FINAL

ENVIRONMENTAL ASSESSMENT

ADOPTION OF

THE CLEAN WATER RULE: DEFINITION OF WATERS OF THE UNITED STATES

26 May 2015

U.S. Army

Office of the Assistant Secretary of the Army for Civil Works

Washington DC

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FINAL

ENVIRONMENTAL ASSESSMENT

ADOPTION OF 

THE CLEAN WATER RULE: DEFINITION OF WATERS OF THE UNITED STATES

1.0 INTRODUCTION

The Assistant Secretary of the Army for Civil Works (ASA(CW)) has prepared this 

Environmental Assessment (EA) to evaluate the potential impacts of adopting the final 

proposed rule entitled: Adoption of the Clean Water Rule: Definition of Waters of the 

United States A draft rule entitled: 33 CFR Part 328 Definition of Waters of the United 

States of title 33 Chapter I of the Code of Federal Regulations was published in the 

Federal Register (Vol. 79, No. 76) for public comment from April 21, 2014 to November 

14, 2014. This EA has been prepared consistent with the National Environmental Policy 

Act (NEPA) of 1969 and the Council on Environmental Quality’s Regulations (40 CFR 

1500-1508). Electronic copies of the documents incorporated into this EA as well as the 

final EA are located in the docket for this rulemaking, Docket EPA-HQ-OW-2011-0880.

The scope of this EA is to (1) document the potential environmental effects of the

proposed clarification of the definition of waters of the United States pursuant to the 

Clean Water Act (proposed action) and, (2) to determine whether to prepare an 

environmental impact statement for the proposed clarification or a finding of no 

significant impact (FONSI). This EA includes a brief discussion of the need for the

proposed action and, the potential environmental impacts of the proposed action and 

the alternative (no action).

1.1 PURPOSE

The foundation of the Clean Water Act is a desire by the Nation to restore and maintain 

the chemical, physical, and biological integrity of the waters of the United States. The 

term “waters of the United States” identifies waters which are subject to the Federal 

Water Pollution Control Act Amendments of 1972 (Clean Water Act).The purposes of 

the final proposed rule are to (1) clarify the scope of the regulatory term “waters of the 

United States”, and (2) simplify implementation of the Clean Water Act consistent with 

its purposes through clearer definitions and increased use of bright-line rules. The 

Environmental Protection Agency (EPA) and the U.S. Army Corps of Engineers 

(USACE) have developed this rule based upon language in the Clean Water Act, 

available science, Supreme Court decisions, public comments, and the agencies’ 

experience and technical expertise. Because the purpose of the final proposed rule is 

to define a waters of the United States the implementation of the rule would not affect 
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or alter the Department of the Army permit application process or the decision-making 

processes in place by the agencies. The final proposed rule, Adoption of the Clean 

Water Rule: Definition of Waters of the United States is herein incorporated by 

reference.

1.2 NEED

The need addressed by promulgating this rule is to resolve the ambiguity that exists 

under current regulations and practices following recent Supreme Court decisions, 

under which virtually all waters and wetlands across the country theoretically could be 

subject to a case-specific jurisdictional determination.

In Solid Waste Agency of Northern Cook County v. U.S. Army Corps of Engineers, 531 

U.S. 159 (2001) (SWANCC), the Supreme Court held that the use of “isolated” nonnavigable intrastate ponds by migratory birds was not by itself a sufficient basis for the 

exercise of federal regulatory authority under the Clean Water Act. Although the 

SWANCC decision did not call into question earlier decisions upholding the Clean 

Water Act’s coverage of wetlands or other waters “adjacent” to traditional navigable 

waters, it created uncertainty with regard to the jurisdiction of other waters and wetlands 

that, in many instances, may play an important role in protecting the integrity of the 

nation’s waters. The majority opinion in SWANCC introduced the concept that it was a 

“significant nexus” that informed the Court’s reading of Clean Water Act jurisdiction over 

waters that are not navigable in fact.

Five years later, in Rapanos v. United States, 547 U.S. 715 (2006) (Rapanos), all 

Members of the Court agreed that the term “waters of the United States” encompasses 

some waters that are not navigable in the traditional sense. In addition, Justice 

Kennedy’s opinion stated that the critical factor in determining the Clean Water Act’s 

coverage is whether a water has a “significant nexus” to downstream traditional 

navigable waters such that the water is important to protecting the chemical, physical, or 

biological integrity of the navigable water, referring back to the Court’s decision in 

SWANCC.

