EO12866_CWPG_RIN2010-ZA11_Draft Guidance_20101220.docx

Guidance on Identifying Waters Protected byDetermining Geographic 

Jurisdiction

Under the Clean Water Act 

This draft guidance clarifiesdescribes how the Environmental Protection Agency 

(EPA)*a and the U.S. Army Corps of Engineers (the Corps)b(“Corps”)

c

 will identify 

waters protected bysubject to jurisdiction under the Federal Water Pollution Control Act 

Amendments of 19721 (Clean Water Act or CWA or Act) and implement the Supreme 

Court’s decisions concerning the extent of waters covered by the Act (Solid Waste 

Agency of Northern Cook County v. U.S. Army Corps of Engineers (SWANCC)2

 and 

Rapanos v. United States (Rapanos)3). This document clarifies how the EPA and the 

Corps understand existing requirements of the CWA and the agencies' implementing 

regulations in light of SWANCC and Rapanos and provides guidance to agency field staff 

in making determinations about whether waters are protected by the CWA.United States 

v. Rapanos (Rapanos)4). The agencies understand that decisions concerning whether a 

waterbody is subject to the CWA have consequences for tribal, state, and local 

governments, and for private parties. Key goals of this guidance are to reduce the 

complexity of EPA and Corps decisions concerning coverage of waters by the CWA, 

improve predictability in the process of identifying waters covered under the CWA, and 

increase consistency of these decisions across the country. 

 This draft guidance document is intended to describe for agency field staff the 

agencies’ current understandings; it is not a rule, and hence it is not binding and lacks the 

force of law. Once finalized, this guidance will supersede existing guidance to field staff 

issued in 2003 and 2008 on the scope of “waters of the United States” (also “waters of 

the U.S.”) subject to CWA programs.d Although guidance does not have the force of 

law, it is frequently used by Federal agencies to explain and clarify their understandings

of existing requirements. In this case, the agencies believe that field staff across the 

country will benefit from new guidance that is informed by lessons learned since 2008 

and that reflects the agencies’ understandings with respect to CWA jurisdiction, 

consistent with Supreme Court decisions and existing agency regulations. Each 

 

* To increase clarity of this document, endnotes that primarilysimply provide citations will be indicated 

with Arabic numerals,numerically, and footnotes that provide additional substantive information will be 

indicated with Roman numerals.alphabetically. a

 EPA Regions will use this guidance to oversee and implement programs under the Clean Water 

Act,CWA, including those under sectionsSections 303, 311, 401, 402 and 404, 33 U.S.C. §§ 1313, 1321, 

1341, 1342 and 1344. (See endnote 1 for an explanation of the relevant history of the Clean Water 

Act.)404. b

 Corps Districts will utilize this guidance to implement Clean Water Act section 404, 33 U.S.C. § 1344.

c Corps Districts will utilize this guidance to implement CWA Section 404.

d

 Specifically, this memorandum supersedes the “Joint Memorandum” providing clarifying guidance on 

SWANCC, dated January 15, 2003 (68 Fed. Reg. 1991, 1995), and “Clean Water Act Jurisdiction Following 

the U.S. Supreme Court’s Decision in Rapanos v. United States & Carabell v. United States,” dated 

December 2, 2008.
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 2

jurisdictional determination, however, will be made on a case-by-case basis considering 

the facts and circumstances of the case and consistent with applicable statutes, 

regulations, and case law.

After receiving and taking account of public comments on this document, EPA 

and the Corps expect to finalize it and to undertake rulemaking consistent with the 

Administrative Procedure Act. This process is expected to start with a proposed rule, to 

clarify further via regulation the extent of Clean Water Act jurisdiction, consistent with 

the Court's decisions. EPA and the Corps decided to begin this process with draft, 

nonbinding guidance in order to clarify their existing understandings while also 

considering and receiving the benefit of public comments.Congress enacted the Clean 

Water Act “to restore and maintain the chemical, physical, and biological integrity of the 

Nation’s waters,” and this guidance will help the agencies implement specific provisions 

of the Act to achieve this objective.5 The CWA has a number of programs designed to 

protect and restore the Nation's waters. Together, these achieve this goal. The Clean 

Water Act, however, applies only to waters that are “waters of the United States.” This 

guidance provides that EPA and the Corps will implement programs provide effective 

protection from pollution for waterbodies acrossto protect waters consistent with the 

country, including waters that supply drinking water, filter pollutants, provide water for 

irrigation,Clean Water Act, the SWANCC and support huntingRapanos decisions, and 

fishing, outdoor recreation, and tourism. sound science.

The Clean Water Act, however, applies only to waters that are “waters of the 

United States.” This draft guidance clarifies how EPA and the Corps will identify waters 

to be protected under the Act consistent with the statute, regulations, Supreme Court 

caselaw, relevant science related to aquatic ecosystems, and the agencies' field 

experience. As noted above, this guidance, once finalized, will supersedeguidance 

supersedes previously issued guidance on the scope of “waters of the United States” (also 

“waters of the U.S.”) subject to CWA programs. However, it is not 6 This guidance 

reflects the relevant science and responds to the agencies’ intention that previously issued 

jurisdictional determinations be re-opened as a result of this guidance. 

The U.S. Supreme Court has addressed the scope of waters of the United States 

protected by the CWA in three cases. In United States v. Riverside Bayview Homes, Inc.

(474 U.S. 121 (1985)), the Supreme Court held that wetlands adjacent to a traditional 

navigable water were properly considered to be “waters of the United States.” In 

SWANCC, the Court addressed the question of CWA jurisdiction over isolated, nonnavigable, intrastate ponds, and concluded that CWA jurisdiction could not be based 

solely on the presence of migratory birds. In Rapanos, the Court addressed CWA 

protections for wetlands adjacent to non-navigable tributaries, and issued five opinions 

with no single opinion commanding a majority of the Court. The plurality opinion, 

authored by Justice Scalia, stated that “waters of the United States” extended beyond 

traditional navigable waters to include “relatively permanent, standing or flowing bodies 

of water.” Id. at 739. The plurality went on to clarify that relatively permanent waters 
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 3

”do not necessarily exclude” streams, rivers, or lakes that might dry up in extraordinary 

circumstances, such as drought, and seasonal rivers, which contain continuous flow 

during some months of the year but no flow during dry months. The plurality opinion 

also asserted that only wetlands with a “continuous surface connection” to other 

jurisdictional waters are considered “adjacent” and protected by the CWA. Id. at 742. 

Justice Kennedy’s concurring opinion took a different approach from Justice 

Scalia’s. Justice Kennedy concluded that “waters of the United States” included 

wetlands that had a significant nexus to traditional navigable waters, “if the wetlands, 

either alone or in combination with similarly situated lands in the region, significantly 

affect the chemical, physical, and biological integrity of other covered waters more 

readily understood as ‘navigable’” (id. at 780). The four justices who signed on to 

Justice Stevens’ opinion would have upheld jurisdiction under the agencies' existing 

regulations and stated that they would uphold jurisdiction under either the plurality or 

Justice Kennedy's opinion (id. at 810). 

The agencies continue to believe, as expressed inexperience implementing

previous guidance, that it is most consistent with the Rapanos decision to assert 

jurisdiction over waters that satisfy either the plurality or the Justice Kennedy standard, 

since a majority of justices would support jurisdiction under either standard. However, 

after careful review of these opinions, the agencies concluded that previous guidance did 

not make full use of the authority provided by the CWA to include waters within the 

scope of the Act, as interpreted by the Court. This draft guidance provides a more 

complete discussion of the agencies’ interpretation, including of how waters with a 

"significant nexus" to traditional navigable waters or interstate waters are protected by 

the CWA. documents. In addition, this guidance explains the legal basis for coverage of 

waters by the CWA in cases that werealleviates the need to develop extensive 

administrative records for certain jurisdictional determinations that caused delays and 

added costs to both federal agencies and the regulated community. 

The 2008 Rapanos guidance reflected a policy choice to interpret Justice 

Kennedy’s opinion narrowly, resulting in fewer waterbodies found to be jurisdictional 

under the CWA than under a more faithful interpretation. This guidance clarifies and 

refines the agencies’ interpretation of the “significant nexus” standard many waterbodies 

must meet to be jurisdictional under the CWA that is more consistent with Justice 

Kennedy’s opinion and the science of aquatic ecosystems. The guidance also addresses 

how to determine the jurisdictional status of waters not addressed by the previous 

guidance (for example, interstate waters). The Therefore, the agencies expect, based 

on relevant science and recent field experience, that under the understandings stated in 

this draft guidance, the extentnumber of waters over which the agencies assert found to 

be subject to CWA jurisdiction under the CWA will increase significantly compared to 

practices under the extent2003 SWANCC guidance and the 2008 Rapanos guidance. 

Note, however, that the scope of waters over whichsubject to CWA jurisdiction has been 

asserted under existing guidance, though certainlywill still not to the full extent that be as 
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 4

extensive as it was typically asserted prior to the two Supreme Court decisions in 

SWANCC and Rapanos. However, each jurisdictional determination will be made on a 

case-by-case basis considering the facts and circumstances of the case and consistent with 

applicable statutes, regulations, and case law.. 

The agencies understand that decisions concerning whether or not a waterbody is 

subject to the CWA have consequences for State, tribal, and local governments and for 

private parties. Consistent with Executive Order 13563, and in particular its emphasis on 

predictability and certainty, key goals of this draft guidance are to increase clarity and to

reduce costs and delays in obtaining CWA permits by reducing the complexity of Corps 

of Engineers and EPA decisions concerning waters protected by the CWA, thus

improving the predictability of the process of identifying waters protected by the Act, and 

increasing consistency of decisions across the country. 

There is only one CWA definition of “waters of the United States.” Thus, this

draft guidance, like the earlier guidance it replaces, necessarily will applyThis guidance 

applies to decisions concerning whether a waterbody is subject to any of the programs 

authorized under the CWA. Although SWANCC and Rapanos specifically involved 

sectionSection 404 of the CWA and discharges of dredged or fill material, the this 

guidance addresses the scope of the term “waters of the United States” must be 

interpreted consistently for all CWA provisions thatwhich use the term. These provisions 

include the sectionSection 402 National Pollutant Discharge Elimination System 

(NPDES) permit program, the sectionSection 311 oil spill program,7 the water quality 

standards and total maximum daily load programs under sectionSection 303, and the 

sectionSection 401 State water quality certification process. However, whileWhile there 

is only one CWA definition of “waters of the United States,” there may be other statutory 

factors that define the reach of a particular CWA program or provision.8 

 This draft guidance does not address the regulatory exclusions from coverage 

under the CWA for waste treatment systems and prior converted croplands, or practices 

for identifying waste treatment systems or prior converted croplands.9

 Itcroplands, nor

does notit affect any of the exemptions from CWA sectionSection 404 permitting 

requirements provided by CWA sectionSection 404(f), including those for normal 

agriculture, forestry and ranching practices.10 This guidance also does not address the 

statutory and regulatory exemptions from NPDES permitting requirements for 

agricultural stormwater discharges and return flows from irrigated agriculture.11

 The CWA provisions and supporting regulations described in this document 

contain legally binding requirements. The agencies emphasize that thisThis guidance 

does not substitute for those provisions or regulations and, nor is not itselfit a regulation.

itself. It does not impose legally binding requirements on EPA, the Corps, or the 

regulated community, and may not apply to a particular situation depending on the 

circumstances. Any decisions regarding a particular water will be based on the applicable 

statutes, regulations, and case law. Therefore, interested persons are free to raise 
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 5

questions regarding the application of this guidance to a particular situations,situation,

and EPA and/or the Corps will consider whether or not the recommendations or 

interpretations of this guidance are appropriate in that situation based on the statutes, 

regulations, and case law. The use of language such as "recommend," "may," "should" 

and "can" is intended to describe agency policies and recommendations, while the use of 

mandatory terminology such as "must" and "required" is intended to describe the 

agencies’ interpretations of controlling requirements under the terms of the CWA, its 

implementing regulations, and relevant case law.

This draft guidance is divided into eight sections: 

• The first two sections address the fundamental classes of waters subject to Clean 

Water Act jurisdiction: traditional navigable waters (Section 1) and interstate 

waters (Section 2). .

• The next section provides general guidance relating to the “significant nexus” 

standard described by Justice Kennedy in the Rapanos decision (Section 3). 

• The next three sections provide guidance on determining whether various types of 

waters are subject to CWA jurisdiction, including: 

o Tributaries (Section 4); 

o Adjacent wetlands (Section 5); and 

o Other waters (Section 6). 

• The next section provides examples of waters that are generally not waters of the 

United States under the CWA (Section 7). 

• The final section provides guidance on the documentation necessary to support 

decisions concerning whether waters are protectedcovered by the CWA (Section 

8). 

Additional scientific and legal information concerning these topics is provided in an 

appendix at the end of this document. 

 
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 6

Finally, the agencies intend to propose revisions of existing regulations in 2011 to 

provide further clarification of the waters that are subject to CWA jurisdiction, consistent 

with the Supreme Court’s decisions.

Summary of Key Points 

The following waters are subject to Clean Water Act jurisdiction: 

• Traditional navigable waters; 

• Interstate waters; 

• Wetlands adjacent to either traditional navigable waters or interstate waters; 

• Non-navigable tributaries to traditional navigable waters that are relatively permanent, 

meaning at least seasonal; and 

• Wetlands that directly abut relatively permanent waters. 

In addition, the following waters are subject to Clean Water Act jurisdiction if a fact-specific 

analysis determines they have a “significant nexus” to a traditional navigable water or interstate 

water: 

• Tributaries to traditional navigable waters or interstate waters; 

• Wetlands adjacent to jurisdictional tributaries to traditional navigable waters or 

interstate waters; 

• Waters that fall under the “other waters” category of the regulations. 

The following aquatic areas are generally not subject to Clean Water Act jurisdiction as waters 

of the United States: 

• Wet areas that are not tributaries or open waters or do not meet the agencies’ 

regulatory definition of “wetlands”; 

• Waters excluded from coverage under the CWA by existing regulations; 

• Waters that lack a “significant nexus” where one is required for a water to be subject to 

CWA jurisdiction; 

• Artificially irrigated areas that would revert to upland should irrigation cease; 

• Artificial lakes or ponds created by excavating and/or diking dry land and used 

exclusively for such purposes as stock watering, irrigation, settling basins, or rice 

growing; 

• Artificial reflecting pools or swimming pools created by excavating and/or diking dry 

land; 

• Small ornamental waters created by excavating and/or diking dry land for primarily 

aesthetic reasons; 

• Water-filled depressions created incidental to construction activity. 

Summary of Key Points 

Based on the agencies’ interpretation of the statute, implementing regulations and relevant 

caselaw, the following waters are protected by the Clean Water Act: 

• Traditional navigable waters; 

• Interstate waters; 

• Wetlands adjacent to either traditional navigable waters or interstate waters; 

• Non-navigable tributaries to traditional navigable waters that are relatively permanent, 

meaning they contain water at least seasonally; and 

• Wetlands that directly abut relatively permanent waters. 

In addition, the following waters are protected by the Clean Water Act if a fact-specific analysis 

determines they have a “significant nexus” to a traditional navigable water or interstate water: 

• Tributaries to traditional navigable waters or interstate waters; 

• Wetlands adjacent to jurisdictional tributaries to traditional navigable waters or 

interstate waters; and 

• Waters that fall under the “other waters” category of the regulations. The guidance 

divides these waters into two categories, those that are physically proximate to other 

jurisdictional waters and those that are not, and discusses how each category should be 

evaluated. 

The following aquatic areas are generally not protected by the Clean Water Act: 

• Wet areas that are not tributaries or open waters and do not meet the agencies’ 

regulatory definition of “wetlands”; 

• Waters excluded from coverage under the CWA by existing regulations; 

• Waters that lack a “significant nexus” where one is required for a water to be protected 

by the CWA; 

• Artificially irrigated areas that would revert to upland should irrigation cease; 

• Artificial lakes or ponds created by excavating and/or diking dry land and used 

exclusively for such purposes as stock watering, irrigation, settling basins, or rice 

growing; 

• Artificial reflecting pools or swimming pools created by excavating and/or diking dry 

land; 

• Small ornamental waters created by excavating and/or diking dry land for primarily 

aesthetic reasons; 

• Water-filled depressions created incidental to construction activity; 

• Groundwater drained through subsurface drainage systems and 

• Erosional features (gullies and rills), and swales and ditches that are not tributaries or 

wetlands. 
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 7

Section 1: Traditional Navigable Waters 

 EPA and the Corps will continue to assert CWA jurisdiction over “[a]ll waters 

which are currently used, or were used in the past, or may be susceptible to use in 

interstate or foreign commerce, including all waters which are subject to the ebb and flow 

of the tide.”12 These waters are referred to in this guidance as “traditional navigable 

waters.” The traditional navigable waters include all of the “navigable waters of the 

United States,” as defined in 33 C.F.R. partPart 329 and by numerous decisions of the 

federal courts, plus all other waters that are navigable-in-fact (for example, the Great Salt 

Lake, Utah,UT, and Lake Minnetonka, Minnesota).MN). Thus, the traditional navigable 

waters include, but are not limited to, the “navigable waters of the United States” within 

the meaning of sectionSection 10 of the Rivers and Harbors Act of 1899 (also known as 

“Section 10 waters”). 13

 For purposes of CWA jurisdiction and this guidance, waters will be considered 

traditional navigable waters if: 

• They are subject to sectionSection 9 or 10 of the Rivers and Harbors Act; or 

• A federal court has determined that the water body is navigable-in-fact under 

federal law; or 

• They are waters currently being used for commercial navigation, including 

commercial waterborne recreation (for example, boat rentals, guided fishing trips, 

or water ski tournaments);tournaments, etc.); or 

• They have historically been used for commercial navigation, including 

commercial waterborne recreation; or 

• They are susceptible to being used in the future for commercial navigation, 

including commercial waterborne recreation. Susceptibility for future use may be 

determined by examining a number of factors, including the physical 

characteristics and capacity of the water to be used in commercial navigation, (for 

example, size, depth, and flow velocity,e etc.), including commercial recreational 

navigation (for example, size, depth, and flow velocityf),, and the likelihood of 

future commercial navigation, including commercial waterborne recreation. A 

likelihood of future commercial navigation, including commercial waterborne 

recreation, can be demonstrated by current boating or canoe trips for recreation or 

other purposes.g A determination that a water is susceptible to future commercial 

 

e While a traditional navigable water need not be capable of supporting navigation at all times, the 

frequency, volume, and duration of flow are relevant considerations for determining if a waterbody has the 

physical characteristics suitable for navigation. f

 While a traditional navigable water need not be capable of supporting navigation at all times, the 

frequency, volume, and duration of flow are relevant considerations for determining if a waterbody has the 

physical characteristics suitable for navigation.

g A trip taken solely for the purpose of demonstrating a waterbody can be navigated would be sufficient. 

See, e.g., FPL Energy Marine Hydro LLC v. FERC, 287 F.3d 1151, 1157 (D.C. Cir. 2002).
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 8

navigation, including commercial waterborne recreation, should be supported by 

evidence. h

 

 

h

 A trip taken solely for the purpose of demonstrating a waterbody can be navigated would be sufficient. 

See, e.g., FPL Energy Marine Hydro L.L.C. v. FERC, 287 F.3d 1151, 1157 (D.C. Cir. 2002).
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 9

Section 2: Interstate Waters EPA and the Corps will assert jurisdiction 

over all interstate waters, consistent with the agencies’ current regulations defining

“waters of the United States” to include “interstate waters including interstate 

wetlands.”14 Interstate waters, defined by the federal water pollution control statutes 

prior to the CWA as “all rivers, lakes, and other waters that flow across, or form a part of, 

State boundaries,” remain jurisdictional waters under the CWA, even if such waters are 

not traditional navigable waters as described in Section 1 above.15 For purposes of this 

guidance, lakes, ponds, and similar lentic (or still) water features crossing state 

boundaries are jurisdictional as interstate waters in their entirety. For streams and rivers, 

including impoundments, field staff should determine the upstream and downstream 

extent of the stream or river crossing a state boundary that should be considered the 

“interstate water.” One method of determining the extent of a riverine “interstate water” 

is the use of stream order. Thus, for rivers and streams the “interstate water” would 

extend upstream and downstream of such boundary for the entire length that the water is 

of the same stream order.16

The agencies will analyze tributaries to interstate waters17 consistent with the 

treatment of tributaries to traditional navigable waters under Justice Kennedy's standard 

discussed in Section 4 below. Similarly, the agencies will analyze wetlands adjacent to 

interstate waters (except wetlands that are adjacent to interstate wetlands)18 consistent 

with the treatment of adjacent wetlands under Justice Kennedy's standard discussed in 

Section 5 below. Finally, EPA and the Corps will analyze other waters relative to an 

interstate water consistent with Section 6 below. Section 3: Significant Nexus 

AnalysisThe agencies will assert jurisdiction over waters with a significant nexus to 

traditional navigable waters or interstate waters in accordance with SWANCC and 

Rapanos. Justice Kennedy stated: 

“In Solid Waste Agency of Northern Cook Cty. v. Army Corps of 

Engineers, 531 U.S. 159 (2001) (SWANCC), the Court held, under the 

circumstances presented there, that to constitute ‘navigable waters’ under the Act, 

a water or wetland must possess a ‘significant nexus’ to waters that are or were 

navigable in fact or that could reasonably be so made.”19 

Waters have the requisite significant nexus if they, either alone or in combination 

with similarly situated waters in the region, significantly affect the chemical, physical, or 

biological integrity of traditional navigable waters or interstate waters.i There is one 

significant nexus standard for waters of the United States, and this section provides 

general guidance for determining the presence or absence of a significant nexus. 

 

i

 In discussing the significant nexus standard, Justice Kennedy stated: “The required nexus must be 

assessed in terms of the statute’s goals and purposes. Congress enacted the [CWA] to ‘restore and maintain 

the chemical, physical, and biological integrity of the Nation’s waters’ . . . .” 547 U.S. at 779. Consistent 

with Justice Kennedy’s instruction, EPA and the Corps will apply the significant nexus standard in a 

manner that restores and maintains any of these three attributes of traditional navigable waters and 

interstate waters. 
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 10

Sections 4, 5 and 6 provide more specific guidance to field staff for applying the 

significant nexus standard when determining jurisdiction over:

• tributaries, 

• adjacent wetlands, and 

• other waters.

To evaluate the presence or absence of a significant nexus, the agencies intend to, 

as a general matter, consider: 

(1) Waters to be “similarly situated” with waters of the same resource type, 

specifically (a) tributaries; (b) adjacent wetlands; or (c) other waters that are in 

close physical proximity to traditional navigable waters, interstate waters, or 

their jurisdictional tributaries (“proximate other waters”);jWaters to be “in the 

region” if they fall within the same watershed. For the purposes of this 

analysis, the watershed is defined by the area draining into the traditional 

navigable water or interstate water; and 

(2) Waters to have a significant nexus if they alone or in combination with other 

similarly situated waters in the same watershed have an effect on the 

chemical, physical, or biological integrity of traditional navigable waters or 

interstate waters that is more than “speculative or insubstantial.” 

Therefore, field staff should first determine whether the water to be evaluated is a 

tributary, adjacent wetland, or proximate other water under the regulations - waters in the 

same category should be considered the similarly situated waters.

