site costs and timelines, page-3

Hydro depends heavily upon the difference in height between where the water was before it ran through the turbine, and where it ends up after it runs through. The smaller the height differential, the less energy you can generate. (Also the lower the water flow.) Or, in other words: how much energy does the running water have? You can only extract energy through hydro if there's energy to be extracted. Placid water flow - say, the Melbourne Yarra near Port Philip Bay - is useless for this purpose, even though there's plenty of water "running" through the city.

So having "plentiful water" means nothing if the energy of the running water is low. We'd need to know more about the topology of the site, and where the water runs. Also, you would need to build a dam somewhere to hold the water back, so it can be put through at a controlled rate when the power is required. This is likely to be impossible - I have a feeling that there's no suitable site within (or near) Ngualla. Bear in mind that I have no hard data to back up that feeling.

There may be some value to Peak in paying for mains power to be put through to the site - I don't know how much that would cost, nor how reliable the mains would be, but in the long run it's almost certainly going to be cheaper that way (and it's not unreasonable for Peak to ask the government to sure up the electricity supply - after all, if this ends up being as big as it looks like it will be, it'll bring in a significant amount of export revenue, and hence it's in the government's interest to keep it running smoothly.) It's certainly feasible to set things up so you have a constantly spinning turbine driven by mains, generating electricity to site; such an arrangement would ensure that if the mains power is cut for some reason, cutover to diesel power with minimal interruption is easily arranged.

All of this stuff would be part of a feasibility study - which is one of the things that comes after the JORC, assuming that the JORC shows an economically viable resource.