I have never seen a weatherhead on a utility companies pole for a riser. The conduit will be filled with water most of the time, regardless.
In fact here in NYC Con Edison has given up trying to seal underground conduit. I see them regularly installing 4" steel conduit with no threads on either end. They fit loosely together with non threaded sleeve type couplings they are only held in place by the dirt around them. They are designed so that the water flows through.
