Tulare Lake, named “Pa'ashi” by the native Tachi Yokut tribe, disappeared 130 years ago from California. Now, after a series of extreme weather events, the lake is back, with positive and harmful effects.
California's San Joaquin Valley, para supplying a significant percentage of the country's food, is however a dry, arid place. Fresno, in the heart of the valley, receives just over 10 inches of rain a year on average, according to the National Weather Serviceand sometimes just 3.
And yet, by the late 19th century, the San Joaquin Valley had a lake over 100 miles long and over 30 miles wide.
Tulare Lake “was the largest body of fresh water west of the Mississippi River. It's really hard to imagine now,” he says Vivian Underhill, former postdoctoral researcher at Northeastern University with the Research Institute of Social Sciences and Environmental Health.
In research conducted while at NortheasternUnderhill describes the lake's recent, spectacular comeback as a result of 2023 atmospheric rivers over Californiaand the effects the lake's return has had on indigenous communities, wildlife, and farmworkers in the San Joaquin Valley.
At one time, Underhill says, there was so much water that a steamboat could carry “agricultural supplies from the Bakersfield area to Fresno and then to San Francisco” — a distance of nearly 300 miles.
The “ancestral lakes” and connecting waterways that made such a route possible have all but disappeared thanks to human-made irrigation, Underhill says.
Tulare Lake, called “Pa'ashi” by the native Tachi Yokut tribe, was fed primarily by snowmelt from the Sierra Nevada mountains, Underhill says, as opposed to rainfall. And because “there is no natural outlet into the valley,” the water collects to form a lake.
For many traveling the San Joaquin Valley today, it's hard to imagine such a large volume of water coexisting alongside such an arid landscape, Underhill says. But in the 1800s, “Fresno was a lake town.”
An anonymous prospector, he continues, reported that “there was driftwood piled up in the trees of downtown Fresno” due to the recent flooding.
Where did the water go?
The lake first began to disappear in the late 1850s and early 1860s, Underhill says, driven by “the desire of the state of California to take public land and put it into private ownership.”
However, Underhill continues, “when we say 'public land,' that is historically indigenous land that the state of California has declared to be 'public'.”
“They really wanted to get [land] into private hands so that indigenous land claims – which were ongoing at the time – would be nullified until they went through the courts.'
This process was called “reclamation” and often involved “either draining the flooded land or irrigating the desert to create arable land. The restoration was really a process across the entire western US,” says Underhill.
If “people could drain this land,” he says, “they would be granted ownership of parts of this land. So there was a big incentive for the white settlers to start doing this work.”
“It was a deeply settler colonial project” that “progressed in fits and starts.”
The first time the lake completely disappeared was around 1890, when “its water was essentially [used to] irrigates all the arid lands around this region.'
“Now the valley is criss-crossed by hundreds of irrigation canals, which were originally built to take this lake water and put it into irrigated fields,” he says.
But in 2023, Tulare Lake – Pa'ashi – is back. “California just got flooded with snow in the winter and then rain in the spring,” says Underhill. “If you have a rain and snow event, the snow melts very quickly.”
And all that Sierra snow and rain still runs into the depression where Tulare Lake once was.
A complicated homecoming
But Underhill notes that this isn't the lake's only comeback since the 1800s. “It happened in the '80s, it happened once in the '60s, a couple of times in the '30s.”
The implications for the return of the lake are complex and multi-layered, Underhill says, with sometimes opposing effects between the wildlife and the people living in the valley.
Before the lake's disappearance into irrigation canals and irrigation, “People talk about there being so many wetland birds,” says Underhill, “that if you startled them, when they lifted it, it was like a giant clap that echoed across the landscape.” .
Now, after less than a year back, “birds of all kinds – pelicans, hawks, waterfowl” are returning. And Underhill notes that “the Tachi also say they have seen owls nesting around the coast,” a species described as “vulnerable or threatened.” from the US Fish and Wildlife Service.
Tulare Lake was once part of the Pacific Flyway, Underhill says—it was an important staging area for migratory birds. “The loss of this habitat has been a major issue for bird conservation and bird diversity.”
“One thing that continues to amaze me is… [the birds] they know how to find the lake again. It's like they're always looking for it.”
In addition to the returning species — including fish and amphibians that were probably brought down from the Sierras by rain and flooding — winds from the lake can drop temperatures by as much as 10 or 20 degrees, Underhill says. A real boon when summers in the San Joaquin Valley often exceed 100 degrees Fahrenheit.
Differential effects
In terms of human occupation of the Central Valley, Underhill says there are three distinct groups that have been affected by the return of the lake.
The first is the Tachi Yokuts, for whom “the return of the lake was just an incredibly powerful and spiritual experience. They hold ceremonies at the edge of the lake,” says Underhill. “They were able to resume traditional hunting and fishing practices.”
The other two groups that Underhill says are most affected are those involved in agricultural production: farmers on the one hand and planters on the other — those who own the land and employ the workers.
Growers, “over the last five decades or so, have created a complex flood prevention system,” says Underhill. In the last flood, these measures “protected part of their agricultural land, which was essentially the lowest elevation part of the historic lake.”
But barring this low-lying farmland with canals and wells were the surrounding working-class communities now inundated by Tulare Lake.
Many of these farmers “don't speak English or are procedurally too far from the state,” Underhill says. Unfortunately, they are also the ones who “experience the most personal, place-based impact of flooding in their homes [or] they lose their homes completely.”
Looking out over the lake
“Most of the news coverage around this time was talking about it as a catastrophic flood,” says Underhill. “And I don't want to ignore the personal and property losses that people experienced, but what hasn't been talked about as much is that it wasn't just an experience of loss, it was also an experience of resurgence.”
He points to the return of native wildlife as one example, and the ability of the Tachi to practice their traditions in water.
Efforts are already underway to drain the lake once more, and Underhill expects it to remain in some form for about another two years — though new river atmospheric events over California this year could complicate this prediction.
“Under climate change,” says Underhill, “floods of this magnitude or greater will occur with increasing frequency.”
“At a certain point, I think the state of California would have to realize that Tulare Lake wants to stay. And in fact, there's a lot of financial benefit to be gained from staying.”
As for what happens next, Underhill says “this landscape has always been one of lakes and wetlands, and our current irrigated agriculture is just a century-long fragment of that larger geological history.”
“This was not actually a flood. This is a returning lake.”