When you called it a creek, I assumed you meant flowing water. It is probably a lot less restrictive to put a dam on a gully but it isn't going to make much of a fishing lake. Maybe a catfish pond. May turn into a mudhole in dry weather.
Jerry
Judging from what's happened with neighbors, these impoundments usually fill up in a year or so with run-off. It's taking the water from around 35 acres-- give-or-take. We'd be able to stock it after it one winter's precip filling it. Max depth as my neighbor planned it is 40+ feet at the dam. I think he's not being realistic-- the state might let 20-30 feet go. We'll adjust to fit reality.
Here's a lake we see on the way into Falmouth that's smaller, but has some of the same feel.
You can see from the aerial view the dam itself is pretty deep.