The Clean Water Act (1972) gives the Corps of Engineers control over nearly all private property in America by changing the definition of "wetlands" under the Clean Water Act of 1972 vastly expanding the regulatory reach of the Corps of Engineers over private property.
Personally I would not worry about berms and swales. Go ahead and make them. Odds are no-one will notice if you use hand tools or small equipment. Giant excavators, on the other hand, are more likely to get noticed.
I email every single water harvesting idea I have to our state engineers office. As they have no idea what I am talking about they usually say fine. That is how I got government permission to build a mini krater. I did not specify the number of mini kraters in my email and as such I am digging all I want.
This has a little more history than what is cited.
The original language of the act never really changed, but it was confusing, and so from 1972 until 2016 or so, The Army Corp of Engineers only dealt with NAVIGATABLE waterways.
Then the Supreme Court got involved, and clarified the act, stating that they control most water and wetlands in the United States. I believe it is anything under 5000 feet in elevation. It was a devastating ruling for private landowners. Now, not only is my land, located high on a hill, and with no sizable streams, still falls under the State Dept of Environmental protection, Federal EPA, and now Army Corp of Engineers.
Here is the kicker. The Army Corp of Engineers never got an increase of funding or staff, so if you file for a project today, it will be AT LEAST 2-3 years before they can even come out to see your proposed project. But there is a ton of fines to pay if you get caught without the multiple permits.