The world’s rivers, ponds and wetlands are disappearing beneath concrete, and a team of international scientists says that the professionals designing our cities need to step up to stop it.
A new study published in the Journal of Environmental Planning and Management argues that urban planners represent a critical but largely untapped force in the effort to reverse the catastrophic decline of freshwater wildlife.
Freshwater animal populations have fallen by an estimated 84% in recent decades, which represents a steeper collapse than anything seen in marine or terrestrial environments, yet the people making day-to-day land-use decisions in cities are rarely equipped or empowered to respond.
Freshwater habitats cover just 2.3% of the Earth’s land surface but support a third of all animal species. In cities, these habitats have been buried, concreted over and squeezed into engineered channels for generations. Only 37% of the world’s longest rivers still flow freely along their entire length, while wetlands are disappearing at more than three times the rate of forests.
Lead author Dr Helen Currie, from the University of Portsmouth’s Centre for Blue Governance, said: ‘Our rivers, ponds and wetlands have been treated as plumbing for decades – nuisances to be controlled rather than living ecosystems to be valued. Urban planners are uniquely placed to help fix this problem, if we give them the knowledge and support to act.’
The research team, drawn from 16 institutions worldwide, identified six priorities: giving planners the tools to assess and value biodiversity; supporting community involvement; removing barriers in planning education; improving the flow of knowledge between planners and ecologists; developing enforceable standards; and filling gaps in practical scientific guidance.
Co-author Professor Steven Cooke of Carleton University said: ‘The planner working in a local authority has more power to protect freshwater life than most people realise. What’s missing is the systemic commitment to train them in freshwater ecology and give them the policy frameworks to act.’
Encouraging examples already exist. In South Korea, a buried urban stream was restored following the demolition of a motorway above it, with benefits for both wildlife and local communities. In Vancouver, nature-based stormwater systems have been embedded into the urban fabric alongside engagement with indigenous communities.
In England, rules introduced two years ago now require most new developments to deliver at least a 10% net gain in biodiversity value. But the authors caution that the policy places heavy demands on planning authorities that often lack the ecological expertise to deliver on it.
The researchers’ vision is of cities designed around water from the outset, with floodplains reconnected, buried streams brought back to the surface, and stormwater ponds managed as living wetlands. As Dr Currie put it: ‘Housing, roads, parks and industry should be planned in harmony with the freshwater landscape.’
The full report can be read here.
Photo: Thirdman
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