 Next, field staff should determine the watershed, as defined by the area20

draining into the nearest traditional navigable water or interstate water, and should 

identify the “similarly situated” waters in that watershed. The logical and scientifically 

valid "region" for determining whether similarly situated waters have a significant nexus 

is the watershed that drains to the nearest traditional navigable water or interstate water 

through a single point of entry. There may be circumstances in which field staff, for 

efficiency purposes, elect to begin the case-by-case significant nexus analysis utilizing a 

smaller watershed (for example, in some circumstances, the Hydrologic Unit Code 

(HUC)-10 "watershed" as identified by the U.S. Geological Survey and the Natural 

Resources Conservation Service, which are typically between 40,000-250,000 acres in 

size).21 Field staff should not, however, utilize an area larger than the watershed that 

drains to the nearest traditional navigable water or interstate water through a single point 

of entry. When a smaller watershed provides sufficient science-based justification to 

 

j

For other waters that are not in close physical proximity to traditional navigable waters, interstate waters, 

or their jurisdictional tributaries, the agencies will apply the significant nexus standard to each of these 

waters individually, except in cases where there is a compelling scientific basis for treating a group of such 

waters as similarly situated waters in the same region (see Section 6).
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 11

establish jurisdiction, field staff need not unnecessarily expend administrative time and 

resources analyzing the entire single point of entry watershed. However, field staff 

should not use a watershed smaller than the single point of entry watershed as the basis 

for a finding of no jurisdiction.Finally, field staff should determine whether the water 

they are evaluating, in combination with other similarly situated waters in the watershed, 

has a significant nexus to the nearest traditional navigable water or interstate water. 

Functions of waters that might demonstrate a significant nexus include sediment trapping, 

nutrient recycling, pollutant trapping and filtering, retention or attenuation of flood 

waters, runoff storage, and provision of aquatic habitat. A hydrologic connection is not 

necessary to establish a significant nexus, because in some cases the lack of a hydrologic 

connection would be a sign of the water’s function in relationship to the traditional 

navigable water or interstate water, such as retention of flood waters or pollutants that 

would otherwise flow downstream to the traditional navigable water or interstate water. 

Within a single point of entry watershed, over a period of time there will probably be 

multiple jurisdictional determinations. While field staff will have to make case-specific 

determinations, they may use information used in previous determinations, and the 

agencies would generally expect that if a significant nexus has been established for one 

water in the watershed, then other similarly situated waters in the watershed would also 

be found to have a significant nexus, because under Justice Kennedy’s test, similarly 

situated waters in the region should be evaluated together. However, the documentation 

for each case should be complete enough to support the specific jurisdictional 

determination without cross-references to other files, including an explanation of which 

waters were considered together as similarly situated and in the same region. 

Among the most important tasks for field staff is demonstrating that a significant

nexus exists between the “similarly situated” waters that are the subject of a case-specific 

jurisdictional determination and the relevant traditional navigable water or interstate 

water. Justice Kennedy provides guidance about the nature of the nexus when he 

concludes that waters are not jurisdictional when their effects on the physical, chemical, 

or biological integrity of downstream traditional navigable waters are speculative or 

insubstantial. In the context used by Justice Kennedy, a “significant nexus” includes 

having a predictable or observable chemical, physical, or biological functional 

relationship between the similarly situated waters and the traditional navigable water or 

interstate water. EPA and the Corps should further demonstrate that the similarly situated 

waters significantly affect the traditional navigable water or interstate water.

Thus, field staff should look for indicators of hydrology, effects on water quality, 

and physical, chemical, and biological (including ecological) connections or functions 

when assessing whether a water, alone or in combination with similarly situated waters, 

has a more than speculative or insubstantial effect on the chemical, physical, or biological 

integrity of downstream traditional navigable waters or interstate waters. Examples of 

ways in which hydrology can significantly affect downstream waters include, but are not 

limited to, transport of water and materials and compounds carried by the water (e.g., 

suspended materials, dissolved compounds), water retention, as a medium for the 
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 12

movement of aquatic organisms such as fish and invertebrates, and water discharge (e.g., 

release of retained water to other waters). Effects on the chemical integrity of 

downstream waters may include the extent to which the waters have the capacity to carry 

pollutants (for example, petroleum wastes, toxic wastes, and sediment) or flood waters 

downstream to traditional navigable waters or interstate waters; the extent to which the 

waters reduce the amount of pollutants or flood waters that would otherwise enter 

traditional navigable waters or interstate waters; and the extent to which the waters 

perform physical functions related to the maintenance of downstream water quality such 

as sediment trapping. Biological functions performed by the waters that may affect 

downstream traditional navigable waters or interstate waters include the capacity to 

transfer nutrients and organic carbon to downstream food webs (for example, 

macroinvertebrates present in headwater streams convert carbon in leaf litter, making it 

available to species downstream), and the maintenance of habitat that provides spawning 

areas for species in downstream waters. 

Analysis of the above indicators, whether documented for an individual water or 

based on scientific literature describing functions applicable to the waters in question, 

along with an analysis of how the described functions affect a traditional navigable water 

or interstate water will allow field staff to evaluate whether the water alone or in 

combination with similarly situated waters in the watershed is likely to have a more than 

speculative or insubstantial effect on the chemical, physical, or biological integrity of a 

traditional navigable water or interstate water. It is not appropriate to determine 

significant nexus based solely on any specific threshold of distance (for example, 

between a tributary and the traditional navigable water). Watershed ecosystems, and 

their interrelationships, are constructed of component parts that have relevance when 

considered collectively. Failure to protect the components can undermine the ecosystem 

in its entirety. Therefore, the agencies have an obligation to evaluate waters in terms of 

how they interrelate and function as ecosystems rather than as individual units, especially 

in the context of complex ecosystems where their integrity may be compromised by 

environmental harms that individually may not be measurably large but collectively are 

significant. It is important to clarify that agency field staff, in conducting a significant 

nexus analysis, are not required to identify or evaluate every similarly situated water 

located within a particular watershed being assessed. Staff should evaluate as many 

waters of the same type as is necessary to support and document the presence or absence 

of a significant nexus for that type of water (e.g., adjacent wetland, tributary or proximate 

other water). Staff should be confident that their significant nexus determination based 

on evaluation of a representative subset of adjacent wetlands, tributaries, or proximate 

other waters in a particular watershed would be fully consistent with a determination 

based on an evaluation of all waters of the same type in the watershed. Field staff should 

look at the best available information to identify the similarly situated waters in the point 

of entry watershed and their effects on downstream traditional navigable waters or 

interstate waters. In many circumstances, a reliable affirmative jurisdictional 

determination may be based on consideration of a subset of similarly situated waters, 

since including additional waters in the analysis would only establish a more significant 
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 13

nexus to the traditional navigable water or interstate water. In general, field staff are not 

expected to develop new information on similarly situated waters (e.g., the identification 

or delineation of as yet unmapped wetlands or tributaries). In many cases, scientifically 

credible (e.g., peer reviewed) literature on the functions and effects of similarly situated 

waters generally will be sufficient, along with site-specific information for the water for 

which a determination is being conducted, to support a significant nexus jurisdictional 

determination. This information should be incorporated into a site-specific explanation 

of how the waterbody and similarly situated waters in the region significantly affect the 

physical, chemical, or biological integrity of a traditional navigable or interstate water.

Section 4: Tributaries EPA and the Corps will assert jurisdiction over tributaries 

under either the plurality standard or the Kennedy standard, as described below.

For purposes of this guidance, a water may be a tributary if it contributes flow to a 

traditional navigable water or interstate water, either directly or indirectly by means of 

other tributaries. A tributary can be a natural, man-altered, or man-made water body. 

Examples include rivers and streams, as well as lakes and certain wetlands that are part of 

the tributary system and flow directly or indirectly into traditional navigable waters or 

interstate waters. A tributary is physically characterized by the presence of a channel with 

defined bed and bank. The bed of a stream is the bottom of the channel. The lateral 

constraints (channel margins) are the stream banks. Channels are formed, maintained, 

and altered by the water and sediment they carry, and the forms they take can vary 

greatly. 

A means of identifying the lateral limits of a tributary, including where there are no 

contiguous wetlands, is the existence of an ordinary high water mark (OHWM). Corps 

regulations define OHWM as “that line on the shore established by the fluctuations of

water and indicated by physical characteristics such as a clear, natural line impressed on 

the bank, shelving, changes in the character of soil, destruction of terrestrial vegetation, 

the presence of litter and debris, or other appropriate means that consider the 

characteristics of the surrounding areas.”22 In many tributaries, the bed is that part of the 

channel below the OWHM, and the banks often extend above the OHWM. Channel 

characteristics depend on variables such as hydrology, lithology, climate, physiography, 

and gradient,23 among others. A tributary continues as far as a channel (i.e., bed and 

bank) is present. A natural or manmade break (e.g., rock outcrop, underground flow, 

dam, weir, diversion, or similar break) in the presence of a bed and bank or ordinary high 

water mark does not establish the upstream limit of a tributary in cases where a bed and 

bank and an ordinary high water mark can be identified upstream and downstream of the 

break. Tributaries that have been channelized by being lined with concrete are still 

considered tributaries for the purposes of this guidance.Certain types of erosional 

features, such as gullies and rills, are not tributaries for purposes of this guidance. 

Gullies24 are relatively deep channels that are ordinarily formed on valley sides and floors 

where no well-defined channel previously existed. They are commonly found in areas 

with low-density vegetative cover or with soils that are highly erodible. Rills25 are 
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 14

formed by overland water flows eroding the soil surface during rain storms. Erosional 

features that are not tributaries for the purposes of this guidance can also be found in 

environments where compacted soil and sparse vegetation have increased overland flow 

significantly. The two main processes that result in the formation of gullies and similar 

erosional features are downcutting and headcutting, which are forms of longitudinal 

(incising) erosion. These actions ordinarily result in erosional cuts that are often deeper 

than they are wide, with very steep banks, often small beds, and typically only carry 

water during precipitation events. The principal erosional processes that modify streams 

are also downcutting and headcutting. In streams, however, lateral erosion is also very 

important. The result is that streams, except on steep slopes or where soils are highly 

erodible, are characterized by the presence of more defined bed and banks as compared to 

typical erosional features that are more deeply incised. Field staff should consider these 

factors as they distinguish streams and other tributaries that may be subject to Clean 

Water Act jurisdiction from other types of erosional features. Non-tidal ditches (including 

roadside and agricultural ditches) are also not tributaries except where they have a bed, 

bank, and ordinary high water mark; connect directly or indirectly to a traditional 

navigable or interstate water; and have one of the following five characteristics:

• natural streams that have been altered (e.g., channelized, straightened or 

relocated); 

• ditches that have been excavated in waters of the U.S., including wetlands; 

• ditches that have relatively permanent flowing or standing water; 

• ditches that connect two or more jurisdictional waters of the U.S.; or

ditches that drain natural water bodies (including wetlands) into the tributary 

system of a traditional navigable or interstate water.If a ditch is considered a tributary, it 

will be evaluated in the same manner as other tributaries (i.e., plurality standard or 

Kennedy standard, as appropriate). Note that tidal ditches are by definition waters of the 

U.S.

Natural and man-made swales are also not tributaries for purposes of this 

guidance. In certain circumstances, however, ditches or swales include areas that meet 

the regulatory definition of “wetlands.” Wetland ditches and swales will be evaluated as 

wetlands under the plurality or Kennedy standard, not as tributaries (unless the ditch itself 

is considered a tributary for one of the reasons stated above). Ditches and swales are 

considered wetlands when they meet the applicable criteria in the Corps of Engineers 

Wetland Delineation Manual or the appropriate regional supplement to that Wetland 

Delineation Manual.

Even when not jurisdictional waters, these geographic features (e.g., swales, ditches) may 

still contribute to a surface hydrologic connection between an adjacent wetland and a 

traditional navigable water or interstate water. In addition, these geographic features may 

function as “point sources” (i.e., "discernible, confined and discrete conveyance[s]" under 

CWA section 502(14)), such that discharges of pollutants to waters through these features 
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 15

could be subject to other CWA regulations (e.g., CWA section 402).Tributaries Covered

under the Rapanos Plurality Standard 

EPA and the Corps will assert jurisdiction over “relatively permanent, standing or 

continuously flowing bodies of water” connected to traditional navigable waters.k Under 

the plurality standard, relatively permanent waters are jurisdictional without making a 

significant nexus finding.

Under the plurality standard, a non-navigable tributary is jurisdictional when it 

satisfies the following characteristics:

(1) The tributary is connected, directly or indirectly through other tributaries, 

to a downstream traditional navigable water, and

(2) Flow in the tributary, except for drought years, is at least seasonal.

A central issue to the plurality standard is what constitutes “seasonal flow.” In 

this context, a water is “seasonal” when it has predictable flow during wet seasons in 

most years. The time period constituting “seasonal” will vary across the country. Rather 

than having distinct, rigid boundaries, stream reaches classified as perennial, intermittent, 

and ephemeral may more accurately be described as dynamic zones within stream 

networks. The length or extent of these zones may be highly variable and is dictated by 

multiple factors such as annual precipitation, evapotranspiration, and land- and water-use 

practices.26 Thus, determination of whether a water meets the plurality standard for 

relatively permanent should involve determination of the length and timing of seasonal 

flows in the ecoregion in question. 

Tributaries that are not relatively permanent will be evaluated under the Kennedy 

standard. Tributaries Covered under the Rapanos Kennedy StandardEPA and Corps 

regulations define “waters of the United States” to include tributaries to traditional 

navigable waters and to interstate waters.27 Consistent with the agencies’ interpretation 

of the CWA, these regulations and the relevant case law, EPA and the Corps expect to 

assert jurisdiction over all tributaries to traditional navigable waters or interstate waters, 

provided that the tributary, alone or in combination with other similarly situated 

tributaries in the watershed, significantly affects the chemical, physical, or biological 

integrity of traditional navigable waters or interstate waters.

Thus, a tributary is jurisdictional where:

(1) It is a tributary as defined for purposes of this guidance to a traditional 

navigable water or an interstate water; and

 

k 547 U.S. at 739.k The agencies will not assert jurisdiction over such waters under the plurality standard 

within the Eleventh Circuit, i.e., waters in the states of Florida, Georgia and Alabama. See United States v. 

Robison, 505 F.3d 1208 (11th Cir.); 2007); reh’g en banc denied, 521 F.3d 1319 (11th Cir. 2007), cert. 

denied, sub nom. United States v. McWane, Inc., 129 S. Ct. 627, 630 (2008). Instead the agencies will use 

the Kennedy standard only.
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 16

(2) The tributary, alone or in combination with other tributaries in the 

watershed, has a significant nexus with the traditional navigable water or 

interstate water. 

When performing a significant nexus analysis for a tributary, the first step is to 

determine whether that tributary has a bed and bank and an ordinary high water mark. If 

the tributary possesses those characteristics, the next step is to determine whether the 

tributary drains, or is part of a network of tributaries that drain, into a downstream 

traditional navigable water or interstate water. If it can be demonstrated that the tributary 

has a bed and bank, and an OHWM, and is part of a tributary system to a traditional 

navigable water or an interstate water, and, therefore, can transport pollutants, flood 

waters or other materials to a traditional navigable water or interstate water, then the 

agencies would generally expect that the tributary, along with the other tributaries in the 

watershed (the "similarly situated" waters), can be demonstrated to have a significant 

nexus with the downstream traditional navigable water or interstate water. This 

expectation is based on the significant harm that pollutants can have on the physical, 

chemical, or biological integrity of the downstream traditional navigable water or 

interstate water.28 The presence of a bed and bank and an OHWM are physical indicators 

of flow and it is likely that flows through all of the tributaries collectively in a watershed 

with the above characteristics are sufficient to transport pollutants, or other materials 

downstream to the traditional navigable water or interstate water in amounts that would

significantly affect its chemical, physical or biological integrity. 

When considering whether the tributary being evaluated eventually flows to an 

interstate water or traditional navigable water, field staff should trace the tributary 

connection using resources such as direct observation or U.S. Geological Survey maps, 

aerial photography or other reliable remote sensing information, soil survey data or other 

appropriate information. 

Although the agencies generally expect that tributaries will be found to have a 

significant nexus with downstream traditional navigable waters or interstate waters, as 

explained above, it is still important that field staff document such a significant nexus 

through a site-specific analysis for tributaries that are not relatively permanent. Field 

staff should document, using available or readily obtainable information wherever 

possible, the flow characteristics and functions of the tributary or tributaries, and their 

hydrologic relationship to the nearest downstream traditional navigable water or interstate 

water. Hydrologic information may include volume, duration, and frequency of flow (if 

such information is readily available, e.g., through publicly available reports or on-line 

resources), as well as physical indicators of flow. Field staff may document the flow 

characteristics of tributaries by using physical indicators of flow, observations of flow 

considered in the context of local precipitation patterns and recent precipitation events, 

field reports, local expert statements, and other sources of information. Ordinary high 

water mark determinations are made by examining recent physical evidence of flow.29 It 

is not necessary to document actual flow data via stream gages.30 Field staff should also 
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 17

document other functions provided by the tributary, and describe how those functions 

may significantly affect the physical, chemical, or biological integrity of downstream 

traditional navigable waters or interstate waters. 

Flow characteristics and functions of the tributary or tributaries and their 

hydrologic relationship to the nearest downstream traditional navigable water or interstate 

water may include topographic maps, gage data, historic records of water flow, statistical 

data, personal observations/records, and other relevant information. Consideration may 

also be given to relevant contextual factors that directly influence the hydrology of 

tributaries, including the size of the watershed, average annual rainfall, and average 

annual winter snow pack. The significant nexus evaluation should also discuss the 

potential for the tributaries to transport pollutants to a traditional navigable water or 

interstate water. Direct observation of the tributary is not necessary if other available 

documentation is sufficient to establish the significant nexus.

Examples of other functions provided by tributaries that may significantly affect 

the physical, chemical, or biological integrity of downstream traditional navigable waters 

or interstate waters include: distributing sediment31 to maintain stream and riparian 

habitat; nutrient cycling and removal; providing habitat for amphibians, fish, and other 

aquatic or semi-aquatic species living in and near the stream that may use the 

downstream waters for other portions of their life stages (e.g., spawning areas for 

recreationally or commercially important species); improving or maintaining biological 

integrity in downstream waters; and transferring nutrients and organic carbon vital to 

support downstream food webs (e.g., macroinvertebrates present in headwater streams 

convert carbon in leaf litter making it available to species downstream).32 Disruptions in 

these biological processes can significantly affect the functional capacity of the entire 

downstream system.33 Tributaries help to maintain base flow in the larger rivers 

downstream, which is particularly important in times of drought. At the same time, a 

network of tributaries can regulate the flow of water into downstream waters, moderate 

low flow and high flow extremes, reduce local and downstream flooding, and prevent 

excess erosion caused by flooding.34 Section 5: Adjacent Wetlands

The agencies will assert Clean Water Act jurisdiction over adjacent wetlands that 

meet either the plurality standard or the Kennedy standard under Rapanos.

Wetlands Covered Under the Rapanos Plurality Standard

EPA and the Corps will assert jurisdiction over “wetlands with a continuous 

surface connection to” “relatively permanent, standing or continuously flowing bodies of 

water” connected to traditional navigable waters.l

 

l

 547 U.S. at 739, 742. As noted, the agencies will not assert jurisdiction over such waters under the 

plurality standard within the Eleventh Circuit, i.e., waters in the states of Florida, Georgia and Alabama. 

See United States v. Robison, supra, footnote h.
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 18

 The plurality opinion in Rapanos created a standard for finding statutory 

jurisdiction under the CWA for wetlands, which is related to the presence of a physical 

connection between the wetland and the relatively permanent water to which it is 

adjacent. Under the plurality standard, wetlands with a continuous surface connection to 

relatively permanent waters are jurisdictional without the legal obligation to make a 

significant nexus finding.

Under the plurality standard, an adjacent wetland is jurisdictional when it satisfies 

the following characteristics:

(1) The wetland is adjacent to a relatively permanent, non-navigable tributary, 

that is connected to a downstream traditional navigable water, andA

continuous surface connection exists between the wetland and a relatively 

permanent tributary where the wetland directly abuts the water (e.g., they 

are not separated by uplands, a berm, dike, or similar feature). A 

“continuous surface connection” does not require the presence of water at 

all times in the connection between the wetland and the jurisdictional 

water.

Wetlands Covered Under the Rapanos Kennedy Standard

The agencies will assert Clean Water Act jurisdiction over wetlandsm adjacent to 

traditional navigable waters or non-wetland interstate waters or to another water 

of the U.S. where such wetlands have a significant nexus with downstream 

traditional navigable or interstate waters.n Adjacent wetlands will be considered 

to have a significant nexus if they, alone or in combination with similarly situated 

wetlands, have an effect on the chemical, physical, or biological integrity of 

traditional navigable waters or interstate waters that is more than “speculative or 

insubstantial.”35 As a general matter, “similarly situated” adjacent wetlands 

include all adjacent wetlands located in the point-of-entry watershed. Wetlands 

adjacent to traditional navigable waters or non-wetland interstate waters are per se

jurisdictional and do not require a showing of significant nexus.36Thus, an 

adjacent wetland is jurisdictional where such wetland meets the definition of 

“adjacent” as that term is defined in the agencies’ regulations and is either:(1) 

Adjacent to a traditional navigable water or non-wetland interstate water; or(2)

Adjacent to a tributary, lake, reservoir, or other jurisdictional water (except 

 

m Under normal circumstances, a wetland will meet all three factors of hydrology, hydrophytic vegetation, 

and hydric soils, as required by agency regulations, and described in the United States, U.S. Army Corps of 

Engineers, Wetlands Delineation Manual (Washington, D.C.: U.S. Army Corps of Engineers,1987) or 

appropriate Regional Supplement. The regulatory definition of waters of the U.S. includes “wetlands 

adjacent to waters (other than waters that are themselves wetlands) identified [as jurisdictional].” 33 C.F.R. 

§ 328.3(a)(7); 40 C.F.R. § 230.3(s)(7).

n

 The plurality standard in Rapanos may provide an alternative basis for asserting jurisdiction. See Section 

5.
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 19

another wetland) and either alone or in combination with other adjacent wetlands 

in the watershed has a significant nexus to the nearest downstream traditional 

navigable or interstate water.

 The regulations define “adjacent” as follows: “The term adjacent means 

bordering, contiguous, or neighboring. Wetlands separated from other waters of the 

United States by man-made dikes or barriers, natural river berms, beach dunes and the 

like are ‘adjacent wetlands.’”37 Under this definition, a wetland does not need to meet all 

criteria to be considered adjacent. The agencies consider wetlands to be bordering, 

contiguous, or neighboring, and therefore “adjacent” if at least one of following three 

criteria is satisfied: 

(1) There is an unbroken surface or shallow sub-surface hydrologic connection 

between the wetland and jurisdictional waters; or

(1)(2) The wetlands are physically separated from jurisdictional waters by “manmade dikes or barriers, natural river berms, beach dunes, and the like”; 

orWhere a wetland’s physical proximity to a jurisdictional water is reasonably 

close, that wetland is “neighboring” and thus adjacent. For example, wetlands 

located within the riparian area or floodplain of a jurisdictional water will 

generally be considered neighboring, and thus adjacent. One test for whether a 

wetland is sufficiently proximate to be considered “neighboring” is whether 

there is a demonstrable ecological interconnection between the wetland and 

the jurisdictional waterbody. For example, if resident aquatic species (e.g., 

amphibians, aquatic turtles, fish, or ducks) rely on both the wetland and the 

jurisdictional waterbody for all or part of their life cycles (e.g., nesting, 

rearing, or feeding), that may demonstrate that the wetland is neighboring and 

thus adjacent. The agencies recognize that as the distance between the 

wetland and jurisdictional water increases, the potential ecological 

interconnection between the waters is likely to decrease. 

