Client Alert


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Scott B. Birkey

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Clark Morrison

Land Use & Natural Resources



On Tuesday of this week, the Army Corps of Engineers and EPA released draft regulations intended to clarify their jurisdiction over wetlands and other Waters of the United States.  The draft regulations attempt to respond to the considerable confusion created by over 25 years of conflicting guidance from the U.S. Supreme Court.  

In some ways, the new regulations would limit jurisdiction over certain discrete types of water features, such as ditches, non-wetland swales and water treatment facilities.  In fact, the regulations appear to expand the number of features that may be exempt from Clean Water Act jurisdiction.  However, the proposed regulations add a number of new definitions that would both significantly expand federal jurisdiction and make the delineation of wetlands and other waters an even more lengthy and subjective exercise than before.  

For example:

  • Tributaries – For the first time, the Corps and EPA would limit the definition of “tributaries” to those water features that have both a “bed and bank” and an “ordinary high water mark.”  Although these are helpful limitations, any such water would still be considered a jurisdictional water if it eventually drains to normal navigable waters.  That is, the tributary need not be directly connected to the water for which it serves as a tributary.  Moreover, the draft regulations specifically state that they cover man-made or man-altered water features.  
  • Adjacent or Neighboring Wetlands – The regulations vaguely define the circumstances under which a neighboring wetland is jurisdictional (e.g., it falls within the same “riparian area” or “floodplain” or shares a shallow groundwater or surface water connection).  But more importantly, the regulations would dramatically expand this concept to include not just wetlands, but any “neighboring” water.
  • Other Waters – If a water feature does not meet any of the regulations’ new definitions, then that “other water” will still be jurisdictional if it can be shown, on a case-by-case basis, that it bears a “significant nexus” to a regulated water.  In determining significant nexus, the agencies will not limit their evaluation to the specific water under consideration, but would consider the nexus of all other similarly situated waters in the region.  So even if a particular vernal pool does not have a significant nexus to a nearby stream, it will still be jurisdictional if all such pools in the region, collectively, can be determined to have a nexus.

These are, of course, draft regulations.  It remains to be seen what will happen as the Corps and EPA consider public comments on their new definitions.  But one thing is certain.  Because of the regulations’ heavy reliance on factors like hydrologic connections and significant nexus, the delineation of waters will become far more technical, expensive, and time-consuming.  In many cases it will require the retention of hydrologists and geologists in addition to a traditional wetlands consultant, and drive a need for multi-year technical evaluations. This, in addition to the expanded definitions themselves, will give the agencies’ greater leverage in permit negotiations because of their ability to exploit the technical uncertainties and ask for more studies over a longer period of time.

If you have any questions concerning the subject of this article, please contact a member of our Land Use & Natural Resources group:


Clark Morrison at (415) 262-5113 or

Scott Birkey at (415) 262-5162 or


3121 Michelson Drive, Suite 200
Irvine, CA 92612

949.260.4600    949.260.4699

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San Francisco, CA 94111

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