As to snow accumalation discussion David G and Alan are both right - if it was left as is then yes it would not hold, but with strategically placed snow fences, tree regeneration and piste management then I think you could get some lasting runs down to to Glenmore.
I guess we need some clarity as to what Snow Making is envisaged - is it strategically placed making to cover areas such as the zig zags or full mountain cover for the lean years. I guess it it ever happened it would sart off with the former and progress to the later.
I may regret asking this but does anyone know what volume of water would be required to feed say 10 state of the art snow canons 12 hours a night? and what the electric bill
The points that you raise with respect to Coire Cas have already been discussed, at length, with the the CML management.
The critically important factor that most influences demand is to have the run to the Daylodge available. The first phase of any snowmaking installation should therefore be to ensure that the Zig Zags/Sheiling and Burnside runs are 'covered' We measured these areas so that CML would know how much snow would need to be made to cover these runs to any given depth. The volume of water necessary together with the power requirements could then be relatively easily calculated.
It's known from the snow cannon trials that there isn't sufficent water so tanks will be needed.
It was suggested to CML that small scale Hydro might provide the solution to power costs. This was investigated but the viability hasn't been made public.
The necessity of having a run to the Daylodge available has clearly been bought into by CML management and top marks to them for the efforts made last season to 'farm' snow for this purpose and for the plans to reconstruct the bridge across to the Carpark Tow, so that snow can be 'farmed' from the carpark.