Providing individuals with environmental awareness from a young age is very important for a livable and sustainable world. In this context, this study aims to investigate the impacts of the environmental science project, the Water Explorer Program, on middle school students' water usage behaviors, and attitudes. A quasi-experimental research design was used. The participants were 87 (36 girls and 51 boys) eighth-grade students from four different classes in a public school. Whereas the textbook-based instructional approach was used in the control group, the Water Explorer Program was used in the experimental group. Water usage attitudes and water usage behavior scales were administered to the groups at the beginning and end of the study. In addition to pre-post tests, reflection papers were gathered from students in the experimental group. The findings of the study revealed that students in the experimental group developed significantly better water usage behaviors, and attitudes than their counterparts in the control group. Therefore, environmental projects should be involved in science curricula.