Cycles of drought and downpours are making Los Angeles’s water supplies more unreliable than ever. Our imported snowpack travels great distances at great social and environmental cost. How can LA source and store more of its water locally?

Los Angeles is not a desert. But the way that we’ve paved over the region, it’s not surprising that people mistake it for one. And although the region can go months without precipitation, when it does finally rain, the design of our cities means that precious resource runs downhill, past our drought-parched neighborhoods, all the way to the Pacific, gathering a toxic stew of pollution that sickens marine life and litters the coast. But that’s not even the worst part. At the same time that rain is being flushed out to sea, we are spending billions to maintain a century-old system that imports two-thirds of Southern California’s drinking water from hundreds of miles away. The whole process makes little sense in a good water year — and it’s downright reckless at a time when climate change is eradicating what little reliability the region’s water supplies ever had.

Our Mediterranean climate has always been unpredictable from a hydrologic perspective, subjecting LA to both decade-long droughts and weeks-long rain. What we now know as atmospheric river storms can dump a year’s worth of water onto the state, like the 43-day event in 1861 that turned the Central Valley into an inland lake, forced a flooded Sacramento to build an entirely new downtown, and changed the course of the LA River. But a hotter, drier planet doesn’t necessarily guarantee a future of hotter and drier weather. Warming oceans mean an atmosphere that holds more moisture, and more moisture ups the potential for those supercharged storms. Californians have become very familiar with El Niño years, where warm pockets of the Pacific generate powerful winter storms that drop record snowfall on the Sierra Nevada. Now hurricanes, which rarely gained strength in the Pacific’s cold waters, are becoming more frequent in the summer. So there’s another phenomenon scientists are telling us to brace for: “precipitation whiplash,” meaning our increasingly extreme weather will oscillate between very wet and very dry years, sometimes back to back. When it comes to water, LA needs to be prepared for anything.

The waterways that LA chose to pin its fortunes to over a century ago — fed by snowpack of the Sierra Nevada to the north and the Rocky Mountains to the east — seemed like reliable sources at the time. LA’s growth was fueled by the erection of multiple networks of dams, tunnels, reservoirs, and aqueducts to draw water to its taps. But this came at great societal and environmental cost: decimating the livelihood of Native communities and eradicating several species, not to mention the energy required to siphon water over mountain ranges and across fault lines — which also makes our water supply particularly vulnerable in an earthquake. Now, despite LA’s 100 years of investments, waves of drought have forced leaders to contend with a future where dwindling rivers and decimated reservoirs are certain. It is not ethical nor is it sustainable to continue the practices of a century ago; LA needs to source more of its water here in LA. 

In 2023, LA County’s Board of Supervisors approved the LA County Water Plan to source 80 percent of the region’s water locally by 2045. The new plan, which was developed with dozens of county water partners, proposes to do this by reducing demand — right now the county uses about 1.7 million acre-feet-per-year — recycling more wastewater, and allowing much, much more stormwater to filter down into local aquifers instead of sluicing it out to sea.

Using less water is one area in which we already excel, as most Angelenos might be surprised to learn. Over the last few decades, LA has become the poster child for urban water conservation. Despite adding one million more residents in the last few decades, the city of LA uses less water than it did in the 1970s. In 2022, in the midst of drought, LA used less water than it had for any June in history. And while Colorado River negotiations are forcing some cities in Nevada, Arizona, and even elsewhere in California to implement more draconian cuts like rationing, the LA region is already meeting its conservation targets early. 

Even more impressively, nearly all of the reductions have been voluntary, like recommendations to irrigate outdoor landscaping only two days a week, or utilities offering incentives or rebates that help property owners swap their thirsty grass with drought-tolerant natives, affix rain barrels to gutters, or install low-flow showerheads. The goal isn’t necessarily to incentivize every homeowner to install gravel-strewn, faux-turfed landscapes (which carry other grave environmental concerns); it’s actually way more simple: less water, consumed more efficiently, and sticking around for longer.

Reducing water use is only one part of LA’s conundrum: we actually need to re-use it, too. While wastewater is already recycled throughout LA — about 23 percent statewide — it’s only currently treated for release into local waterways or non-potable uses like irrigation (there are various state and local restrictions on using potable water for ornamental grass). In 2023, the State Water Resources Control Board approved sophisticated new water treatment methods that use reverse osmosis, carbon filtering, and UV light to purify LA’s wastewater to drinking standards. By 2028, Southern California’s Metropolitan Water District plans to have the U.S.’s largest water-recycling facility online in Carson, and eventually produce 150 million gallons of drinking water per day. While recycling water can be energy-intensive, it’s not as energy-intensive as importing water, and the process will get more efficient as it scales up. Recycling water is also far less energy-intensive than ocean desalination, which is often floated as a solution for coastal communities, but which carries destructive consequences for marine ecosystems. Additionally, recycling offers flexibility in dry years: water can be purified to distribute directly to taps or treated to traditional standards to recharge aquifers for later use. Recycling is the way forward.