An unbroken surface or shallow sub-surface hydrologic connection to 

jurisdictional waters may be established by a physical feature or discrete conveyance that 

supports periodic flow between the wetland and a jurisdictional water. Water does not 

have to be continuously present in this hydrologic connection and the flow between the

wetland and the jurisdictional water may move in either or both directions. The 

hydrologic connection need not itself be a water of the U.S. A shallow subsurface 

hydrologic connection is lateral water flow through a shallow subsurface layer, such as 

may be found in steeply sloping forested areas with shallow soils, soils with a restrictive 

horizon, or in karst systems.38 Shallow subsurface connections may be found below the 

ordinary root zone (below 12 inches), where other wetland delineation factors may not be 

present. A combination of physical factors may reflect the presence of a shallow 

subsurface connection, including, position in the landscape (for example, on a slope 

directing flow from wetland to jurisdictional waters), stream hydrograph, and soil surveys 

(for example, exhibiting indicators of high transmissivity over an impermeable layer).If 
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 20

uplands separating a wetland from jurisdictional water can reasonably be characterized as 

“man-made dikes or barriers, natural river berms, beach dunes, and the like,” then, under 

the agencies’ regulations, the wetlands are adjacent even if no apparent hydrologic 

connection exists. It is important to note that natural river berms are formed by sediment 

deposits accumulating at or near the stream bank during flood events. Such berms vary 

in height from inches to feet, and also can be quite wide.39 Similarly, multiple beach 

dunes may exist between a wetland and jurisdictional water (including primary and 

secondary dunes), because beach dunes typically function as an interdunal system 

(particularly on barrier islands). 

 The link between physical proximity and a physical or ecological (biological) 

connection is well documented in the scientific literature. A wetland within the riparian 

area40 or floodplain41 typically has such an interconnection. For example, adjacent 

wetlands typically help to store floodwaters, pollutants, and sediments that could 

otherwise reach a jurisdictional water.42 Adjacent wetlands often provide important 

sources of stored water that augment stream flow during low-flow periods.43 Species, 

such as amphibians, certain reptiles (e.g., watersnakes), waterfowl, invertebrates, and fish 

(including anadromous and catadromous fish), move between an adjacent wetland and a 

jurisdictional water for spawning, nesting, feeding, refuge, and other life stage 

requirements.44 Species that move between an adjacent wetland and a jurisdictional 

water are distinguishable from migratory species. Migratory species use the wetland 

during a journey to a different area45 and are not to be used as a scientific basis for 

demonstrating an ecological interconnection for adjacency. While it is not appropriate to 

determine adjacency based solely on any specific threshold of distance, as the distance 

between the wetland and jurisdictional water increases, the potential interconnection 

between the waters will decrease and a finding of adjacency is less likely. The distance 

between a tributary and its adjacent wetlands may vary by region, as well as based on 

site-specific factors within regions.

All wetlands within a wetland mosaic should ordinarily be considered collectively 

when determining adjacency. Wetlands present in such systems act generally as a single 

ecological unit. A “wetland mosaic” refers to a landscape where wetland and nonwetland components are too numerous and closely associated to be appropriately 

delineated or mapped separately. These areas often have complex microtopography, with 

repeated small changes in elevation occurring over short distances. Tops of ridges and 

hummocks are often non-wetland but are interspersed with wetlands having hydrophytic 

vegetation, hydric soils, and wetland hydrology. Under Justice Kennedy’s standard, the 

following legal test for Clean Water Act jurisdiction applies: If a wetland is adjacent to a 

traditional navigable water or a non-wetland interstate water, a finding of adjacency is 

sufficient in and of itself to demonstrate that the wetland is subject to Clean Water Act 

jurisdiction. On the other hand, a finding that a particular wetland is adjacent to a 

jurisdictional waterbody other than a traditional navigable water or non-wetland interstate 

water is not sufficient in and of itself to establish Clean Water Act jurisdiction over that 

wetland. For the latter category of adjacent wetlands, in order to establish Clean Water 
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 21

Act jurisdiction, field staff, on a case-by-case basis, must determine whether the 

particular adjacent wetland, alone or in combination with similarly situated wetlands in 

that watershed, has a significant nexus with traditional navigable waters or non-wetland 

interstate waters (see discussion below).A determination of adjacency is based on an 

evaluation of the relationship between a wetland and the nearest jurisdictional water, 

which includes consideration of both physical and ecological connections between those 

waterbodies. In contrast, a determination of significant nexus is a different inquiry, 

which is based on evaluating whether there is a significant nexus between that adjacent 

wetland (in combination with similarly situated adjacent wetlands in the watershed) and a 

traditional navigable water or a non-wetland interstate water.

As discussed in Section 3, the agencies generally consider all wetlands within the 

watershed that are adjacent to jurisdictional waters to be “similarly situated” waters “in 

the region.” (Wetlands adjacent to non-jurisdictional waters are considered “other 

waters.”) The relevant watershed is defined by the topographic area draining into the 

nearest traditional navigable water or interstate water. However, as with tributaries, field 

staff may utilize a smaller area for a significant nexus analysis where this is sufficient to 

establish the presence or absence of a significant nexus for adjacent wetlands within the 

watershed as a whole. When identifying other adjacent wetlands in the watershed to be 

considered in the significant nexus analysis, field staff may use resources such as direct 

observation or U.S. Geological Survey maps, aerial photography, or other reliable remote 

sensing information. Using such information, staff should include in the evaluation as 

many adjacent wetlands as is necessary to support and document the presence or absence 

of a significant nexus. Field staff are not required to identify or evaluate every adjacent 

wetland located within a particular watershed being assessed and are generally not 

expected to develop new information on the location of such wetlands. As with 

tributaries, field staff should use the best available information on the adjacent wetlands 

in the point of entry watershed, which may include scientific literature on the functions 

and effects of wetlands within the watershed generally and how those wetlands 

significantly affect the physical, chemical, or biological integrity of the traditional 

navigable waters or interstate waters. For affirmative determinations especially, 

consideration of a subset of adjacent wetlands may be sufficient, since including 

additional adjacent wetlands in the analysis would only establish a more significant nexus 

to the traditional navigable water or interstate water.

 When evaluating significant nexus for adjacent wetlands, field staff should 

consider the many functions of waters such as sediment trapping, nutrient recycling, 

pollutant trapping and filtering, retention or attenuation of flood waters, runoff storage, 

and provision of habitat. In general, tributaries and their adjacent wetlands function as an 

integrated hydrologic system, and as a unit they may affect the amount of pollutants and

floodwaters that reach the downstream traditional navigable waters or interstate waters. 

Section 6: Other Waters

 The “other waters” or “(a)(3) waters” provision of EPA’s and the Corps 

regulations includes:All other waters such as intrastate lakes, rivers, streams (including 
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 22

intermittent streams), mudflats, sandflats, wetlands, sloughs, prairie potholes, wet 

meadows, playa lakes, or natural ponds, the use, degradation or destruction of which 

could affect interstate or foreign commerce. . . . 46

 The agencies recognize that Supreme Court decisions in SWANCC and Rapanos 

have identified limitations on the scope of (a)(3) waters that may be determined to be 

jurisdictional under the CWA. The agencies expect to further clarify the scope of waters 

subject to CWA jurisdiction, including jurisdiction over (a)(3) waters after SWANCC and

Rapanos, as part of a notice and comment rulemaking. In the meantime, the agencies 

will make case-by-case, fact-specific determinations of jurisdiction under (a)(3) in the 

manner discussed below.

Physically Proximate Other Waters 

EPA and the Corps will make fact-specific determinations of jurisdiction for other 

waters that are in close physical proximity to traditional navigable waters, interstate 

waters, or their jurisdictional tributaries, and that alone or in combination with similarly 

situated proximate other waters in the region significantly affect the chemical, physical, 

or biological integrity of traditional navigable waters or interstate waters. For purposes 

of this guidance, proximate other waters are non-wetland waters that would satisfy the 

regulatory definition of “adjacent” if they were wetlands. They include lakes, ponds, and 

other non-wetland waters that are bordering, contiguous, or neighboring to jurisdictional 

waters, including waters that are separated from jurisdictional waters by man-made dikes 

or barriers, natural river berms, beach dunes and the like. Such waters have many of the 

same functions and effects with respect to jurisdictional waters as adjacent wetlands. The 

agencies believe it is scientifically appropriate and consistent with Justice Kennedy’s 

opinion to evaluate significant nexus for such waters in the same manner as for adjacent 

wetlands. 

 For purposes of the significant nexus analysis, all physically proximate other 

waters in the same point-of-entry watershed should be evaluated together as similarly 

situated waters in the region. This is appropriate for the same reasons as it is appropriate 

to evaluate all adjacent wetlands in the point-of-entry watershed together as similarly 

situated waters. 

Other Waters that Are Not Physically Proximate to Jurisdictional Waters

Non-physically proximate other waters are isolated, intrastate, non-navigable 

waters and wetlands that would not meet the regulatory definition of “adjacent” with 

respect to jurisdictional waters. The agencies note that the (a)(3) provisions of our 

regulations remain in effect and that the SWANCC decision specifically addressed only 

the presence of migratory birds as a basis for asserting jurisdiction, and not the validity of 

the (a)(3) provisions generally. However, the agencies interpret Justice Kennedy’s 

opinion as suggesting that the same significant nexus standard that he articulated for 

adjacent wetlands is appropriate for (a)(3) waters, and we have thus clarified above how 
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 23

this standard should be applied in the case of (a)(3) waters that are in close physical 

proximity to jurisdictional waters. At the same time, we recognize that for other waters 

that are geographically separated from jurisdictional tributaries, establishing a significant 

nexus may be more challenging. Thus, at this time, we are not providing specific 

guidance on making such determinations and are instead directing agency field staff to 

continue the current practice of referring determinations for non-physically proximate 

other waters to their respective Headquarters and obtaining formal project-specific 

approval before asserting or denying jurisdiction. 

The general approach for determining significant nexus for such waters would be 

the same as discussed in Section 3. Because such waters may be widely scattered 

geographically, and physically remote from jurisdictional waters, field staff should 

generally conduct significant nexus analyses for such waters individually, unless there is 

a compelling scientific basis for treating a group of such waters as similarly situated 

waters in the same region. In accordance with the decision in SWANCC, consideration of 

use by migratory species is not relevant to the significant nexus determination for such 

waters.

The agencies emphasize that this document is guidance, which lacks the force of law; the

agencies expect to proceed with notice and comment rulemaking to further clarify the 

regulatory definition of the term “waters of the United States.” As a part of that process, 

we will further consider, based on a review of the scientific literature, how a significant 

nexus analysis should be conducted for non-physically proximate other waters.Section 7: 

Waters Generally Not Jurisdictional

The scope of “waters of the United States” does not include all waters. EPA and 

the Corps previously have described in preambles to CWA regulations waters that the 

agencies generally do not consider to be waters of the U.S.47 The agencies’ position 

regarding these waters is unchanged. The categories of waters generally not “waters of 

the U.S.” include:

• Wet areas that are not tributaries or open waters and do not meet the regulatory 

definition of wetlands.48

• Waterbodies excluded from coverage under the CWA by existing 

regulations.Waters that lack a significant nexus when one is required for 

jurisdiction.Artificially irrigated areas which would revert to upland if the 

irrigation ceased. 

• Artificial lakes or ponds created by excavating and/or diking dry land to collect 

and retain water and which are used exclusively for such purposes as stock 

watering, irrigation, settling basins, or rice growing. 

• Artificial reflecting pools or swimming pools excavated in uplands.
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 24

• Small ornamental bodies of water created by excavating and/or diking dry land to 

retain water for primarily aesthetic reasons.

• Water-filled depressions created in dry land incidental to construction activity and 

pits excavated in dry land for the purpose of obtaining fill, sand, or gravel, unless 

and until the construction or excavation operation is abandoned and the resulting 

body of water meets the definition of waters of the United States.

• Groundwater drained through subsurface drainage systems.o

Erosional features (gullies and rills), and swales and ditches that are not tributaries or 

wetlands (see Section 4).Section 8: Documentation

• EPA and Corps field staff should document in the administrative record the 

available information supporting a jurisdictional determination. In addition to 

location and other descriptive information regarding the water at issue, the record 

should include a clear explanation of the rationale for the jurisdictional 

conclusion, and include, as appropriate:Information leading to a conclusion that a 

water falls within a category considered in this guidance to be jurisdictional 

without the need to demonstrate a significant nexus; 

• Information used to conclude that a water has a significant nexus when one is 

required for jurisdiction;

• Information supporting a conclusion that a water lacks a significant nexus, when 

one is required for jurisdiction; or

• Information supporting a conclusion that a water falls within one of the 

categories of geographic features generally considered non-jurisdictional.

 In short, both affirmative and negative jurisdictional determinations should be 

well-documented, to ensure both public transparency and defensibility should a 

jurisdictional conclusion be challenged. The level of documentation may be greater for 

jurisdictional determinations associated with complex projects. 

 Other sections of this guidance discuss the findings necessary for particular 

categories of waters to be considered jurisdictional and/or to have a significant nexus. 

Information relevant to these findings can come from many sources, including but not 

limited to maps, aerial photography, soil surveys, watershed studies, local development 

plans, literature citations, and references from studies pertinent to the parameters being 

reviewed. Such information need not always be specific to the water whose jurisdictional 

 

o A “subsurface” drainage system is an agricultural practice designed to drain subsurface water through a 

below ground pipe system in order to maintain the groundwater table below the root zone to facilitate crop 

production. The construction or maintenance of subsurface drain systems may require a CWA permit, if it 

involves discharges of dredged or fill material into waters of the U.S.
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 25

status is being evaluated; regional and national studies of the same type of water or 

similarly situated waters can help to inform a jurisdictional analysis as long as they are 

applicable to the water being evaluated. Information derived from field observation is 

not required in cases where a "desktop" analysis can provide sufficient information to 

make the requisite findings. However, for more complex or difficult jurisdictional 

determinations, it may be important to supplement such information with field 

observation.

 An important part of a jurisdictional analysis is the location and type of water 

under consideration, so as to readily determine if the jurisdictional status of similarly 

situated waters in the region has been previously determined. If so, the jurisdictional 

conclusion, rationale, and supporting information for a similarly situated water are 

directly relevant. As Justice Kennedy noted in Rapanos, where a significant nexus has 

been established for a particular wetland, “it may be permissible, as a matter of 

administrative convenience or necessity, to presume covered status for other comparable 

wetlands in the region.”49 Therefore, once the jurisdictional status for a particular water 

within a watershed has been established, field staff can apply the significant nexus 

analysis for that water to any subsequent determinations if they establish (and document) 

that the water at issue is the same type and in the same watershed as the jurisdictional 

water.

 
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 26

APPENDIX

DISCUSSION OF LEGAL AND SCIENTIFIC BASIS FOR 

GUIDANCE SECTIONS 

The U.S. Supreme Court has addressed the scope of waters of the United States 

protected by the CWA in three cases. In United States v. Riverside Bayview Homes, Inc. 

(474 U.S. 121 (1985)), the Supreme Court held that wetlands adjacent to a traditional 

navigable water were properly considered to be “waters of the United States.” In 

SWANCC, the Court addressed the question of CWA jurisdiction over isolated, nonnavigable, intrastate ponds, and concluded that CWA jurisdiction could not be based 

solely on the presence of migratory birds. In Rapanos, the Court addressed CWA 

protections for wetlands adjacent to non-navigable tributaries, and issued five opinions 

with no single opinion commanding a majority of the Court. The plurality opinion, 

authored by Justice Scalia, stated that “waters of the United States” extended beyond 

traditional navigable waters to include “relatively permanent, standing or flowing bodies 

of water.”50 The plurality went on to clarify that relatively permanent waters ”do not 

necessarily exclude” streams, rivers, or lakes that might dry up in extraordinary 

circumstances, such as drought, and seasonal rivers, which contain continuous flow 

during some months of the year but no flow during dry months. The plurality opinion 

also asserted that only wetlands with a “continuous surface connection” to other 

jurisdictional waters are considered “adjacent” and protected by the CWA.51 Justice 

Kennedy’s concurring opinion took a different approach than Justice Scalia’s. Justice 

Kennedy concluded that “waters of the United States” included wetlands that had a 

significant nexus to traditional navigable waters, “if the wetlands, either alone or in 

combination with similarly situated lands in the region, significantly affect the chemical, 

physical, and biological integrity of other covered waters more readily understood as 

‘navigable’” (id. at 780). The four justices who signed on to Justice Stevens’ opinion 

would have upheld jurisdiction under the agencies' existing regulations and stated that 

they would uphold jurisdiction under either the plurality or Justice Kennedy's opinion (id.

at 810). Neither SWANCC nor the opinions in Rapanos invalidated any of the regulatory

provisions defining “waters of the United States.” 

Section 1: Traditional Navigable WatersLegal Basis 

 The Supreme Court has recognized that navigability“[N]avigability is a flexible 

concept and “[e]ach application of [the [Daniel Ball test] . . ... is apt to uncover variations 

and refinements which require further elaboration.”52 EPA and the Corps will be guided 

by examples of some of the types of evidence found relevant and sufficient for a 

traditional navigable waters determination in court decisions, although these will be factspecific determinations and not every type of evidence will be available or needed in 

every circumstance. Field staff have sought guidance in particular on how to determine 
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 27

whether a water is susceptible to being used for commercial navigation such that it is a 

traditional navigable water. The cases discussed below provide specific examples of the 

types of evidence courts have found sufficient to demonstrate such susceptibility. 

 In FPL Energy Marine Hydro L.L.C. v. FERC,, a case involving the Federal 

Power Act, the U.S. Court of Appeals for the District of Columbia Circuit reiterated the 

fact that “actual use is not necessary for a navigability determination” and repeated 

earlier Supreme Court holdings that navigability and capacity of a water to carry 

commerce could be shown through “physical characteristics and experimentation.”53 In 

that case, the D.C. Circuit upheld a Federal Energy Regulatory Commission navigability 

determination that was based upon three experimental canoe trips taken specifically to 

demonstrate the river’s navigability.54 The navigability determination was affirmed 

although the stream had five sets of rapids, and all parties agreed that the stream has 

never been used for commercial traffic, that there was no evidence of recreational use of 

the stream, and that the only evidence indicating actual use of the stream came from the 

three trips made for the purpose of litigation.55

 The U.S Court of Appeals for the Ninth Circuit has also implemented the 

Supreme Court’s holding that a water need only be susceptible to being used for 

waterborne commerce to be navigable-in-fact.56 In Alaska v. Ahtna, Inc., the Ninth9th

Circuit held that current use of an Alaskan river for commercial recreational boating is 

sufficient evidence of the water’s capacity to carry waterborne commerce at the time that 

Alaska became a state.57 It was found to be irrelevant whether or not the river was 

actually being navigated or being used for commerce at the time, because current 

recreational boating showed that the river always had the capacity to support navigation

by the types of boats that were in use at the time of statehood.58.

59 Here, the stream was 

found to be navigable although the shallowest part of the river is just a foot deep during 

the low season; the river is customarily used, or is susceptible to use, by watercraft such 

as powerboats, 12-foot-long inflatable rafts, and motorized freight canoes and doubleended paddle canoes; hunters and fishermen travelled the river by boat in the past; most 

of the use of the river is recreational; and it is possible to take guided fishing and 

sightseeing trips on the river.60

Section 2: Interstate Waters

Section 2: Interstate Waters EPA and the Corps will assert jurisdiction over all 

interstate waters, consistent with the agencies’ current regulations defining “waters of 

the United States” to include “interstate waters and interstate wetlands.”

61 Interstate 

waters, defined by the federal water pollution control statutes prior to the CWA as “all 

rivers, lakes, and other waters that flow across, or form a part of, State boundaries,”

remain jurisdictional waters under the CWA. For purposes of this guidance, lakes, 

reservoirs, and similar lentic (or still) water features crossing state boundaries are 

jurisdictional in their entirety to the lateral limits of their ordinary high water mark. For 

purposes of this guidance, streams, rivers, and similar lotic (or flowing) water features 
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 28

crossing a state boundary are jurisdictional upstream and downstream of such boundary 

for the entire length that the water is of the same stream order (i.e., the entire reach of the 

water crossing a state boundary that is of the same order).

The agencies will consider tributaries to interstate waters jurisdictional when they 

have a significant nexus with such interstate waters, consistent with the treatment of 

tributaries to traditional navigable waters in Section 4 below. Tributaries to interstate 

waters will be evaluated using the same significant nexus framework articulated by 

Justice Kennedy for tributaries to traditional navigable waters. A stream is a tributary to 

an interstate water if it flows directly or indirectly into the reach determined to be an 

interstate water. Tributaries located downstream of the interstate stream reach are not 

tributary to that interstate stream reach, but instead to the stream reach into which those 

tributaries flow. 

Similarly, the agencies will assess jurisdiction over wetlands adjacent to interstate 

waters (except wetlands that are adjacent to interstate wetlands)62 consistent with the 

framework established by Justice Kennedy’s standard. Thus, wetlands adjacent to nonwetland interstate waters themselves will be considered jurisdictional consistent with 

Justice Kennedy’s conclusion that wetlands adjacent to traditional navigable waters are 

jurisdictional under the Act based on a showing of adjacency alone.63 Wetlands adjacent 

to tributaries of an interstate water are jurisdictional where they have a significant nexus 

with that interstate water alone or in combination with similarly situated wetlands, 

consistent with Section 5. Finally, EPA and the Corps will analyze other waters relative 

to an interstate water consistent with Section 6.

Legal Basis 

 The language of the CWA indicates that Congress intended the term “navigable 

waters” to include interstate waters without imposing a requirement that they be 

traditional navigable waters themselves or be connected to traditional navigable waters. 

The precursor statutes to the CWA always subjected interstate waters and their tributaries 

to federal jurisdiction.p

 The text of the CWA, specifically a provision in the CWA

section 303 that establishes ongoing requirements for interstate waters, in conjunction 

with the definition of navigable waters, provides clear indication of Congress’ intent to 

protect interstate waters that were previously subject to federal regulation. Other 

 

p

 See endnote 13. Section1948 Act § 2(d)(1) of the Water Pollution Control Act of 1948,,(4), 62 Stat. at 

1156, stated: 

The 1156-1157, declaring the pollution of interstate waters in or adjacent to any State or States (whether, 

“whether the matter causing or contributing to such pollution is discharged directly into such waters or 

reaches such waters after discharged into a tributary of such waters),waters,” which endangers the health or 

welfare of persons in a State other than that in which the discharge originates, is hereby declared to be a 

public nuisance and, subject to abatement as herein provided. by the Act, including suit by the United 

States. 
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 29

provisions of the statute provide additional textual evidence of the scope of the primary 

jurisdictional term of the Act. 

 Congress defined “navigable waters” in CWA section 502(7) to mean “the 

waters of the United States, including the territorial seas.” Interstate waters are 

the waters of the several States and, thus, the United States. While the 1972 Act 

was clearly not limited to interstate waters, it was equally clearly intended to 

include interstate waters. Most importantly, there is a specific provision in the 

1972 CWA establishing requirements for those interstate waters which were 

subject to the prior Water Pollution Control Acts. The CWA requires States to 

establish water quality standards for navigable waters and submit them to the 

Administrator for review, including “interstate waters.” CWA section 303(a)(1) 

states:states, “In order to carry out the purpose of this Act, any water quality 

standard applicable to interstate waters which was adopted by any State and 

submitted to, and approved by, or is awaiting approval by, the Administrator 

pursuant to this Act as in effect immediately prior to the date of enactment of the 

Federal Water Pollution Control Act Amendments of 1972, shall remain in effect. 

. . . 

(Emphasis added.) ...” (emphasis added). Thus, Congress intended continued protection 

of interstate waters. 

 While EPA and the Corps believe congressional intent is clear, the agencies also 

have a longstanding regulatory interpretation of the CWA that interstate waters fall 

within the scope of CWA jurisdiction.64 The agencies’ interpretation was promulgated 

contemporaneously with the passage of the CWA and is consistent with the statutory and 

legislative history of the Act. Furthermore, the Supreme Court has never addressed the 

CWA’s coverage of interstate waters, and its decisions in SWANCC and Rapanos do not 

question the jurisdictional status of interstate waters or impose additional jurisdictional 

requirements on interstate waters. 

