Those Upstream Flood Control Lakes were built in the 70s to prevent flood damage and keep roads and bridges from washing out. To my kinowledge, almost all the eastern and mid-west states have them.
Here in Oklahoma, if you have a new or reclaimed pond, you can get fingerlung fish to stock your pond free from our department of wildlife. The only requirements are that there are no fish present (as certified by the law enforcement division) and you have a current fishing permit. You don't have to allow public access. A portion of our state's Sportfish Restoration Funds are used to raise the fish, so technically i guess they are not free, but pre-paid for when we purchase fishing equipment and such.