A good site on lakes and streams, from Scout Report, on which some of you may sail.
http://waterontheweb.org/curricula/index.html
Water is the essential element of life, and efforts to understand it and its use (and abuse) can form part of an essential learning experience in the natural sciences classroom. Created by the University of Minnesota (in tandem with a wide range of other organizations), the Water on the Web curricula website offers instructional materials in two areas: basic science and water science. In the basic science area, visitors will learn through study lessons that detail such important topics as solubility, conductivity, and the basic properties of water. The water science section of the site contains materials that could be used by instructors who are teaching students about data collection and management in a water resource management course.
>From The Scout Report, Copyright Internet Scout Project 1994-2006. http://scout.wisc.edu/