Approved by the Energy, Environment, and Water Policy Committee on November 6, 2018
Approved by the Public Policy Committee on March 12, 2019
Adopted by the Board of Direction on July 13, 2019


The American Society of Civil Engineers (ASCE) supports the U.S. Army Corps of Engineers (USACE) and the Environmental Protection Agency (EPA) in maintaining regulations that protect national wetlands and enforcing clearly defined wetlands subject to jurisdictions under Section 404 of the Clean Water Act (CWA). ASCE supports a final rule that:

  • Maintains federal jurisdiction over all interstate and navigable waters, their tributaries, and all adjacent wetlands;
  • Clarifies state jurisdiction over isolated, non-navigable intrastate waters and adjacent wetlands, (including vernal pools, playas, and prairie potholes), that is based on environmental and wildlife regulations promulgated by the Department of the Interior or the EPA; and
  • Provides clarity on federal jurisdiction over intermittent and ephemeral streams and their adjacent wetlands under section 404 to the USACE, in coordination with the EPA.


To ensure that wetland issues are properly addressed in a timely and predictable manner during the project development process, it is important that the level of government having jurisdiction - federal or state - be clearly identified. The EPA and USACE use the 1987 Corps of Engineers Wetlands Delineation Manual and Regional Supplements to define wetlands for the CWA Section 404 permit program. Section 404 requires a permit from the USACE or authorized state for the discharge of dredged or fill material into Waters of the United States, including wetlands. The 2015 Clean Water Rule, defining "Waters of the United States (WOTUS)," is now in effect in 22 states pursuant to federal district court order. Parties to the case, including the EPA and the Department of the Army (Army), have filed motions appealing the order and seeking a stay of the federal district court's decision.

The EPA and the Army are working through a two-step process to consider revisions to the definition of "waters of the United States," consistent with the February 2017 Presidential Executive Order 13778. The Executive Order states that it is in the national interest to ensure that the nation's navigable waters are kept free from pollution, while also promoting economic growth, minimizing regulatory uncertainty, and showing due regard for the roles of Congress and the states under the Constitution. In June 2018, the EPA and the Army issued a supplemental proposal to the July 2017 proposed action to repeal the 2015 definition of WOTUS. The June 2018 proposal specifically requested comment on the legal basis of the 2015 WOTUS rule, which the agencies believe has led to uncertainty and confusion across the country.


The 2015 final rule was created after decades of court confusion, primarily stemming from the Rapanos decision, where the controlling opinion of Justice Kennedy stated that "through regulations or adjudication, the USACE may choose to identify categories of tributaries that, due to their volume of flow (either annually or on average), their proximity to navigable waters, or other relevant considerations, are significant enough that wetlands adjacent to them are likely, in the majority of cases, to perform important functions for an aquatic system incorporating navigable waters." In response to this and other court decisions, USACE and EPA issued a proposed rule on April 21, 2014. Following a six-month public comment period and eight months of rewriting the rule incorporating public feedback, a final rule was issued which addresses most concerns raised by stakeholders and simultaneously improves transparency, strengthens coordination between agencies, increases public participation and promotes use of the best available science and technical data for making case-specific significant nexus determinations.

ASCE Policy Statement 378
First Approved in 1991