My friend Chris whipped this together and has a full 6' water feature already for one table. We talked about making a muddy one for the jungle and a winter themed one also!
It is simple and cheap....purchase some caulk from your DIY store....crimp the end flat to help the flow come out thicker and spread out. Make the base, put it down on wax paper or other surface it will not stick to. As it dries, use another color to build the banks on the side. Add other bits like rocks and such. Once it dries, paint it up and add flock! Easy!