2018/02/02     Dresden, Germany

Image: istockphoto/MHLE

Reporting by Kurt Brüggemann and Vaitheswari Thiruvengadam Selvam, Water Resources Management

Secondary cities will undergo massive expansion in the next few decades. Especially in the southern hemisphere, they are severely underserviced in terms of basic infrastructure and flood protection. We can find solutions in nature itself – such as in urban wetlands. But, at this point, there is very little knowledge about the number of existing constructed wetlands worldwide and their contribution to wastewater treatment.

Based on a recently concluded survey by UNU-FLORES among water professionals, there is a clear demand for a global platform on constructed wetlands. A majority of the 173 respondents was convinced about the usefulness of such an initiative for scientists, practitioners, and other stakeholders.

What are wetlands? Wetlands are distinct ecosystems in themselves and are considered as one of the most biologically diverse. They provide multiple benefits such as flood control, water purification, or wastewater treatment, and can promote water uses like urban gardening and thereby enhance human well-being. Particularly urban wetlands (natural or constructed) not only make the environment aesthetically more enjoyable but also make urban areas liveable by providing many benefits and making cities develop into more sustainable areas. Image: The Ramsar Convention Secretariat To achieve the targets set out in the 2030 Agenda for Sustainable Development, there is an increased need for nature-based solutions like constructed wetlands for wastewater treatment and reuse. Constructed wetlands are viable options for peri-urban as well as rural areas, because of the higher land requirement and their ability to function as decentralised systems. On 2 February every year, the international community celebrates World Wetlands Day. This day marks the date of the adoption of the Convention on Wetlands on 2 February 1971, in the Iranian city of Ramsar on the shores of the Caspian Sea. The theme for World Wetlands Day 2018 is ‘Wetlands for a Sustainable Urban Future’.

The survey is an initial step towards bringing together the existing bits of knowledge on constructed wetlands. Researchers at UNU-FLORES have been working on creating a central online platform about constructed wetlands worldwide entailing a global database, called the “Constructed Wetlands Knowledge Platform”.

Data from the platform are envisioned to also be visualised in maps (web-based geographic information system, webGIS).

Overall, we aim to assess the amount of wastewater that is treated globally by constructed wetlands and in so doing support stakeholders such as scientists, representatives of UN organisations, implementers, funding bodies, further experts, and members of civil society in their efforts in constructed wetlands-related research, policymaking, financing, implementation, and operation and maintenance.

The survey gathered input on requirements of potential users of the platform, confirming the need for a global database on constructed wetlands. Participants from more than 60 countries completed the global questionnaire. Potential users indicated that the platform functions should include upload and download of data as well as generation of statistical information, download of maps, and queries.

Ultimately, information and data about all constructed wetlands existing worldwide will be stored on the Constructed Wetlands Knowledge Platform.

Data from scientific journals are currently being added by the project team at UNU-FLORES, but given that there are tens of thousands of articles out there and a lot more non-scientific documents, support from the global constructed wetlands community will be useful in establishing the platform. Input from a larger number of people via the internet (crowdsourcing), e.g., from scientists, practitioners, engineers who have designed constructed wetlands, other members of civil society (e.g., students), and so forth is highly desired.

Through such concerted efforts, the robustness of data on constructed wetlands will be increased manifold, which in turn will support constructed wetlands research, implementation, and operation, e.g., through refining design parameters based on a larger database. This might eventually help us derive an estimate on the number of existing systems and their contribution to wastewater treatment overall and in the long run could potentially serve as a tool for monitoring the achievement of the Sustainable Development Goals (SDGs).

UNU-FLORES aims to launch the platform in the second half of 2018. Stay tuned for further developments.