I'm no pro at this, but I can try to help.
I hope I don't give out bad advice.
In general, when entering grad school, you'll want to specialize in something. So start thinking what you want to focus in civil engineering and why you want to focus in that area. Apparently, I hear that admission officers love students who do research, especially if you're aiming for a phd. So you might want to look a bit into that and ask your professors about it so you can look really good. Speaking of professors, get to know them well. If you let them know more about you, the more good things they can write about you when you need them for Letter of Recommendations.
I'm not a civil engineer major, so I don't know which grad programs are good. But you can try looking into this? Though, you probably have seen it already maybe. Best Civil Engineering Programs | Top Engineering Schools | US News Best Graduate Schools
Er, I hope this helps a bit.