Sasaki Turns a Disused Rail Yard Into Lovely Bonnet Springs Park

What do you do with 300,000 cubic yards of arsenic-contaminated soil? (That’s enough to fill nearly 100 Olympic-size swimming pools.) This was the question the landscape architects at Sasaki faced when their team was hired to turn a 168-acre former rail yard in Lakeland, Florida, into an ecological jewel and public park. The toxins in the soil are the result of arsenic-based herbicides that were used back when the rail yard was one of Florida’s largest, at its peak servicing 25 trains per day. After the rail yard closed in 1952, the land, located less than a ten-minute walk from downtown, languished for almost 50 years before a group of developers, philanthropists, and former park professionals decided to purchase it (and roughly a dozen adjoining properties) for use as a public park. 

By the time Sasaki got involved, says Anna Cawrse, co-director of the firm’s Denver office, most remnants of the rail yard were gone. The contaminants, however, remained and became a key driver of the design. “We could have proposed taking [the soil] off-site to try to create a clean slate, but instead [we started] talking about reusing it and seeing it as a design opportunity—as a moment to create a whole new landscape,” Cawrse explains. “That started to unravel all these other opportunities. How do we tie in architecture? How do we think about engineering? How do we use these big infrastructure moves to create these incredible places?” 

Completed in fall 2022, Bonnet Springs Park is now an amenity-rich public space and a prime example of the heavy-duty environmental work that modern parks are increasingly being asked to do. In addition to remediating toxic soils, the park voluntarily treats 300 acres of urban runoff that had made the adjacent Lake Bonnet one of the most polluted in the city. This component, which was not mandated by city regulations, has ripple effects for Florida’s natural environment, says Andrew Gutterman, another principal at Sasaki: “By improving the water quality of Lake Bonnet, you’re really impacting a whole chain of other water bodies and environments all the way from Lakeland to Tampa Bay.”

This isn’t the first time that refuse has been repurposed in an act of land-making. New York City is currently laboring to transform the Fresh Kills Landfill on Staten Island into a 2,200-acre oasis, and Los Angeles County is undertaking a similar effort at the 1,356-acre Puente Hills Landfill east of downtown L.A. In Lakeland, the contaminated soils became the raw material for two massive, 45-foot-tall landforms, which buffer the park from a nearby highway and offer 360-degree views of low-lying Lakeland. To comply with federal regulations, the sculpted hills were capped with clean soils dredged from Lake Bonnet, a move that allowed the design team to establish a naturalistic, boardwalk-lined lagoon and wetland ecosystem along the lake’s eastern edge.

Strung between the hills is the new home of the Florida Children’s Museum, which occupies a pair of clean white volumes connected by a ribbonlike roof structure and punctuated with pops of primary colors. “Early on, we came up with this concept of the ‘bridge building,’ ” Cawrse says. “We wanted it to be something that when you walked through the building it was like entering a different world.” From that gateway, the crescent-shaped park spools out to the north and south, wrapping around Lake Bonnet. Paved paths whisk visitors to a collection of variously wild and cultivated garden spaces, including a nature-inspired playground, a Zen-like nature pavilion, and a curvilinear canopy walk that weaves through moss-covered mature oaks.

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In general, those spaces become quieter and more contemplative as a person moves from the eastern, more active edge of the park toward the lake. “With big parks, you want to create that attitude of gathering and celebration of being together. But you also have to have those really small, intimate, quiet moments,” Cawrse explains. “What we want to do when we’re designing these parks is 

create spaces where everyone can have the moment that they need, whether it’s to sit down, unplug, and just look out at the lagoon or [have] a crazy afternoon with their kids going to the children’s museum and getting ice cream.” 

A spirit of preservation and reuse informed more than the park’s remediation strategy. Sasaki carefully designed around an existing spring in the northern half of the site and cataloged and preserved nearly every tree larger than six inches in diameter, including an oak that had fallen over. “The client, Bill [Tinsley, president of Bonnet Springs Park], said, ‘This is going to be that climbing tree that every kid comes to,’ and that’s exactly what it is,” Cawrse recalls. 

What visitors won’t find, outside of a small, train-shape play structure, are overt nods to the former rail yard. This is partly because most of the rail infrastructure had been removed prior to design. But it’s also in recognition of the many forces that shaped the site over the years. The linear plantings and ladderlike follies in the park’s heritage gardens are nods to the orange groves that once occupied the area, while the denser, wilder plantings and wetland areas celebrate the rich native ecology of central Florida. 

Bonnet Springs Park counted a million visitors in its first seven months, making it a clear success as a cultural and recreational draw. But the designers at Sasaki hope that it will also help inspire a new ethic of landscape-based resilience and reuse. “People are looking for these old, abandoned lands and being more creative in how they’re finding spaces for parks,” Cawrse says. “But what you do with it varies. And this, we hope, is showcasing how you can utilize land that is right next to downtown to create this amenity that is helping clean the water, that is helping with a huge contamination issue, and that is really trying to set up a new standard for environmental stewardship.”