The “significant nexus” standard articulated and refined in these Supreme Court 

opinions is the touchstone for the agencies’ interpretation of the Clean Water Act’s 

jurisdictional scope. In response to these opinions, the agencies issued guidance in 

2003 (post-SWANCC) and 2008 (post-Rapanos). However, these two guidance 

documents are not effective in providing the public or agency staff with the information 

needed to ensure timely, consistent, and predictable jurisdictional determinations.

Many waters are currently subject to case-specific jurisdictional analysis to determine 

whether a “significant nexus” exists, and this time and resource intensive process can 

result in inconsistent interpretation of Clean Water Act jurisdiction and perpetuate 

ambiguity over where the Clean Water Act applies. Members of Congress, developers, 

farmers, state and local governments, energy companies, and many others requested 

new regulations to make the process of identifying waters protected under the Clean 

Water Act clearer, simpler, and faster. In the rule, the agencies are responding to those 

requests from across the country to make the process of identifying waters protected 
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under the Clean Water Act easier to understand, more predictable, and more consistent 

with the law and peer-reviewed science. 

2.0 ALTERNATIVES

This EA analyses the impacts of either implementing the proposed action (adoption of 

the final proposed rule) or selecting the No Action alternative (the existing rule and 

guidance would remain unchanged).

2.1 ADOPTION OF THE FINAL PROPOSED RULE ALTERNATIVE (Proposed Action)

The agencies administer the Clean Water Act Section 404 process and the USACE 

issues four types of permits: standard permits, letters of permission, nationwide permits, 

and regional general permits. In most situations a jurisdictional determination 

(preliminary or approved) is required to be completed. Jurisdictional determinations are

conducted by the USACE to establish the geographic extent of on-site waters and 

wetlands subject to the Clean Water Act. Current practice for the determination of the 

extent of jurisdictional waters of the United States is based upon regulations dated 

November 16, 1986, and interagency guidance documents dated January 15, 2003 and 

December 2, 2008.

The agencies developed a draft rule (appendix A) that was published in the Federal 

Register (Vol. 79, No. 76) on April 21, 2014 for a public comment period through July 

21, 2014. At the request of stakeholders the comment period was extended until 

November 14, 2014. Approximately 1.2 million comments were received during the 

comment period. After publication of the draft rule approximately 400 stakeholder 

engagements in the form of meetings, webinars, and phone calls were conducted to 

gather input and listen to stakeholders concerns with the draft rule. Upon review of the 

comments received, 20,567 were identified as unique; the remaining comments were 

form letters from mass letter writing efforts. The unique comments were evaluated 

further to identify comments that were substantive. Responses to the substantive 

comments have been developed by the agencies and are located in the docket for this 

rulemaking, Docket EPA-HQ-OW-2011-0880. Based upon a review of the comments 

and discussions with stakeholders, Federal agencies, and Congress, the draft rule was 

amended to incorporate changes into a final proposed rule (appendix B) that address 

the ambiguity that exists under current regulations and practices, while striving to 

simplify the process for identifying waters of the United States.

The final proposed rule establishes jurisdiction for: waters that are jurisdictional in all 

instances (traditional navigable waters and impoundments of jurisdictional waters), 

waters that are jurisdictional, but only if they meet specific definitions in the rule

(tributaries and adjacent waters), and a narrowed category of waters subject to casespecific analysis (other waters). Decisions about these waters are based on the law, 

peer-reviewed science, and the agencies’ technical expertise, and were informed by 

public comments. The final proposed rule replaces existing procedures and guidance 

that often depend on individual, time-consuming, and often inconsistent analyses of the 

relationship between a particular stream, wetland, lake, or other water with downstream 
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navigable waters. The agencies have greatly reduced the extent of waters subject to an

individual review by incorporating the scientific literature described in the EPA’s science 

report characterizing the nature and strength of the chemical, physical, and biological 

connections between upstream and downstream waters. The result of applying this 

scientific analysis is that the agencies can more effectively focus the rule on identifying 

waters that are clearly covered by the Clean Water Act and those that are clearly not 

covered, making the final proposed rule easier to understand, more consistent, in 

application, and environmentally more protective.

Traditional navigable waters (including interstate waters and the territorial seas) are 

jurisdictional by rule in all cases. Impoundments of jurisdictional waters are also 

jurisdictional by rule in all cases. The waters in the next two categories, “tributaries” and 

“adjacent” waters are jurisdictional by rule, as defined, because the science confirms 

that, as defined, they have a significant nexus to traditional navigable waters, interstate 

waters, or territorial seas. For waters that are jurisdictional by rule, no additional 

significant nexus analysis is required.

