"Faamin' fish ain't haad" said the crusty mainer, " It's gettin yer wife ta clean em that's haad.."
While Farming fish isn't hard, getting enough of a pond to grow them in year round can be troublesome. A plan is in the works to build a pond on the property, but in the meantime we have been blessed with neighbors that allow us access to their couple acre pond to harvest bluegill and catch and release crappy and some of the biggest bass I've ever seen...
Ponds are nice in that you have slightly more control over whats in your water than a river or lake. Changes can be made in the ponds surrounding ecology to help deal with some runoff issues. Placement of plants that help filter the incoming water as well as provide habitat to birds and insects are examples of positive changes you can facilitate.
Another positive of having a pond on your property is the holding of water. A natural bottom pond will hold water while slowly releasing moisture to the surrounding soil and air. For more information on the building of earthworks on your property look into Geof Lawton's books on permaculture, he is the god of water conservation through earthworks.