As a senior in high school going for a civil engineer degree,
where can i expect to find engineering internships?
To be honest, hs students do not yet have much to offer engineering companies. There are a few that specifically offer opportunities to hs students that I noticed looking thru them for my son but very few. What you might want to do is just find summer work in an engineering/architecture office to be exposed to a civil engineering environment doing anything they need help with.
Your best luck may be networking with anyone your parents know who works in the field and see if they will let you “intern” for no pay just to help.