The final two categories of jurisdictional waters are those waters subject to case-specific 

analysis to determine whether they have a significant nexus to traditional navigable 

waters, interstate waters, or the territorial seas, either alone or in combination with 

similarly situated waters in the region.

Consistent with existing regulations and the April 2014 proposed rule, the final proposed 

rule includes traditional navigable waters, interstate waters, territorial seas, and 

impoundments of jurisdictional waters in the definition of “waters of the United States.” 

These waters are jurisdictional by rule.

Tributaries

Previous definitions of “waters of the United States” regulated all tributaries without 

qualification. This final proposed rule more precisely defines “tributaries” as waters that 

are characterized by the presence of physical indicators of flow – bed and banks and 

ordinary high water mark – and that contribute flow directly or indirectly to a traditional 

navigable water, an interstate water, or the territorial seas. The final proposed rule 

concludes that such tributaries are “waters of the United States.” The great majority of 

tributaries as defined by the final proposed rule are headwater streams that play an 

important role in the transport of water, sediments, organic matter, nutrients, and 

organisms to downstream waters. The physical indicators of bed and banks and 

ordinary high water mark demonstrate that there is sufficient volume, frequency, and 

flow in such tributaries to a traditional navigable water, interstate water, or the territorial 

seas to establish a significant nexus. “Tributaries,” as defined, are jurisdictional by rule.

The final proposed rule only covers as tributaries those waters that science tells us 

provide chemical, physical, or biological functions to downstream waters and that meet 

the significant nexus standard. The agencies identify these functions in the definition of 

“significant nexus” at paragraph (c)(5) of the final proposed rule. Features not meeting 

this legal and scientific test are not jurisdictional under the final proposed rule. The final 
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proposed rule continues the current policy of regulating ditches that are constructed in 

tributaries or are relocated tributaries or, in certain circumstances drain wetlands, or that 

science clearly demonstrates are functioning as a tributary. These jurisdictional waters 

affect the chemical, physical, and biological integrity of downstream waters. The rule 

further reduces existing confusion and inconsistency regarding the regulation of ditches 

by explicitly excluding certain categories of ditches, such as ditches that flow only after 

precipitation. Further, the rule explicitly excludes from the definition of “waters of the 

United States” erosional features, including gullies, rills, and ephemeral features such 

as ephemeral streams that do not have a bed and banks and ordinary high water mark.

Adjacent Waters

The agencies determined that “adjacent waters,” as defined in the final proposed rule, 

have a significant nexus to traditional navigable waters, interstate waters, and the 

territorial seas based upon their hydrological and ecological connections to, and 

interactions with, those waters. Under the final proposed rule, “adjacent” means 

bordering, contiguous, or neighboring, including waters separated from other “waters of 

the United States” by constructed dikes or barriers, natural river berms, beach dunes 

and the like. Further, waters that connect segments of, or are at the head of, a stream 

or river are “adjacent” to that stream or river. “Adjacent waters” include wetlands, 

ponds, lakes, oxbows, impoundments, and similar water features. However, it is 

important to note that “adjacent waters” do not include waters that are subject to 

established normal farming, silviculture, and ranching activities as those terms are used 

in Section 404(f) of the Clean Water Act.

The final proposed rule establishes a definition of “neighboring” for purposes of 

determining adjacency. In the final proposed rule, the agencies identify three 

circumstances under which waters would be “neighboring” and therefore “waters of the 

United States”:

(1) Waters located in whole or in part within 100 feet of the ordinary high water mark of 

a traditional navigable water, interstate water, the territorial seas, an impoundment 

of a jurisdictional water, or a tributary, as defined in the final proposed rule.

(2) Waters located in whole or in part in the 100-year floodplain and that are within 

1,500 feet of the ordinary high water mark of a traditional navigable water, 

interstate water, the territorial seas, an impoundment, or a tributary, as defined in 

the final proposed rule (“floodplain waters”).

(3) Waters located in whole or in part within 1,500 feet of the high tide line of a 

traditional navigable water or the territorial seas and waters located within 1,500 

feet of the ordinary high water mark of the Great Lakes.

The agencies emphasize that the rule has defined as “adjacent waters” those waters 

that currently available science demonstrates possess the requisite connection to 

downstream waters and function as a system to protect the chemical, physical, or 

biological integrity of those waters. The agencies also emphasize that the rule does not 

cover “adjacent waters” that are otherwise excluded. Further, the agencies recognize 

the establishment of bright line boundaries in the final proposed rule for adjacency does 

not in any way restrict states from considering state specific information and concerns, 
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as well as emerging science to evaluate the need to more broadly protect their waters 

under state law. The Clean Water Act establishes both national and state roles to 

ensure that states specific circumstances are properly considered to complement and 

reinforce actions taken at the national level.

