I had a cattail issue in the shallow feeder end of our 1AC pond and rented a mini excavator and dug them out in an afternoon. You become pretty brave with the excavator after a half hour or so. Drove it into the water up to the top of the tracks with no problem. If it gets a little slippy, use the bucket to pull yourself out. Haven't seen a cattail in there in close to 10 yrs or more now.