Governing the Gradient: Clarity and Discretion at the Water's Edge

In promulgating the Clean Water Rule of 2015, U.S. EPA and the Army Corps of Engineers responded to more than a decade of legal turmoil and calls from all quarters that they clarify their Clean Water Act (CWA) jurisdiction. The rulemaking combined the agencies’ response to four decades of judicial precedent with a massive gathering, sorting, and interpreting of the available scientific evidence describing the composition and functioning of the Nation’s “waters.” The resulting exclusions and inclusions by rule will clarify several jurisdictional boundaries. But the rule leaves certain decisive concepts, especially the notion of a tributary and the connectedness of aquatic systems, open to individuated findings of fact — findings that inevitably involve agency discretion. This article articulates and responds to the gravamen of the legal challenges to the rule now being litigated in several federal courts. Some subset of those claims is likely to reach a Supreme Court very different from that which last heard two CWA jurisdictional challenges a decade ago. In the end, the article argues that the rule is a compromise all would be wise to accept.