Ann: Torrens Drilling Recommences, page-88

I am not @Scarpa but to answer your first question zero. Even if the entire lake is one artisan waterbody the mining will come in underneath it. On top of this the major issue in the area is a lack of water (look at Olympic Dam), to have too much water is a problem any miner in the area will be very happy to have.

In regards the second they obviously didn't think they would hit water. After the first water hit they plan around it and then hit sand on the third hole. Now they plan for both sand and water.

Casing is the answer for the final question. None of this is unusual and those in the gas and oil industry deal with water on a daily basis. The only complication is how to deal with it in an environmentally sensitive location.

My only complaint from all of this is all of this could have been much better explained by AIS.