With the increasing complexity of societal and environmental problems in the Anthropocene, the use of both classification-based approaches, which provide in-depth understanding within disciplinary boundaries, and citation-based approaches, which provide interdisciplinary research, has been encouraged. However, there are limited comparisons of the knowledge networks produced between these two approaches, which compromises our capacity to manage technological development. This paper aims to investigate the similarities and differences of river technology networks produced using classification-based and citation-based approaches. The World Intellectual Property Organization (WIPO) database from 1863 to 2020 was used as the data source. River technology systems contained three interactive subsystems: water demand, water supply, and water management, and the structure was measured using network-based metrics. It was found that river technology systems constructed using the classification-based and the citation-based approaches developed similarly in terms of their temporal, spatial, and compositional features. The structural differences were attributed to the addition of an external system that draws upon interdisciplinary knowledge beyond water resources. Both approaches can be used for guiding technology management, with the classification-based approach being more effective for understanding the content of innovations and the citation-based approach being more effective in gathering information beyond the water resource discipline. Technologies from more diverse disciplines should be encouraged to address increasingly complex water challenges.