As climate-driven extreme weather events continue to intensify, risk mitigation and governance are a critical aspect of urban climate change adaptation. Interdisciplinary knowledge integration is critical in order to account for varied perspectives related to the impacts of extreme weather events on urban systems. Despite advances made to integrate different strands of knowledge through systems-based approaches, few methods exist to contextualize and analyze the diversity of the knowledge being integrated. Assessing knowledge diversity exposes varying ways in which stakeholders identify and problematize the impacts of extreme weather events, uncovering knowledge gaps as well as dominant knowledge framings that might bias and/or hinder risk governance processes. This study presents a novel methodology that integrates a mental models approach with the social-ecological-technological systems (SETS) framework to assess and compare the perceptions of individual stakeholders on the impacts of extreme weather events on an urban system. By classifying system components and interactions into social, ecological, and technological domains, mental models enable the visualization of knowledge diversity, as well as the identification of potential gaps and silos in stakeholder understanding. The methodology is applied to New York City, engaging 20 expert stakeholders from diverse disciplines and sectors involved in mitigating the impacts of extreme precipitation. Findings reveal significant variability in how stakeholders emphasize SETS domains and interactions. By supporting more holistic and inclusive co-production processes, this approach provides a theoretical and empirical foundation for addressing the multifaceted challenges posed by climate change in urban environments.