We have something here for whatever science you teach!
All links are organized by category.
Watersheds - http://hawp.org/what-is-a-watershed/
Ralph S. Hosmer, First Terrestrial Forester, Hawaii once said, "In Hawai'i, the most valuable product of the forest is water, not wood."
The Hawaii Association of Watershed Partnerships website includes information on what a watershed is, why watersheds matter, a gallery of images, and linkages between forested watersheds and Native Hawaiian cultural resources.
Hosmer's quote is one of those that makes you think.