The Administration has announced that it will propose new regulations to protect wetlands and smaller streams; unfortunately, specifics are lacking at present. The Administration appears to believe that their new regulations will fit within the constraints imposed by recent U.S. Supreme Court cases on Federal jurisdiction over navigable waterways.
To obtain at least an impression of what is likely to be proposed, see http://www.whitehouse.gov/sites/default/files/microsites/ceq/Clean%20Water%20Framework.pdf, an overview report by the Council on Environmental Quality, EOP.
The importance of wetlands to water quality and the reproduction of various biota is well known. See http://water.epa.gov/type/wetlands/ and the links thereto.
It will be interesting to see how the Administration intends to put into regulation the jurisdictional holdings of the U.S. Supreme Court. As noted in prior posts, the lower courts have basically taken Justice Kennedy's opinion as the jurisdictional rule since 4 Justices wanted a broader interpretation of wetland jurisdiction, and 4 wanted a narrower interpretation.