From what I have seen in areas north of there it is most likely flooded( or at least part of it).As for directions,take highway 75 south out of Nebraska City and turn left at the sign for the OPPD power plant. Follow that road to the south side of the plant and you are there.The road on the south side runs straight into the north entrance and if you take it about a little further to the south you will come to a "t" turn left there and you will be at the south entrance.