At 51 miles long, it’s one of America’s largest infrastructure projects.
Angelenos live, work and play along it, but know little of its origins
… nor its role in protecting them from devastating flood waters.
February 1938 was a wet month in Los Angeles. The ground, where it hadn’t been paved over, was saturated, which meant rain had nowhere to go except into the streets, canals and washes. On the 27th, a storm arrived. During the following days, the city received its second-highest 24-hour rainfall in history. Reservoirs overflowed, dams topped out and floodwaters careered down Pacoima Wash and Tujunga Wash toward the Los Angeles River. By the time the river peaked at Long Beach, its flow exceeded the Mississippi’s at St. Louis. “It was as if the Pacific had moved in to take back its ancient bed,” wrote Rupert Hughes in “City of Angels,” a 1941 novel that climaxes with the flood. In an instant, the Lankershim Bridge in North Hollywood collapsed, and five people were swept away. Sewer and gas lines ruptured; communications were cut; houses were lifted straight off their foundations and sank into the water. In all, 87 people died.
The Los Angeles River after the 1938 flood.
The Los Angeles River was never a storybook river of the kind that, like the Hudson or the Seine, we associate with great cities. It was an arid, Janus-faced watercourse — most of the time hardly more than a shallow, burbling brook, which ran underground in places and occasionally turned bone-dry. But with heavy rains, it was prone to flooding, occasionally gaining the full, deadly force of the Mississippi or the Colorado and violently overreaching its low banks.
That violence, as the geographer Blake Gumprecht recounts in his history of the river, was due, in part, to its extreme topography. You might not think of the river’s course as steep, because it emerges in the San Fernando Valley. But over 51 miles, beginning behind the football field of a high school in Canoga Park and ending at the ocean in Long Beach, the Los Angeles River descends more than the Mississippi does over its entire 2,000-plus-mile stretch — meaning it gathers tremendous speed and power when the waters run high.
Los Angeles repeatedly tried to tame and channel the river. A massive flood in 1914 turned Long Beach into an island and increased public pressure on authorities to subjugate the waterway, which only really became possible after the completion of the Los Angeles Aqueduct in 1913. A feat of engineering often compared to the construction of the Panama Canal, the aqueduct brought the Owens River on the eastern side of the Sierra Nevada to the San Fernando Valley, liberating Los Angeles from dependence on its erratic river, which could then be repurposed to channel floodwaters.
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That job turned out to be an equally Pharaonic effort. Requiring decades of complex construction and finally completed in the 1960s, the channel remains the largest public works project the United States Army Corps of Engineers has undertaken west of the Mississippi. It meant widening, deepening and straitjacketing the river into a dogleg and entombing it in concrete for most of its length. Where it once naturally snaked along a shallow, quixotic route, sometimes turning west, sometimes south, the new channel charted a beeline for the ocean, resembling an airport runway for long stretches, broad enough to land jumbo jets, with a sad, narrow groove carved down the middle to handle the normal trickle of water.
Protecting downtown and the city’s infrastructure from floods, the channel made possible the emergence of Los Angeles as a great, global megalopolis of booming businesses and single-family houses with green lawns and swimming pools. It solved an existential problem, but it also left a gaping scar across the region, one that exacerbated growing racial and economic tensions. The vanquished river soon became a dumping ground and frequent crime scene, much of it fenced off, crisscrossed by bridges, hemmed in by railway tracks, highways and heavy industry. Increasingly, immigrant and working-class communities, victims of redlining and other discriminatory practices, found themselves concentrated in neighborhoods wedged between the freight trains and freeways that hugged the channel and its polluted, industrialized banks.
“Erased from the city’s mental map,” as Patt Morrison, the Los Angeles Times columnist and author of “Río L.A.,” put it, the river all but disappeared from the news except when someone drowned or Hollywood used the channel to stage an invasion of giant ants in “Them!” or a drag race in “Grease” or an epic chase in “Terminator 2.” Millions of Angelenos were only too happy to forget that the river even existed.
