Final Rule on Definition of Waters of the United States Published by EPA and Corps

On Monday, June 29, 2015, after two years of development and review, the U.S. Environmental Protection Agency (EPA) and the U.S. Army Corps of Engineers (Corps) published their Final Rule on the definition of Waters of the United States (80 FR 124: 37054-37127).  The Final Rule replaces all prior rules and guidance on the definition as used in implementing the Clean Water Act and becomes effective on August 28, 2015.

Why was a new definition developed?

final rule1The Final Rule was developed primarily to clarify and codify rulings by the Supreme Court in 2001 (“SWANCC”) and 2006 (“Rapanos”) that significantly affected how the Corps conducts determinations and delineations of waters of the United States (U.S.), including wetlands. Following each of these rulings, the EPA and Corps issued guidance on how to conduct delineations based on new criteria included in the Court’s opinions. The guidance, however, was confusing to many and did not fully clarify jurisdictional limits. The Final Rule provides greater clarity and consistency across the U.S. as to the delineation of jurisdictional waters and reduces the need for special case-specific evaluations.


What does the new rule say?

The Final Rule specifically maintains the existing definitions of traditional navigable waters, interstate waters, the territorial seas, and impoundments and keeps all of these types of waters within jurisdictional waters of the U.S. The Final Rule, however, alters the way the Corps deals with tributaries to these waters and associated waters and wetlands. It also contains specific language regarding certain special types of waters.


The Final Rule emphasizes the concept of a “significant nexus test,” drawn from Justice Kennedy’s opinion in Rapanos, which analyzes whether waters have a significant effect on the chemical, physical, or biological integrity of a traditional navigable water, interstate water, or territorial seas. The Final Rule includes as waters of the U.S. all tributaries to and waters adjacent to traditional navigable waters, interstate waters, or territorial seas. Tributaries are defined as waters that contribute flow to waters of the U.S. and have physical indicators of a bed, banks, and ordinary high water mark. Waters are considered adjacent, and therefore are included as waters of the U.S., if they are within 100 feet of a water of the U.S.; within the 100-year floodplain and not more than 1,500 feet from a water of the U.S.; or within 1,500 feet of the high tide line.


The Final Rule requires case-specific application of the significant nexus test for certain types of identified waters (i.e., prairie potholes, Carolina bays and Delmarva bays, pocosins, western vernal pools, and Texas coastal prairie wetlands) and for any waters found within a 100-year floodplain or within 4,000 feet of a water of the U.S.


The Final Rule requires that similarly situated waters be evaluated collectively for effects on waters of the U.S. and defines the region in which similarly situated waters are evaluated as the watershed. All specifically named types of waters in the Final Rule (listed above) are presumed to be similarly situated. Significantly, once a determination of jurisdictional status has been made on a water of the U.S., all similar features within a watershed may automatically be considered to be likewise jurisdictional.


What waters are excluded from jurisdiction?

The Final Rule provides a long list of waters and other features that are explicitly excluded from jurisdiction regardless of their position on the landscape (e.g., even if they are adjacent to a water of the U.S.). Most of the features listed in the Final Rule were excluded from jurisdictional waters under previous Corps procedures. For example, the following features are specifically excluded by the Final Rule: waste treatment ponds; artificial lakes, ponds, reflecting pools, swimming pools, or small ornamental waters created in dry land; water-filled depressions created in dry land incidental to mining or construction activity; erosional features, including gullies and rills; puddles; groundwater; stormwater control features; wastewater recycling structures constructed in dry land; detention and retention basins built for wastewater recycling; groundwater recharge basins; percolation ponds built for wastewater recycling; and water distributary structures built for wastewater recycling.


Of note are the descriptions of “ditches” that are not considered jurisdictional: 1) ditches with ephemeral flow that are not a relocated or excavated tributary; 2) ditches with intermittent flow that are not a relocated or excavated tributary and do not drain wetlands; and 3) ditches that do not flow into a traditional navigable water, interstate water, or the territorial seas (either directly or through another water).


Waters and wetlands on agricultural lands are addressed in the Final Rule, but there is no substantial change from current practice by the Corps. The Final Rule excludes prior converted cropland (as determined by EPA); artificially irrigated areas that would revert to dry land should application of water to that area cease; and artificial, constructed lakes and ponds created in dry land such as farm and stock watering ponds, irrigation ponds, settling basins, fields flooded for rice growing, log cleaning ponds, or cooling ponds. The Corps’ requirement to remove artificially applied water for sufficient time to determine if wetlands are present appears to remain the necessary approach.


So what does this mean for Clean Water Act jurisdiction in California?

The Final Rule will change how delineations are conducted in California, but not necessarily change the extent of jurisdictional waters delineated. With its various distance and floodplain criteria, the Final Rule creates some clear boundaries to use in the determination of jurisdictional waters. It maintains many current practices, such as the three parameter test for wetlands and identification of ordinary high water mark, but will likely expand the effort necessary for evaluation of significant nexus for waters outside the boundaries stated in the Final Rule.


final rule2California vernal pools are specifically discussed in the Final Rule and are a frequent occurrence in delineations conducted in the Central Valley, Sierra Nevada foothills, and Southern California coastal terraces. The Final Rule requires that vernal pools that are not part of a tributary system or adjacent to a water of the U.S. (these are jurisdictional by rule) be evaluated for significant nexus to waters of the U.S. Once a significant nexus test has been completed in a watershed, all similarly situated vernal pools may be considered to have the same test result; therefore, future delineations should be less complicated.


In case-specific evaluations of waters and wetlands, the geographic point at which the effects on downstream waters become insubstantial (i.e., not a significant nexus) will need to be determined. To make this determination, it likely will be necessary to gather more types of information and more detailed data than has been typically collected in the past.


The Final Rule makes clear that federal jurisdiction under the Clean Water Act does not affect the extent of state jurisdiction of waters. Waters, wetlands, and riparian habitats regulated by the State of California under Section 1600 et seq. of the California Fish and Game Code and the Porter-Cologne Act typically extend state jurisdiction beyond the boundaries of the federal jurisdiction.


We hope that this short summary is helpful to our clients and other parties interested in the EPA and Corps Final Rule on waters of the U.S. and future implementation of the Clean Water Act. If you need help with the delineation of waters or the permitting process for waters found on your property or would like to discuss the Final Rule and its ramifications further, please feel free to contact us at ECORP Consulting.


Northern California: Paul Cylinder, Ph.D. or Lourdes Gonzalez-Peralta at (916) 782-9100.

Southern California: Scott Taylor at (909) 307-0046 or Margaret Bornyasz at (858) 279-4040.


About ECORP Consulting, Inc.

ECORP Consulting, Inc. has assisted public and private land owners with environmental regulation compliance since 1987. Find out more at ECORP Consulting's mission is to consistently deliver high-quality environmental consulting services through outstanding science and timely, creative solutions for our clients, while providing an excellent work environment for our staff.
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