configurations

Hey people, justa small question, making a map and its got all waterfall, with small rocks poking out, how would i go about simulating a splash of some sort, i'm familiar with quake editing and stuff, so be as technical as you need to thx. The waterfalls shown here

I'm new to mapping but i already made a few maps but just for half-life. I wanted to create them for ESF but I have got no idea on how to configure Worldcraft or Hammer. Could someone help me on how to configure Valve (and I'd prefer some screenies of your configuration plz!!) Thnx for your...