Yeah, I had a similar experience early on with my pond idea. Don't get bummed out yet - move on and collect some more opinions.
If you havn't already, get a copy of the USDA Agricultural Handbook 590. Many factors to consider, but it suggests that in SW Virginia you may need about 2 acres of drainage area to sustain each acre-foot of pond.
Also, check out your local Soil & Water Conservation District website and give them a call. Someone there may be able to help you answer the question of what's adequate drainage area in your part of VA.