 As noted above, the precursor statutes to the CWA always subjected interstate 

waters and their tributaries to federal jurisdiction. While Congress clearly intended 

tributaries to interstate waters to be subject to the CWA, the statute does not define the 

extent of tributaries that are covered. In light of Justice Kennedy’s opinion, the agencies 

believe it is reasonable to assert jurisdiction over tributaries, adjacent wetlands and other 

waters which have a significant nexus to interstate waters consistent with the framework 

established by Justice Kennedy’s standard in Rapanos for establishing jurisdiction over 

waters with a significant nexus to traditional navigable waters (see sections 4, 5, and 6 of 

this guidance for additional information).. Justice Kennedy’s standard seeks to ensure 

that waters Congress intended to subject to federal jurisdiction are indeed protected, both 

by recognizing that waters and wetlands with a significant nexus to covered waters have 

important beneficial effects on those waters, and by recognizing that polluting or 

destroying waters with a significant nexus can harm downstream covered waters. 
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 30
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 31

Section 3: Significant Nexus Analysis

The agencies will assert jurisdiction over waters with a significant nexus to 

traditional navigable waters or interstate waters. Waters have the requisite nexus if they, 

either alone or in combination with similarly situated waters in the region, significantly 

affect the chemical, physical, or biological integrity of traditional navigable waters or 

interstate waters.65 This section provides general guidance for determining the presence 

or absence of a significant nexus; the following sections provide more specific guidance 

for determining jurisdiction over tributaries, adjacent wetlands, and other waters under 

the agencies’ regulations.

To evaluate the presence or absence of a significant nexus, the agencies will, as a 

general matter, consider: 

(3) Waters to be “similarly situated” with other waters of the same regulatory or 

resource type (i.e., the same subsection of the regulatory definition at 33 CFR 

328.3(a) and 40 CFR 230.3(s); but see Section 6 for additional guidance on 

how to determine whether waters within the other waters regulatory category 

are “similarly situated”); 

(4) Waters to be “in the region” if they fall within the same watershed. For the 

purposes of this analysis, the watershed is defined by the area draining into the 

nearest traditional navigable water or interstate water. However, there may be 

circumstances in which field staff may utilize a smaller area for a significant 

nexus analysis (see discussion below); and

(5) Waters to have a significant nexus if they alone or in combination with other 

similarly situated waters in the same watershed have an effect on the 

chemical, physical, or biological integrity of traditional navigable waters or 

interstate waters that is more than “speculative or insubstantial.” 

Therefore, field staff should first determine whether the water to be evaluated is a 

tributary, adjacent wetland, or other water under the regulations - waters in each of these 

categories should be considered the similarly situated waters (again, see Section 6 for 

additional guidance on how to determine whether waters within the other waters 

regulatory category are “similarly situated”).

Next, field staff should determine the watershed as defined by the area66 draining 

into the nearest traditional navigable water or interstate water and should generally 

identify the “similarly situated” waters in that watershed. Generally, the logical and 

scientifically valid "region" for determining whether similarly situated waters have a 

significant nexus is the geographic area that drains through a single point of entry to the 

traditional navigable water or interstate water given that significant nexus determinations 

are made in reference to the closest downstream traditional navigable water or interstate 

water. There may be circumstances in which field staff, for efficiency purposes, elect to 

begin the case-by-case significant nexus analysis utilizing a smaller watershed (i.e., the 
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 32

Hydrologic Unit Classification (HUC)-10 "watershed" as identified by the U.S. 

Geological Survey and the Natural Resources Conservation Service). Field staff should 

not however utilize an area larger than the watershed that drains through a single point of 

entry to the traditional navigable water or interstate water. When a smaller watershed 

provides sufficient science-based justification to establish jurisdiction, field staff need not 

unnecessarily expend administrative time and resources analyzing the entire single point 

of entry watershed. However, field staff should use the single point of entry

watershed as the basis for a finding of no jurisdiction.

Finally, field staff should determine whether the water they are evaluating, in 

combination with other similarly situated waters in the watershed, has a significant nexus 

to the nearest traditional navigable water or interstate water. Justice Kennedy’s opinion 

pointed to many functions of waters that might demonstrate a significant nexus, such as 

sediment trapping, nutrient recycling, pollutant trapping and filtering, retention or 

attenuation of flood waters, runoff storage, and provision of habitat. Furthermore, Justice 

Kennedy noted that a hydrologic connection is not necessary to establish a significant 

nexus, since in some cases the lack of hydrologic connection would be a sign of the 

water’s function in relationship to the traditional navigable water or interstate water, such 

as retention of flood waters or pollutants that would otherwise flow downstream to the 

traditional navigable water or interstate water. 

Thus, field staff should look for indicators of hydrology, effects on water quality, 

and physical, chemical, biological and ecological connections or functions when 

assessing whether a water, alone or in combination, has a more than speculative or 

insubstantial effect on the integrity of downstream traditional navigable waters or 

interstate waters. Hydrologic data may include volume, duration, and frequency of flow, 

as well as physical characteristics. Effects on the chemical integrity of downstream 

waters may include the extent to which the waters have the capacity to carry pollutants 

(for example, petroleum wastes, toxic wastes, and sediment) or flood waters downstream 

to traditional navigable waters or interstate waters; the extent to which the waters reduce 

the amount of pollutants or flood waters that would otherwise enter traditional navigable 

waters or interstate waters; and the extent to which the similarly situated waters perform 

physical functions related to the maintenance of downstream water quality such as 

sediment trapping. Ecological functions performed by the waters that may affect 

downstream traditional navigable waters or interstate waters include the capacity to 

transfer nutrients and organic carbon to downstream food webs (for example, 

macroinvertebrates present in headwater streams convert carbon in leaf litter, making it 

available to species downstream), and the maintenance of habitat that provides spawning 

areas for recreationally or commercially important species in downstream waters. 

Analysis of such indicators, whether documented for an individual water or based 

on scientific literature describing functions of the types of waters in question, will allow 

field staff to evaluate whether the water alone or combination with similarly situated 

waters in the watershed is likely to have an effect that is more than speculative or 
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 33

insubstantial on the chemical, physical, or biological integrity of a traditional navigable 

water or interstate water. It is not appropriate to determine significant nexus based solely 

on any specific threshold of distance (for example, between a tributary and its adjacent 

wetland or between a tributary and the traditional navigable water). Watershed 

ecosystems, and their interrelationships, are constructed of component parts that have 

relevance when considered collectively. Failure to protect the components undermines 

the ecosystem in its entirety. Therefore, the agencies have an obligation to evaluate 

waters in terms of how they interrelate and function as ecosystems rather than as 

individual units, especially in the context of complex ecosystems where their integrity 

may be compromised by environmental harms that individually may not be measurably 

large but collectively are so. 

Among the most difficult questions for field staff is determining how 

“significant” a nexus must be and how to document its presence or lack thereof. Justice 

Kennedy provides guidance about the nature of the nexus when he concludes that waters 

are not jurisdictional when their effects on the physical, chemical, or biological integrity 

of downstream traditional navigable waters are speculative or insubstantial. Although the 

word “significant” has different meanings in different statutes and environmental 

programs, here it can fairly be interpreted to mean “more than speculative or 

insubstantial.” In the context used by Justice Kennedy, a “significant nexus” does not 

require that the effect on the traditional navigable water be “substantial” or “measurably 

large.”67 Instead, Justice Kennedy’s use of the terms “related to” and “more than 

speculative and insubstantial” suggest that he meant that “significant,” as used in this 

context, includes having a predictable or observable chemical, physical, or biological 

functional relationship. 

It is important to clarify that agency field staff, in conducting a significant nexus 

analysis, are not required to identify or evaluate every similarly situated water located 

within a particular watershed being assessed.Section 3: Significant Nexus Staff should 

evaluate as many adjacent wetlands, tributaries or other waters as is necessary to support 

and document the presence or absence of a significant nexus for the type of water being 

assessed. Staff should be confident that their significant nexus determination based on 

evaluation of a representative subset of adjacent wetlands, tributaries, or other waters in a 

watershed would be fully consistent with a determination based on an evaluation of all 

waters of the same type in the watershed. 

Legal and Scientific Basis 

In Rapanos, Justice Kennedy provides an approach for determining what 

constitutes a “significant nexus” that can serveserving as a basis for statutory

jurisdiction.q “The required nexus must be assessed in terms of the statute’s goals and 

 

q

 Again, the four justices who signed on to Justice Stevens’ opinion would have upheld jurisdiction under 

the agencies' existing regulations and so stated that they would uphold jurisdiction under either the plurality 

or Justice Kennedy's opinion. Justice Kennedy concludes that Riverside Bayview and SWANCC “establish 
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 34

purposes. Congress enacted the law to ‘restore and maintain the chemical, physical, and 

biological integrity of the Nation’s waters,’ 33 U.S.C. § 1251(a), and it pursued that 

objective by restricting dumping and filling in ‘navigable waters,’ §§ 1311(a), 

1362(12).”681362(12).69 Justice Kennedy provided further guidance for determining 

whether wetlands should be considered to possess the requisite nexus in the context of 

assessing whether wetlands are jurisdictional: “if the wetlands, either alone or in 

combination with similarly situated [wetlands] in the region, significantly affect the 

chemical, physical, and biological integrity of other covered waters more readily 

understood as ‘navigable.’”70‘navigable’.”71 While Justice Kennedy focused on adjacent 

wetlands in light of the facts of the cases before him, it is reasonable to utilize the same 

analysis for tributaries and other waters such as ponds, lakes and non-adjacent wetlands 

that are not themselves directly connected to a tributary system but may still have a 

significant nexus to a traditional navigable water or interstate water. 

In determining which waters to consider “similarly situated” for purposes of 

analyzing whether they have a significant nexus “in combination” with the water at 

issue,combination,” it is reasonable to begin with the categories of waters the agencies 

identified in promulgating their definition of “water of the United States.” For example, 

tributaries are similarly situated within the landscape because they are part of a stream 

network that providesprovide flow to the downstream traditional navigable water or 

interstate water. and provide similar functions to that water. Adjacent wetlands are 

similarly situated within the landscape because the agencies’ definition is focused on 

their proximity to another water of the United States – “adjacent” is defined in 

regulations as bordering, neighboring or contiguous (see Section 5 for further discussion). 

 Similarly, other waters (“(a)(3) waters”) that are in close physical proximity to 

traditional navigable or interstate waters or their tributaries are similarly situated with 

respect to those waters in much the same way as adjacent wetlands. Justice Kennedy’s 

standard allows the agencies to analyze whether all similarly situated waters in a region 

together have a significant nexus to the downstream traditional navigable water. With 

this standard, Justice Kennedy has recognized the scientific reality that even wherewhile

it ismay be difficult to demonstrate that a particular individual wetland adjacent to a small 

headwater tributary has a significant nexus to a traditional navigable water, the 

destruction of all such adjacent wetlands in a region could have a significant effect on the 

traditional navigable water and, thus, in such circumstances the CWA must protect those 

wetlands in order to protect the traditional navigable water. The same logic applies to 

tributaries and physically proximatesimilarly situated other waters. 

Waters should generally be considered “in the region” if they are within a 

watershed that drains to a traditional navigable water or interstate water, defined by the 

 the framework for” determining whether an assertion of jurisdiction constitutes a reasonable interpretation 

of “navigable waters” - “the connection between a nonnavigable water or wetland and a navigable water 

may be so close, or potentially so close, that the Corps may deem the water or wetland a 

‘navigable“navigable water’water” under the Act”;Act; “[a]bsent a significant nexus, jurisdiction under the 

Act is lacking.” 547 U.S.Id. at 767.2241.
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 35

point at which a tributary system first enters a traditional navigable water or interstate 

water. Using a watershed as the framework for conducting significant nexus evaluations 

is scientifically supportable. Watersheds are generally regarded as the most appropriate 

spatial unit for water resource management.72 Anthropogenic actions and natural It is 

more effective than focusing on a specific site, such as an individual stream segment, 

because actions by humans, wildlife, and climactic events can have widespread effects 

within the watershed that collectively impact the quality of the relevant traditional 

navigable water or interstate water.73  For this reason, it is more appropriate to conduct a 

significant nexus determination at the watershed scale than to focus on a specific site, 

such as an individual stream segment. The watershed that contributes flow to thethat

point of entry to a traditional navigable or interstate water is a logical spatial framework 

for the evaluation of the nexus. TheReasonably, the functions of the contributing waters 

are inextricably linked and havein having a cumulative effect on the integrity of the 

traditional navigable water or interstate water. The size of that watershed can be 

determined by identifyingtracing the topographic area that drainsflowpath from the water 

being evaluated to the nearest a traditional navigable water or interstate water, and then 

using that point of entry to define the watershed to conduct a significant nexus 

evaluation.74, including all the waters that contribute to the flow at that point.75  

 Justice Kennedy’s opinion provides guidance pointing to many functions of 

waters that might demonstrate a significant nexus, such as sediment trapping, nutrient 

recycling, pollutant trapping and filtering, retention or attenuation of flood waters, runoff 

storage, and provision of habitat.76 Furthermore, Justice Kennedy noted that a hydrologic 

connection is not necessary to establish a significant nexus, becausesince in some cases 

the lack of hydrologic connection would show be a sign of the significance of a

waterwater’s function in relationship to the aquatic system,covered water, such as 

retention of flood waters or pollutants that would otherwise flow downstream to the 

traditional navigable water or interstate water.77 Finally, If a water has a systematic 

physical, chemical, hydrological, biological, or ecological relationship to the integrity of 

traditional navigable waters or interstate waters, then showing that a water of this type, 

individually or in aggregate, performs such a function is sufficient to demonstrate a 

significant nexus. As noted above, Justice Kennedy was clear that the requisite 

significant nexus musthere can fairly be interpreted to mean “more than “speculative or 

insubstantial”78 in order to be significant.insubstantial,” and the agencies reasonably 

interpret significant nexus to mean having a predictable or observable chemical, physical, 

or biological functional relationship. 

Section 4: Tributaries 

EPA and the Corps will assert jurisdiction over tributaries under either the 

plurality standard or the Kennedy standard, as described below.

For purposes of this guidance, a water is a tributary when it contributes flow to a 

traditional navigable water or interstate water, either directly or indirectly by means of 
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 36

other tributaries. A tributary can be a natural, man-altered, or man-made water body. 

Examples include rivers and streams, and lakes and certain wetlands that are part of the 

tributary system and flow directly or indirectly into traditional navigable waters or 

interstate waters. A tributary may be physically characterized by the presence of a 

channel with defined bed and bank. The bed of a stream is the bottom of the channel. The 

lateral constraints (channel margins) are the stream banks. One means of identifying the 

lateral constraints is the existence of an ordinary high water mark (OHWM). Corps 

regulations define OHWM as “that line on the shore established by the fluctuations of 

water and indicated by physical characteristics such as a clear, natural line impressed on

the bank, shelving, changes in the character of soil, destruction of terrestrial vegetation, 

the presence of litter and debris, or other appropriate means that consider the 

characteristics of the surrounding areas.”

79 As a general rule, the bed is that part of the 

channel below the “normal” water line, and the banks often extend above the water line. 

Channel characteristics depend on variables such as hydrology, lithology, climate, 

physiography, and gradient,80 among others, and are subject to local interpretation. A 

tributary continues as far as a channel (i.e., bed and bank) is present. A natural or 

manmade break (e.g., rock outcrop, underground flow, dam, weir, diversion, or similar 

break) in the presence of a bed and bank or ordinary high water mark does not establish 

the limit of a tributary in cases where a bed and bank and an ordinary high water mark 

can be identified upstream and downstream of the break. 

Certain types of erosional features, such as gullies and rills, are not tributaries for 

purposes of this guidance. Gullies are relatively deep channels that are generally formed 

on valley sides and floors where no well-defined channel previously existed. They are 

commonly found in areas with low-density vegetative cover or with soils that are highly 

erodible. Rills81 are formed by overland water flows eroding the soil surface during rain 

storms. Erosional features that are not tributaries for the purposes of this guidance can 

also be found in environments where compacted soil and sparse vegetation have 

increased overland flow significantly. The two main processes that result in the 

formation of gullies and similar erosional features are downcutting and headcutting, 

which are forms of longitudinal (incising) erosion. These actions generally result in 

erosional cuts that are often deeper than they are wide, with very steep banks, often small 

beds, and typically only carry water during precipitation events. The principle erosional 

processes that modify streams are also downcutting and headcutting. In streams 

however, lateral erosion is also very important. The result is that streams, except on steep 

slopes or where soils are highly erodible, are characterized by the presence of more 

defined bed and banks as compared to typical erosional features that are more deeply 

incised. Field staff should consider these factors as they distinguish streams and other 

tributaries that may be subject to Clean Water Act jurisdiction from other types of 

erosional features. 

Tributaries Covered under the Rapanos Plurality Standard 
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 37

EPA and the Corps will assert jurisdiction over “relatively permanent, standing or 

continuously flowing bodies of water” connected to traditional navigable waters.r Under 

the plurality standard, relatively permanent waters are jurisdictional without making a 

significant nexus finding.

Under the plurality standard, a non-navigable tributary is jurisdictional when it 

satisfies the following characteristics:

(3) The tributary is connected, directly or indirectly through other tributaries, 

to a downstream traditional navigable water, and

(4) Flow in the tributary, except for drought years, is at least seasonal.

Other tributaries will be evaluated under the Kennedy standard. 

Tributaries Covered under the Rapanos Kennedy Standard 

EPA and Corps regulations define “waters of the United States” to include 

tributaries to traditional navigable waters and to interstate waters.82 EPA and the Corps 

will assert jurisdiction over all tributaries to traditional navigable waters or interstate 

waters, provided that the tributary, alone or in combination with other similarly situated 

tributaries in the watershed, significantly affects the chemical, physical, or biological 

integrity of traditional navigable waters or interstate waters.

Thus, a tributary is jurisdictional where:

(3) It is a tributary as defined for purposes of this guidance to a traditional 

navigable water or an interstate water; and

(4) The tributary, alone or in combination with other tributaries in the 

watershed, has a significant nexus with the traditional navigable water or 

interstate water. 

When performing a significant nexus analysis for a tributary, the first step is to 

determine whether that tributary has a bed and bank and an ordinary high water mark. If 

the tributary possesses those characteristics, the next step is to determine whether the 

tributary drains, or is part of a network of tributaries that drain, into a downstream 

traditional navigable water or interstate water. If it can be demonstrated that the tributary 

has a bed and bank, an OHWM and is part of a tributary system to a traditional navigable 

water or an interstate water, and, therefore, can transport pollutants, sediments, flood 

 

r 547 U.S. at 739.r The agencies will not assert jurisdiction over such waters under the plurality standard 

within the Eleventh Circuit, i.e., waters in the states of Florida, Georgia and Alabama. See United States v. 

Robison, 505 F.3d 1208 (11th Cir.); 2007); reh’g en banc denied, 521 F.3d 1319 (11th Cir. 2007), cert. 

denied, sub nom. United States v. McWane, Inc., 129 S. Ct. 627, 630 (2008). Instead the agencies will use 

the Kennedy standard only.
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 38

waters and other materials to a traditional navigable water or interstate water, generally 

EPA and the Corps will conclude that the tributary can be demonstrated on a case-bycase basis to have a significant nexus with the downstream traditional navigable water or 

interstate water. This conclusion is based on the significant harm that pollutants can have 

on the physical, chemical, or biological integrity of the downstream traditional navigable 

water or interstate water.83 The presence of a bed and bank and an OHWM are physical 

indicators of flow and it is likely that flows through tributaries with the above 

characteristics are generally sufficient to transport pollutants, sediments, and other 

materials downstream to the traditional navigable water or interstate water. 

Thus, field staff may conclude on a case-by-case basis that a tributary is 

jurisdictional when they have determined and documented that the tributary has a bed and 

bank and an OHWM, is part of a tributary system to a traditional navigable water or an 

interstate water, and that there is no reasonable basis to conclude that pollutants, if 

introduced, would not be transported to the downstream traditional navigable water or 

interstate water. Wherever possible, field staff should also document, using available or 

readily obtainable information, the flow characteristics and functions of the tributary or 

tributaries, and their hydrologic relationship to the nearest downstream traditional 

navigable water or interstate water. Field staff should also address other functions, as 

appropriate, provided by the tributary that may affect the physical, chemical, or 

biological integrity of downstream traditional navigable waters or interstate waters. In 

addition, a tributary is a jurisdictional water when, either alone or in combination with 

other tributaries in the same watershed, it has a significant nexus with the nearest 

downstream traditional navigable or interstate water. Therefore, to further support a 

significant nexus determination for a tributary, field staff should determine whether the 

tributary, in combination with other tributaries in the watershed, has a significant nexus 

with a downstream traditional navigable water or interstate water.

When considering whether the tributary at hand eventually flows to an interstate 

water or traditional navigable water, field staff should trace the tributary connection using 

resources such as direct observation or U.S. Geological Survey maps, aerial photography 

or other reliable remote sensing information, soil survey data or other appropriate 

information. 

When field staff provide additional information on the flow characteristics and 

functions of the tributary or tributaries, and their hydrologic relationship to the nearest 

downstream traditional navigable water or interstate water, such information may include 

topographic maps, gage data, historic records of water flow, statistical data, personal 

observations/records, etc., as well as other information that characterizes the hydrologic 

and ecological relationships between the tributaries and the nearest downstream 

traditional navigable water or interstate water. Consideration may also be given to 

certain relevant contextual factors that directly influence the hydrology of tributaries,

including the size of the watershed, average annual rainfall, and average annual winter 
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 39

snow pack. The significant nexus evaluation should also discuss the potential for the 

tributaries to transport pollutants to a traditional navigable water or interstate water. 

Examples of other functions provided by tributaries that may affect the physical, 

chemical, or biological integrity of downstream traditional navigable waters or interstate 

waters include: distributing sediment84 to maintain stream and riparian habitat; nutrient 

cycling and removal; providing habitat for amphibians, fish, and other aquatic or semiaquatic species living in and near the stream that may use the downstream waters, 

including traditional navigable waters, for other portions of their life stages (e.g.,

spawning areas for recreationally or commercially important species); improving or 

maintaining biological integrity in downstream waters; and transferring nutrients and 

organic carbon vital to support downstream food webs (e.g., macroinvertebrates present 

in headwater streams convert carbon in leaf litter making it available to species 

downstream).85 Disruptions in these biological processes affect the functional capacity of 

the entire downstream system.86 The network of tributaries also regulates the flow of 

water into downstream traditional navigable waters and interstate waters, moderate low 

flow and high flow extremes, reduce downstream flooding, and prevent excess erosion 

caused by flooding.87 Field staff may document any of these functions to bolster the 

conclusion that a tributary is jurisdictional.

To further support a significant nexus determination, field staff should, using their 

best professional judgment, knowledge of the area, and relevant maps, assess the 

contribution of all tributaries in the watershed in evaluating the significance of the 

chemical, physical, or biological nexus with the nearest traditional navigable water or 

interstate water. When identifying other tributaries in the watershed to be considered in 

combination for a significant nexus analysis, field staff may use resources such as direct 

observation or U.S. Geological Survey maps, aerial photography, or other reliable remote 

sensing information. Field staff are not required to identify or evaluate every tributary 

located within a particular watershed being assessed. Using available maps and other 

appropriate information, staff should include in the evaluation as many tributaries as is 

necessary to support and document the presence or absence of a significant nexus. 

