Science has a piece on the changes occurring to the Clean Water Act controls. As Science states:
The confl ict is rooted in the Clean Water Act of 1972, which requires anyone wanting to dredge or fi ll a stream or wetland to get a permit from the federal government. (Many agricultural activities are exempt.) For decades, U.S. offi cials and the courts held that the law applied not just to the “navigable waters” mentioned in the act, but also to all the smaller streams, wetlands, and ponds connected to them in a variety of ways. Numerous groups challenged that interpretation, however, and in the 2000s the U.S. Supreme Court dealt the government several setbacks. In a 2006 split decision, for instance, it ruled that EPA could not regulate any waters unless it demonstrated that they had a “signifi cant nexus” with downstream navigable waters, such as affecting their physical, chemical, or biological integrity. Since then, confusion has reigned over the legal status of ephemeral streams and isolated wetlands. In 2010, EPA began to try to clarify matters by writing the new rule. It calls for the Clean Water Act to cover all tributaries, headwater streams, and “adjacent” wetlands.
Namely we now see ditches becoming part of navigable waters. That is "dry" ditches. It is not even clear how deep a ditch has to be. The actions of the EPA will make it illegal for anyone anywhere altering in anyway a run-off area without prior EPA authorization. This clearly affects hills, slopes, gulleys, and almost any and every piece of land everywhere.
Admittedly there are agricultural carve outs but the new regulation, yes regulations written without a new law are now laws, the new regulation delimits plowing of a field, setting up a home garden, and yes folks watering your lawn.