Can I get a job in the water field without doing all the water electives offered at my university?

I am a fourth year civil engineering major, with one semester left. I love water. I am worried that if I don't take all the water electives, that I will not be able to find a job in the water field when I finish. For example, do I need to take hydraulic structures analysis and design in order to work in the field of water when I graduate?