I believe Tordon is restricted from use below the high-water mark. A wipe with an aquatic-approved glyphosate formulation with the "glove of death" works very well. You can Google "glove of death". Be sure to use a rubber glove that is impenetrable by pesticides and herbicides.
I am pretty sure that the usage instructions for the "glove of death" mandate that you wear a hooded black robe and carry a scythe when treating weeds in that manner!