In this year’s tech & design issue, the magazine collaborated with The Times’s Headway team to present an issue about how people around the world approach rebuilding during a time of continuous disaster.
But over time, the river has slowly come back into focus. Since 1938, Los Angeles hasn’t suffered a flood as disastrous as the one that year, thanks in no small part to the channel’s engineering, which has also allowed Angelenos to forget the danger the river originally posed. As the threat of flooding receded in people’s minds, objections to the channel — and its effects — have grown. Droughts have increasingly raised questions about the logic of a channel built to hasten billions of gallons of rainwater out of the region and into the ocean. Environmentalists, concerned about the despoliation of nature, have been lobbying for the concrete to be removed and the river rewilded, with new marshes and wetlands to green the city and mitigate flooding. And social activists have focused on how the channel worsens racial and income disparities, depriving underserved communities of healthy open spaces and concentrating poverty along the industrialized margins of the river.
Several decades after its completion, it is the flood channel itself — not the floods it was built to contain — that many Angelenos have come to see as the disaster.
In June, the Los Angeles County Board of Supervisors approved the first new master plan for the river in more than a quarter-century. Like all master plans, it lacks legislative teeth and has its share of detractors. But it is the most ambitious vision for the river since the channel was constructed, forward-looking and socially minded — a blueprint for encouraging legislators, private developers and community groups to come together around financing and new laws. It calls for tens of billions of dollars to go toward hundreds of projects in and around the river over the coming decades: the creation of a land bank, playing fields, cultural and community centers, public transportation and, of course, water management. Water and access to nature are treated as inseparable from issues like public transit and affordable housing.
The river traverses more than a dozen jurisdictions, flowing past almost every conceivable kind of neighborhood, through industrial zones, downtown and the urban wilderness of Griffith Park. It skirts the Warner Bros. and CBS studios on its northern end, and on its southern end divides some of the poorest towns in Southern California. In a sense, reimagining the river means reconsidering the governance and connectivity of the whole region.
Among the projects the master plan endorses is a proposal by the architect Frank Gehry for that southern stretch of the river. Collaborating with the landscape architect Laurie Olin and the engineering firm Geosyntec Consultants, Gehry imagines building platform parks levitated above the concrete channel at the river’s confluence with the Río Hondo and a new $150 million Gehry-designed cultural center beside the parks.
This is the area of the Gateway Cities, which include South Gate, Lynwood, Downey, Compton and Bell Gardens, and which for decades benefited from generous federal support. When companies like General Motors and Firestone shuttered factories during the 1970s and ’80s, white working-class families fled the area, and Latino immigrants moved in. Residents soon began to suffer the effects of huge public disinvestment and of the toxic waste left by the departed industries. These same towns were bereft of green parks and open spaces, a common determinant of public health. Today residents of southeast Los Angeles live, on average, a decade less than residents in neighborhoods on Los Angeles’s west side, a statistic that Gehry says stirred him to conceive the platform parks.
“When the former mayor of South Gate came to see me with his 4-year-old son,” Gehry recalls, “and said his son had a 10-year-shorter life span than kids on the west side because he doesn’t have enough parks and open spaces, that really hit me.”
His proposal involves constructing immense platforms or decks — holding troughs of dirt that support a landscape of hills, trees, horse paths and walking trails — creating green bridges as much as a mile long that span the two rivers. During extreme weather, the concrete channel can rapidly fill to the top of the embankment walls. The platform parks, raised on concrete stilts several feet above those walls, allow floodwaters to flow unimpeded into the Pacific. “We studied the river upside and down,” Gehry says, “and found that less than 1 percent of the time it runs very fast and is very dangerous. That meant we couldn’t remove the concrete, because it would cause the river to flood. So, we thought maybe we could deck the river instead.”
