Brighton’s Wild Park rainscape uses green stormwater infrastructure to filter toxic chemicals from highway runoff, protecting the chalk aquifer that supplies 90% of the city’s drinking water.
Green stormwater infrastructure in Brighton offers a model for cities worldwide facing the challenge of road pollution. After six years of development, the Wild Park rainscape uses vegetated swales and planted basins to filter contaminants from a 2.5-mile stretch of the A27 motorway before they seep into the chalk aquifer that supplies drinking water to approximately 365,000 people in Brighton and Hove.
The Aquifer Project (TAP), a partnership between Brighton and the Hove City Council, the Environment Agency, Southern Water, and The Living Coast UNESCO Biosphere, played a central role in shaping this approach. The TAP focuses on protecting the Brighton Chalk Aquifer through nature-based solutions, community engagement, and sustainable urban drainage systems. Its research and public outreach, including demonstrations of rainscapes, rain gardens, and pollution-prevention actions, helped lay the groundwork for large-scale interventions like Wild Park.
Road runoff carries a dangerous mixture of chemicals and microplastics into waterways worldwide. Car tires alone account for 25% of all environmental microplastics. The chemicals they release can kill aquatic life and spread through food chains.
In 2020, runoff caused a massive die-off of silver salmon along the U.S. West Coast. Researchers in southern China recently detected tyre-derived chemicals in most human urine samples they tested. This raises serious concerns because some of these compounds are known carcinogens.
Yet most governments do not monitor this pollution. The UK government does not track road runoff on a national level. The chemical cocktail varies from country to country and from one road to another, making standardized monitoring difficult.
The problem worsens as climate change brings heavier rainfall that overwhelms urban sewage systems faster. Local authorities face new challenges in managing stormwater. Most have no comprehensive plan to address the millions of gallons of toxic runoff washing into the environment each year.
Brighton cannot afford to ignore the issue. The city relies on its underground chalk aquifer for nearly all of its drinking water. Professor Martin Smith from the University of Brighton found contamination levels exceeding recommended limits in baseline testing before construction began.
Lead from old leaded gasoline lingers in the water. Chromium leaches from road paint. Harmful polyaromatic hydrocarbons seep from asphalt and rubber tyres. These contaminants pose a threat to both public health and the local environment.
The Wild Park stormwater green infrastructure project intercepts highway water before it reaches the aquifer. The system captures runoff and guides it through a 1.2-mile filtration route. Two vortex separators in a balancing pond near The Keep first remove solid particles like grains and granules.
Smith’s research showed that 80% of contaminants bind to these solids. Removing them through the initial separation stage accomplishes most of the treatment work.
The water then flows through three planted reed beds. The plants filter out finer materials while adding oxygen to the water. Sunlight and plant processes break down remaining pollutants through natural biological and chemical reactions. Finally, settlement basins in Wild Park complete the treatment before releasing clean water into the ground.
The system can hold nearly two million liters of water during heavy storms. This capacity helps reduce flood risk while protecting water quality.
The Aquifer Project secured 2.4 million pounds from National Highways to build the system. Brighton and Hove City Council led the construction. The project also partners with The Living Coast UNESCO Biosphere.
Green stormwater infrastructure delivers benefits beyond water protection. Wild Park sits in Moulsecoomb, a highly deprived neighborhood. Project managers hope that the ponds and wetlands will provide residents with better access to nature and enhance the quality of life.
Nearby, Moulsecoomb Primary School installed its own rain garden with support from the Aquifer Project. Students spend lunch breaks exploring ponds and learning about water pollution and flooding. The school’s rain garden funnels rooftop water through drainpipes into flowerbeds, water storage systems, and ponds.
Cities worldwide are adopting similar green stormwater infrastructure approaches. Michigan created permeable pavements and rain gardens. Guangxi in China reduced stormwater runoff by 75% using multiple strategies.
Brighton has implemented additional rain garden projects at Carden Avenue, Darcey Drive, Carden School, and Wallands Primary School in Lewes. These systems cost less than expanding underground pipes and treatment facilities. They also create habitats for wildlife and recreational spaces for communities.
The Wild Park rainscape includes 24 new parkland trees, eight orchard trees, and areas of hazel coppice. New pathways, seating, bins, and signage make the area more accessible. Construction began in autumn 2024 and was completed in autumn 2025.
Smith and his students will track the rainscape’s performance over the coming years. They will measure impacts on water quality, pollutant removal, and biodiversity. Smith plans to share data with other councils to encourage similar projects.
The Wild Park rainscape offers a blueprint for cities facing similar challenges. As rainfall patterns shift and urban runoff increases, communities require effective measures to safeguard their drinking water. Brighton proves that green stormwater infrastructure can work at the scale needed to protect public water supplies while creating community benefits and wildlife habitats.
