At work I drink 2-3 cups of coffee in the morning, then from around midday I drink about a litre of water (sometimes more). As soon as I hit the water I'm in the bathroom constantly. From 12-5pm I visit the loo around 4 or 5 times. I also drink water in the evenings and depending on how much water I drink depends on how frequently I use the loo.
If you are drinking 3 litres (I only manage 1.5 - 2 litres per day!) then you will urinate more than the average person.