In Indonesia, river pollution due to inorganic solid waste has become an enormous issue. This article explores the (re)production of relations between communities, river and inorganic solid waste in the Surabaya River Basin. It does so by analysing activities based on interviews, observations and measurements. It tries to explain the current situation in the Surabaya River Basin and shows how ’river water’ and ’waste’ shape ontologies. Furthermore, how these two nonhuman actors act differently (or the same) in different ontologies. The definition used in this study for an ontology is "a construction of how concepts of reality are constructed". Several analyses are used. Firstly, statistics are used to support narratives where deemed necessary. In addition, QGIS is used to visualise data. Lastly, a flow diagram is made to show the flow of waste into the Surabaya River. Existence of multiple ontologies in the Surabaya River Basin is described. It is found that both reproduction of actions is present (on the short term) as well as production of different actions, which becomes more visible in the long term. For example, waste burning every afternoon is a reoccurring action. However, the reduction of single-use plastics is an evolved state. The riverbank is an important location in the relations and could serve as a suitable location for such actions. Lack of information, communication and facilities are identified to be the most important issues. In general, people are optimistic and motivated concerning the environment. However there are some people not engaged. This causes a divide and together with social control leads to tensions in the community. Recommendations include, among others, setting up an information sharing platform between institutions and community members and making use of the cultural resources to work towards a common goal. Including the multiple ontologies in decision-making processes could lead to inclusive and sustainable river management and waste management.