I have been coming up here since 1996 and became full time six years ago. Last summer is the thickest the weeds have ever been around my dock. I think it is due to the water clarity more than the run off. The water has gotten a lot clearer than it was years ago.
It might also have had something to do with the light ice cover from last winter, the early ice out, and the warm temperatures. I'm not an expert, but that seems like the perfect combination for weed growth.