I have Stage 3 Kidney Disease, so I always feel guilty about not drinking as much water as they tell me to drink. This Mayo Clinic article says 11.5 cups (2.7 liters) for women per day, and 15.5 cups (3.7 liters) for men. I think I'd be happy if I could drink half that.
But I know I should be doing better, so I keep trying to think of ways to increase my intake. I've heard that all hydration is hydration, so I count the liquid I drink with bicarbonate and pills in the morning, my morning cup of coffee, and my usual beer or whisky that's three cups. And drinking another three cups of ice water is reasonable. That's six cups, but it's a far cry from the 15.5 cups I'm supposed to be drinking.
But I'm working on it. My doctor says, "Yeah, you have stage three kidney disease, but you're doing pretty well." I love my kidney doc.