Swales or erosional features (e.g., gullies, small washes characterized by low 

volume, infrequent, or short duration flow) are generally not waters of the United States 

because they are not tributaries or they do not have a significant nexus to downstream 

traditional navigable waters or interstate waters. In addition, ditches (including roadside 

ditches) excavated wholly in and draining only uplands and that do not carry relatively 

permanent flow of water are generally not waters of the United States because they are 

not tributaries or they do not have a significant nexus to downstream traditional navigable 

waters or interstate waters.s Even when not jurisdictional waters subject to § 404, these 

 

s Consistent with longstanding guidance, "the Corps reserves the right on a case-by-case basis to determine 

that a particular waterbody within these categories of waters is a water of the United States. EPA also has 

the right to determine on a case-by-case basis if any of these waters are 'waters of the United States.'" Final 

Rule for Regulatory Programs of the Corps of Engineers, 51 FR 41206, 41217 (Nov. 13, 1986); see also 
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 40

geographic features (e.g., swales, ditches) may still contribute to a surface hydrologic 

connection between an adjacent wetland and a traditional navigable water or interstate 

waters. In addition, these geographic features may function as point sources (i.e., 

"discernible, confined, and discrete conveyances"), such that discharges of pollutants to 

other waters through these features could be subject to other CWA regulations (e.g., 

CWA §§ 311 and 402).

To clarify, only certain types of non-tidal ditches will be considered tributaries for 

the purposes of this guidance (tidal ditches are, by definition, waters of the U.S.). For a 

non-tidal ditch to be considered a tributary, it must first have a bed and bank, an ordinary 

high water mark, and connect directly or indirectly (through other tributaries or 

conveyances) to a traditional navigable water or interstate water. If these requirements

are satisfied, ditches are considered tributaries for the purposes of this guidance if they 

are:

• natural streams that have been altered (e.g., channelized, straightened or 

relocated); 

• ditches or portions of ditches that have been excavated in waters of the U.S., 

including wetlands; 

• ditches that have relatively permanent flowing or standing water; or

• ditches that connect two or more jurisdictional waters of the U.S.

If a ditch is considered a tributary, it will be evaluated in the same manner as 

other tributaries (i.e., plurality standard or Kennedy standard, as appropriate).

Exempt activities defined at 33 CFR 323.4 are not affected by this guidance.

Erosional features such as gullies and rills are not part of the tributary system, are 

not jurisdictional waters, and shall not be assessed as part of the significant nexus 

determination. Natural and man-made swales are also not tributaries for purposes of this 

guidance.

In certain cases, ditches or swales include areas that meet the regulatory definition 

of “wetlands.” Wetland ditches will be evaluated as wetlands under the plurality or 

Kennedy standard, not at as tributary (unless the ditch itself is considered a tributary for 

one of the reasons stated above).

Field staff should assess the contribution of all tributaries in the watershed in 

evaluating the significance of the chemical, physical, or biological nexus with the nearest 

 Clean Water Act Section 404 Program Definitions and Permit Exemptions; Section 404 State Program 

Regulations, Final Rule, 53 FR 20764, 20765 (June 6, 1988). Any such case-by-case determinations would 

be made consistent with the standards in Rapanos. EPA expects that such case-by-case determinations 

would generally be limited to circumstances in which a person discharges a pollutant into this category of 

waters that could adversely impact downstream water quality.
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 41

traditional navigable water or interstate water. Generally EPA and the Corps will 

conclude that the tributary can be demonstrated on a case-by-case basis to have a 

significant nexus with the downstream traditional navigable water or interstate water 

based on the significant harm that pollutants can have on the physical, chemical, or 

biological integrity of the downstream traditional navigable water or interstate water. In 

addition, in light of the flow contributed by all the tributaries in a watershed and the 

scientific consensus on the functions provided by tributaries, the agencies expect that 

tributaries will generally be found to have a significant nexus on a watershed basis. The 

agencies expect that the substantial volume of flow contributed by the combination of 

tributaries in the watershed will be sufficient to demonstrate that the tributaries 

significantly affect the physical, chemical and biological integrity of the downstream 

traditional navigable water or interstate water. Tributaries help to maintain base flow in 

the larger rivers downstream, which is particularly important in times of drought. At the 

same time, a network of tributaries can regulate the flow of water into downstream 

waters, moderate low flow and high flow extremes, reduce local and downstream 

flooding, and prevent excess erosion caused by flooding.88

As when assessing a tributary on its own, field staff may also, if necessary, assess

the other functions provided by the tributaries as a whole in a watershed. The agencies 

expect that in light of the substantial functions provided by the tributaries in combination 

in a watershed, such tributaries will generally be found jurisdictional.

Legal and Scientific Basis 

Tributaries Covered Under the Rapanos Plurality Standard

As noted above, jurisdictionalJurisdictional determinations based on the plurality 

standard would have the support of the four justices joining the plurality opinion as well 

as the four dissenting justices. The As noted above, the plurality concluded that the 

agencies’ regulatory authority should extend only to “relatively permanent, standing or 

continuously flowing bodies of water”89 connected to traditional navigable waters, and to 

“wetlands with a continuous surface connection to” such relatively permanent waters.90 

“Relatively permanent waters” were described as waters that typically flow year-round 

except in times of drought, or waters that have a continuous flow at least seasonally. The 

plurality opinion emphasized that relatively permanent waters do not include tributaries 

“whose flow is ‘[c]oming‘coming and going at intervals . . . [b]roken,... broken,

fitful.’”91 Therefore, “relatively permanent waters” do not include ephemeral tributaries 

which flow only in response to precipitation and intermittent streams which do not have 

continuous flow at least seasonally.t

 

t

 Note that under the Kennedy standard, such waters may be jurisdictional where they have a significant 

nexus. 
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 42

Moreover, waters that have had at least seasonal flow on a historic basis remain 

jurisdictional despite the fact that man-made diversions for irrigation, water supply or for 

other reasons have caused a tributary, or portion thereof, to flow less than seasonally.u

A central issue to the plurality standard is what constitutes “seasonal flow.” In 

this context, a water is “seasonal” when it has predictable flow during wet seasons in 

most years. The time period constituting “seasonal” will vary across the country. Rather 

than having distinct, rigid boundaries, stream reaches classified as perennial, intermittent, 

and ephemeral may more accurately be described as dynamic zones within stream 

networks. The length or extent of these zones may be highly variable and is dictated by 

multiple factors such as annual precipitation, evapotranspiration, and land-use practices.

92

Thus, determination of whether a water meets the plurality standard for relatively 

permanent should involve determination of the length and timing of seasonal flows in the 

ecoregion in question. 

Field staff have flexibility to determine what seasonal flow means in each 

particular case.93 Seasonal flowrunoff can be the result of snow melt, seasonal patterns in 

precipitation, and seasonal fluctuations in ground water levels. In the arid west, stream 

discharges are driven by three large-scale weather patterns.94 Precipitation produced by 

these weather patterns varies greatly for any given locality, but generally, precipitation 

shifts from winter in the north to summer in the south. The variation of precipitation in 

time, coupled with the highly variable topography of the arid west, results in spatially 

variable precipitation patterns.95 For example, seasonal flow in most of New Mexico and 

large portions of Arizona and Colorado would be during the period of just two months, 

July and August, when they normally receive between 30-50 percent of their annual 

precipitation as rain.96 In some areas, snow melt drives stream flow, and seasonal flow is 

typically in the spring.97 Seasonal patterns of flow may be less pronounced in the semiarid Midwest, perhaps because of less seasonal precipitation patterns and relatively more 

vegetative cover.98 In the east precipitation is more uniform but increased 

evapotranspiration during the growing season can reduce ground water levels and surface 

flows to create seasonal and ephemeral flows.99 

Tributaries Covered Under the Rapanos Kennedy Standard

Justice Kennedy rejected the plurality’s approach that only “relatively permanent” 

tributaries are within the scope of CWA jurisdiction. Instead, Justice Kennedy concluded 

that “Congress could draw a line to exclude irregular waterways, but nothing in the 

statute suggests it has done so”;so;” in fact, he states that Congress has done 

“[q]uite“quite the opposite.”100 Further, Justice Kennedy concludes, based on “a full 

reading of the dictionary definition” of “water,” that “the Corps can reasonably interpret 

 

u

 See S. D. Warren Co. v. Maine Bd.Board of Envtl. Prot.,Environmental Protection, 547 U.S. 370, 379

n.5 (2006)("[N]or(2006)("nor can we agree that one can denationalize national waters by exerting private 

control over them."). 
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 43

the Act to cover the paths of such impermanent streams.”v Even in Justice Kennedy’s 

rejection of Justice Stevens'Steven’s opinion it is clear that he was specifically 

rejectingonly rejects the broad scope of jurisdiction over wetlands without further 

analysis, and not specifically addressingnot jurisdiction over tributaries: “[T]he

regardless of their size or characteristics: “the dissent would permit federal regulation 

whenever wetlands lie alongside a ditch or drain, however remote and insubstantial, that 

eventually may flow into traditional navigable waters. The deference owed to the Corps’ 

interpretation of the statute does not extend so far.”101 

Elsewhere, Justice Kennedy suggests that it may be appropriate to assert 

jurisdiction over all tributaries with an ordinary high-water mark. Justice Kennedy 

described the Corps’ standard for asserting jurisdiction over tributaries: “[T]he“the Corps 

deems a water a tributary if it feeds into a traditional navigable water (or a tributary 

thereof) and possesses an ordinary high-water mark . . . .”102 Justice Kennedy concluded 

that this standard “presumably provides a rough measure of the volume and regularity of 

flow.”103 In addition, if it is applied reasonably consistently, the Corps’ existing standard 

for tributaries “may well provide a reasonable measure of whether specific minor 

tributaries bear a sufficient nexus with other regulated waters to constitute ‘navigable 

waters’ under the Act.”104 Thus, Justice Kennedy’s opinion may reasonably be read as 

allowing the agencies to determine that a case-specific significant nexus determination is 

not necessary for tributaries possessing an ordinary high water mark, though it also 

indicates that he considers the presence of a significant nexus to be the appropriate 

test.not overturning the existing agency regulations for tributaries. 

The However, the agencies have decided that, given Justice Kennedy’s indication 

that significant nexus is still the guiding standard, it is appropriateto address per se

jurisdiction over tributaries through the rulemaking process and for purposes of this 

guidance to assert jurisdiction over tributaries utilizing the same standard Justice 

Kennedy articulated for adjacent wetlands. In establishing the significant nexus standard, 

Justice Kennedy recognized that upstream adjacent wetlands can have significant effects 

on the physical, chemical and biological integrity of downstream waters covered waters 

under the CWA. As a scientific matter, tributaries can, of course, have similar effects 

and it is reasonable to utilize the same standard for determining whether tributaries have a 

significant nexus to downstream covered waters. Through rule making, the agencies will 

further consider whether the existence of an ordinary high-water mark alone is sufficient 

 

v 547 U.126 S.Ct. at 770.2243 (emphasis added). First, Justice Kennedy notes that the term “waters” can 

mean “‘flood“flood or inundation,’”inundation,” according to the Webster’s Second definition, and that 

these events are “impermanent by definition.” Id. Second, even looking to the plurality’s preferred 

dictionary definition of “waters,” i.e., “‘water“water “[a]sas found in streams and bodies forming 

geographical features such as oceans, rivers, [and] lakes,”’” Justice Kennedy notes that “intermittent flow 

can constitute a stream.” Id. (alteration in original). And finally, Justice Kennedy notes that the plurality’s 

reference to the statement by the Riverside Bayview Court comparing “wetlands to ‘rivers,“rivers, streams, 

and other hydrographic features more conventionally identifiable as “waters”’ . . . .‘waters’ ... could just as 

well refer to intermittent streams.” Id. at 771 (citations omitted).
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 44

to establish a significant nexus to downstream traditional navigable or interstate waters, 

without requiring a site-specific analysis, as Justice Kennedy invites in his opinion.

As noted in Section 3, it is reasonable to consider all tributaries in a watershed to 

be “similarly situated” for purposes of a significant nexus analysis because they 

contribute flow to the downstream traditional navigable water or interstate water and 

provide similar functions to those downstream waters. Further, Section 3 demonstrated 

that it is reasonable to consider the region for significant nexus analysis to be a watershed 

defined by the area draining into the nearestpoint at which a tributary system first enters a

traditional navigable water or interstate water through a single point of entry..

The agencies’ identification of the presence of an ordinary high water mark as one 

of the factors for considering a water to be a tributary for purposes of this guidance is 

consistent with Justice Kennedy’s observation that an ordinary high water mark may be a 

reasonable measure of whether a tributary possesses a significant nexus with a traditional 

navigable water or interstate water. This observation, in turn, is supported by both the 

agencies’ scientific judgment in the past and the scientific literature of the present. As 

the Corps stated in promulgating the definition of “waters of the U.S.” in 1977 to include 

tributaries, “[t]he regulation of activities that cause water pollution cannot rely on . . . 

artificial lines, however, but must focus on all waters that together form the entire aquatic 

ecosystem. Water moves in hydrologic cycles, and the pollution of . . .... part of the 

aquatic ecosystem . . .... will affect the water quality of the other waters within that 

aquatic ecosystem.”105 For In fact, the agencies made the assessment of the nexus 

between tributaries and traditional navigable waters envisioned by Justice Kennedy: for

more than 30 years, EPA and the Corps have interpreted the CWA to protect “the many 

tributary streams that feed into the tidal and commercially navigable waters . . .... since 

the destruction and/or degradation of the physical, chemical, and biological integrity of 

each of these waters is threatened by the unregulated discharge of dredged or fill 

material.”106 As Congress and the Supreme Court have recognized, “‘[w]ater“[w]ater

moves in hydrologic cycles and it is essential that discharge of pollutants be controlled at 

the source.’”107source.”108

A large volume of scientific literature documents the important functions that 

tributaries, including headwater streams, provide to downstream waters.w Headwater

streams, which may include perennial,, intermittent, and ephemeral streams, are the most 

common streams types in the United States. Collectively, they determine the chemical, 

physical, and biological integrity of downstream waters, and provide many of the same 

functions as non-headwater and perennial streams.109 Headwater, intermittent, and 

ephemeral streams and their associated riparian areas reduce the amount of sediment 

delivered to downstream waters by trappingstabilizing stream banks to reduce bank 

 

w For purposes of applying the current body of scientific literature to the questions created by the Rapanos

Supreme Court decision, traditional navigable waters can be considered analogous to downstream waters. 

This is because the vast majority of traditional navigable waters are downstream of headwater, intermittent, 

and ephemeral streams. 
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 45

erosion and filtering sediment from water and runoff.110 HeadwaterThe smallest streams 

are responsible for most nutrient cycling and removal, and thus transforming and 

changing the amount of nutrients delivered to downstream waters.111 A close connection 

exists between the water quality of these streams and the water quality of downstream 

water bodies.112 Activities such as discharging a pollutant into one part of the tributary 

system are well-documented to affect other parts of the system, even when the point of 

discharge is far upstream from the navigable water that experiences the effect of the 

discharge.113 These streams provide habitat and protection for amphibians, fish, and 

other aquatic or semi-aquatic species living in and near the stream that may use the 

downstream waters, including traditional navigable waters, for other portions of their life 

stages.114 They also serve as migratory corridors for fish. TributariesThese areas can 

improve or maintain biological integrity and control water temperatures in the 

downstream waters. Headwater streams serve as a source of food materials such as 

insects, larvae, and organic matter to nourish the fish, mammals, amphibians, and other 

organisms in downstream streams, rivers, and lakes.115 Disruptions in these biological 

processes affect the ecological functions of the entire downstream system.116 Headwater, 

intermittent, and ephemeral streams help to maintain base flow in the larger rivers 

downstream, which is particularly important in times of drought. At the same time, the 

network of headwaterthese small streams can regulate the flow of water into downstream 

waters, mitigating low flow and high flow extremes, reducing local and downstream 

flooding, and preventing excess erosion caused by flooding.117 

Section 5: Adjacent Wetlands

The agencies will assert Clean Water Act jurisdiction over adjacent wetlands that 

meet either the plurality standard or the Kennedy standard under Rapanos.

Wetlands Covered Under the Rapanos Plurality Standard

EPA and the Corps will assert jurisdiction over “wetlands with a continuous 

surface connection to” “relatively permanent, standing or continuously flowing bodies of 

water” connected to traditional navigable waters.118

The plurality opinion in Rapanos created a standard for finding jurisdiction under 

the CWA for wetlands, which is related to the presence of a physical connection between 

the wetland and the relatively permanent tributary to which it is adjacent. Under the 

plurality standard, wetlands with a continuous surface connection to relatively permanent 

waters are jurisdictional without the legal obligation to make a significant nexus finding.

Under the plurality standard, an adjacent wetland is jurisdictional when it satisfies 

the following characteristics:

(1)(2) The wetland is adjacent to a relatively permanent, non-navigable tributary, 

that is connected to a downstream traditional navigable water, and
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 46

(2) A continuous surface connection exists between the wetland and a 

relatively permanent tributary where the wetland directly abuts the 

tributary (e.g., they are not separated by uplands, a berm, dike, or similar 

feature). A “continuous surface connection” refers to a physical

connection between the wetland and the jurisdictional water, but does not 

require the presence of water between the wetland and the jurisdictional 

water.

Wetlands Covered Under the Rapanos Kennedy Standard

The agencies will assert Clean Water Act jurisdiction over wetlandsx adjacent to 

another water of the U.S. where such wetlands have a significant nexus with downstream 

traditional navigable or interstate waters.y Adjacent wetlands will be considered to have 

a significant nexus if they, alone or in combination with similarly situated wetlands, have 

an effect on the chemical, physical, or biological integrity of traditional navigable waters 

or interstate waters that is more than “speculative or insubstantial.” As a general matter, 

“similarly situated” adjacent wetlands include all adjacent wetlands located in the region. 

Wetlands adjacent to traditional navigable waters or interstate waters are per se

jurisdictional and do not require a showing of significant nexus.

Thus, an adjacent wetland is jurisdictional where such wetland meets the 

definition of “adjacent” as that term is defined in the agencies’ regulations and is either: 

(1) Adjacent to a traditional navigable water or interstate water; or

(2) Adjacent to a tributary, lake, reservoir, or other jurisdictional water (except 

another wetland) and either alone or in combination with other adjacent wetlands 

in the watershed has a significant nexus to the nearest downstream traditional 

navigable or interstate water.

The regulations define “adjacent” as follows: “[t]he term adjacent means 

bordering, contiguous, or neighboring. Wetlands separated from other waters of the 

United States by man-made dikes or barriers, natural river berms, beach dunes and the 

like are ‘adjacent wetlands.’”119 Under this definition, a wetland does not need to meet 

all criteria to be considered adjacent. The agencies consider wetlands to be bordering, 

contiguous, or neighboring, and therefore “adjacent” if at least one of following three 

criteria is satisfied: 

 

x Under normal circumstances, a wetland will meet all three parameters of hydrology, hydrophytic 

vegetation, and hydric soils, as required by agency regulations, and described in the Corps of Engineers 

Wetlands Delineation Manual (1987) or appropriate Regional Supplement. The regulatory definition of 

waters of the U.S. includes “wetlands adjacent to waters (other than waters that are themselves wetlands) 

identified [as jurisdictional].” 33 CFR § 328.3(a)(7); 40 CFR § 230.3(s)(7).

y The plurality standard in Rapanos may provide an alternative basis for asserting jurisdiction, see Section 

7.
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 47

(2) There is an unbroken surface or shallow sub-surface hydrologic connection 

between the wetland and jurisdictional waters; or

(3) The wetlands are physically separated from jurisdictional waters by “manmade dikes or barriers, natural river berms, beach dunes, and the like;” or

(4) Where a wetland’s physical proximity to a jurisdictional water is reasonably 

close, that wetland is “neighboring” and thus adjacent. For example, wetlands 

located within the riparian area or floodplain of a jurisdictional water will 

generally be considered neighboring, and thus adjacent. One test for whether a 

wetland is sufficiently proximate to be considered “neighboring” is whether 

there is a demonstrable ecological interconnection between the wetland and 

the jurisdictional waterbody. For example, if resident aquatic species (e.g., 

amphibians, reptiles, fish, mammals, or waterfowl) rely on both the wetland 

and the jurisdictional waterbody for all or part of their life cycles (e.g., 

nesting, rearing, feeding, etc.), that may demonstrate that the wetland is 

neighboring and thus adjacent. The agencies recognize that as the distance 

between the wetland and jurisdictional water increases, the potential 

ecological interconnection between the waters is likely to decrease. 

An unbroken surface or shallow sub-surface hydrologic connection to 

jurisdictional waters may be established by a physical feature or discrete conveyance that 

supports periodic flow between the wetland and a jurisdictional water. Water does not 

have to be continuously present in this hydrologic connection and the flow between the 

wetland and the jurisdictional water may move in either or both directions. The 

hydrologic connection need not itself be a water of the U.S. A shallow subsurface 

hydrologic connection is lateral water flow through a shallow subsurface layer, such as 

may be found in steeply sloping forested areas with shallow soils, soils with a restrictive 

horizon, or in karst systems.120 Shallow subsurface connections may be found below the 

ordinary root zone (below 12 inches), where other wetland delineation parameters may 

not be present. A combination of physical factors may reflect the presence of a shallow 

subsurface connection, including close proximity, position in the landscape (for example, 

on a slope directing flow from wetland to jurisdictional waters), stream hydrograph, and 

soil surveys (for example, exhibiting indicators of high transmissivity over an 

impermeable layer).121 Indicators such as these may support an inference of a shallow 

subsurface connection without requiring a case-specific field verification. 

If uplands separating a wetland from jurisdictional water can reasonably be 

characterized as “man-made dikes or barriers, natural river berms, beach dunes, and the 

like,” then, under the agencies’ regulations, the wetlands are adjacent even if no apparent 

hydrologic connection exists. It is important to note that natural river berms are formed 

by sediment deposits accumulating at or near the stream bank during flood events. Such 

berms vary in height from inches to feet, and also can be quite wide.122 Similarly, 

multiple beach dunes may exist between a wetland and jurisdictional water (including 
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 48

primary and secondary dunes), since beach dunes typically consist and function as an 

interdunal system (particularly on barrier islands). 

The link between physical proximity and an ecological connection is well 

documented in the scientific literature. A wetland within the riparian area123 or 

floodplain124 typically has such an ecological interconnection. For example, adjacent 

wetlands typically help to store floodwaters, pollutants, and sediments that could 

otherwise reach a jurisdictional water.125 Adjacent wetlands often provide important 

sources of stored water that augment stream flow during low-flow periods.126 Species, 

such as amphibians, certain reptiles (e.g., watersnakes), waterfowl, invertebrates, and fish 

(including anadromous and catadromous fish), move between an adjacent wetland and a 

jurisdictional water for spawning, nesting, feeding, refuge, and other life stage 

requirements.127 Species that move between an adjacent wetland and a jurisdictional 

water are distinguishable from migratory species, which use the wetland during a journey 

to a different area128 and are not to be used as a scientific basis for demonstrating an 

ecological interconnection for adjacency. The agencies recognize that as the distance 

between the wetland and jurisdictional water increases, the potential ecological 

interconnection between the waters is likely to decrease. As a result, field staff should 

generally increase the record support and technical basis for demonstrating that an 

ecological interconnection is present as the distance between waters increases. 

Under Justice Kennedy’s standard, the following legal test for Clean Water Act 

jurisdiction applies: If a wetland is adjacent to a traditional navigable water or a nonwetland interstate water, a finding of adjacency is sufficient in and of itself to 

demonstrate that wetland is subject to Clean Water Act jurisdiction. On the other hand, a 

finding that a particular wetland is adjacent to a jurisdictional waterbody other than a 

traditional navigable water or non-wetland interstate water is not sufficient in and of itself 

to establish Clean Water Act jurisdiction over that wetland. For the latter category of 

adjacent wetlands, in order to establish Clean Water Act jurisdiction, field staff, on a 

case-by-case basis, must determine whether the particular adjacent wetland, alone or in

combination with similarly situated wetlands in that watershed, has a significant nexus 

with traditional navigable waters or non-wetland interstate waters (see discussion below).

