Go to the title company you are going to use and ask them who currently holds title on the mineral rights. I am guessing it is a 3rd party and that is why the language is in there. If not, you have your answer and can negotiate accordingly.

As for water rights - those are HUGELY important if they are part of the existing property. It should include a certain number of water acres per yer in a given aqueduct for a given period of time - withindrawn through a given number of wells -- all pursuant to the terms and conditions of the office of the state engineers.

I prefer to have the water rights as a separate quit claim deed from the rest of the property.