My sediment pond is about 1/10th acre and my forage pond is about half that size.
You can do a lot in a tenth acre. One thing that can really affect a small BOW is the amount of runoff that passes through it. If you have a huge runoff area, like my sediment pond has, the large water exchanges can stress the fish. The other thing is if you really push a small pond, make it really productive, aeration is really beneficial. You can push your feed levels more.
With feeding and aeration I raised a bunch of CNBG to transfer to my main pond.
I may have already posted this on another thread so forgive me if I am repeating, but here is a thread with lots of links to specialty ponds which include small ponds.
Thread on specialty ponds