A determination of adjacency is based on an evaluation of the relationship between a 

wetland and the nearest jurisdictional water, which may include considerations of an 

ecological connection between those waterbodies. In contrast, a determination of 

significant nexus is a different inquiry, which is based on evaluating whether there is a 

significant nexus between that adjacent wetland (in combination with similarly situated 

adjacent wetlands in the watershed) with a traditional navigable water or a non-wetland 

interstate water.

All wetlands within a wetland mosaic should generally be considered collectively 

when determining adjacency or jurisdiction. Wetlands present in such systems act 

generally as a single ecological unit. A wetland mosaic refers to a landscape where 

wetland and non-wetland components are too numerous and closely associated to be 
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 49

appropriately delineated or mapped separately. These areas often have complex 

microtopography, with repeated small changes in elevation occurring over short 

distances. Tops of ridges and hummocks are often non-wetland but are interspersed with 

wetlands having hydrophytic vegetation, hydric soils, and wetland hydrology. Section 5: 

Adjacent Wetlands Examples of wetland mosaics include ridge-and-swale topography in 

large floodplains, coastal flatwoods and savannas containing numerous shallow 

depressions, and coastal dune and swale systems.129 

As discussed in Section 3, an adjacent wetland is a jurisdictional water when, 

either alone or in combination with other similarly situated waters in the region, such 

wetland has a significant nexus with the nearest downstream traditional navigable or 

interstate water. In addition, as discussed in Section 3, the agencies consider all wetlands 

within the relevant watershed area that meet the regulatory definition of adjacency to be 

“similarly situated.” Adjacent wetlands will be considered to be “in the region” if they 

fall within the same watershed. As discussed in Section 3, for the purposes of this 

analysis, the watershed is defined by the area draining into the nearest traditional 

navigable water or interstate water. However, there may be circumstances in which field 

staff may utilize a smaller area for a significant nexus analysis. When identifying other 

adjacent wetlands in the watershed to be considered in combination for a significant 

nexus analysis, field staff may use resources such as direct observation or U.S. 

Geological Survey maps, aerial photography, or other reliable remote sensing 

information. Field staff are not required to identify or evaluate every adjacent wetland 

located within a particular watershed being assessed. Using available maps and other 

appropriate information, staff should include in the evaluation as many adjacent wetlands 

as is necessary to support and document the presence or absence of a significant nexus. 

To determine whether adjacent wetlands in the watershed have the requisite 

significant nexus, field staff should first evaluate the tributaries as described in Section 4. 

Field staff will then evaluate whether the adjacent wetlands, in combination with 

similarly situated wetlands in the watershed, have the requisite significant nexus, taking 

into consideration the integral role of the tributary system in linking the wetlands to the 

downstream traditional navigable water or interstate water. When evaluating adjacent 

wetlands, field staff should consider the many functions of waters such as sediment 

trapping, nutrient recycling, pollutant trapping and filtering, retention or attenuation of 

flood waters, runoff storage, and provision of habitat. When documenting the significant 

nexus of adjacent wetlands, field staff should consider the physical, hydrological and 

ecological relationships between the tributaries and their adjacent wetlands and their 

closely linked role in protecting the chemical, physical or biological integrity of the 

nearest downstream traditional navigable water or interstate water. Adjacent wetlands 

and their tributaries function as an integrated hydrologic system, and as a unit they affect 

the amount of pollutants and floodwaters that reach the downstream traditional navigable 

waters or interstate waters. Furthermore, a hydrologic connection is not necessary to 

establish a significant nexus, since in some cases the lack of hydrologic connection would 

be a sign of the water’s function in relationship to the traditional navigable water or 
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 50

interstate water, such as retention of flood waters or pollutants that would otherwise flow 

downstream to the traditional navigable water or interstate water. 

Legal and Scientific Basis 

Adjacent Wetlands Covered under the Rapanos Plurality Standard

Under the plurality standard, wetlands that have a continuous surface connection 

with a relatively permanent, non-navigable tributary are jurisdictional without the need 

for a significant nexus finding. The plurality opinion indicates that “continuous surface 

connection” is a “physical connection requirement.”130 A continuous surface connection 

does not, however, require surface water to be continuously present between the wetland 

and the tributary. 

Adjacent Wetlands Covered under the Rapanos Kennedy Standard

 Because the question in Rapanos was whether particular adjacent wetlands were 

“waters of the U.S.,” Justice Kennedy’s opinion focused on the standard for determining 

whether wetlands have the requisite nexus: 

With respect to wetlands, the rationale for Clean Water Act regulation is, 

as the Corps has recognized, that wetlands can perform critical functions 

related to the integrity of other waters—functions such as pollutant 

trapping, flood control, and runoff storage. 33 CFR § 320.4(b)(2). 

Accordingly, wetlands possess the requisite nexus, and thus come within 

the statutory phrase “navigable waters,” if the wetlands, either alone or in 

combination with similarly situated lands in the region, significantly affect 

the chemical, physical, and biological integrity of other covered waters 

more readily understood as “navigable.” When, in contrast, wetlands’ 

effects on water quality are speculative or insubstantial, they fall outside 

the zone fairly encompassed by the statutory term “navigable waters.”131

With respect to wetlands adjacent to traditional navigable waters, Justice Kennedy 

concluded that the agencies’ regulation “rests upon a reasonable inference of ecologic 

interconnection, and the assertion of jurisdiction for those wetlands is sustainable under 

the Act by showing adjacency alone.”132 The agencies will apply Justice Kennedy’s 

reasoning to conclude wetlands adjacent to non-wetland interstate waters are similarly 

jurisdictional without the need of demonstrating a significant nexus. 

For wetlands adjacent to tributaries that have a significant nexus to a traditional 

navigable water or interstate water,other covered waters, however, absent more specific 

regulations, the agencies must establish that the wetland alone or in combination with 

other adjacent wetlands in the watershed has a significant nexus to a traditional navigable 
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 51

water or interstate water. Justice Kennedy provided some guidance as to the analysis 

necessary to conclude that a water has a sufficient nexus. Justice Kennedy’s concern was 

that neither the Corps nor the reviewing courts applied the proper legal standard.z

 

Although evidenceEvidence was presented in one of the consolidated cases that the 

wetlands were providing habitat, sediment trapping, nutrient recycling, flood peak 

diminution and reduction, and flow water augmentation, the Corps did not marshall this 

evidence to conclude that the wetlands had a significant nexus to downstream traditional 

navigable waters.133augmentation.

134 The administrative record in one of the other 

caseconsolidated cases noted the wetland’s connection to wildlife habitat and water 

quality and “also noted that the project would have a major, long-term detrimental effect 

on wetlands, flood retention, recreation and conservation and overall ecology.”135

ecology.136 Justice Kennedy did not indicate that this evidence was irrelevant, in fact, he 

concluded that “[m]uchmuch the same evidence” previously analyzed by the Corps could

establishshould permit the establishment of a significant nexus with traditional navigable 

waters, particularly with additionalif supplemented by further evidence about the 

connection between the wetlands and the navigable water.137 

A hydrologic connection is neither determinative of nor required to show a 

significant nexus. Justice Kennedy noted that a “mere hydrologic connection 

shouldwould not suffice in all cases; the connection may be too insubstantial for the 

hydrologic linkage to establish the required nexus with navigable waters as traditionally 

understood.”138understood.139 On the other hand, Justice Kennedy was also clear that a 

hydrologic connection between a wetland and a tributary is not required to establish a 

significant nexus: “Given the role wetlands play in pollutant filtering, flood control, and 

runoff storage, it may well be the absence of hydrologic connection (in the sense of 

interchange of waters) that shows the wetlands’ significance for the aquatic system.”140 

Section 6: Other Waters

The “other waters” or “(a)(3) waters” provision of EPA’s and the Corps 

regulations includes: 

“All other waters such as intrastate lakes, rivers, streams (including intermittent 

streams), mudflats, sandflats, wetlands, sloughs, prairie potholes, wet meadows, 

playa lakes, or natural ponds, the use, degradation or destruction of which could 

affect interstate or foreign commerce ...”

 

zz Id. at 2251. Justice Kennedy thought that in both the consolidated cases before the Supreme Court, “the 

record contains evidence suggesting the possible existence of a significant nexus according to the principles 

outlined above. Thus the end result in these cases and many others to be considered by the Corps may be 

the same as that suggested by the dissent, namely, that the Corps' assertion of jurisdiction is valid.” 547 

U.S.Id. at 783.2250.
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 52

The agencies recognize that Supreme Court decisions in SWANCC and Rapanos 

have identified limitations on the Section 6: Other Watersgeographic scope of (a)(3) 

waters that may be determined to be jurisdictional. The agencies intend to address, in 

greater detail in future notice-and-comment rulemaking, the full extent that Clean Water 

Act jurisdiction may reach over (a)(3) waters. In the meantime, the agencies will make 

case-by-case, fact-specific determinations of jurisdiction under (a)(3) of whether waters 

or particular types of other waters, alone or in combination with similarly situated other 

waters in the region, significantly affect the chemical, physical, or biological integrity of 

traditional navigable waters or interstate waters. 

The agencies believe that the fewer of a particular water type in a watershed, the 

less likely there is to be a fact specific basis for concluding that those waters in 

combination have a significant nexus to a downstream traditional navigable water or 

interstate water. By contrast, the agencies believe that non-wetland waters that are 

adjacent to jurisdictional tributaries or to traditional navigable waters or interstate waters 

will usually be determined on a case-by-case basis to have a significant nexus to the 

traditional navigable water or interstate water (for example, an oxbow lake which, 

because of its close proximity to a jurisdictional tributary, contributes significantly to the 

chemical, physical, or biological integrity of a traditional navigable water, or prairie 

potholes that, together in the same watershed, significantly reduce flooding of an 

interstate water). While as a scientific matter a geographically isolated other water may 

have a significant nexus to a traditional navigable water or interstate water, as a practical 

matter in the field, it may be difficult to demonstrate that water has a significant nexus, 

individually or in combination with similarly situated other waters.

Examples of the nature of effects that support a significant nexus finding are the 

same as those considerations identified under Section 3 above. In conducting the 

significant nexus analysis, field staff should specifically consider the distance between 

the other water and the nearest traditional navigable water or interstate water, and the 

impact of proximity on potential chemical, physical, or biological effects. Consideration 

of use by migratory species is not relevant to the significant nexus determination.

Legal and Scientific Basis 

 Other waters are those The starting point for which any assertion of jurisdiction 

was previously asserted under section (a)(3) of remains the Corps’EPA and Corps

regulations, which defining the term “waters of the United States.” As noted above, 

those regulations provide for CWA jurisdiction over “[a]ll“all other waters . . .... the use, 

degradation, or destruction of which could affect interstate or foreign commerce. . . .” 

These include isolated, non-navigable intrastate waters.commerce...”141 This provision 

of the regulations was the focus of the SWANCC decision. In that case, the Court was 

considering the validity of the Corps’ assertion of jurisdiction over ponds and mudflats 

under (a)(3). of the Corps’ regulations. In rejecting the assertion of jurisdiction in that 

case, the Court held that “[i]t it “was the significant nexus between the wetlands and 
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 53

‘navigable waters’ that informed our reading of the CWA in Riverside Bayview 

Homes.”142 Justice Kennedy further explained the SWANCC decision – and his 

understanding of when EPA and the Corps could assert jurisdiction over “other waters” – 

in his concurring opinion in Rapanos: “In Solid Waste Agency of Northern Cook Cty. v. 

Army Corps of Engineers, 531 U.S. 159 (2001) (SWANCC), the Court held, under the 

circumstances presented there, that to constitute ‘navigable waters’ under the Act, a water 

or wetland must possess a ‘significant nexus’ to waters that are or were navigable in fact 

or that could reasonably be so made.”143 BecauseSince the Court in SWANCC was 

considering the validity of the Corps’ assertion of jurisdiction over ponds and mudflats 

under (a)(3) of the Corps’ regulations, it is reasonable to concludeclear that Justice 

Kennedy intends for his significant nexus standard to apply to the “other waters” of this 

regulation. 

An “other water” is jurisdictional only if it both has a significant nexus to a 

traditional navigable water or interstate water and meets the regulatory definition. One of 

the ways of demonstrating that a water is one “the use, degradation or destruction of 

which could affect interstate or foreign commerce” under (a)(3) of the regulations is 

through demonstration that the water has a significant nexus to a traditional navigable 

water or interstate water. If aA water that meets Justice Kennedy’s significant nexus 

standard, means that the degradation or destruction of that water could harm the

downstream traditional navigable water or interstate water and therefore could affect 

interstate or foreign commerce. 

For purposes of the significant nexus evaluation, similarly situated waters means 

those waters of a similar type having like physical and ecological characteristics and 

performing similar functions in the same watershed. For example, similarly situated 

waters may include all oxbow lakes, prairie potholes, all lakes and ponds, or all vernal 

pools in the same watershed. Both the position of the waters in the landscape 

(headwaters, riparian, flood plain) and the type of water (Cowardin class, wetlands 

defined by hydrogeomorphic classification type, or other classifications based on 

functions and values) are factors in determining similarly situated waters. When 

conducting a significant nexus analysis for a pond or lake, for example, which is not 

directly connected to the tributary system and therefore falls under (a)(3) of the agencies’ 

regulations, field staff should evaluate the effects of the lake or pond in combination with 

the effects of all other non-tributary lakes and ponds within the same watershed. 

Similarly, the effects of a non-adjacent wetland together with the effects of all other nonadjacent wetlands of the same type (for example, prairie potholes, vernal pools, etc.) 

within the same watershed should be assessed in making a significant nexus 

determination for a particular non-adjacent wetland. 

While all adjacent wetlands are reasonably proximate to a jurisdictional water by 

regulation and, therefore, “similarly situated,” the other waters provision of the 

regulations encompasses a wide-range of waters. For purposes of this guidance, the 

agencies have decided that it is more scientifically appropriate to divideassess significant 
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 54

nexus for other waters into two classes, those combination with waters of a similar type 

rather than, for example, aggregating all other waters that are physically proximate 

towere located approximately the same distance in the watershed from a traditional 

navigable water or interstate waters or their tributaries, and those that are not. For the 

first group, it is reasonable to treat these in much the same manner as adjacent wetlands, 

since they stand in the same relationship to and serve many of because the types of 

waters identified in the sameregulation can provide quite different functions as such 

wetlands with respect to the aquatic systems that they are near.. For instance, physically 

proximate waters canprairie potholes function to retain floodwaters, recharge 

groundwater, provide habitat for waterfowl and other species, and process and retain 

nutrients and pollutants that may otherwise enter tributaries; they may even beoxbow 

lakes are connected to athe river during high floods and provide a protected habitat for 

eggs and young of many fish species, as well as provide refuge for spawning for some 

species. 144

For the reasons articulated in Section 3 of this guidance, the agencies will 

interpret “in the region” for such proximate other waters to be the watershed boundary 

defined by the geographic area that drains through a single point of entry to the nearest 

downstream traditional navigable or interstate water through a single point of entry.. 

 In applyingFinally, the agencies will need to identify a significant chemical, 

physical or biological nexus standard to such waters, it. It is important to note that 

Justice Kennedy concluded that a water may have a significant nexus even if it does not 

have a hydrologic connection to the downstream traditional navigable water or interstate 

water: “Given the role wetlands play in pollutant filtering, flood control, and runoff 

storage, it may well be the absence of a hydrologic connection (in the sense of 

interchange of waters) that shows the wetlands’ significance for the aquatic system.”145 

This statement applies equally to proximate other waters. Thus, effects that should be 

considered include circumstances where proximate “other waters” trap pollutants such as 

nutrients or sediment, for example, or where they hold precipitation or snow melt, 

thereby reducing contamination or flooding of traditional navigable or interstate waters. 

Surface flow in streams draining mountain headwater areas in the arid west is commonly 

physically isolated from downstream playa lakes, wetlands, or larger streams and rivers 

by stream reaches that are dry much of the time. Such physical isolation may be broken 

for brief periods after rainfall. Despite the physical isolation of surface flow in these 

streams, they are an integral part of the hydrologic system in arid regions.146 There are 

often strong biological connections: many aquatic and semi-aquatic animals move 

between land-locked waters, adjacent wetlands, and stream channels. Some wetlands that 

are not adjacent may be hydrologically isolated most of the time but connected to the 

stream network during rare high-flow events. Geographically remote prairie potholes, for 

example, may be able to store significant amounts of runoff, thus reducing flooding as 

well as nutrient and soil pollution in downstream waters.147 Filling wetlands reduces 

water storage capacity in the landscape and causes runoff from rainstorms to overwhelm 

the remaining available water conveyance system.148 Wetlands improve water quality by 
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 55

accumulating nutrients, trapping sediments, and transforming a variety of substances.149 

In many watersheds, wetlands have a disproportionate effect on water quality because 

they receive dissolved and suspended compounds and materials from large areas, 

releasing higher quality water.

150 For an individual wetland, this is most pronounced 

where it lies immediately upstream of a drinking water intake, for example.151 But in the 

aggregate, such wetlands may have significant effects on the quality of water many miles 

away.152

Section 7: Waters Generally Not Jurisdictional

The scope of “waters of the United States” does not include all waters. EPA and 

the Corps previously have described in preambles to CWA regulations waters that the 

agencies generally do not consider to be waters of the U.S.153 The agencies’ position 

regarding these waters is unchanged. The categories of waters generally not “waters of 

the U.S.” include:

• Wet areas that are not tributaries or open waters and do not meet the regulatory 

definition of wetlands.154

• Waterbodies excluded from coverage under the CWA by existing regulations

• Waters that lack a significant nexus when one is required for jurisdiction. 

• Artificially irrigated areas which would revert to upland if the irrigation ceased. 

• Artificial lakes or ponds created by excavating and/or diking dry land to collect 

and retain water and which are used exclusively for such purposes as stock 

watering, irrigation, settling basins, or rice growing. 

• Artificial reflecting pools or swimming pools excavated in uplands.

• Small ornamental bodies of water created by excavating and/or diking dry land to 

retain water for primarily aesthetic reasons.

• Water-filled depressions created in dry land incidental to construction activity and 

pits excavated in dry land for the purpose of obtaining fill, sand, or gravel, unless 

and until the construction or excavation operation is abandoned and the resulting 

body of water meets the definition of waters of the United States.aa

 

aa Ditches should be evaluated consistent with Section 4 to determine whether they are tributaries, and then 

should further be considered under Section 4 to determine if they are waters of the U.S. 
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 56

• Groundwater drained through subsurface drainage systemsbb are not "waters of 

the United States." While groundwater associated with such subsurface drainage 

systems are not waters of the U.S., construction and the associated maintenance of 

a subsurface drainage system built in waters of the U.S. (e.g. wetlands) may 

require a CWA Section 404 permit.

Section 8: Documentation

EPA and Corps field staff should document in the administrative record the 

available information supporting a jurisdictional determination. In addition to location 

and other descriptive information regarding the water at issue, the record should include a 

clear explanation of the rationale for the jurisdictional conclusion, and include, as 

appropriate:

• Information leading to a conclusion that a water falls within a category 

considered in this memorandum to be jurisdictional without the need to 

demonstrate a significant nexus; 

• Information used to conclude a water has a significant nexus when one is 

required for jurisdiction;

• Information supporting a conclusion that a water lacks a significant nexus, when 

one is required for jurisdiction; or

• Information supporting a conclusion that a water falls within one of the 

categories of geographic features generally considered non-jurisdictional.

In short, both affirmative and negative jurisdictional determinations should be 

well-documented, to ensure both public transparency and defensibility should a 

jurisdictional conclusion be challenged. The level of documentation may be greater for 

jurisdictional determinations associated with complex projects. 

Other sections of this guidance discuss the findings necessary for particular 

categories of waters to be considered jurisdictional and/or to have a significant nexus. 

Information relevant to these findings can come from many sources, including but not 

limited to maps, aerial photography, soil surveys, watershed studies, local development 

plans, literature citations, and references from studies pertinent to the parameters being 

reviewed. Such information need not always involve the specific water whose 

jurisdictional status is being evaluated; regional and national studies of the same type of 

water or similarly situated waters can help to inform a jurisdictional analysis.

Information that is often an important part of a jurisdictional analysis is the 

location and type of water under consideration, so as to readily determine if jurisdictional 

 

bb A subsurface drainage system is an agricultural practice designed to drain subsurface water through a 

below ground pipe system in order to maintain the groundwater table below the root zone to facilitate crop 

production.
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 57

status of similarly situated waters has been previously determined. If so, the 

jurisdictional conclusion, rationale, and supporting information for a similarly situated 

water may be directly relevant. As Justice Kennedy noted in Rapanos, where a 

significant nexus has been established for a particular wetland, “it may be permissible, as 

a matter of administrative convenience or necessity, to presume covered status for other 

comparable wetlands in the region.”155 

 
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 58

In contrast, applying the significant nexus standard to geographically isolated 

other waters is more challenging. Justice Kennedy recognized that physical proximity

can be an important factor in the analysis of significant nexus.cc In light of the challenges 

in applying the significant nexus standard to geographically isolated other waters, the 

agencies have identified physical proximity as an important factor when conducting a 

significant nexus analysis for such waters. 

The agencies believe that the significant nexus test articulated by Justice Kennedy is the 

right theoretical approach for assessing all other waters, isolated and proximate, but 

because of the greater practical difficulty of applying this standard to geographically 

isolated other waters, we are directing field staff to continue for now the current practice 

of referring determinations for non-physically proximate other waters to their respective 

Headquarters and obtaining formal project-specific approval before asserting or denying 

jurisdiction. Because such waters are often geographically dispersed and isolated from 

each other, as well as from other jurisdictional waters, it is also not clear at this time how 

such waters should be grouped for purposes of considering them “similarly situated” and 

“in the region.” For this reason, until the agencies are able to further consider this issue 

through rule making, significant nexus determination will generally evaluate such waters 

individually, unless there is a compelling scientific basis for treating a group of such 

waters as similarly situated waters in the same region. In accordance with the decision in 

SWANCC, consideration of use by migratory species is not relevant to the significant 

nexus determination for such waters.

 

cc "Through regulations or adjudication, the Corps 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.” 547 U.S. at 

780.
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 59

ENDNOTES 

 

1

 The Federal Water Pollution Control Act Amendments of 1972, Pub. L. No. 92-500, 86 Stat. 816. The 

1972 legislation extensively amended the Federal Water Pollution Control Act (FWPCA), which was 

originally enacted in 1948. Further amendments to the FWPCA enacted in 1977 changed the popular name 

of the statute to the “Clean Water Act.” See Pub. L. No. 95-217, 91 Stat. 1566; 33 U.S.C. 1251 note. The 

current FWPCA is codified at 33 U.S.C. §§ 1251-1387. This guidance will refer to provisions of the 

current act by relevant “CWA section.” 

2

 531 U.S. 159 (2001). 

3 Carabell v. U.S. Army Corps of Eng’rs, 391 F.3d 704 (6th Cir. 2004); United States v. Rapanos, 376 F.3d 

629 (6th Cir. 2004). After certiorari was granted, these cases were consolidated, and the resulting opinion 

cited as Rapanos v. United States, 547 U.S. 715 (2006). 4 Carabell v. U.S. Army Corps of Eng’rs, 391 F.3d 704 (6th Cir. 2004), United States v. Rapanos, 376 F.3d 

629 (6th Cir. 2004). After certiorari was granted, these cases were consolidated, and the resulting opinion 

cited as Rapanos v. United States, 547 U.S. 715 (2006). 5

 CWA section 101(a).5 33 U.S.C. §1251(a). 6 Specifically, this memorandum supersedes the “Joint Memorandum” providing clarifying guidance on 

SWANCC, dated Jan. 15, 2003 (68 FR 1991, 1995), and “Clean Water Act Jurisdiction Following the U.S. 

