The WaterCircle (WC) project was implemented in a school, with young adolescents, to address environmental problems. Framed in a participatory research (PR) approach, this school-and-community based intervention includes the use of online tools through which environmental problems in the community are discussed within and by a group of students. Using a quasi-experimental design, with intervention and control groups, the present study involved 361 young adolescents, in grades 7 to 9, from a public school in the northern region of Portugal. Mixed methods were used for data collection and analysis, namely based on questionnaires administered in the pre- and post-test moments, as well as on students' discourses produced in the classroom during planned activities. Statistically significant changes on self-efficacy were found for the experimental group, suggesting that the intervention program has the potential to raise young people's empowerment regarding environmental issues. The WC program seems to foster students' awareness of the socio-political dimensions of environmental problems, since they were able to identify different actors in the community who should be involved in the proposed solutions. Longer-term intervention is required to foster the impact of the PR on the students' experience.