It would help if you can put some of the weeds in a white container with water, the pictures aren't clear enough to get a good id. If I were to guess I would guess variable leaf watermilfoil or Eurasian watermilfoil.

https://aquaplant.tamu.edu/plant-identification/alphabetical-index/variable-leaf-watermilfoil/

https://aquaplant.tamu.edu/plant-identification/alphabetical-index/eurasian-watermilfoil/