building codes and engineering projects with crippling costs attached.

In Sonoma County, Highway 37, built on a base of mud, flooded on 27 days last winter and has already sunk more than two feet, according to Sonoma County Supervisor David Rabbitt. He said that the state’s transportation agency, Caltrans, told local officials that it could get to the problem in 2088.

Four affected counties, unable to wait 71 years, are considering a number of options, including putting the critical commuter highway atop a 6-foot levee. The price tag for the 20-mile project is as much as $4 billion, and no one knows who will pay for it.

Foster City, on San Francisco Bay, reckons it will take more than $90 million to shore up its eight miles of rock levees that protect neighborhoods from encroaching water.

The city of Goleta, just north of Santa Barbara, compiled this list two years ago: an estimated $7.9 million to $63.2 million to cap or recap oil wells in flood-risk areas, flood damage expected on private and public property estimated at $14 million by the end of the century, $500,000 to add four to six inches of asphalt to local roads to elevate them above the water for the next decade.

In Southern California, cities such as Del Mar and Carlsbad are still assessing the cost of moving highways, railroad tracks, parks and a variety of public buildings, while at the same time shoring up bluffs and replenishing sand on already-slender beaches.

Driving across the soaring Dumbarton Bridge into Menlo Park at the south end of San Francisco Bay, Travis—who is now a consultant— is a grim tour guide. Where most would find serenity in the shimmering necklace of the California coastline, Travis sees an inventory of potential calamity for the state’s bridges, levees, homes and sewage plants. He points to a neat grid of commercial salt ponds that create a colorful mosaic of water behind long lines of levees. Colorful yes, but the marshes that could swell with seawater are held back only by flimsy earthen berms.

There is much at stake here, where the soggy, low-lying coast is the most heavily developed in the state. The density of people, and public and private assets, coupled with the region’s vulnerable geography, put the Bay Area at the top of the state’s triage list.

This is the gateway to Silicon Valley, formerly known as Valley of Heart’s Delight—a reference to once-sprawling fruit orchards—now home to Tesla, Apple, eBay, Facebook, Google and Hewlett Packard. State officials are keenly aware that its critical economic driver is in the path of eventual disaster.

Adaptation projects in this region show how nature is being harnessed to hold back Pacific waters. The Bay begins with a deficit, having lost more than 80 percent of its marshes in the last 200 years, each new development gouging out some natural protection. Multiple efforts are underway to reclaim those wetlands, restoring vegetation that absorbs floodwater and slows storm surges.

Voters in nine Bay Area counties last year approved a parcel tax to raise a half-billion dollars in the next 20 years, with plans to restore tidal marshes along the bay and creeks.

Facebook’s campus sprawls amid such a restoration project, one piece of the Coastal Conservancy’s plan to bring back more than 15,000 acres of marshland. It is part of the largest reclamation project in the western United States and will knit together tens of thousands of acres of marsh and wetland into a natural floodwater buffer zone.

The remedy has been difficult for some to visualize. When Travis met with representatives of the cutting-edge companies sprinkled in the expanse of dampness, they didn’t see why they would concern themselves with the ocean, which lies on the other side of the Santa Cruz Mountains.

Facebook’s parking lot is ringed by an elevated levee, used as a jogging path and bikeway, that few employees realized was engineered for flood protection. Fewer still understood that the waters of the bay, propelled by the rising Pacific, would inevitably fill the entire area with sea water.

Travis paid Facebook a visit with his charts and maps. The company eventually got the message. Its new campus, with its nine-acre green roof, was hiked up off the ground—although even with that design, the parking area and roads around the building are projected to flood.

Will Travis, an expert on sea level rise is shown in Foster City in an area that will flood. Photography by Penni Gladstone

More sobering for the public is the question of how to protect the international airports in San Francisco and Oakland. San Francisco airport, which, like Oakland’s, juts like a finger into the bay, has crumbling cement along its eight miles of sea wall. SFO officials are developing a $60 million shoreline protection project. At both airports, efforts will focus on buttressing and expanding existing walls and barriers.

“The choice will be: armor or retreat,” said Schuchat. “It’s easy to talk about retreat, but where are you going to retreat to? Where are you going to move San Francisco airport? It’s gonna have to be a big honkin wall.”

Although Los Angeles International Airport, the nation’s third busiest, likewise borders the Pacific Ocean, its facilities are more than 100 feet above sea level, affording it a natural protection that the Bay Area’s airports don’t have. Likewise for San Jose’s Mineta International Airport.

Back in San Francisco is Mission Rock, an ambitious, 300-acre development in low-lying Mission Bay next to AT&T Park, home to baseball’s San Francisco Giants. A new $1 billion arena, scheduled to open in 2019, will be added here to house the Golden State Warriors basketball team.

A 2016 study examining options for the area suggests converting nearby Third Street into a levee, reinforcing sea walls and even allowing marshy areas nearest the water to flood periodically. Some plans call for elevating the surrounding land by four feet. Project renderings depict glass panels on top of berms intended to block the advancing sea’s spray.

