The performance assessment of embankment dams in respect to main deterioration mechanisms is a major challenge for managers in charge of their security. One model developed knowledge-based models for assessing the performance of embankment dams. They have three hierarchical levels: performance of the analysed component (embankment, foundations), performance of the functions and status indicators. However, while these dams are frequently located upstream elements at risk, small dams are rarely equipped with drains and monitoring instruments, and woody vegetation is often present. These features were partially or not dealt with in the previous models. To cope with them, we propose to firstly, identify the specific status indicators linked with woody vegetation and secondly, adapt and complete the existing models. A modular approach is notably proposed in order to evaluate different types of dam. The approach was applied to a group of seven French and Italian dams and showed its relevance.