Fostering environmental flows (e-flows) stewardship is challenging as rivers and their catchments are complex social-ecological systems comprised of diverse communities, ecologies, knowledge types, and stakeholders. Navigating this complexity requires meaningful participatory approaches that centre on value-driven collaborative strategies. Despite understanding the importance of stakeholder engagement, water managers often face significant barriers to implementing engagement strategies and lack the tools to assess the effectiveness of engagement programs. We undertook an e-flows assessment for the Kaiela (Lower Goulburn) River in Victoria, Australia, which incorporated aspects of structured decision making and participatory modeling with technical approaches. We used a novel evaluation method to assess the effectiveness of the participatory process. Three process objectives (transparency, knowledge exchange, and community ownership) were identified by the stakeholder group during an initial workshop. We conducted a thematic analysis on semi-structured interviews obtained before and after the engagement process. We then evaluated the success of the participatory process based on how well these objectives were achieved according to the participants. We identified that community members and water managers have different motivations for engaging with participatory processes, with community members valuing the opportunity to meaningfully influence project outcomes. In the project exit interviews, we found that 80% of respondents expressed positive sentiments regarding the process objectives and 90% had an overall positive experience. This indicates that stakeholder engagement can be effective even in resource-constrained projects, especially when the participatory approaches center on shared values and are appropriate to the decision-making context.