Phoebe,
For what it's worth...
I checked with the town and county and have letters stating no permits were needed.
Had Corp of Engineers verify the ditch my pond runoff ran into was not considered navigable, and that I was over 500' from any navigable waterway (or COE would have needed to approve).
Talked with the DNR since it was classified as wetland. Since the wetland area had already been disturbed by original pond and ditch work (25yrs ago), He gave me the OK to build up the back berm (technically in the wetland area) as long as I didn't move it further into the wetland.
Then he said since I was going to hold water above the surrounding grade, I needed a Small Dam Permit from the DNR. Did the engineering work for that, submitted my plans and drawings and I am a Small Dam Operator.
The long and short...
If the creek is not navigable, your property is not registered as wetland, you are not withing 500' of any navigable waters of the state, and your town and county don't require permits you should be good. Otherwise... On the bright side, you've got seven years with no issues, statute of limitations??? If you are in a wetland, it is still ok to dig, but you cannot raise the level of any wetland area with berms or roads etc.