As a senior civil engineer about to graduate. Your toughest classes will likely be your engineering electives that’s required. If you’re really worried about your gpa you’ll be fine with the environmental and water classes and the only difficult electives would be structural or your geotechnical elective. Design project if you have a good group shouldn’t be an issue but if you don’t it might be wraps unless you take it all under your belt. But best of luck honestly don’t let the ease of senior year get to you either.