There is a tremendous amount of material available on water from a variety of government agencies and local organizations. A strong statement should be made to support the attendance by every California 5th or 6th grader to a COSA certified residential outdoor science school for a one week program. Outdoor schools have correlated their curriculum to the content standards and the experiential philosophy of these programs helps student retain the concept presented. The week long program is academic and creates life long positive experiences about the natural environment. It is much more impressive to see translation, subduction, etc.
Students can study photosynthesis in the plants found near their school.
Wherever and whenever possible, connect students to their personal surroundings. Same as previous suggestion. Use actual data from the natural environment to teach this concept. Not only should students know the difference between renewable and non-renewable resources, but they should learn how their actions on a daily basis can make a difference to protect and preserve precious resources. Good environmental education programs get students to think, to have an understanding of concepts in science and math, and encourage students to enjoy these content areas.