At the start of the 20th century, the upstart city was wilting under a drought that had delivered just half an inch of rain per month during the previous three years, well under the already-low norm. It was scarcely enough to meet the needs of a modest city, let alone the booming metropolis its leaders imagined.

William Mulholland, the visionary head of the city’s water department, had rationed residents’ water use and installed newfangled meters to limit waste, but reports still rolled in lamenting foul-tasting water tainted by algal blooms in the city’s reservoirs and fire hydrants that lacked the pressure to protect homes and businesses.

If the city’s fickle weather offered its 100,000 residents little hope for salvation, conditions in the surrounding regions offered even less. Beyond the mountains to the north, south, and east: desert. To the west: the salty Pacific Ocean. By 1904 the city’s population had doubled, further straining its water reserves. But still the skies refused to budge. Without a steady source of water, the future was fraught.

The scheme that slaked L.A.’s thirst has been immortalized in books and movies, its story becoming a foundational text for understanding the city and “the Ur story of water in the West,” says Jon Christensen, a professor at UCLA’s Institute of the Environment and Sustainability.

Mulholland and Fred Eaton, the city’s former mayor, paired canny foresight with double-dealing and deception to acquire the rights to nearly all of the farmland in the Owens Valley, an oasis more than 200 miles to the north. Along with it came water—and lots of it—squeezed out of the sky by the Sierra Nevadas and stored as snowpack that melted down their eastern slopes into the Owens River. In rerouting the river to Southern California, they desiccated Owens Lake and devastated agriculture in the valley, fomenting anger and resentment that persist today.

To carry the water across mountains, canyons, and desert required a feat of engineering and municipal strength unlike anything the United States had seen. Water began to flow down the Los Angeles Aqueduct in 1913 after five years of backbreaking labor and groundbreaking innovations.

Mulholland had prophesied that “whoever brings the water will bring the people” to L.A. And so the story goes. But electrical engineer Ezra Scattergood, Mulholland’s oft-forgotten counterpart in the aqueduct’s development, knew water wouldn’t be enough.

In a young Los Angeles, power sources were nearly as scarce. The closest significant coal deposits lay hundreds of miles away in Utah and Arizona, and the lack of a reliable energy source impeded the city’s industrialization, says Josh Lappen, a historian of energy in the Southwest.

“Water and hydroelectric power,” Scattergood declared, “are the basis and measure of our progress. They are locked up in our natural streams and to possess the key is to control the destiny of our people.”

A smattering of private utility companies had used oil and hydropower to keep the city’s streets lit and railcars running, but residents were wary of corporate control of their electricity.

“We assume that when people thought about the aqueduct they were thinking always and only about water, but much of the time what Angelenos were thinking of, and fighting over, and imagining was electricity as a critical product that this aqueduct was going to offer the city,” Lappen says.

The city built two gravity-fed hydroelectric plants along the northern end of the aqueduct to power its construction, then established a dozen more plants over the ensuing decades to capitalize on the free energy flowing through. When Power Plant 1, the first plant to send power to the city, opened in 1917 in San Francisquito Canyon, some 40 miles north of Los Angeles, it supplied more than enough electricity to run the city. In doing so, it wrested control of the city’s power supply from the private companies and established what remains one of the country’s largest public utilities.

From his vantage at Big Pine Power Plant, a 3.2-megawatt hydropower facility four hours north of downtown L.A., operator Brad Varnum can see evidence of the enormous undertaking that brought the aqueduct to life. Occasionally he comes across a wheel from a defunct pushcart or a section of railing piled like junk in a scrapyard, reminders of how burdensome it was to shepherd workers and materials to the remote environments the aqueduct traverses.

The original aqueduct, which has since been expanded, ran 233 miles and included 142 tunnels. To support its creation, the city laid 120 miles of railroad track and 500 miles of highways and trails. It opened a cement plant in the unincorporated town of Monolith to make the concrete that was the project’s most prevalent material.

Inside Big Pine, built in 1925, there’s no plywood in the concrete formations, Varnum says, nor welds in the metal. Their absence indicates just how long ago this work was conducted. 

“That was back when labor was labor,” Varnum says. “It shortened your life, and you felt it at the end of the day. That’s what built this.”

“The age of men and mules,” Christensen calls it.

Indeed, 50-mule teams hauled much of the aqueduct’s riveted steel pipe into place, but even their strength had limits. The cement plant, like so much else in the construction process, required electrical power.