Some of the opposition to the master plan and to Gehry’s proposals comes from environmentalists who are pressing for a more natural version of the river. And some of it is from community activists who fear that any new development (not least development by an architect like Gehry, known for glamorous projects like the Walt Disney Concert Hall and the Guggenheim Museum in Bilbao, Spain) will trigger displacement of poor residents. Among the naysayers is a venerable organization called Friends of the Los Angeles River, founded by the Texas-born poet and performance artist Lewis MacAdams. In 1985, MacAdams enlisted three friends to cross the First Street Bridge with him and cut a hole in a fence along the river. The quartet clambered down into the channel and walked upstream past the old city jail, to where Capt. Gaspar de Portolá and Spanish colonists first came upon the river and its centuries-old settlements of native Tongva, Kizh and Tataviam people in 1769.
For MacAdams, who died in 2020, removing concrete and restoring the waterway became a lifelong crusade, what he called his “40-year artwork to bring the Los Angeles River back to life.” That campaign is now carried on by, among others, Dennis Mabasa, chief operating officer for Friends of the Los Angeles River. We met one sweltering September afternoon at the Willow Street Estuary in Long Beach, south of the Gateway Cities. This is where 20 miles of concrete ends and the flood channel regains its natural bottom before swelling into the ocean.
The goal, Mabasa said, should not be building decks over the concrete channel but looking at removing it, installing permeable pavement and capturing more storm water. Mabasa cited a 2016 report done by the Army Corps of Engineers suggesting that restoring natural habitats could help mitigate the impact of severe floods and lessen strains on the channel, which FoLAR contends would make possible more spots like the Willow Street Estuary.
“Who wouldn’t want more of the river to look like this?” Mabasa asked as I watched an egret wade through brackish water. It was hard to disagree.
Concrete pouring for channelization, 1938.
“The study simply isn’t accurate,” says Jessica Henson, who wrote much of the county master plan and is a partner at Olin, the landscape architecture firm founded by Laurie Olin and Robert Hanna.
Just as FoLAR doesn’t believe that the county and Olin have fully considered alternative scenarios, the county and Olin insist FoLAR is ignoring the basic science. In fact, the master plan recommends soft-bottom improvements in some places. But removing all the concrete and returning grasses and other natural features slows floodwaters, Henson told me, causing the water to build up and potentially breach the embankments unless the channel is significantly widened. That, in turn, would require moving large communities along its banks, not to mention many factories and much of the county’s critical infrastructure. Henson says that habitat repair along the lines FoLAR envisions would displace between 60,000 and 100,000 people. “When Interstate 105 was built in 1993, it displaced 25,000 people in neighborhoods like Watts and Compton,” Henson added. “Widening the river would repeat that history at a far greater scale. L.A. hasn’t had a giant flood in years, but it’s only a matter of time, and the areas most at risk are among the county’s poorest.”
For his part, Gehry told me he also hoped to remove the concrete but the facts didn’t allow it: “Two movie guys came to me after the opening of the High Line,” he said, referring to the park atop an abandoned railway viaduct in Manhattan, “and they said: New York is doing this exciting thing. Would I look at the river and see whether Los Angeles could do something like it? I thought, Well, the river runs through all these different communities, maybe we could make a great park out of it if we got rid of the concrete — which seemed a beautiful idea, a 51-mile garden — and so we worked on that plan for two years, pro bono, because I simply refused to believe it wasn’t possible.”
But he and his partner on the project, Tensho Takemori, couldn’t figure out how to engineer the concrete away. “We did all sorts of studies and finally accepted the fact that every once in a while Godzilla arrives and fills the channel up to the edge with water. We just did the research and stuck to the facts, and the facts were that communities along the river were suffering, they needed parks and open space and they also needed to be protected from floods. The platform parks were the only plan I could come up with that worked for that site.”
I asked him whether it was true that the platform parks, should they actually move ahead someday, might cost billions of public dollars to construct.
“With all the problems L.A. is facing,” he said, “even if it costs $50 billion to fix the river, we should just effing do it.”
The headwaters of the Los Angeles River aren’t easy to find. I stumbled on them in Canoga Park one morning, behind the town’s high school. That’s where two tributaries, Bell Creek and Arroyo Calabasas, converge in a Y-shaped funnel that the Army Corps of Engineers built to link them up with the river, whose concrete basin was nearly dry the morning I was there. It was hard to imagine a less Edenic setting for the wellspring of a great paradisiacal metropolis.
