I homeschool (unschool) my son, and the Magic School Bus series is GREAT for teaching kids science. We now have all the DVD sets and a few VHS's.
If you're unfamiliar with the premise, the central characters are Ms. Frizzle (a teacher), her class, Liz the lizard and the Bus. Ms. Frizzle takes her class on crazy field trips, where Bus--and sometimes the kids!--experience a transformation so they can get closer to the action. (For example, become a bee or turning into water droplets.)
I recently purchased The Magic School Bus: Catches a Wave for my son to complete our collection. As usual, it's excellent!
This particular DVD has a run time of 80 minutes and features these three episodes:
Wet All Over - The Friz takes her class on a rainy ride through the life cycle of a water drop.
Rocks and Rolls - Friz and the kids go on a rough-n-tumble journey as they see a boulder subject to water erosion.
Ups and Downs - This bubbly trip takes place at the bottom of Walkerville lake!
There's not much in the way of bonus material, as usual (only What Comes Next?: How Fast Can YOu Unravel These Water Mysteries). The languages available are English, Spanish and French.
Highly recommend edutainment for children, especially if you want to introduce or reinforce science concepts!