It's very important to properly hydrate yourself at all times. Drinking water is vital to keeping your body healthy.
Yes coffee and soda do count, but they also have ingredients that are not good for you and do not flush out your body like water does.
It's also very common to wean yourself off soda with water. Soda is a hard habit to break believe me I know first hand how hard.
Drinking water also combats water weight. It sounds silly, but your body won't retain and hold excess water if you are properly hydrated.
So drink your eight glasses today!!