Re: "I'm from the Government and I'm here to help you.'
Rules are generally created for a reason, and this appears to be one of them. Preventing flooding caused by man made structures is a very sensible application of government regulation.
I'd bet folks with houses downhill from this proposed pond would agree with me on that.
Side note- I used to own a house downhill from a city park pond, so I'm quite familiar with being concerned that all prudent measures were followed when its pouring and that pond is overflowing.