Every consideration of the river’s function ultimately comes down to how much water Los Angeles has at hand, whether too much or too little. For centuries, the river sustained small communities of native peoples. Under Spanish rule, and with the exploitation of Tongva labor, the river made the new pueblo the most important agricultural settlement on the Pacific Coast. It then nurtured hundreds of vineyards and orange groves during the 1800s, which spread Los Angeles’s reputation as a wonderland around the globe. But as the city grew, it drained marshes, chopped down trees along the riverbanks to make way for railroad tracks and paved over land that had helped mitigate floods. The city’s growing population, with newcomers soon consuming water at three times the rate residents did in many Eastern cities, placed unprecedented demands on the river, which it was eventually unable to meet. Droughts increasingly became even more of a threat than floods.
Farmland and the Los Angeles River before the 1920s.
Today, with climate change bringing ever-more-extreme weather, the river is no longer the sole or even a minor source of potable water for the county. But it remains integral to a vast, complex water-management system that regulates the flow and use of water across the entire region and that tries to anticipate both floods and droughts. This spring, residents in Canoga Park were among six million Southern Californians subject to new restrictions on water use because of a major drought. “We are seeing conditions unlike anything we have seen before,” Adel Hagekhalil, general manager for the Metropolitan Water District of Southern California, told The Los Angeles Times.
Officials in Los Angeles say they’re prepared for future droughts. Since 2007, both total and per capita water usage in California have significantly declined. Angelenos now use 44 percent less water per person annually than they did during the early 1980s, according to the Los Angeles Department of Water and Power. The drop is thanks to water treatment facilities, more water-efficient appliances and various conservation policies, according to authorities.
That said, there’s still plenty of cause for concern. Los Angeles now imports about half of its water from the Los Angeles Aqueduct and another 40 percent from the Metropolitan Water District of Southern California, which relies on the Colorado River and Northern California. Both the Owens and Colorado Rivers have suffered from droughts, and their reliability is increasingly uncertain; the drought that forced restrictions on residents in Southern California this spring included Northern California. As the hydrologist Newsha Ajami told Bloomberg News, droughts “ripple through the system,” adding, “That’s the problem with imported water.”
For authorities, the various sources of imported water are precisely what safeguard Los Angeles, creating the equivalent of a balanced investment portfolio: When one source becomes stressed, the others can make up for its losses. To demonstrate how the local system operates, Martin Adams, general manager of the city’s Department of Water and Power, and Mark Pestrella, director of the county’s Department of Public Works, which oversees flood management, took me one afternoon on a helicopter ride over the Los Angeles River, the San Gabriel Mountains and the San Fernando Valley. It was a sweltering day, and through headphones over the whoosh of the helicopter’s rotor, the two of them pointed out the area’s network of dams, spreading grounds and reservoirs, diamond-dusted in the high sun. In 2019, Los Angeles County captured 97 billion gallons of water in the reservoirs, enough to supply 2.4 million residents with water for a year. We flew over construction sites that Adams told me would soon become some of the largest groundwater treatment plants in the world. There are also upgrades underway to local wastewater treatment plants. The goal, Adams said, is that, by 2045, 70 percent of the city’s water will come from local sources, from storm-water capture and groundwater, not imported, at great cost, from faraway rivers. Which also means that Los Angeles can continue to grow, responsibly building much-needed new multifamily housing without overtaxing the water supply.
As for the Los Angeles River and the concrete flood channel, Adams gestured at hundreds of square miles of houses, highways and office buildings below us. “Look at it,” he said. “Hydrologists have studied the problem. Even if all the development in the San Fernando Valley was magically gone and the valley became a giant sponge, it still wouldn’t capture enough rain during the heaviest storms to prevent severe flooding downstream, which is only getting worse with climate change. That’s why the flood channel remains necessary.”
Pestrella agreed: “Millions of people are simply not going to move out of the valley or agree to leave their homes along the river. You’re also not going to move all those rail and power lines that run right along the channel. Much of the time the channel is dry. But on those rare days when the rains are worst, the channel does its job.”
