Author ORCID Identifier


Document Type


Publication Date



As it reaches its half century mark, the modern version of the federal Clean Water Act (CWA) remains a definitional quagmire. The U.S. Supreme Court, lower courts, and the two federal agencies charged with implementing the law have struggled to interpret its scope ever since its 1972 enactment. As a result, we still lack clarity regarding the most basic questions about the law’s reach. That causes massive uncertainty for regulated businesses and landowners, the federal and state agencies that implement the law, and members of the public Congress intended to protect. A unified interpretive approach focuses on the statutory text and its stated goals, considering the whole statute in context rather than individual terms construed in isolation. This analysis negates the inappropriate assumption that Congress was simply sloppy in its use of multiple terms to define the scope of various CWA programs. Rather, Congress adopted a nested set of scope terms to apply to different statutory provisions and purposes rather than a single definition applicable throughout the statute. Under this analysis, the CWA is not as limited by the concept of navigability as the Supreme Court has suggested in some cases. Read in the context of the whole statute, the term “navigable waters” extends beyond the traditional notion of navigability as reflected in cases such as The Daniel Ball. In the CWA, Congress designed multiple strategies, to be implemented by varying players, to achieve the broad and ambitious statutory objective and goals. The definitional terms applicable to each program, therefore, should be construed to effectuate the statutory goals Congress articulated for those programs in the text and structure of the whole statute.