Supreme Court’s Decision in Rapanos v. United States & Carabell v. United States,” dated December 2, 

2008.

7

 While sectionSection 311 uses the phrase "navigable waters of the United States," EPA has interpreted it 

to have the same breadth as the phrase "navigable waters" used elsewhere in sectionSection 311, and in 

other sections of the CWA. See, United States v. Texas Pipe Line Co., 611 F.2d 345, 347 (10th Cir. 1979); 

United States v. Ashland Oil & Transp. Co., 504 F.2d 1317, 1324-25 (6th Cir. 1974). In 2002, EPA revised 

its regulatory definition of “waters of the United States” in 40 C.F.R. part 112 to ensure that the actual 

language of the rule was consistent with the regulatory language of other CWA programs. Oil Pollution & 

Response; Non –Transportation-Related Onshore & Offshore Facilities, 67 Fed. Reg. 47,042 (July 17, 

2002). A district court vacated the rule for failure to comply with the Administrative Procedure Act, and 

reinstated the prior regulatory language. American Petroleum Ins.Institute v. Johnson, 541 F.Supp. 2d 

165No. 02-2247, 2008 U.S. Dist. LEXIS 25859 (D.D.C. Mar. 31, 2008). However, EPA interprets 

"navigable waters of the United States" in CWA sectionSection 311(b), in the pre-2002 regulations, and in 

the 2002 rule to have the same meaning as "navigable waters" in CWA sectionSection 502(7). 7 For example, the CWA Section 402 program regulates discharges of point sources to waters of the United 

States, whether these pollutants reach jurisdictional waters directly or indirectly. The plurality opinion in 

Rapanos noted that “... there is no reason to suppose that our construction today significantly affects the 

enforcement of §1342 ... The Act does not forbid the ‘addition of any pollutant directly to navigable waters 

from any point source,’ but rather the ‘addition of any pollutant to navigable waters.’” (emphasis in 

original) 126 S. Ct. 2208, 2227. Section 311(b)(1) provides that: "[I]t is the policy of the United States that 

there should be no discharges of oil or hazardous substances into or upon the navigable waters of the 

United States (or) adjoining shorelines. . . . or which may affect natural resources belonging to,

appertaining to, or under the exclusive management authority of the United States." (emphasis added).

8 8

For example, the CWA sectionSection 402 program regulates discharges of pollutants from “point 

sources” to waters of the United States, whether these pollutants reach jurisdictional waters directly or 

indirectly. The plurality opinion in Rapanos noted that ““... there is no reason to suppose that our 

construction today significantly affects the enforcement of §1342. . . . ... The Act does not forbid the 

‘addition of any pollutant directly to navigable waters from any point source,’ but rather the ‘addition of 

any pollutant to navigable waters.’” 547 U.(emphasis in original) 126 S. at 743. Clean Water Act 

sectionCt. 2208, 2227. Section 311(b)(1) provides: that: "[I]t is the policy of the United States that there 

should be no discharges of oil or hazardous substances into or upon the navigable waters of the United 

States [or](or) adjoining shorelines. . . . or which may affect natural resources belonging to, appertaining 
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 60

 

to, or under the exclusive management authority of the United States." (Emphasis(emphasis

added.)added). "Discharge" is broadly defined in CWA section§ 311(a)(2) to include "any spilling, 

leaking, pumping, pouring, emitting, emptying or dumping," with certain enumerated exceptions, and is not 

limited to point source discharges. 

9

 33 C.F.R. § 328.3(a)(8); 40 C.F.R. § 230.3(s); 40 C.F.R. § 122.2 (“waters of the U.S.”). 10 CWA section§ 404(f); 40 C.F.R. § 232.3; 33 C.F.R. § 323.4.323.3.

11 CWA section 402(l)(1) ("The Administrator shall not require a permit under this section for 

discharges composed entirely of return flows from irrigated agriculture. . . .”); CWA section);

502(14)("[The]502(14)("The term [point source] does not include agricultural stormwater discharges 

and return flows from irrigated agriculture."); 40 C.F.R. §CFR 122.3(f) (return( Return flows from 

irrigated agriculture are excluded from the NPDES program); 40 C.F.R. §CFR 122.2 (The term "point 

source" "does not include return flows from irrigated agriculture or agricultural storm water runoff."). 12 See, e.g., 33 C.F.R. § 328.3(a)(1); 40 C.F.R. § 230.3(s)(1); 40 C.F.R. § 122.2 (“waters of the 

U.S.”(a));US (a), 40 C.F.R. § 110.1 (“navigable waters” (a)).110(a). 13 Rivers and Harbors Appropriation Act of 1899, § 10, 33 U.S.C. § 403.

14 See, e.g., 33 C.F.R. § 328.3(a)(2); 40 C.F.R. § 230.3(s)(2); 40 C.F.R. § 122.2 (“waters of the U.S.”(b)), 

40 C.F.R. §110.1 (“navigable waters” (b)).

15 Water Pollution Control Act of 1948, § 10(e), 62 Stat. 1155, 1161.

16 Field staff generally should use the Strahler method. In Strahler’s method, a first-order stream has no 

tributaries, a second-order stream is formed by the joining of any two first-order streams, and a third order 

stream is formed by the junction of any two second-order streams. Arthur N. Strahler, "Quantitative 

Analysis of Watershed Geomorphology," American Geophysical Union Transactions 38 (1957): 913-920. 17 33 C.F.R. § 328.3(a)(5); 40 C.F.R. § 230.3(s)(5); 40 C.F.R. § 122.2 (“waters of the U.S.”(e)). 18 33 C.F.R. § 328.3(a)(7); 40 C.F.R. § 230.3(s)(7); 40 C.F.R. § 122.2 (“waters of the U.S.”(e)).

19 547 U.S. at 759.

20 James M. Omernik, “The Misuse of Hydrologic Unit Maps for Extrapolation, Reporting and Ecosystem 

Management,” Journal of the American Water Resources Association 39.3 (2003): 563-73. 21 The country is divided and subdivided into successively smaller watersheds, and the U.S. Geological 

Survey has developed a standardized watershed classification system--the Hydrologic Unit System--to 

organize watershed boundaries in a nested hierarchy by size. A unique hydrologic unit code (HUC) 

consisting of two to twelve digits (based on the level of classification) identifies each watershed in the 

country. The system divides the country into 21 regions, and progressively smaller sub-regions, accounting 

units, cataloging units, watersheds, and sub-watersheds, with the Natural Resources Conservation Service 

delineating the boundaries for the smallest two levels. The 10-digit HUC, for instance, is the "watershed" 

level in the classification system. See United States, Department of Agriculture, Natural Resources 

Conservation Service, "Overview and History of Hydrologic Units and the Watershed Boundary Dataset," 

Natural Resource Conservation Service. Web. 25 Jan. 2011.; United States, United States Geological 

Survey, USGS Water-Supply Paper 2294, Hydrologic Unit Maps (Washington, D.C.: U.S. Government 

Printing Office, Paul R. Seaber, F. Paul Kapinos, and George L. Knapp, 1987).

22 33 C.F.R. § 328.3(e).

23 Luna B. Leopold, M. Gordon Wolman, and John P. Miller, Fluvial Processes in Geomorphology (San 

Francisco: W.H. Freeman and Company, 1964).

24 Nyle C. Brady and Ray R. Weil, The Nature and Properties of Soils, 13th Edition (Upper Saddle River, 

NJ: Prentice Hall).

25 Luna B. Leopold, L.B., A View of the River (Cambridge: , (Harvard University Press,, 1994) p. 3. 26 United States, U.S. Environmental Protection Agency, EPA/600/R-06/126: Field Operations Manual for 

Assessing the Hydrologic Permanence and Ecological Condition of Headwater Streams (Washington D.C.: 

U.S. Environmental Protection Agency, Ken M. Fritz, Brent R. Johnson, and David M. Walters, 2006) 5. 27 See, e.g., 33 C.F.R. § 328.3(a)(2), (5); 40 C.F.R. § 230.3(s)(2)(5).
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 61

 28 Richard B. Alexander, et al., “The Role of Headwater Streams in Downstream Water Quality,” Journal 

of the American Water Resource Association 43.1 (2007): 41-59; Stephen R. Carpenter, et al., “Nonpoint 

Pollution of Surface Waters with Phosphorous and Nitrogen,” Ecological Applications 8.3 (1998): 559-68; 

Dana W. Kolpin, et al., “Pharmaceuticals, Hormones and Other Organic Wastewater Contaminants in U.S. 

Streams: 1999-2000: A National Reconnaissance,” Environmental Science and Technology 36.6 (2002): 

1202-1211.

29 United States, U.S. Army Engineer Research and Development Center, Cold Regions Research and 

Engineering Laboratory, ERDC TR-04-1: Review of Ordinary High Water Mark Indicators for Delineating 

Arid Streams in the Southwestern United States (Hanover, NH: U.S. Army Engineer Research and 

Development Center, Robert W. Lichvar and James S. Wakeley, 2004).

30 Generally, only the very large streams and rivers in the U.S. are monitored with stream gages for flow 

and the U.S. Geological Service maintains a network of only 7500 stream gages. United States, USGS, 

Fact Sheet 2009-3020, National Stream Flow Information Program Implementation Status Report (March 

2009). Smaller streams often do not have gages located on them, and not only would it be costly to 

monitor flow at sites like small headwater streams that are not currently gaged (Ken M. Fritz, Brent R. 

Johnson, and David M. Walters, "Physical Indicators of Hydrologic Permanence in Forested Headwater 

Streams." Journal of the North American Benthological Society 27.3 (2008): 690-704), monitoring studies 

can take one to two years (United States, U.S. EPA, EPA 600/R-06/126, Field Operations Manual for 

Assessing the Hydrologic Permanence and Ecological Condition of Headwater Streams (Cincinnati, Ohio: 

U.S. EPA Office of Research and Development, National Exposure Research Laboratory, Fritz et al., 

2006)).

31 Joan L. Florsheim, Jeffery F. Mount, and Anne Chin, “Bank Erosion as a Desirable Attribute of Rivers,” 

Bioscience 58 (2008): 519-29. 32 Takashi Gomi, RoyT., R. C. Sidle, and JohnJ. S. Richardson, “Understanding Processes and 

Downstream Linkages of Headwater Systems,” BioScience 52 (2002): 905-16 (Gomi, et al.).:905-916 at 

911 (2002).

33 Louis A. Kaplan, Richard A. Larson, and Thomas L. Bott, “Patterns of Dissolved Organic Carbon in 

Transport,” Limnology and Oceanography 25 (1980): 1034-43; Robin L. Vannote, et al., “The River 

Continuum Concept,” Canadian Journal of Fisheries and Aquatic Sciences 37 (1980): 130-37; J. Bruce 

Wallace, Sue L. Eggert, Judith L. Meyer, and Jackson R. Webster, “Multiple Trophic Levels of a Stream 

Linked to Terrestrial Litter Inputs,” Science 277 (1997): 102-04; Mark S. Wipfli and David P. Gregovich, 

“Export of Invertebrates and Detritus from Fishless Headwater Streams in Southeastern Alaska: 

Implications for Downstream Salmonid Production,” Freshwater Biology 47.5 (2002): 957-69. 34 Id.34 State of Ohio Environmental Protection Agency, “The Importance and Benefits of Primary 

Headwater Streams,” <http://www.epa.state.oh.us/dsw/wqs/headwaters/HWH_import_jan2003.pdf>

(2003a).; State of Ohio Environmental Protection Agency, “Clean Rivers Spring from Their Source: The 

Importance & Management of Headwater Streams,” 

<http://www.epa.state.oh.us/dsw/wqs/headwaters/fact_sheet10_final.pdf> (2001). 35 547 U.S. at 779-80.

36 Id. at 780. 37 33 CFR § 328.3(c); 40 CFR § 230.3(b).

38 Kevin J. Devito, Alan R. Hill, and Nigel Roulet, “Groundwater-Surface Water Interactions in Headwater 

Forested Wetlands of the Canadian Shield,” Journal of Hydrology 181 (1996): 127-47; Michael A. 

O’Driscoll and Richard R. Parizek, “The Hydrologic Catchment Area of a Chain of Karst Wetlands in 

Central Pennsylvania, USA,” Wetlands 23 (2003): 171-79; Bradley J. Cook and F. Richard Hauer, “Effects 

of Hydrologic Connectivity on Water Chemistry, Soils, and Vegetation Structure and Function in an 

Intermontane Depressional Wetland Landscape,” Wetlands 27 (2007): 719-38.

39 Charles H. Wharton, Wiley M. Kitchens, and Timothy W. Sipe, The Ecology of Bottomland Hardwood 

Swamps of the Southeast: A Community Profile (Washington, D.C.: U.S. Fish and Wildlife Service, 

FWS/OBS-81/37, 1982) 9.

40 As defined by the National Research Council, “riparian areas” are “transitional between terrestrial and 

aquatic ecosystems and are distinguished by gradients in biophysical conditions, ecological processes, and 
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 62

 biota. They are areas through which surface and subsurface hydrology connect waterbodies with their 

adjacent uplands. They include those portions of terrestrial ecosystems that significantly influence 

exchanges of energy and matter with aquatic ecosystems (i.e., a zone of influence). Riparian areas are 

adjacent to perennial, intermittent, and ephemeral streams, lakes, and estuarine-marine shorelines.” United 

States, National Research Council, Riparian Areas: Functions and Strategies for Management

(Washington, D.C. : National Academy Press, 2002) 33.

41 A “flood plain” is the relatively broad and smooth valley floor that is constructed by an active river and 

periodically covered with floodwater from that river during intervals of overbank flow. See also Theodore 

H. Schmudde, “Floodplain,” The Encyclopedia of Geomorphology, ed. Rhodes W. Fairbridge (New York: 

Reinhold, 1968) 359-62. 

42 William J. Mitsch, W.J., and James J.G. Gosselink, “The Value of Wetlands: Importance of Scale and 

Landscape Setting,” Ecological Economics 35.200 (2000): 35(200):25-33; Curtis J. (2000); Richardson, 

C.J., “Ecological Functions and Human Values in Wetlands: A Framework for Assessing Forestry 

Impacts,” Wetlands 14.1 (1994): 14(1):1-9. (1994). 43 Arid West Water Quality Research Project, Habitat Characterization Study Final Report (Phoenix:. URS 

Corporation, Phoenix, AZ. (2002); William J. Mitsch, W.J. and James J.G. Gosselink, Wetlands, 4th ed.Ed., 

(Hoboken, NJ: John Wiley & Sons, Inc., Inc.) (2007), p.347.

44 Robin L. Wellcomme, R.L., Fisheries Ecology of Floodplain Rivers (London: Longman,, (Longman: 

London, UK, 1979); Virginia Carter, V., “Wetland Hydrology, Water Quality, and Associated Functions,” 

in J.D. Fretwell, J.S. Williams, and P.J. Redman (eds.), National Water Summary on Wetland Resources, 

eds. Judy D. Fretwell, John S. Williams, and Phillip J. Redman (Washington, D.C.: U.S. Department of the 

Interior, U.S. Geological Survey, USGS Water-Supply Paper 2425, (Washington, DC, 1996), pp. 35-48; 

Alexander D. Huryn, A.D., and K. ElizabethE. Gibbs, “Riparian Sedge Meadows in Maine: Aa 

Macroinvertebrate Community Structured by River-Floodplain Interaction,” in D. Batzer, R.B. Rader, and 

S.A. Wissinger (eds.), Invertebrates in Freshwater Wetlands of North America: Ecology and Management,

eds. Darold Batzer, Russell B. Rader, and Scott A. Wissinger (New York: (John Wiley & and Sons, New 

York, NY, 1999), 363-82; Victor S.pp. 363-382; Lamoureux, V.S., and Dale D.M. Madison,

“Overwintering Habitats of Radio-Implanted Green Frogs, Rana clamitans,” Journal of Herpetology

33:430-435 (1999): 430-35; Leonard A.(1999); Smock, L.A., “Riverine Floodplain Forests of the 

Southeastern United States: Invertebrates in an Aquaticterrestrial Ecotone,” in: D. Batzer, R.B. Rader, and 

S.A. Wissinger (eds.), Invertebrates in Freshwater Wetlands of North America: Ecology and Management,

eds. Darold Batzer, Russell B. Rader, and Scott A. Wissinger (New York: (John Wiley & and Sons, New 

York, NY, 1999) 137-65; James H.pp. 137-165; Harding, J.H., Amphibians and Reptiles of the Great Lakes 

Region, (Ann Arbor, MI: University of Michigan Press, 2000); Ted R. Sommer, Louise T.R., L. Conrad, 

GavinG. O’Leary, FrederickF. Feyrer, and William W.C. Harrell, “Spawning and Rearing of Splittail in a 

Model Floodplain Wetland,” Transactions of the American Fisheries Society 131:966-974 (2002): 966-74; 

Daniel D.(2002); Magoulick, D.D., and Robert R.M. Kobza, “The Role of Refugia for Fishes During 

Drought: A Review And Synthesis,” Freshwater Biology 48:1186-1198 (2003): 1186-98; Joseph L.(2003); 

Ebersole, et al.,J.L., P.J. Wigington, J.P. Baker, M.A. Cairns, M.R. Church, B.P. Hansen, B.A. Miller, H.R. 

LaVigne, J.E. Compton, and S.G. Leibowitz, “Juvenile Coho Salmon Growth and Survival Across Stream 

Network Seasonal Habitats,” Transactions of the American Fisheries Society 135 (2006): 681-1697.

(2006).

45 United States, U.S. Fish and Wildlife Service, Semipalmated Sandpiper Habitat Model (Washington, 

D.C.: U.S. Fish and Wildlife Service, 2001). 

(<http://www.fws.gov/r5gomp/gom/habitatstudy/metadata/semipalmated_sandpiper_model.htm>.)

46 33 C.F.R. § 328.3(a)(3); 40 C.F.R. § 230.3(s)(3); see also 40 C.F.R. § 122.2 (“waters of the U.S.” (c)). 47 51 Fed. Reg. at 41,217; 41206, 41217 (November 13, 1986), 53 Fed. Reg. at 20,765.20764, 20765 (June 

6, 1988).

48 33 C.F.R. §328.3(b); 40 C,F.R. § CFR §230.3(t), 40 C.F.R. § 122.2 (“waters of the U.S.”US (b)).(b).

49 547 U.Rapanos, 126 S.Ct. at 782. 50 Id. at 739. 51 Id. at 742.
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 63

 52 United States v. Appalachian Elec. Power Co., 311 U.S. 377, 406 (1940). 53 FPL Energy Marine Hydro L.L.C.LLC v. FERC, 287 F.3d at1151, 1157 (internal quotation 

omitted).(D.C. Cir. 2002). 54 Id. at 1157-59.1158-59. 55 Id. at 1157. 56 Alaska v. Ahtna, Inc., 891 F.2d 1404 (9th Cir. 1989). 57 Alaska v. Ahtna, Inc., 891 F.2d 1401, 1405 (9th Cir. 1989).57 Id. at 1405. 58 Id. at 1404.

59 Id. at 1404. 60 Id. at 1402-03. 61 33 C.F.R. § 328.3(a)(2); 40 C.F.R. § 230.3(s)(2); 40 C.F.R. § 122.2 waters of the US (b), 40 C.F.R. 

§112.2.

62 33 C.F.R. § 328.3(a)(7); 40 C.F.R. § 230.3(s)(7). 63 126 S.Ct. at 2248. 64 The term "waters“waters of the United States" is defined by regulation to include "allStates” includes “all

interstate waters including interstate wetlands." 33 C.F.R. § 328.3(a)(2), (5);wetlands.” 40 C.F.R. § 

230.3(s)(2)(5). .3(s)(2), 33 C.F.R. 328.3(a)(2). 65 See, id. In discussing the significant nexus standard, Justice Kennedy stated: “The required nexus must 

be assessed in terms of the statute’s goals and purposes. Congress enacted the [CWA] to ‘restore and 

maintain the chemical, physical, and biological integrity of the Nation’s waters’ . . .” 126 S.Ct. at 2248. 

Consistent with Justice Kennedy’s instruction, EPA and the Corps will apply the significant nexus standard 

in a manner that restores and maintains any of these three attributes of traditional navigable waters and 

interstate waters. 

66 See Omernik, J.M., “The Misuse of Hydrologic Unit Maps for Extrapolation, Reporting, and Ecosystem 

Management.” Journal of the American Water Resources Association 39(3):563-573 (2003). 67 See, e.g., Merriam-Webster Online Dictionary, 2010. 68 Id. at 779. 69 Rapanos, 126 S.Ct. at 2248. 70 Id. at 780. 71 Id. 72 See, e.g., United States, EPA 841-B-08-002: U.S. Environmental Protection Agency, "Handbook for 

Developing Watershed Plans to Restore and Protect Our Waters: Planning & Implementation Steps, U.S. 

Environmental Protection Agency, EPA 841-B-08-002 (Washington D.C.: U.S. EPA,, DC, March 2008); 

James M. Omernik, J.M., and Robert R.G. Bailey, “Distinguishing Between Watersheds and Ecoregions,” 

Journal of the American Water Resources Association, 33.533(5):935-949 at 939, 940 (1997): 939-40; 

David R.(1997); Montgomery, D.R., “Process Domains and the River Continuum,” Journal of the 

American Water Resources Association 35 (1999): :397-410; Thomas C. (1999); Winter ,“, T.C., The 

Conceptconcept of Hydrologic Landscapes,”hydrologic landscapes. Journal of the American Water 

Resources Association 37: 335-349 (2001): 335-49; Jill S.(2001); Baron, et al.,J.S., N.L. Poff, P.L. 

Angermeier, C.N. Dahm, P.H. Gleick, N.G. Hairston, R.B. Jackson, C.A. Johnston, B.D. Richter, and A.D. 

Steinman, “Meeting Ecological and Societal Needs for Freshwater,” Ecological Applications 12:1247-1260

(2002): 1247-60; J. David(2002); Allan, J.D., “Landscapes and Riverscapes: The Influence of Land Use on 

Stream Ecosystems,” Annual Review of Ecology Evolution and Systematics 35 (2004): 257-84.:257-284

(2004).

 United States, U.S. EPA and USDA/ARS Southwest Watershed Research Center, EPA/600/R-08/134, 

ARS/2330462008:73 Levick et. al., The Ecological and Hydrological Significance of Ephemeral and 

Intermittent Streams in the Arid and Semi-arid American Southwest (Washington, D.C.: , U.S. EPA and 

USDA/ARS Southwest Watershed Research Center, Levick et al., EPA/600/R-08/134, ARS/2330462008, 

102pp (2008) (Levick, et. al.).. 74 Peter E. Black, “Watershed Functions,” Journal of the American Water Resources Association 33.1 

(1997): 1-11. 
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 64

 75 Black, P.E., “Watershed Functions,” Journal of the American Water Resources Association, 33(1):1-11 

(1997).

76 547 U.S. at 775, 779-80.

77 Id. at 775. 78 Id. at 780. 79 33 C.F.R. § 328.3(e). 80 Leopold L.B., M.G. Wolman, and J.P. Miller, Fluvial Processes in Geomorphology, 522 pp (Dover, 

1964).

81 Luna B. Leopold, L.B., A View of the River (Cambridge: , (Harvard University Press,, 1994) p. 3. 82 33 C.F.R. § 328.3(a)(2), (7); 40 C.F.R. § 230.3(s)(2)(7). 83 Alexander, R.B., E.W. Boyer, R.A. Smith, G.E. Schwarz and R.B. Moore. (2007) The role of headwater 

streams in downstream water quality. Journal of the American Water Resources Association, 43(1): 41-59.

