Some times a pond or area will be real popular with waterfowl in spring and summer, and then when fall rolls around, they quit using it......why? only the ducks know, and they ain't talkin'.
If it were me, I'd keep an eye on it off and on throughout the summer and just before season.....keep an eye on the areas that the birds are seen most frequently, but remember that birds will land into the wind, so that may change your plans come opening day.
Small ponds can offer some great hunting, but they can also be burned off pretty quickly.....I once found a pond no bigger than my living room that was holding about 100 wood ducks. After we flushed them, I hunted it one more time before the close of season.....it only had one duck on it then, and it hasn't produced a duck since.

Lots of sticks & trees in the water? BE CAREFUL!....esp. if you are hunting with a dog...those sticks can impale a dog jumping out for a retrieve. They can also tear up a good pair of waders.
Good luck to you this fall...........