Thanks for the replies, guys. I will keep up with my work to at least cut the willows down with a lopper or pull what I can out, so that I can keep them whacked down with a gas weed whacker every so often this summer and in the future. If anybody knows of a safe chemical to kill these things, please reply.
Besides bullrushes, are there some other plants I should keep along the shoreline, or just keep it all cleared out to prevent leaves from going in to add to the yearly decay?