Urban wetlands to keep cities afloat

Photo: Samurdhi Ranasinghe / IWMI

Increasing recognition of the value of urban wetlands for flood mitigation and a host of other co-benefits could usher in a new era of management that benefits city communities and their environments.


Wetlands in and around urban settlements have historically been considered impediments to development. Drainage, filling in and pollution have long been a feature of urbanization, both planned and otherwise. But wetlands are often what makes living possible for residents. The most important of these benefits may be mitigation of floods through the absorption of rainwater, which would otherwise flow as run-off on the impervious surfaces typical of cities – 2021’s flooding in New York highlighted the high human and financial toll that extreme events may increasingly have for cities in the future. Urban and peri-urban wetlands also play a key role in improving the quality of municipal water, regulating climate, supporting the production of food, conserving biodiversity and providing space for recreation and leisure. However, these benefits are often overlooked and poorly integrated into urban planning and management.


WLE has supported much-needed biophysical research that provides evidence of the role wetlands play in the hydrological cycle, and thereby urban and peri-urban communities and the health of their environments. Work on the Zambesi River Basin, the largest in the Southern African Development Community, and Kenya’s Upper Tana River Basin, highlights the value of ‘natural infrastructure’ such as floodplains, mangroves and lakes in providing ecosystem services and protecting communities from extreme weather events. It also illustrates the complexity involved in predicting the functions of wetlands, which tend to be context-specific.

WLE helps urban planners and managers to understand these contexts. As one of 18 cities that were declared Ramsar Wetlands Cities in 2018, Colombo showcases the value of researcher involvement in planning, strategy and management for urban wetlands. The International Water Management Institute (IWMI), supported by WLE, is a member of Sri Lanka’s National Wetland Steering Committee. IWMI is consulted on policy-level discussions and works closely with government institutions to conserve wetlands.

Promoting the true worth of Colombo’s wetland ecosystem (IWMI)


IWMI supported Colombo’s designation as a Ramsar city, in part by building the evidence base to make the case for its designation. It has played an important role as a facilitator, bringing together siloed institutions in Sri Lanka. It also helped the 18 Ramsar cities share experiences through capacity-building workshops, for instance in Colombo and in Vientiane, Laos – where 40 planners were presented with the Colombo ‘success story’.

WLE-supported research from Kolkata, India, provided ‘wise use’ recommendations for urban and peri-urban wetlands, drawing on the Ramsar Convention’s principles. WLE has contributed to the shift in interpretation of ‘wise use’ over the years, towards sustainable use by and for communities and for biodiversity.  


Buy-in from policymakers has been high, as the example of Sri Lanka demonstrates. But the lack of quantitative data on hydrological processes, particularly in the tropics and in developing countries, makes it challenging for decision makers to incorporate integrated wetland management in specific contexts. Wetland resources are still undervalued and are often perceived as obstacles to development. Strategic wetland policies may be in place but the lack of an operational management framework poses a challenge. There is an urgent need to mainstream and streamline wetland management across government departments, working with stakeholders to disseminate information and guidance that will incorporate wetland ecosystems into policy and planning in light of the continued expansion of cities against a backdrop of changing climatic conditions.

Next steps

A promising example of stakeholder engagement, resilience building and government commitment is the Darwin Initiative, funded by the United Kingdom’s Department for Environment, Food and Rural Affairs. Supported by the British High Commission in Sri Lanka, it has great potential to promote community best practices and citizen science for wetland management. This aligns with the country’s ongoing efforts to maintain its capital city’s status as a Ramsar Wetland City, and set an example for urban centers across the world.


What’s next for the world’s first official Wetlands Cities?Darwin InitiativeRamsar’s Good Practices Handbook for Integrating Urban Development and Wetland Conservation

SDGs supported

End poverty in all its forms everywhere End hunger, achieve food security and improved nutrition and promote sustainable agriculture Ensure healthy lives and promote well-being for all at all ages Achieve gender equality and empower all women and girls Promote inclusive and sustainable economic growth, employment and decent work for all Build resilient infrastructure, promote sustainable industrialization and foster innovation Make cities inclusive, safe, resilient and sustainable

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