Thanks for your question and sorry for the delay in an answer.
The MI DEQ has a great resource in regards to pond creation and regulation found here:
The portion regarding permits states as below:
Will I need a permit prior to building a pond?
A permit from the DEQ is required (under Part 301, Inland Lakes and Streams, and Part 303, Wetlands Protection, of the Natural Resources and Environmental Protection Act, 1994 PA 451, as amended, prior to construction of a pond if the pond will be:
• Within 500 feet of a lake or stream, or connected to a lake or stream;
• Within a regulated wetland;
• Within the 100-year floodplain of a river or stream;
• Five surface acres or more in size; or
• Created by construction of a dam across a river or stream. Dams with a height of six feet or more and which impound five acres or more, will require a plan prepared by a licensed engineer. Height and surface area are determined based on design flood conditions.
FYI it is important to make sure you don't fall within any of these criteria before moving forward. Contact info for your local DEQ office is provided on the linked document.
A helpful tool as well is the MI wetland mapper which can be found below and will help you determine if you are in a wetland area or not:
If you have other questions regarding pond ecology, pond management, sports fish, etc feel free to reach out to our Lakes, Streams and Watershed Experts (link below, click on experts):