“Increasingly, the river has become a catalyst for talking not just about water but also equity, affordable housing, habitat restoration — all of it together,” says Jon Christensen, an environmental historian at U.C.L.A. “In 1996, many Angelenos didn’t know there was a river. Now they say they not only know the river exists but that they want it to be everything, that it represents all sorts of goals for the city, which you can call a problem, because some of the goals are contradictory and unrealistic, but is also a sign that the river is a place where dreams and hopes about the city are coming together. I’m not saying it is front-of-mind for most Angelenos. It isn’t. But it is helping to focus more attention on some of our big challenges.”
I first started visiting the river nearly a decade ago, when Los Angeles was going through an earlier drought. Rents were rising, as were the numbers of homeless people, some of whom I found camped under bridges on its banks. With a landscape architect and urbanist named Mia Lehrer, who for years has designed parks and promenades and reimagined other parts of the river, I kayaked along a bumpy, natural-bottom stretch. With Mayor Eric Garcetti, I toured a 42-acre patch of brownfield in 2018 that the city acquired from the Union Pacific Railroad, in Cypress Park. The mayor talked about growing up near the river and about turning the vacant parcel into a green jewel. The project is still in development.
The site sits across from Elysian Valley, a neighborhood also called Frogtown, which has become Exhibit A for green gentrification on the river. In 2004, Julia Meltzer founded a nonprofit there called Clockshop, which is working to establish a new state park called the Bowtie adjacent to the mayor’s brownfield site. Meltzer was stunned by how rapidly Elysian Valley gentrified. “I remember the change happening rapidly after the stock-market crash in 2008,” she recalled, “when real estate investors started capitalizing on talk about improving the river, and then in 2014 when the Army Corps of Engineers got federal money to do some things FoLAR wanted.
“Taco trucks disappeared,” she went on. “An upscale taco place took over a Mazda repair shop. Artists moved in. MacAdams spread the notion of letting the river out of her corset, which was fueled by a nostalgic dream. It moved many people emotionally. And it began to expose conflicts between environmentalists who wanted habitats and community residents who wanted playing fields and not to be priced out of their neighborhood. They aren’t the same thing.”
During the past several years, real estate developers, seeing the potential for rising property values, have been gobbling up properties not just in Frogtown but in other places near the river. The county master plan recommends but cannot institute regulations like rent controls, which are up to each town and city. In August, Bell Gardens passed a town rent-stabilization and tenant-eviction protection ordinance out of fears that predatory developers would push out poor tenants in anticipation of Gehry’s parks and an extension of the Metro line. The master plan also encourages but can’t require the construction of affordable housing, and the county now has in place inclusionary zoning regulations for new multifamily developments at only a few riverside spots.
This is why some critics have argued that the plan is not attentive enough to community interests. Wilma Franco, executive director of the SELA Collaborative, represents various community groups in Southeast Los Angeles, including East Yard Communities for Environmental Justice, which has declined to back the master plan. Franco told me that people in the area want parks but fear the consequences. She said Gehry and his team have been open to ideas from community members like including a culinary school at the cultural center. But, as is widely acknowledged, it’s the county that needs to pass laws to prevent displacement. “There is excitement in the area about resources coming in,” Franco said, “but a lot of cynicism because of decades of broken promises and disinvestment. Our cement parks are 110 degrees in the summer. Our kids have no place to play baseball or soccer. But changes along the river can’t be driven by developers.”
Sissy Trinh, executive director of the Southeast Asian Community Alliance, agrees. Her office in Chinatown is just a short walk from the river. She told me she never paid much attention to the river before 2014, when the Army Corps of Engineers, lobbied by river advocates for years, secured $1.6 billion in federal funds to restore habitats and create bike trails and wetlands along an 11-mile stretch that runs from Griffith Park to downtown. For Trinh’s Chinatown constituents, the news that more than $1 billion would go to redevelop their backyard seemed both an opportunity and a threat.
