The health of rivers is crucial to both human and ecological health and wellbeing. In Malaysia, rivers are the source of almost all drinking water—a source that is vulnerable to pollution, as urban residents in Selangor and Kuala Lumpur discovered during multiple water cuts in 2020. Rivers also host a complex ecology, with many forms of life—such as the Tor tambra (Javan mahseer or ikan kelah in Malay)—requiring pristine waters to survive. Water cuts and fish populations are just two of many complex social and ecological phenomena that take place in and around rivers. How might we hope to understand all these interactions and act in effective ways for sustainability?

River health is the product of a social-ecological system. This means that fixing the problems of river pollution requires more than a technical understanding of rivers, their ecosystems, and the infrastructure we build to channel water to rivers. We also need to grapple with the socio-cultural dynamics that shape how we perceive and interact with drains and rivers. Social-ecological systems are self-perpetuating: if left alone the status quo, whether good or bad, tends to persist. This is the result of feedback loops that create and maintain that status quo.

What are these feedback loops and how do they shape our interaction with rivers? The level of crowding at scenic river sites is an illustrative example. The more people visit a river site, the more well-known it becomes as visitors tell others about the site through word-of mouth (or, these days, through photos on social media), and the more people visit the site. This creates a reinforcing feedback loop (see R loop in diagram below) that keeps increasing the number of visitors to the site

However, the number of visitors to a site cannot increase forever—so what might limit this growth? One possible factor is crowding. The more visitors there are, the more crowded the site feels, which would make some visitors less likely to return; if the number of visitors drops, however, the site becomes less crowded and more attractive, bringing visitors back. This cycle is a balancing feedback loop (see B loop in diagram above) that tends to keep the number of visitors at the site at a certain level.

“Langkawi Malaysia Mangrove Tour Jetty” by CE. Licenced by CEphoto, Uwe Aranas under CC BY-SA 3.0.

These two simple feedback loops describe a complex set of interactions between visitors and the river, which influences their experience and understanding of the place. Feedback loops like these also drive ecological processes around rivers and the individual and societal choices that impact river health. For sustainability efforts to have sustained impacts, we need to think beyond one-off events and ask how our interventions fit into or change the feedback loops that shape river health.
A system diagram like the one shown above gives us a generic framework for thinking about river sites. However, each site is a unique system with the interactions (described by the arrows) playing out differently in different places. One river site has more open space and can accommodate more visitors without feeling crowded. Another is in a remote location and so receives fewer visitors than other, less well-known sites. Efforts to change perceptions of and behaviours toward rivers through placemaking must account for the peculiarities of the place and its stakeholders.