Farmers have the most significant and effective influence on how irrigation and drainage schemes are implemented and operated. Every decision made by farmers is reflected in their behavior, which is influenced by structural (predictive) and mediating variables. Therefore, the main goal of this study was to investigate the structures that affect farmers' intention to participate in irrigation and drainage projects among the Miyanab section of Shushtar County using the developed theory of planned behavior. The statistical population included all water users in the Miyanab section of Shushtar County (N=1400) in 2023. Based on the Krejci and Morgan table, the sample size of 301 users was selected through completely random sampling. The data collection tool was a questionnaire, the validity of which was determined based on the opinions of the faculty members of Khuzestan University of Agricultural Sciences and Natural Resources, and its reliability was determined through Sequential theta. The correlation coefficient was used to examine the relationship between variables, and the structural equation model was used to analyze the structures affecting farmers' intention to participate in irrigation and drainage projects. The results of structural equations showed that the variables of attitude and perceived behavioral control predict 88% of the changes in the variable of behavioral intention of farmers towards participation in irrigation and drainage projects. Also, based on the results obtained from the developed theory of planned behavior, the variables of attitude, perceived behavioral control, motivation, and perceived knowledge can predict 91% of the changes in the behavioral intention variable. According to the research results, it is necessary for official institutions, and specifically the Agricultural Jihad Organization, to present the positive results and outcomes of some small and successful projects to beneficiaries in order to build their trust and motivation to participate in the planning, implementation and operation process.