A new final regulation issued on September 12, 2019 by the Environmental Protection Agency and the Army Corps of Engineers repealed the Obama administration’s 2015 “Clean Water Rule,” but did little to clear up longstanding confusion over the scope of federal authority and jurisdiction under the Clean Water Act. The current regulation simply repeals the 2015 rule, without any replacement, with the result that the pre-existing Clean Water Act regulations and guidance continue to apply until there is new regulatory guidance in place. For a discussion of the new final rule and the reasons for repeal of the 2015 rule, see our Update by Marc Bruner.