I have what i think is Variable-leaf watermilfoil according to the description on TAMU. My big problem now for treatment is that they're in my creek. So there is constantly a little water leaving and I think it would be hard to maintain the amount of chemicals necessary to kill it. There are parts of the creek further upstream adjacent to my property that are completely covered in it. Luckily i only have about 25' in length of it out of my 300' or so wide lot.

Heres some pictures:
https://imgur.com/XVL6slQ
https://imgur.com/LgIKmN6
https://imgur.com/KOUfogV

You can see the small driver-over dam at allows just a little water (less than.5") over it.

What are my options? I was thinking about trying a Lake Bottom Blanket or heavyweight burlap. Blocks out the sun and too tight of a weave for it to sprout through.