I have an acre pond on my farm which was once a tobacco farm. Ponds were created so during drought years the tobacco could be watered.
The pond is man made and fed by rain run-off from about 1/2 the farm acreage. It has a an overflow drain pipe as well as dip in the earthen dam should the drainpipe get overwhelmed - which it has a few times. The overflow feeds into the marsh that runs down the right side of my property.
In the picture below, which is over tens years old, you can see the pond on the left side, maybe an acre/acre and a half in size. As you can see the fields are wet from a recent rain.
The good:
Wildlife magnet. I'll sit in the breezeway at the stable, settle in before dusk and quietly watch the parade.
Low maintenance, especially if it is already aerated and designed properly. I would have whoever does pond inspections in the area come take a look. Figure a few hundred a year in maintenance, etc., if you don't have plant life issues. Your local ag agent will know the details in your area.
If it is deep enough, you can stock it, especially since you already have the aerator.
Nice to look at.
The bad:
Wildlife magnet.
As other have mentioned, make sure you understand the legal and environmental liabilities in your area.
Ice. When the pond freezes over once a year or so, we had to watch the dogs constantly so they don't venture our on the ice and fall through. I keep an long, extendable ladder and rope, as well as one of my old kayaks, at the stable just in case. Since we board horses, we also made the owners sign a waiver if they have kids...ice or not.
Other than that, you do have to deal with bank erosion, at least I do. I also keep the grass trimmed around the pond, which is a pain but worth it.
