ediosyam, I didn't watch the whole video, so I don't know what expression he used... the bump map doesn't need to be 3d texture, it could be whatever the water texture you will use. as for the bump value, you have to try it youself, it's not that differicult, right?
"how to do dynamics?"
are you asking how he did the softbody? just pick the surface and select create softbody..., then apply some force to it, that's it...... if you're asking for particle dynamics, Maya help has just the information you needed. Search "flow" in maya help. there're two kinds of flow, curve flow and surface flow. Here is a link to curve flow in case you can't find it.
http://caad.arch.ethz.ch/info/maya/manu ... 2.fm2.html