More progress I had a go at making the mountain waterfall tonight using an Idea I picked up from a model railway website. Basically it involved using clear silicone sealant to make a water effect on a clear plastic backing sheet.
On the plus side I think it's come up quite well for a first try. On the down side it was really messy the £$"$%*^ sealant got every where and wasn't nearly as easy to work with as the model railway tutorial made out.
One other slightly problem was I couldn't connect the bottom of the waterfall to the bottom pond as I wouldn't then be able to to remove the top to allow access to the cave behind the waterfall. Which means there is a slight gap at the bottom and the waterfall doesn't look quite as good as it could have done.
Right next up more shacks to dot the mountain side.