Usually if you are building a pond where there is no perminent water flow there are no questions asked.
The main thing we have to do is keep the highest part of the dam under 15' anything over has to be approved by the state. you can did the pond 40' deep but the dam can't be over 15 ' tall.
We've only been shut down once in many years. Had a helicopter taking some very nice arial photos of the jobsite and the wetlands that we were in. the next day the nice white state truck came out a gave use a little pink sheet that said stop work!! Homeowner gave someone a nice check a we were back to work in a week