Elsewhere in the city, the sea wall that rims the waterfront Embarcadero office park and promenade of shops requires a multi-billion-dollar upgrade. The Port of San Francisco is soliciting improvement proposals and has set aside $40 million for the project. The venerable rock pile is a critical bulwark: Behind it sits nearly $40 billion in commercial development.

As if those numbers aren’t staggering enough, Travis’s back-of-the-envelope calculation for protecting just the San Francisco Bay with a simple levee—not accounting for any relocating, rebuilding or constructing more sophisticated defensive measures: As much as $100 billion. His bleak coda: The cost of doing nothing and paying to clean up the mess is four times that figure.

“In the Bay Area, adapting to sea-level rise is not an environmental issue, it’s an economic imperative,” Travis said. “If you are a thoughtful businessman, you have to start thinking: “If we say ‘retreat,’ it becomes ‘how far?’ And if we say ‘build up,’ it becomes ‘how high?’”

One thing all experts agree upon: There is not one perfect way to respond to the threats of sea-level rise. These illustrations, created by the San Francisco Bay Area Planning and Urban Research Association, offer mitigation options for a bayfront development in San Francisco. Among the suggestions: erecting plexi-glass walls to protect fans at the Giant’s baseball stadium from sea-spray, installing a lock system to control water flow into a basin that collects water from storm surges, and restoring wetlands that absorb water and offer greenspace.

Sea level will eventually have a profound effect on coastal cities as architects design for safety and adaptability. Some cities are considering changing their building codes to set new construction rules.

Longstanding commercial construction norms that placed boilers and bulky electrical operations in basements will become outdated; critical power plant equipment will be located above ground to safeguard it from inundation.

San Mateo County has already moved a jail to higher ground, said Papendick. And although a new hospital was designed for flood protection, with generators and power infrastructure on the second floor, it’s nevertheless located where the sea is expected eventually to push farther inland.

As for the police stations, schools and wastewater treatment plants in at-risk areas and new building codes to reflect the coming tides? “We’re working on it,” she said.

John Englander, executive director of the International Sea Level Institute, a consulting group, works with businesses and governments, advising clients to plan for the worst. “We should raise building codes….It’s just common sense,” he said.

Common sense is not always in good supply. That’s especially true for private residences. People cling to homes that may themselves be clinging to a coastal bluff. Up and down California’s coast, houses teeter at the edges of cliffs or face relentless pounding from rushing waves.

“I wish human beings were rational, but they are not,” said June Grant, an Oakland-based architect whose work focuses on adaptability. It shocks her to see property being sold in flood-prone areas: “You have to be nuts; why would you do that? Nothing will change until the codes change.”

People will have to be forced by law, Grant says, to pull back from the water and the views that are precious to them.

The Coastal Commission is engaged in prolonged battles with homeowners who—in an effort to save their beloved homes—pour concrete, haul rocks and build sea walls that can do unintended damage to surrounding beaches by accelerating erosion there. But the alternative may be retreat or even abandonment.

Many of the disputes end up in the courts. Property owners in Solana Beach challenged that city’s regulations preventing them from erecting any new seawalls and other protection for their homes built atop crumbling sandstone bluffs. Although a court last year ruled largely for the city, the legal fight isn’t over.

Two homeowners in neighboring Encinitas sued the coastal commission, saying the agency’s rules restrict their property rights. The closely watched case is before the California Supreme Court, which is expected to hand down a decision this summer. (Update: The court on July 6, 2017, ruled that the homeowners couldn’t extract themselves from the terms of an existing sea wall permit they had previously agreed to with the Coastal Commission.)

At Malibu’s celebrity-drenched Broad Beach, residents are awaiting state approval for a plan to spend $31 million of their own riches to haul in sand to restore their diminishing coastal frontage.

“You can imagine with billions of dollars of real estate and private property, the political and and financial issues are huge,” said Jack Ainsworth, the Coastal Commission’s executive director. “It’s emotional.”

Democratic Assemblyman Mark Stone of Monterey said if homeowners near the beach are in denial about what is happening, they need only consult local parcel maps.

“If it looks like the parcel goes out into the ocean, that’s because the ocean has moved,” said Stone, who chairs a committee on coastal issues. “That’s kind of a clue as to how much has changed over time.”

Travis, for his part, has seen it all before, going back to the maps and charts that were ignored all those years ago, before frustration drove him out of government in 2012. People who are otherwise meticulous about planning and investments can lose perspective when their sense of place, tugging deep at their center, is threatened.

After all, he said, even scientists who study the Bay Area’s Hayward Fault—one of the the nation’s most dangerous earthquake zones—choose stunning views over safety.

“It’s amazing the number of seismic experts that live in the Berkeley Hills,” he said. “Right on the fault.”

As the sea rise takes its place among earthquakes, drought and wildfires in the pantheon of California catastrophes, it’s tempting to wonder if this one will someday day surpass them all.

Update: Since this article was published, the Broad Beach homeowners’ plan—now priced at $50 million—has been approved. But they face another legal battle, scheduled for next year.

Photo credits: Aerial view of San Francisco Bay salt ponds and marshes by Jitze Couperus via Flickr, 2017 flooding on Highway 37 in northern Marin County by Christopher Chung of The Press Democrat, Solana Beach shoreline and controversial sea walls by Lenny Ignelzi, Associated Press.