South of Varnum’s perch in Big Pine, the creek-fed Cottonwood and Division Creek plants, built in 1908 and 1909, supplied 1.8 megawatts and 600 kilowatts, respectively, to the cement plant, electric dredges used to cut canals, an electric train line that shuttled equipment and laborers, and any number of electric drills and shovels.

The power created along the aqueduct is “the unsung hero” in the story of a young Los Angeles, says Marty Adams, former general manager and chief engineer at the L.A. Department of Water and Power, the agency that formed in 1937 when the city’s water and electric utilities merged. Hydropower allowed the aqueduct project to move forward and gave the city a toehold as it struggled to find its footing.

“The aqueduct power was a catalyst for the city,” he says.

If the role of hydroelectricity in powering Los Angeles’s expansion is underplayed in the modern era, Adams says, it’s likely because the same plants that fueled the city’s growth now represent just a small portion of its power grid.

In 1917, the 28 megawatts produced by Power Plant 1 covered all of the city’s needs and then some. Today, L.A.’s peak capacity surpasses 8,000 megawatts, drawing from sources in Nevada, New Mexico, Wyoming, Utah, Arizona, and Oregon. The plants on the aqueduct, efficient as they may be, comprise just 2% of the grid and a small portion of the 36% of the city’s energy that is renewable. 

Power Plant 1 and its brethren were pivotal in L.A.’s past, but the present and future of hydroelectricity in the city—and beyond—are largely in facilities such as the massive Castaic Pumped-Storage Plant outside of Santa Clarita. The plant serves as a 1,320-megawatt “green battery,” storing potential energy in two reservoirs, seven-and-a-half miles apart and at different elevations. During the day, excess wind and solar power is used to pump water from the lower to the upper reservoir; at night, when energy demand peaks, the water is released to the lower reservoir and harnessed as electricity. The next day, the plant stands ready to repeat the cycle.

The Castaic model offers both scale and flexibility to the energy grid, but it doesn’t make the plants along the aqueduct relics.

“We’re going to continue to operate and maintain these current facilities for as long as we can,” Jose Gutierrez, manager of DWP’s hydro and renewable generation, says. That should be “another 50 years, easily,” he says, as long as DWP is able to make replacement parts in its machine shop. 

Within the plants workers feel a sense of pride, not just about delivering water and power to Los Angeles, but about maintaining these “working museums,” says Power Plant 1 control operator Dean Aldridge. “We’re preserving history here,” he says. “Once history’s gone, it’s gone.”

For a city eyeing a carbon-free energy grid by 2035, aqueduct power serves a dual purpose. It offers the city its cleanest source of both water and energy—and virtually cost-free. Perhaps more important, it also represents a way of thinking that has largely fallen into disuse.

In searching for ways to develop a cleaner power grid, small-scale contributors can go hand-in-hand with large-scale plants, Adams says. He thinks of the aqueduct plants as “a series of 10 little solutions.”

Lappen sees a similar lesson. Where engineers and political leaders once sought to make use of every opportunity for power generation and conservation, they became focused on generating the largest swaths of power possible, he says. Today, hydropower tends to look more like Castaic or the 2,000-megawatt Hoover Dam, built in 1931, than the aqueduct plants. These large-scale facilities rely on reservoirs and dams that disrupt ecosystems and quietly contribute to climate change by emitting methane. Many states, including California, don’t even label them renewable sources of energy because their inclusion alongside other renewable sources would stunt efforts to green the grid, like the one L.A. is undertaking.

In the modern era, “it’s a commonly accepted truism that efficiency is just too hard, and to solve our climate problems we’ve got to produce ever-larger blocks of clean power,” Lappen says. But he believes reaching a carbon-free grid will take solutions of all sizes—and the type of opportunistic mindset Scattergood deployed. Rooftop solar, for example, can generate electricity while simultaneously reducing demand by offering shade that limits the need for air conditioning.

“Where there’s energy to be captured,” Adams says, “we should make an effort to capture it.”

In a city that loves nothing more than a good story, the aqueduct that brought water and power to L.A. more than a century ago has become legend.

In the Owens Valley, its influence has been just as pivotal in an altogether different way. The aqueduct’s creation left Owens Lake a toxic dust bowl and wrought ecological devastation that still plagues the region. But as the turbines along the aqueduct continue to spin, the story keeps unfolding. The city’s energy future could be guided by the ingenuity that defined its past—while turning the page on its history of destruction.