Population growth has and will continue to put pressure on our water resources. Yet students are only exposed to rudimentary basics that lend themselves to engaging in indoor experimentation (e.g. water phase changes and the water cycle) and fact-based assessments. Consequently, the majority of citizens hold on to inaccurate conceptions of where water exists, how it moves, how it gets used, and how it relates to biodiversity and climate change. These more critical concepts, unfortunately, do not appear in state content standards or assessments. The research goal of the water strand of this project is to develop effective teaching strategies and assessments that are culturally engaging to serve as a model for what could be adopted at state and national levels. To achieve this goal, we are currently: 1) Defining a framework of critical water concepts that interweave with our other two strands of Biodiversity and Carbon; 2) Developing a learning progression that accounts for how students learn and see the world and then supports them in developing the new, sophisticated and scientific views of the world that will help them understand the complicated water issues that we face; and 3) Incorporating the complexities of engaging culturally diverse students, fostering scientific inquiry in challenging teaching environments, and taking advantage of local place-based resources. The results of this research will feed back formatively into the teacher professional development being conducted at the partnering LTER sites. These products will provide the foundation for further work in the years 2010-13, including calibration and validation studies that establish the reliability and validity of the framework and assessments, materials for teaching K-12 students and for teachers’ professional development, and research on teaching, professional development, and student learning. The assessments will also provide data for program evaluation.