Willowbrook Park, Fed By Rainwater, Is An Example of LA’s Stormwater Treatment Future

The prevailing goal in Southern California has been to get water that falls from the sky away from our roads and buildings as quickly as possible.

Much of the rain washes out to the ocean — often carrying trash and other pollutants. The L.A. Times reported up to 10 billion gallons poured into the Los Angeles Basin in recent storms and only about 20% will be captured.

“We thought of [stormwater] as a liability as a society,” said waterworks engineer Art Castro at L.A. Department of Water and Power’s Watershed Management Group. “Now we're moving into, 'let's reuse that water. It's a precious resource'.”

L.A. County has plans to double the amount of rainwater currently captured every year and use it to provide nearly two-thirds of the county’s drinking water.

“These projects are not cheap,” Castro told KPCC’s AirTalk. “They're going to help the city to become more resilient and sustainable. That has a price tag.”

Voters approved a new property tax in 2018 meant to raise up to $300 million a year to fund the capture and treatment of stormwater.

It will take decades to build the infrastructure needed. LADWP’s Stormwater Capture Master Plan is a well-saturated 144 pages. 

But we already have examples of what can work. Take, for example, Earvin “Magic” Johnson Park in South L.A.’s unincorporated Willowbrook.

The 126-acre park was once the site of an ExxonMobil Oil Corporation oil storage and distribution site that polluted the ground beneath it and the Ujima Village public housing project.

Nearly two-thirds of the nearby community is Latino and about one-third are Black. More than 40% of the surrounding community makes less than $35,000 a year, according to county documents.

In 2014, the county started creating a master plan to renovate the park for the first time since 1985 and in the process, better utilize natural resources including rainwater.

“They wanted this kind of world-class park for the community of Willowbrook,” said landscape architect Wendy Chan. The firm she works for, AHBE/MIG helped design and shepherd the renovation. “They deserve a park that’s equitable for the community.”

The ongoing $135 million renovations include a 20,000-square-foot community center, a new playground, and the area’s first off-leash dog park in South L.A.

“The importance of having that open space drove me to landscape architecture, bringing that experience of nature back into that urban environment,” said Chan, who grew up in Lincoln Heights. “I didn't really see nature.”

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Mariana Dale

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The goal was also to create a less-thirsty recreational area. The park's two man-made lakes and landscaping had long been maintained by potable — aka drinkable — water.

And since 2021, the park has captured, cleaned, and stored millions of gallons of water annually.

Here’s how it works:

1. A storm drain diverts water from the surrounding 375-acre Compton Creek watershed toward the park. This includes everyday runoff from car-washing and irrigation and rain. The system can handle up to 3.9 million gallons of water (that’s enough to fill almost six Olympic swimming pools) during a big storm. 
2. The water’s first stop is a pump station at the corner of El Segundo and Clovis avenues that filters out urban debris like plastic bags, chunks of wood and candy wrappers. 
3. Then it heads to a white brick building near the park’s community center no larger than a convenience store. Inside, the water is treated with ozone and aluminum sulfate to remove pollutants and bacteria. 
4. The treated water burbles out from discharge boxes throughout the park’s south lake. On a recent visit, the lake was at capacity, so all that was visible was a grated pipe at the water’s surface. 
5. The water replenishes the lake and is used to water the surrounding park’s landscaping. Any excess can be released back into Compton Creek where, now cleaned, it flows toward the ocean. 

The renovation also restores some of the habitat that gave Willowbrook its name. Cattails, bulrush, and willows at the south lake’s edges create a freshwater marsh. The dense wall of vegetation also deters the Canada geese from splattering the walking path with poop — a concern shared by parkgoers early in the design process, Chan said.

Chan’s favorite feature is the chairs and picnic tables that jut into the lake, creating little island-like oases.

“You can hear the trickling of the water or the birds chirping,” Chan said. ”You have a moment of nature in the city.”

Dana Crawford often visits the park with her 2-year-old daughter. A described "big recycler," she was excited to learn it also doubled as a site for stormwater treatment.

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Mariana Dale

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LAist

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“We make memories here,” said Guadalupe Ramos. She visits the park about three times a week with her as her 6 year-old daughter and 8-year-old-son.

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Mariana Dale

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LAist

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These “secret spots,” are one of the highlights of visiting the park for Gardena resident Dana Crawford and her 2-year-old daughter, who loves the renovated playground and feeding the ducks.

“Hopefully people will just take care of it,” Crawford said. “It’s something good to have for this community.