Al, your thoughts are exactly what I'm looking for.

We always have glyphosate based herbicides (i.e., Round Up) on hand for other purposes. What is the "aquatic" herbcide of choice? I can stock some it as well.

The pond will probably be drawn down at least 15%-20% each year. Not sure we'll hit 30%, but we might.

I am not familiar with Arrowhead, but I will check to see if it grows well in my climate. What other shoreline plants do you like, nothwithstanding their slow growth habits?