Flooding is one of the most significant natural hazards, imposing widespread social, economic, and environmental consequences on local communities, particularly in vulnerable regions. In this context, community participation plays a crucial role in enhancing the effectiveness of flood management and mitigating its adverse impacts. The primary objective of this study is to identify the factors influencing local community participation in flood management in Aq Qala and Gomishan counties. Methodologically, this research adopts a quantitative, survey-based approach. The statistical population comprised all urban and rural residents of Aq Qala and Gomishan counties in 2022. Using Cochran’s formula, a sample of 384 respondents was selected through a multistage cluster sampling method. Data were collected using a researcher-developed questionnaire. The validity of the instrument was confirmed through content validity (face validity), and its reliability was verified using Cronbach’s alpha coefficient (α = 0.792), indicating acceptable internal consistency. Data analysis was conducted to examine the effects of key independent variables, including social trust, social participation, social communication, awareness, economic factors, institutional factors, and perceived risk severity, on participatory flood management. The findings reveal that among the examined variables, institutional factors exert the strongest influence on improving participatory management performance, with a beta coefficient of 1.499. Following institutional factors, social trust and interaction demonstrated a significant positive effect on participatory management, with a beta coefficient of 0.731. These results underscore the critical role of effective institutions and trust-based social relationships in fostering community engagement in flood management initiatives. Moreover, the study confirms that the integrated theoretical framework employed provides a robust and suitable model for identifying and explaining the determinants of participatory management in local communities. The constructs of this framework were able to explain the social phenomenon under investigation to a considerable extent. Based on the findings, strengthening the institutional capacity of local councils, village administrations, and disaster management organizations, enhancing transparency and accountability, promoting two-way communication with local communities, and increasing public awareness through targeted and context-specific flood risk education are recommended to encourage informed and effective community participation in flood management.