Lake Kilby is the oldest of the Portsmouth water supply lakes. It is a colonial era millpond. The upper half of this 222-acre is a dense and very scenic cypress swamp. The water is dark-tannin stained and slightly acidic. Under these conditions, fishes such as flier, warmouth, chain pickerel, and black crappie flourish. Other sport fishes in Kilby include bluegill, redear (stocked by VDGIF in 1970s), and largemouth bass. Population sampling has shown that these fisheries are well balanced and perhaps most notable for the large "bream." The bluegills are very dark in color (in response to the dark stained water) and are known locally as "black bream." Pickerel fishing is best during the winter months; for the other sport fishes, it's spring and fall.