Slow Water Quality Depletion

So I notice that the water quality goes down extremely fast for large bodies of water. Two or three large dinos can bring the water quality down to zero in a matter of seconds which does not encourage herding since everyone is usually on the brink of starvation or thirst. Larger bodies of water should not deplete the quality of the water so quickly since it would take MANY dinosaurs to do that. I might understand if the game is encouraging you to group up and move around for water but some dinos are just too slow and would likely die of thirst getting to the body of water before the others.