How did you choose what you want to specialize in for civil engineering?

As a civil engineer you typically take and want to take a one of everything course wise and then specialize in one additional course or in graduate school. You would take one of everything to experience all different aspects in civil engineering such as soils, concrete design, hydraulics, steel design, water resources, materials, water treatment, wastewater. As you take each course as a good general civil engineer you have a good basis to work in a consulting firm, but in one area the light bulb may go off and you will want to specialize, this is particularly important for soils in foundation analysis and structural. In fact many states require a special professional engineering license for structural.
To answer the question, I did not know until my senior year when I took my first wastewater course and then went on to grad school to lean in greater detail, and then spent 30 years as a environmental engineer.
look at each field no rush to decide
good luck

Jorge:

As you can see from the first response, there are a lot of specialties in the Field of Civil Engineering. Taking classes in some of them is a good way to get a feel if you like the work in a particular specialty. Another good approach is to work as a summer intern at a town public works department or for an engineering consulting firm. This allows you to get specific exposure to various types of work. As for me, I always had a particular affinity for the Environment, particularly water. So I pursued a masters degree in Water Resources. I then enjoyed a 40-year career in that Field and the demand is as high, or higher now, than it ever has been.

Good Luck, Peter Sturtevant PE

I recommend that you seriously consider what type of work that you wish to do (or will be able to find what to do) My University did not allow me to specialize in any particular field until the Master's level. As a result I was general in all fields and master of none. In my second engineering job I was assigned to design a railroad. It was no more complicated that a road. However, the engineer across the aisle was assigned to design the road. He had no idea how since he specialized in wood structures in his junior year. In addition to my general engineering curriculum, I ventured into the Electrical, Mining ad Mechanical Colleges. Not very far, but just enough to get a general understanding of the subjects. All of this paid off in tremendous rewards during my career. So my recommendation is to study all fields until you know which one you will want to pursue. I went on to Public Works where I designed or had designed streets, sewer and water systems, street lights. traffic signals, parks, public buildings and everything else located in a city. I hired consultants and was able to hold my own in their specialized fields because of my general and additional training. I do not regret any of the effort. I had fun!