We have this huge pecan tree in the back yard, a bit to the left of my goldfish ponds. A few branches were growing pretty badly over the covered area with the ponds, and already lifting some of the roof shingles up. So hubby decides to cut those branches to not further damage the roof of that covered area. Well, sounds easy, right?
Except when the cutting was finished, all the saw dust was down on the ground (gravity, I know
), and my ponds' floors were covered in that stuff. That combined with some runaway smaller tree branches, leaves and pecans - a big, fat MESS!! I stood there all day yesterday pumping out the water from the ponds, sucking up the bottoms as good as I could, cleaning out some of those veggie filters, which are with no cover of course 
and refilling the ponds. That was 2 300 gl ponds, 3 160 gl and the one 40 gl fry pond. Nice, really.... 
Next time - toss a few pieces of plywood sheets or plastic covers over, and have only a fraction of the cleanup later!