I have let this go on too long and need to cut down the trees on my levee. It is mostly willows with some gum, oak and hickory. I had originally wanted to pull all of them out as I cut them but have wondered if just throwing them in the pond would be OK? I really think I would be making a huge mess and all that wood would not be good for the water. Was wondering what everyone's thoughts were about this. All the trees on the back side of the levee are not a problem to deal with. Once the levee is cleared off I will be keeping it that way. The picture shows how thick the trees are on the pond side of the levee all the way around. I have about 300 ft. of levee to deal with. I appreciate any ideas. Thanks.

Here's my 2 cents. I wouldn't toss most trees or cut branches directly into my pond. There's been lots of discussion on the forum about this, but a primary concern is sap and tannins leaking from newly cut trees causing water toxicity (look for forum discussion on 'bucket tests'). Also, some trees (like black willow in particular) can root from cuttings and fallen branches. So you'd probably spread willow saplings to other banks if you toss those in.
Maybe make a pile and let them dry (for 6 months to a year) and then select some for structure piles.

I would chainsaw girdle them this year.
They will be dead standing next year.
They will provide wildlife habitat and will be much easier to handle due to the
Reduced weight.

Good idea. It's much easier to get rid of a dead, dried tree than a live one. Firewood, brush pile, or fall some of the dead trees into the water.

I used mine to build a huge brush pile away from the pond...it now holds several animals

Good Idea, I didn't think of that being easier to deal with as a dry dead tree. I sure a lot of limbs will fall out but that would be no be deal. All the smaller trees I could drag off green with no problem.
Now I guess chainsaw girdle would be cutting about an inch all the way around?

Yes. I usually do a double girdle.