“Chinatown is one of the poorest neighborhoods in Los Angeles, where the median income is closer to Skid Row than to South L.A.,” Trinh told me. “It’s an area historically devastated by the intrusions of the 110, 101 and 5 freeways, the Union Pacific and light rail lines, by rail yards and a prison, not to mention by commuters avoiding bottlenecks on the freeways by speeding through our streets. We have been feeling the impact of gentrification for years, which for many of our residents leads directly to homelessness. I am talking about a population of seniors, many of whom literally can’t afford a $4 monthly rent increase.
“When I started talking about housing in public meetings about the river, some environmentalists would tell me, ‘That’s too big an issue, it’s mission drift,’ and they would change the subject. But it isn’t mission drift. Poor communities should not have to choose between a more beautiful neighborhood and a home.”
Trinh recalled how she and other community leaders gradually began to shift the conversation toward solutions like land banking and rent control, topics reflected in the new master plan. Coalitions have started forming, she says, “around green gentrification, displacement avoidance, affordable housing — the river has become an opportunity to link equitable development with environmental justice and open space.”
As proof that all this is having some tangible, albeit still modest, effect on politicians, Trinh cites a motion the Los Angeles County Board of Supervisors passed this June setting aside $50 million to establish a land bank for affordable housing. A $50 million land bank may seem a token gesture in a region where a single home can cost twice that and there are few affordable apartments or protections for renters. But the point, Christensen from U.C.L.A. says, echoing Trinh, “is that the broader conversation about the river around equity and housing is spilling over.”
Hubris and wishful thinking are at the heart of any large-scale urban undertaking. No matter how clever or sensitive to the problems of its time, a project that looks to be a solution can itself turn out to be the problem.
In July, the $588 million Sixth Street Viaduct opened. It spans the flood channel where the gentrified Arts District on the west side of the river faces Boyle Heights, a historically working-class neighborhood, on the east side. Replacing an Art Deco landmark, the new bridge became an overnight sensation on Instagram and attracted mobs of fans who camped out on it, making music and partying, blocking traffic. Its popularity resurfaced longstanding concerns about gentrification in Boyle Heights.
The bridge is architecturally striking: a graceful sequence of arches, akin to looping strips of film that tilt over the river. To a driver crossing the bridge, the arches can seem to move like a dancer or a galloping horse in one of Muybridge’s motion studies.
Parks are still being built on either end of the bridge: a lawn on the Arts District side, and tucked beneath the bridge on the Boyle Heights side, acres of playing fields. I met the bridge’s architect, Michael Maltzan, one recent afternoon. He walked me to a cul-de-sac near the center of the bridge, so we could gaze directly over the flood channel, across a panorama of rail lines and industrial warehouses toward the downtown skyline.
“Infrastructure like this defined postwar L.A.,” he said. “The flood channel was built to speed water out of the city, which it divided. Freeways were built to provide access and speed to automobiles, but they turned out to separate people and different parts of the city along racial and economic lines. My hope is that the new bridge doesn’t come to be seen as an instrument of gentrification but suggests a different vision of what infrastructure can accomplish in terms of connecting, not separating, diverse neighborhoods.” He cited the confluence of Angelenos who came to celebrate the opening.
“Los Angeles has always sold a dream of individual fulfillment,” Maltzan went on. “But the river requires collective action and imagination. We’ve crossed a threshold from people thinking it’s preposterous that the river is a vital part of city life to it seeming an inevitability. And now we’re feeling the frictions that arise when people become invested in something and things start moving forward.”
A spiral ramp led from the bridge down toward the street on the Boyle Heights side. From the ramp, Maltzan stopped to point out where the playing fields would go. The bridge will provide much-needed shade on hot days, he said. I noticed an empty dirt lot beside the bridge, flanking the lot where the fields will be. The city leased the lot during construction of the bridge from its private owner. Now the lease has expired. An image popped to mind of a skyscraper rising on the site, overshadowing the bridge, bringing an army of gentrifiers to Boyle Heights.
“I hope the city finds a way to buy the lot,” Maltzan said.