So if Angelenos take major steps to reduce and reuse their water, the rest is going to be up to what LA’s municipalities are doing on the ground. This means pulling up pavement in every neighborhood and planning ambitious public spaces to absorb more water locally. Ideally, these projects can also be multi-benefit, giving park-deprived Angelenos more access to green space: restoring wetlands, carving out greenways, and engineering spreading grounds that can double as gardens, orchards, or sports fields.

In 2018, LA County voters passed Measure W, LA’s Safe Clean Water Program (SCWP), a parcel tax which is meant to incentivize and fund the creation of projects that allow more stormwater to infiltrate into the ground where it can be drawn from local aquifers. Although groundwater contamination and depletion is largely more of a problem for rural and agricultural communities outside of the LA region, it does cause problems with water quality for some smaller water districts, particularly ones that source their water from wells, so some money does go to those projects. But the bulk of funds collected are intended to create more accessible green space. And since voters approved Measure W, and despite over $1 billion invested, the program has only created 30 new acres of new green space. LA County is 3 million acres. In 2023, Heal the Bay, the Natural Resources Defense Council, and LA Waterkeeper published a new vision for the Safe Clean Water Program with bolder targets and timelines. Among the goals to be achieved by 2045 are capturing 300,000 acre-feet-per-year of stormwater — on average, LA County infiltrates 155,000 acre-feet-per-year of stormwater — and replacing 12,000 acres of impermeable surfaces with new green spaces. We have a very long way to go.

LA’s limited efforts to slow, sink, and store water are definitely working, but they often involve giant infrastructural investments: pumps, cisterns, cement-bottomed holding basins. Part of the reason Measure W dollars haven’t resulted in more greening projects is because the county has historically and reflexively relied too heavily on engineering solutions. But nature-based solutions can be simpler, cheaper, and more beneficial to the surrounding communities. It’s just that these solutions require the county to take brand-new approaches to stormwater. 

At the heart of this debate is the conversation about the future of the LA River, cutting a giant channel 51 miles through 14 LA County cities that’s designed to move water as quickly as possible to the ocean. The river was, of course, encased in concrete a century ago by federal engineers to protect adjacent neighborhoods from catastrophic flooding. In recent years, however, plans have emerged to naturalize the river and reclaim its floodplain wherever possible: diverting the river into wetlands, filling adjacent pools and ponds for recreational uses, and, yes, removing some of that concrete. But in 2022 the LA County Supervisors approved a different river master plan which largely leaves the concrete channel intact, adding cultural platforms designed by Frank Gehry that span the river like freeway cap parks. Environmental justice groups withdrew their support for the plan, and LA Waterkeeper and the Center for Biological Diversity sued to stop it. The claim alleges that the county did not conduct a proper environmental review of the plan’s impact on some of the most underserved communities in LA, which, despite billions of dollars in proposed investments, would still not see improved access to the waterway flowing through their backyards.

The opportunities to de-pave LA’s waterways start far upstream. Among the regional efforts are proposals to daylight creeks, which have been buried beneath streets and tucked into storm drains. Some municipalities require permeable pavers in driveways and parking lots. Green alleys are transforming pitted asphalt corridors into permeable rain gardens. Curbs can be similarly redesigned to direct water into bioswales instead of sucking water down into sewers. Wider sidewalks with larger tree wells can trap more water while giving young trees more space and a better chance at survival by using storm runoff as irrigation. Too many Southern California cities incentivize native gardens and tree planting on private property without taking their own advice to re-engineer their shadeless sidewalks and too-wide streets. And the role that these spaces can play can be transformative. Turning streets and sidewalks into spongy filters that can soak up pollutants also ensures that fewer toxic chemicals will pass through our neighborhoods. Water quality declines significantly as fertilizers, bacteria, microplastics, and tire particles flood downstream, presenting a public health disaster that closes beaches every time it rains. About 4,000 tons of trash also ends up on local beaches each year, endangering the lives of marine creatures. The Trash Interceptor, a garbage-collecting barge positioned at the mouth of Ballona Creek scooped up 11.6 tons of trash in a single 2023 storm. Interventions on every block — every place a storm drain warns us that it leads to the ocean — can ensure that garbage never ends up in the water in the first place.

The dystopian water future LA is trying to avoid is already impacting its most marginalized communities already: contaminated taps, toxic runoff, deadly flooding. LA County’s new water plan, and the implementation of Measure W, has finally united all the region’s decision makers around common goals of permeability over pavement. But the work towards a healthier water system has just begun. It will require more nature-based solutions that keep the entire region wetter and cooler. It will require a radical rethinking of our streets and sidewalks. It will require a systemic change in our relationship to rain. But if we get it right, we just might have all the water we need.