Milwaukee parking lot becomes green infrastructure park

A 4-acre former parking lot at the Harley-Davidson headquarters in Milwaukee, Wisconsin, has been redeveloped into a public park that functions as a green infrastructure system. The project, known as Davidson Park, replaces impermeable asphalt with a sunken amphitheatre, bioswales, bioretention areas, native planting and pervious paving, all designed to capture and filter stormwater.

The park’s centrepiece is a sunken amphitheatre called The Hub, a multi-use events space with tiered promenades that double as seating, motorcycle parking and vendor staging. Beneath the amphitheatre, cisterns collect stormwater and release it slowly into the sewer system. The design, reported by Robin Griggs Lawrence in Smart Cities Dive, treats the entire park as a stormwater management device.

Por que importa

Key facts
| Element | Detail |
| — | — |
| Size | 4 acres (approx. 1.6 hectares) |
| Stormwater capacity | Over 225,000 gallons (approx. 851,000 litres) |
| Green infrastructure features | Bioswales, bioretention systems, native landscaping, pervious pavers, underground detention |
| Partners | Harley-Davidson, CIS construction, Milwaukee Metropolitan Sewerage District |

The project was a partnership between the construction company CIS and the Milwaukee Metropolitan Sewerage District. According to the Smart Cities Dive report, the underground detention system is able to capture and filter more than 225,000 gallons of stormwater that previously had nowhere to go, reducing pressure on the combined sewer system during heavy rain.

Contexto

From parking lot to park
The site was originally a paved parking lot on the Harley-Davidson campus. By removing the impervious surface and replacing it with a layered green infrastructure solution, the project addresses both flood risk and the lack of public space in the area. The Hub’s bowl shape collects runoff from the surrounding hardscape, while the cisterns beneath it regulate discharge.

The design also includes bioswales – shallow, planted channels that slow and filter runoff – and bioretention areas that allow water to soak into the ground. Native landscaping reduces the need for irrigation and supports local pollinators. Pervious pavers allow rainwater to infiltrate rather than run off.

Public space and flood resilience
The park serves dual purposes: it provides a new public space for events, gatherings and motorcycle parking, and it functions as a district-scale stormwater management system. The amphitheatre can host concerts, community meetings or corporate events, while the surrounding green areas offer passive recreation.

For cities facing more intense rainfall due to climate change, this type of dual-use infrastructure – combining public amenity with flood mitigation – is increasingly relevant. The Milwaukee project demonstrates how a underused paved surface can be transformed into a multi-functional asset that benefits both the local community and the wider drainage network.

Limitations and context
This report is based on a single article from Smart Cities Dive, as covered by Planetizen News. No independent verification of the figures or project details was available. The project is specific to Milwaukee’s climate, sewer system and regulatory context. While the design principles are transferable, direct comparisons to London’s green infrastructure programmes – such as the Sustainable Drainage Systems (SuDS) policies or the London Green Infrastructure Task Force – would require further site-specific analysis.

Source: Planetizen News, https://www.planetizen.com/news/2026/07/138072-harley-davidson-turned-milwaukee-parking-lot-green-oasis

Datos clave