It really is subjective, but to me 90-100oz is not 'lots' -its just under 3 litres. 2 litres is recommended; so add to that your green tea consumption and your exercise it's possible that while you're not 'dehydrated' you're not 'as hydrated as you used to be'.

If you increase your water and you notice a change in colour then you've got a pretty good indication as to the lay of the land.

Nat