The discharge of nutrients from human activities such as construction and outdoor cooking have a major impact on water catchments. Eutrophication, or algal blooms resulting from too many nutrients in the water, for example, reduces the amount of oxygen available in downstream reservoirs. A systems level understanding of the origins and transport of nutrients is needed to predict algal bloom and other events that can hurt the aquatic environment or kill fish.

This first-of-its-kind alliance between the National University of Singapore (NUS), the Hydroinformatics Institute (H2i), Singapore’s national water agency PUB, and NGO Earthwatch Institute trains volunteers to monitor waterways for nutrient loads and turbidity, or cloudiness.

More than 50 citizen scientists have been enrolled in the project to date.

Using this citizen-science approach, monthly data has been collected over a period of a year from areas with different land-based activities (residential, commercial, industrial) across multiple catchments across the island. Initial results show that even areas with similar land-based activities have different polluting patterns, and that the way people use the areas around water catchments has a bigger impact on runoff than precipitation in influencing the amount of loading.

This means that modifying human activities could help mitigate nutrient discharge, and that policies to mitigate behaviour need to be relooked.