Water is a vital resource for sustainable development. The aim of this research was to develop and evaluate pre-service science teachers' awareness of sustainable water usage. This research was based on a mixed method. The qualitative part of the research was based on a single group pretest-posttest experimental design, and the qualitative data were collected by open-ended questions. The quantitative data were obtained through the "Water Knowledge Test", "Water Consumption Behavior Scale" and "Water Attitude Scale", which were developed by the researcher. The study group consisted of 3rd year pre-service science teachers who were studying during the 2011-2012 academic year at Eskisehir Osmangazi University. Water education for the study group was provided by the researcher for 5 weeks. Quantitative data were analyzed using a t-test for dependent groups, and qualitative data were examined by descriptive analysis. Following the water awareness education, a significant difference was found in the pre-service science teachers' water knowledge, water consumption behavior and attitudes toward water (p < 0.05). The results of the qualitative data showed that the majority of pre-service science teachers had increased concerns about adequate water supply. Most of them experienced increased awareness and to use water more carefully. In addition, 24 of the 33 pre-service science teachers believed that future generations will experience water related problems in 20 or 30 years. The results showed that water education is effective in developing a level of water knowledge, and influencing pre-service science teachers' water consumption behavior and attitudes toward water.