Waters of the United States (WOTUS): Repealing and Revising the 2015 Clean Water Rule [October 23, 2019] [open pdf - 634KB]
From the Background: "Congress passed the Clean Water Act (CWA) to restore and protect the quality of the nation's surface waters (33 U.S.C. §1251 'et seq.'). The statute protects 'navigable waters,' which it defines as 'the waters of the United States, including the territorial seas.' The CWA does not further define the term 'waters of the United States' (WOTUS). Thus, the Army Corps of Engineers and U.S. Environmental Protection Agency (EPA) have defined WOTUS in their regulations. However, Congress's intent as to the meaning of WOTUS has been debated and litigated for more than four decades."
CRS In Focus, IF11339
Congressional Research Service: https://crsreports.congress.gov/