Bluelightning

I'm currently working on my first tf2 map. As such I'm kinda uninformed about using hammer, but for the most part I've gotten by through the developer wiki. However currently I'm stuck attempting to create my own water texture, which looks like lava, and attempting to add a waterfall and flowing water. I can't really find any good tutorials on this, and never got a reply on the steam forums, so I figured I'd ask here. Anyway this is a picture of the main room in my map so far:



And here's a bit of a visual helper on what I want to do:



There are two hallways like that, one in which will have lava the other water.
I understand I may be asking for a lot...but if anyone can help it would be appreciated.