Water availability?

Hi everyone! We are getting very excited and realizing that we have lots of questions! What's the water situation? We know that you should make sure the factory seal is still in place on the waters and have the wait staff open the bottle in front of you, but is water readily available? Can you buy it or do they have it for you when you are out on safari? We have a small water filter that we are thinking of bringing but wondering if that is overkill?
Thanks for all the advice, these forums are a great help to us!