I took a few range management courses in school, I was always surprised by how little attention was given to water supply by alot of people.
Both in terms of damage by livestock to the supply, be it stream, dugout, etc. and the effects it had on the animals as a result. We always watered from dugouts, but would limit access to where cows could only access what they needed to drink. Free access to water usually ends up with animals defecating in it, wrecking any stability in the banks, and therefore making their own supply a possible source of sickness. (Not to mention, in the case of streams, other ecosystems.) I always felt streams should be treated the same way, for obvious reasons. We never had any on our land, but I read of many guys ways of limiting water access and therefore damage. I had an instructor named Jim Stone who did water system setup design using solar power, etc. Smart guy. As for buffalo, definitely a more efficient animal in many ways. General disease tolerance, feed efficiency, calving ease, etc. Can be hard on fences though..