Brownfield Remediation

Done right, it can unearth a “green” jewel

By Anna Cawrse and Andrew Gutterman
Photos: Courtesy of Sasaki

“Great cities have a great park,” is the mantra of the visionary client group behind Bonnet Springs Park in Lakeland, Fla. However, untouched, open green space—just waiting to be recast as public open space—is often hard to come by. The most viable parcels often are either already in use or sold and developed to drive revenue. Therefore, advocates for parks have to be creative in finding new avenues for developing public green space, leading many municipalities to look at their brownfield sites as potential long-term remediation projects. Case studies, such as Bonnet Springs Park, can help inform tactics to realize a new park on remediated land.

The Bonnet Springs Park site has gone through a number of attempts to establish its best use—none of them taking hold until now. In early 2015, David Bunch, a longtime Lakeland realtor, and his wife Jean presented a bold concept to philanthropists Barney and Carol Barnett. Their vision—to create a special public place near downtown that the community could enjoy and make positive use of the underutilized land.

The local activism of these philanthropists, joined by Bill Tinsley, the former Lakeland Parks and Recreation Director, and park planners and designers, has led to an ambitious and fast-moving project that will turn a heavily contaminated brownfield site into a 180-acre park for residents.

From Brownfield To Green Oasis
Between the 1910s and 1950s, the site served as one of the most important railroad centers in Florida. The Lakeland Railyard played a vital role in moving, storing, and repairing the coal-powered locomotives that fueled the region’s economy. At one point, it was the largest employer in the city.

Today, Sasaki, a global design firm based in Boston, Mass., is leading the transformation of this site. The early steps of implementation are underway, and the land will soon undergo a rigorous environmental restoration that includes soil remediation, cleaning of stormwater runoff, and restoring a sand seep spring. Then sustainable planting, programming, and architectural design can begin.

Sasaki has worked closely with state environmental officials to ensure the developed strategy will meet the applicable requirements. The project is enrolled in the Florida Department of Environmental Protection’s Voluntary Cleanup Tax Credit program, designed to encourage landowners to remediate sites that are considered “brownfields” due to the presence of contaminants. A collaborative approach among design teams and city and state officials has helped to keep the project on track to open in 2020.

Improving Water Quality
Land remediation is just one facet of Sasaki’s ecological-improvement strategy. The two major water systems in the future park, Lake Bonnet and Bonnet Springs Valley, face tough environmental challenges. Lake Bonnet is the most polluted lake in the city, and Bonnet Springs Valley, which drains into Lake Bonnet, is experiencing an accelerated rate of erosion along its banks, caused by a 66-inch diameter culvert near the headwaters that releases stormwater runoff from a 300-acre watershed. The Bonnet Springs Park board has decided to implement a stormwater-management design that will help restore Bonnet Springs Valley and prevent further pollution of Lake Bonnet.

The first step will divert water from the culvert, which separates the contaminated urban runoff water from the clean water coming from the sand seep spring. This drastically reduces the velocity of water entering the valley and eliminates unwanted erosion from large storm events. The second step will divert the water through a series of constructed wetland ponds to remove pollutants carried by runoff from nearby roads, parking lots, and buildings.

Not only will this design improve water quality and help restore a sensitive ecosystem, but it will also create new opportunities for park visitors to experience the landscapes along elevated boardwalks, bringing people closer to these clean, natural systems.

Native Restoration And Planting
In later stages, plantings will play an important role in maintaining the ecological health of the new park. Bonnet Springs Park is home to a number of distinct natural systems that reflect native Florida ecoregions that need to be considered in restoration.

The process begins with identifying and removing invasive plants to help native plants grow naturally and survive. Then restoration planting can start. The composition of plantings will vary depending on the desired outcome of the area. For restoration areas, the plant composition will closely resemble the specified native community. For example, Swamp Dogwood and Red Maple will be planted to supplement the existing community.

This investment in restoration and horticultural plantings will make improvements to the ecological health and vibrancy of the public space.

A Plan For Play
The planning and design of the park’s play areas are among many elements key in creating an active social hub and making the park a community asset.

The design team has developed a comprehensive approach to creating the park’s play spaces. For example, the Nature Play Area will feature unstructured elements that promote creativity, build curiosity, and encourage experimentation. Throughout the park, additional elements will invite children to explore the site’s natural vegetation and habitat while providing opportunities to balance, swing, climb, slide, and create. In addition, educational signage and teaching opportunities throughout the park will encourage citizens of all ages to become lifelong stewards of the land.

Thermal Comfort And Energy-Efficient Building Design Strategies
The park will also serve as a social connector, offering gathering facilities such as a large banquet hall at the Event Center, a full-service restaurant at the Welcome Center, and a large event lawn for concerts and festivals. These facilities will also generate revenue to fund ongoing maintenance of the park. Smaller gathering spaces, such as a tree house, tea house, and nature playground, will help bring people closer to the daily magic of the park. Most notably, the Explorations V Children’s Museum will relocate into an expanded facility at the heart of the park and will participate in the development of educational and cultural programming.

When it comes to the designs of the buildings, maintaining connections between the indoors and outdoors was a key aim. By incorporating plenty of doorways and transparent glass for maximizing views and access to nature, Sasaki also had to combat the Florida sun and humidity to keep spaces cool and dry. The team used state-of-the-art technology to test the performance of the design by incorporating deep roof overhangs, adjustable shutters, and tall ventilated spaces that help bring the hot air up and out of cooled spaces.

More than a mere open green space for individuals to utilize, these large reimagined public spaces serve a broader purpose: they support physical and social equity in cities, reinforcing opportunities for shared experiences and new connections within growing and changing communities. The process of converting a brownfield site to a green oasis can be daunting, but the payoff is immense for cities ready to tackle the challenge. For any city looking toward brownfield remediation to free up lands for public use, note that careful coordination of community input, civic stewardship, design vision, soil remediation, water ecology restoration, native planting strategies, active programming, and thoughtful architecture will be the vital ingredients for a successful and inspired transformation.

Anna Cawrse, PLA, is a Landscape Architect and Senior Associate for Sasaki. Reach her at acawrse@sasaki.com.

Andrew Gutterman, ASLA, PLA, is a Landscape Architect and Senior Associate for Sasaki. Reach him at agutterman@sasaki.com.