Choosing a Civil Engineering sub-discipline

Hi all,
I’m graduating college soon with a BS in Civil Engineering. At my particular school, we are asked to choose 2 of the 6 primary sub disciplines of CE; mine being water resources and construction management. I have 3 summers of prior experience working with an esteemed general contractor, and have been offered a full time position upon graduation. However, due to my equal interest in water resources, I’m afraid of missing an opportunity to work in that field.
Are there any practicing engineers who have faced similar issues? I would appreciate any professional advice aimed at helping me decide which field of study I should pursue.