Gadgetnut :

Habitat is approved for aquatic use and livstock use and swimming are not restricted , see the label link below pg.3 which so states. Those concerns should be ok. We use our ponds the same way as you and no problems as long as you follow the label. IMHO with that many cattails you will have a hard time with them unless you use a chem. treatment or a backhoe to dig them up. ewest

http://www.willapabay.org/~coastal/nospartina/control_program/HabitatLabel.pdf