Carpenter, S.R., N.F. Caraco, D.L. Correll, R.W. Howarth, A.N. Sharpley and V.H. Smith. (1998). 

Nonpoint pollution of surface waters with phosphorus and nitrogen. Ecological Applications, 8(3): 559-

568. Kolpin DW, Furlong ET, Meyer MT, Thurman EM, Zaugg SD, Barber LB, Buxton HT. 2002. 

Pharmaceuticals, hormones, and other organic wastewater contaminants in US streams, 1999-2000: A 

national reconnaissance. Environmental Science and Technology 36(6): 1202-121 84 Florsheim, JL, JF Mount, and Anne Chin. “Bank Erosion as a Desirable Attribute of Rivers,” Bioscience

58:519-529 (2008). 85 Takashi Gomi, RoyT., R. C. Sidle, and JohnJ. S. Richardson, “Understanding Processes and 

Downstream Linkages of Headwater Systems,” BioScience 52 (2002): 905-16 (Gomi, et al.).:905-916 at 

911 (2002).

86 Kaplan, L.A., R.A. Larson, T.L Bott, “Patterns of Dissolved Organic Carbon in Transport,” Limnology 

and Oceanography 25:1034-1043 (1980); Vannote, R.L., Minshall, W.G., Cummins, K.W., Sedell, J.R., 

and Cushing, C.E., “The River Continuum Concept,” Canadian Journal of Fisheries and Aquatic Sciences

37:130-137 (1980); Wallace, J.B., S.L. Eggert, J.L. Meyer, and J.R. Webster, “Multiple Trophic Levels of a 

Stream Linked to Terrestrial Litter Inputs,” Science 277:102-104 (1997); Wipfli, M.S., and D.P. Gregovich, 

“Export of Invertebrates and Detritus from Fishless Headwater Streams in Southeastern Alaska: 

Implications for Downstream Salmonid Production,” Freshwater Biology 47(5):957-969(13) (2002). 87 State of Ohio Environmental Protection Agency, “The Importance and Benefits of Primary Headwater 

Streams,” <http://www.epa.state.oh.us/dsw/wqs/headwaters/HWH_import_jan2003.pdf> (2003a).; State of 

Ohio Environmental Protection Agency, “Clean Rivers Spring from Their Source: The Importance & 

Management of Headwater Streams,” 

<http://www.epa.state.oh.us/dsw/wqs/headwaters/fact_sheet10_final.pdf> (2001). 88 Id.88 State of Ohio Environmental Protection Agency, “The Importance and Benefits of Primary 

Headwater Streams,” <http://www.epa.state.oh.us/dsw/wqs/headwaters/HWH_import_jan2003.pdf>

(2003a).; State of Ohio Environmental Protection Agency, “Clean Rivers Spring from Their Source: The 

Importance & Management of Headwater Streams,” 

<http://www.epa.state.oh.us/dsw/wqs/headwaters/fact_sheet10_final.pdf> (2001).

89 547 U.S.Rapanos, 126.S.Ct. at 739.2241.

90 Id. at 742.2226.

91 Id. at 732-33 n.5 (alteration in original).2221.

92 Fritz, K.M, B.R. Johnson, and D.M. Walters, Field Operations Manual for Assessing the Hydrologic 

Permanence and Ecological Condition of Headwater Streams, U.S. Environmental Protection Agency, 

EPA/600/R-06/126, <http://www.epa.gov/eerd/manual/HISSmanual_full.pdf> (Washington, DC, 2006), p. 

5.

93 United States, U.S. Environmental Protection Agency, “EPA, Memorandum to Assert Jurisdiction for 

NWP-2007-945 (Marks Creek)” (Washington D.C.: U.S. Environmental Protection Agency, Creek), 01/23

January 2008)./2008.

94 United States, U.S. Army Engineer Research and Development Center, Cold Regions Research and 

Engineering Laboratory, ERDC TR-04-1: 94 Lichvar, R.W., and J.S. Wakeley, “Review of Ordinary High 

Water Mark Indicators for Delineating Arid Streams in the Southwestern United States (Hanover, NH:,” U. 
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 65

 S. Army Engineer Research and Development Center, Robert W. LichvarCold Regions Research and 

James S. Wakeley,Engineering Laboratory, ERDC TR-04-1, (Hanover, NH, 2004); Lisa Ely, L. Ely,L.,

“Response of Extreme Floods in the Southwestern United States to Climatic Variations in 

Holocene,”Holocence,” Geomorphology 19 (1997): :175-201. (1997).

95 Ian Reid, I., and Lynne L.E. Frostick, “Channel Form, Flowflow and Sediments in Deserts,” in D.S.G. 

Thomas (ed.), Arid Zone Geomorphology: Process, Form and Change in Drylands, 2nd Edition, ed. David 

S.G. Thomas (Chichester,Ed., (Chicester, England: John Wiley & Sons, 1977) 205-29; William L.pp. 205–

229; Graf, W.L., “Definition of Floodplains Along Arid-Region Rivers,” Flood Geomorphology, ed. Victor 

in V.R. Baker, R. Craig C. Kochel, and Peter P.C. Patton (eds.), Flood Geomorphology, (New York: 

Springer-Verlag, 1988) 231-242. 96 Levick, et al. (2008), pp. 14-15. (See endnote 60.) 97 “U.S. EPA, Memorandum to Assert Jurisdiction for NWP-2007-945 (Marks Creek).” (See endnote 

69.)Creek), 01/23/2008.

98 N. Leroy Poff, N.L., and James J.V. Ward, “Implications of Streamflow Variability and Predictability 

for Lotic Community Structure: a Regional Analysis of Streamflow Patterns,” Canadian Journal of 

Fisheries and Aquatic Science 46 (1989): 1805-18,:1805-1818 at 1809. (1989). 99 Matthew J. Czikowsky, M.J., and David D.R. Fitzjarrald, “Evidence of Seasonal Changes in 

Evapotranspiration in Eastern U.S. Hydrological Records,” Journal of Hydrometeorology 5 (2004): 974-

88.:974-988 (2004). 100 547 U. Rapanos, 126 S.Ct. at 770.2242. 101 Id. at 778-79.2246. 102 Id. at 781.2248-49. 103 Id. 104 Id. at 2249 105 42 Fed. Reg. 37,122, 37,128 (July 19, 1977).at 37128. 106 Id. at 37,123. 106 42 Fed. Reg. 37121, 37122 (Jul. 19, 1977). 107 474 U.S. at 133 (quoting S.Rep.No. 414, 92d. Cong., 1st Sess., at 77 (1972)). 108 Riverside Bayview, 474 U.S. at 133 (quoting S.Rep.No. 414, 92nd. Cong., 1st Sess. 77 (1971)).

109 Gomi, et al.; Tracie L. (2002); Nadeau, T.-L., and Mark M.C. Rains,Rains. “Hydrological Connectivity 

Between Headwater Streams and Downstream Waters: How Science Can Inform Policy,” Journal of the 

American Resources Association 43:118-133 (2007): 118-33.;(2007); Levick, et al. (See endnote 

60.)(2008). 110 Martin Dieterich, M. and Norman N.H. Anderson, “Dynamics of Abiotic Parameters, Solute Removal 

and Sediment Retention in Summer-Dry Headwater Stream of Western Oregon,” Hydrobiologia 379

(1998): :1-15; (1998); State of Ohio Environmental Protection Agency, (2003a); S H. Duncan, R E. Bilby, J 

W. Ward, and J T. Heffner, "Transporttate of Road-Surface Sediment through Ephemeral Stream 

Channels," Water Resources Bulletin 23.1 (1987): 113-19.Ohio Environmental Protection Agency (2001). 111 Bruce J. Peterson, et al.,B. J., W. M. Wollheim, P. J. Mulholland, J. R. Webster, J. L. Meyer, J. L. 

Tank, E. Marti, W. H. McDowell, W.K. Dodds, S.K. Hamilton, S. Gregory, D. D. Morrall, “Control of 

Nitrogen Export from Watersheds by Headwater Streams,” Science: 292 (2001): :86-90; Judith.L. (2001);

Meyer, J. L. and J. BruceB. Wallace, “Lost Linkages and Lotic Ecology: Rediscovering Small Streams,” in

M.C. Press, N. J. Huntly, and S. Levin (eds.), Ecology: Achievement and Challenge, ed. Malcolm C. Press, 

Nancy J. Huntly, and Simon Levin (Orlando: (Blackwell Science, 2001), pp. 295- 317, at 310; Ken J. Hall, 

K.J., and Bruce B.C. Anderson, “The Toxicity and Chemical Composition of Urban Stormwater Runoff,” 

Canadian Journal of Civil Engineering 15 (1988): :98-106; David A. (1988); Lieb, D.A., and Robert R.F. 

Carline, “Effects of Urban Runoff from a Detention Pond on Water Quality, Temperature and Caged 

Gammarus Minus (Say) (Amphipoda) in a Headwater Stream,” Hydrobiologia 441.1441(1/3):107-116

(2000): 107-16; Robert E.(2000); Pitt, R.E., “Receiving Water Impacts Associated with Urban Runoff,” 

Handbook of Ecotoxicology, eds. David J. in D. Hoffman, Barnett A. B. Rattner, G. Allen Burton Jr., and 

John J. Cairns Jr. (eds.) Handbook of Ecotoxicology, (Boca Raton, FL: CRC Press, 2002); Richard B. See 

e.g. Alexander, Richard R.B., R.A. Smith, Gregory G.E. Schwarz, “Effect of Stream Channel Size on the 

Delivery of Nitrogen to the Gulf of Mexico,” Nature 403 (2000): 758-61.758-761 (2000).
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 66

 112 State of Ohio Environmental Protection Agency (2003a); United States, State of Ohio Environmental 

Protection Agency, “Nonpoint Source Impacts on Primary Headwater Streams (Columbus, OH: Ohio 

Environmental Protection Agency, 2003) (identified as ,” 

<http://www.epa.state.oh.us/dsw/wqs/headwaters/HWH_nonpoint_jan2003.pdf> (2003b) 

[<http://www.epa.state.oh.us/portals/35/wqs/headwaters/HWH_nonpoint_jan2003.pdf >];; Wipfli and 

Gregovich; Winsor H. (2002); Lowe, W. H. and GeneG. E. Likens, “Moving Headwater Streams to the 

Head of the Class,” BioScience 55:196-197 at 196 (2005):196-97; Mary C.(2005); Freeman, Catherine M. 

C., C. M. Pringle, and C. RhettR. Jackson, “Hydrologic Connectivityconnectivity and the 

Contributioncontribution of Stream Headwatersstream headwaters to Ecological Integrity at Regional 

Scales,”ecological integrity at regional scales,” Journal of the American Water Resources Association 43.1 

(2007): 43(1):5-14. (See endnote 31). (2007). 113 United States,See, e.g., National Research Council, Committee on the U.S. Geological Survey, 

Watershed Research in the U.S. Geological Survey (Washington, D.C.: DC: National Academy Press, 

1997) p. 4; Frank M. Dunnivant, F.M., and ElliotE. Anders, A Basic Introduction To Pollutant Fate and 

Transport: An : an Integrated Approach With Chemistry, Modeling, Risk Assessment, and Environmental 

Legislation (Hoboken, NJ:, (New Jersey: John Wiley & Sons, Inc., 2006). 114 Judith L Meyer, et al.,114 Meyer, J. L., D. L. Strayer, J.B. Wallace, S.L. Eggert, G.S. Helfman, and N.E. 

Leonard, "The Contribution of Headwater Streams to Biodiversity in River Networks," Journal of the 

American Water Resources Association 43.1 (2007): 43(1):86-103. (2007). 115 Gomi, et al. (2002), p. 911. (See endnote 30.) 116 Kaplan. et al.; (1980); Vannote, et al.; (1980); Wallace, et al.; (1997);Wipfli and Gregovich. (See 

endnote 31.) (2002). 117 State of Ohio Environmental Protection Agency (2003a); State of Ohio Environmental Protection 

Agency (2001); Levick, et al.. (See endnote 31.) (2008). 118 The agencies will not assert jurisdiction over such waters under the plurality standard within the 

Eleventh Circuit, i.e. waters in the states of Florida, Georgia and Alabama. See United States v. Robison, 

505 F.3d 1208 (11th Cir. 2007); reh’g en banc denied, 521 F.3d 1319 (11th Cir.), cert. denied sub nom. 

United States v. McWane, Inc., 129 S. Ct. 630 (2008).

119 33 CFR §328.3(c); 40 CFR § 230.3(b). 120 Devito K.J., A.R. Hill, and N. Roulet, “Groundwater-Surface Water Interactions in Headwater Forested 

Wetlands of the Canadian Shield,” Journal of Hydrology 181:127-147 (1996); O’Driscoll, M.A., and R.R. 

Parizek, “The Hydrologic Catchment Area of a Chain of Karst wetlands in Central Pennsylvania, USA,” 

Wetlands 23:171-179 (2003); Cook, B.J., and F.R. Hauer, “Effects of Hydrologic Connectivity on Water 

Chemistry, Soils, and Vegetation Structure and Function in an Intermontane Depressional Wetland 

Landscape,” Wetlands 27:719-738 (2007). 121 Brinson M., F.R. Hauer, L.C. Lee, W.L. Nutter, R.D. Rheinhardt, R.D. Smith, and D. Whigam, A 

Guidebook for Application of Hydrogeomorphic Assessments to Riverine Wetlands, US Army Corps of 

Engineers Waterways Experiment Station, Technical Report WRP-DE-11, (Washington, DC, 1995); Tiner, 

R.W., “Wetland Definitions and Classifications in the United States,” in J.D. Fretwell, J.S. Williams, and 

P.J. Redman (eds.), National Water Summary on Wetland Resources, U.S. Department of the Interior, U.S. 

Geological Survey, USGS Water-Supply Paper 2425, (Washington, DC, 1996), pp. 27-34; Leibowitz, S.G.,

P.J. Wigington , M.C. Rains, D.M. Downing, “Non-navigable Streams and Adjacent Wetlands: Addressing 

Science Needs Following the Supreme Court’s Rapanos Decision,” Frontiers in Ecology and the 

Environment 6: 364-371. 122 Wharton, C.H., W.M. Kitchens, and T.W. Sipe, “The Ecology of Bottomland Hardwood Swamps of the 

Southeast: A Community Profile,” U.S. Fish and Wildlife Service Publication, FWS/OBS-81/37 (1982), p. 

9.

123 As defined by the National Research Council, riparian areas are “...transitional between terrestrial and 

aquatic ecosystems and are distinguished by gradients in biophysical conditions, ecological processes, and 

biota. They are areas through which surface and subsurface hydrology connect waterbodies with their 

adjacent uplands. They include those portions of terrestrial ecosystems that significantly influence 

exchanges of energy and matter with aquatic ecosystems (i.e., a zone of influence). Riparian areas are 
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 67

 adjacent to perennial, intermittent, and ephemeral streams, lakes, and estuarine-marine shorelines. National 

Research Council, Riparian Areas: Functions and Strategies for Management, 428 pp, (Washington, DC: 

National Academy Press, 2002), p. 33.

124 A flood plain is the relatively broad and smooth valley floor that is constructed by an active river and 

periodically covered with floodwater from that river during intervals of overbank flow. See also, 

Schmudde, T.H. "Floodplain" in R.W. Fairbridge, The Encyclopedia of Geomorphology (New York: 

Reinhold, 1968), pp. 359-362. 125 William J. Mitsch, W.J., and James J.G. Gosselink, “The Value of Wetlands: Importance of Scale and 

Landscape Setting,” Ecological Economics 35.200 (2000): 35(200):25-33; Curtis J. (2000); Richardson, 

C.J., “Ecological Functions and Human Values in Wetlands: A Framework for Assessing Forestry 

Impacts,” Wetlands 14.1 (1994): 14(1):1-9. (1994). 126 Arid West Water Quality Research Project, Habitat Characterization Study Final Report (Phoenix:. 

URS Corporation, Phoenix, AZ. (2002); William J. Mitsch, W.J. and James J.G. Gosselink, Wetlands, 4th

ed.Ed., (Hoboken, NJ: John Wiley & Sons, Inc., Inc.) (2007), p.347. 127 Robin L. Wellcomme, R.L., Fisheries Ecology of Floodplain Rivers (London: Longman,, (Longman: 

London, UK, 1979); Virginia Carter, V., “Wetland Hydrology, Water Quality, and Associated Functions,” 

in J.D. Fretwell, J.S. Williams, and P.J. Redman (eds.), National Water Summary on Wetland Resources, 

eds. Judy D. Fretwell, John S. Williams, and Phillip J. Redman (Washington, D.C.: U.S. Department of the 

Interior, U.S. Geological Survey, USGS Water-Supply Paper 2425, (Washington, DC, 1996), pp. 35-48; 

Alexander D. Huryn, A.D., and K. ElizabethE. Gibbs, “Riparian Sedge Meadows in Maine: Aa 

Macroinvertebrate Community Structured by River-Floodplain Interaction,” in D. Batzer, R.B. Rader, and 

S.A. Wissinger (eds.), Invertebrates in Freshwater Wetlands of North America: Ecology and Management,

eds. Darold Batzer, Russell B. Rader, and Scott A. Wissinger (New York: (John Wiley & and Sons, New 

York, NY, 1999), 363-82; Victor S.pp. 363-382; Lamoureux, V.S., and Dale D.M. Madison,

“Overwintering Habitats of Radio-Implanted Green Frogs, Rana clamitans,” Journal of Herpetology

33:430-435 (1999): 430-35; Leonard A.(1999); Smock, L.A., “Riverine Floodplain Forests of the 

Southeastern United States: Invertebrates in an Aquaticterrestrial Ecotone,” in: D. Batzer, R.B. Rader, and 

S.A. Wissinger (eds.), Invertebrates in Freshwater Wetlands of North America: Ecology and Management,

eds. Darold Batzer, Russell B. Rader, and Scott A. Wissinger (New York: (John Wiley & and Sons, New 

York, NY, 1999) 137-65; James H.pp. 137-165; Harding, J.H., Amphibians and Reptiles of the Great Lakes 

Region, (Ann Arbor, MI: University of Michigan Press, 2000); Ted R. Sommer, Louise T.R., L. Conrad, 

GavinG. O’Leary, FrederickF. Feyrer, and William W.C. Harrell, “Spawning and Rearing of Splittail in a 

Model Floodplain Wetland,” Transactions of the American Fisheries Society 131:966-974 (2002): 966-74; 

Daniel D.(2002); Magoulick, D.D., and Robert R.M. Kobza, “The Role of Refugia for Fishes During 

Drought: A Review And Synthesis,” Freshwater Biology 48:1186-1198 (2003): 1186-98; Joseph L.(2003); 

Ebersole, et al.,J.L., P.J. Wigington, J.P. Baker, M.A. Cairns, M.R. Church, B.P. Hansen, B.A. Miller, H.R. 

LaVigne, J.E. Compton, and S.G. Leibowitz, “Juvenile Coho Salmon Growth and Survival Across Stream 

Network Seasonal Habitats,” Transactions of the American Fisheries Society 135 (2006): 681-1697.

(2006).

128 U.S. Fish and Wildlife Service, Semipalmated Sandpiper Habitat Model, (2001) 

<http://www.fws.gov/r5gomp/gom/habitatstudy/metadata/semipalmated_sandpiper_model.htm>.

129 U.S. Army Corps of Engineers, Engineer Research and Development Center, Interim Regional 

Supplement for the Atlantic and Gulf Coastal Plain Region, ERDC/EL TR-08-30, 

<http://el.erdc.usace.army.mil/elpubs/pdf/trel08-30.pdf> (2008), p. 142. 130 547 U.S. at 747. 131 Id.Rapanos, 126 S.Ct. at 779-80.2248. 132 Id. at 780 133 Id. at 783. 134 Id. 135 Id. at 785. 136 Id. at 2251.
***E.O. 12866 Review – Draft – Do not quote, cite or release during review***

DELIBERATIVE PROCESS; CONFIDENTIAL

DRAFT

December 2010 

Page 68

 137 Id. at 784.2250. 138 Id. at 784-85.

139 Id. at 2250-51. 140 Id. at 786.2251. 141 33 C.F.R. § 328.3(a)(3); 40 C.F.R. § 230.3(s)(3); 40 C.F.R. § 122.2.. 142 531 U.S.SWANCC, Slip Op. at 167.6. 143 547 U.S.Id. at 759.1.

144 See, e.g., Ralph W. Tiner, R.W., “Geographically Isolated Wetlands of the United States,” Wetlands

23.3(2003): 23(3):494-516; Dennis F. (2003); Whigham, D.F., and Thomas T.E. Jordan, “Isolated 

Wetlands and Water Quality,” Wetlands 23.323(3):541-549 (2003): 541-49; Charles R.(2003); Goldman, 

C.R., and Alexander A.J. Horne, Limnology, (New York:York, NY: McGraw-Hill, Inc., 1983); Paul H.

Zedler, P.H., “Vernal Pools and the Concept of ‘Isolated Wetlands,’” Wetlands 23.3 (2003): 23(3):597-607; 

Ellen T. (2003); Bauder, Andrew E.T., A.J. Bohonak, BarryB. Hecht, Marie M.A. Simovich, DavidD.

Shaw, David D.G. Jenkins, and MarkM. Rains, A Draft Regional Guidebook for Applying the 

Hydrogeomorphic Approach to Assessing Wetland Functions of Vernal Pool Depressional Wetlands in 

Southern California, (San Diego, CA: San Diego State University, 2009). 145 547 U.Rapanos, 126 S.Ct at 786.2251. 146 Izbicki, J.A., “Physical and Temporal Isolation of Mountain Headwater Streams in the Western Mojave 

Desert, Southern California,” Journal of the American Water Resources Association 43(1):26-40 ( 2007). 147 Hubbard, D.E., and R.L. Linder, “Spring Runoff Retention in Prairie Pothole Wetlands,” Journal of Soil 

and Water Conservation 41(2):122-125 (1997). 148 See e.g. Moscrip, A.L. and D.R. Montgomery, “ Urbanization, Flood Frequency, and Salmon 

Abundance in Puget Lowland Streams,” Journal of the American Water Resources Association 33:1289-

1297 (1997); Beck, N.E., V.J.Brady, D.L. Taylor, V.M. Snarski, and S.L. Batterman, “Relationship of 

Stream Flow Regime in the Western Lake Superior Basin to Watershed Type Characteristics,” Journal of 

Hydrology 309(1-4): 258-276 (2005); Detenbeck and Galatowich (1999); Johnson et al. (1990). 149 National Research Council, Wetlands: Characteristics and Boundaries, (Washington, DC: National 

Academy Press, 1995) p. 38. 150 Id. 151 Johnson et al. 1990. 152 See, e.g., Jansson A., C. Folke, and S. Langaas, “Quantifying the Nitrogen Retention Capacity of 

Natural Wetlands in the Large-Scale Drainage Basin of the Baltic Sea,” Landscape Ecology 13:249-262

(1998); Mitsch, W.J., J.W. Day, Jr., J.W. Gilliam, P.M. Groffman, D.L. Hey, G.W. Randall, and N. Wang, 

“Reducing Nitrogen Loading to the Gulf of Mexico from the Mississippi River Basin: Strategies to Counter 

a Persistent Ecological Problem,” BioScience 51(5): 373-388 (2001). 153 51 Fed. Reg. at 41,217; 41206, 41217 (November 13, 1986), 53 Fed. Reg. at 20,765.20764, 20765 (June 

6, 1988).

154 33 C.F.R. §328.3(b); 40 C,F.R. § CFR §230.3(t), 40 C.F.R. § 122.2 (“waters of the U.S.”US (b)).(b). 155 547 U.Rapanos, 126 S.Ct. at 782.