“Adjacent” waters as defined, are jurisdictional by rule. The agencies recognize that 

there are individual waters outside of the “neighboring” boundaries stated above where 

the science may demonstrate through a case-specific analysis that there exists a 

significant nexus to a downstream traditional navigable water, interstate water, or the 

territorial seas. However, these waters are not determined jurisdictional by rule and 

would be evaluated through a case-specific analysis. The strength of the science and 

the significance of the nexus would be established on a case-specific basis as 

described in the final proposed rule.

The final proposed rule establishes a definition of “neighboring” for purposes of 

determining adjacency. In the final proposed rule, the agencies identify three 

circumstances (bright lines) under which waters would be “neighboring” and therefore 

“waters of the United States”:

(1) Waters located in whole or in part within 100 feet of the ordinary high water mark of 

a traditional navigable water, interstate water, the territorial seas, an impoundment 

of a jurisdictional water, or a tributary.

(2) Waters located in whole or in part in the 100-year floodplain that are within 1,500 

feet of the ordinary high water mark of a traditional navigable water, interstate 

water, the territorial seas, an impoundment, or a tributary (“floodplain waters”).

(3) Waters located in whole or in part within 1,500 feet of the high tide line or the 

ordinary high water mark of a tidally-influenced traditional navigable water, 

including the Great Lakes, or territorial sea.

Case-Specific Significant Nexus

The rule identifies particular waters that are not jurisdictional by rule but are subject to 

case-specific analysis to determine if a significant nexus exists and the water is a “water 

of the United States.” This category of case-specific waters is based upon available 

science and the law, and in response to public comments that encouraged the agencies 

to ensure more consistent determinations and reduce the complexity of conducting 

jurisdictional determinations. Consistent with the significant nexus standard articulated 

in the Supreme Court opinions, waters are “waters of the United States” if they 

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

waters, interstate waters, or the territorial seas. This determination would most typically 

be made on a water individually, but can, when warranted, be made in combination with 

other waters where waters function together.

In the final proposed rule, the agencies have identified by rule, five specific types of 

waters in specific regions that science demonstrates should be subject to a significant 

nexus analysis and are considered similarly situated by rule because they function alike 

and are sufficiently close to function together in affecting downstream waters. These 

five types of waters are Prairie potholes, Carolina and Delmarva bays, pocosins, 
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western vernal pools in California, and Texas coastal prairie wetlands. Consistent with 

Justice Kennedy’s opinion in Rapanos, the agencies determined that such waters 

should be analyzed “in combination” (as a group, rather than individually) in the 

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

territorial seas when making a case-specific analysis of whether these waters have a 

significant nexus to traditional navigable waters, interstate waters, or territorial seas.

The final proposed rule also provides that waters within the 100-year floodplain of a 

traditional navigable water, interstate water, or the territorial seas and waters within 

4,000 feet of the high tide line or the ordinary high water mark of a traditional navigable 

water, interstate water, the territorial seas, impoundments, or covered tributary are 

subject to case-specific significant nexus determinations, unless the water is excluded 

under paragraph (b) of the rule. The science available today does not establish that 

waters beyond those defined as “adjacent” should be jurisdictional as a category under 

the Clean Water Act, but the agencies’ experience and expertise indicate that there are 

many waters within the 100-year floodplain of a traditional navigable water, interstate 

water, or the territorial seas or out to 4,000 feet where the science demonstrates that 

they have a significant effect on downstream waters.

In circumstances where waters within the 100-year floodplain of a traditional navigable 

water, interstate water, or the territorial seas or within 4,000 feet of the high tide line or 

ordinary high water mark are subject to a case-specific significant nexus analysis and 

such waters may be evaluated as “similarly situated,” it must be first demonstrated that 

these waters function alike and are sufficiently close to function together in affecting

downstream waters. The significant nexus analysis must then be conducted based on 

consideration of the functions provided by those waters in combination in the point of 

entry watershed. A “similarly situated” analysis is conducted where it is determined that 

there is a likelihood that there are waters that function together to affect downstream 

water integrity. To provide greater clarity and transparency in determining what 

functions would be considered in determining what constitutes a significant nexus, the 

final proposed rule lists specific functions that the agencies would consider.

In establishing both the 100-year floodplain and the 4,000 foot bright line boundaries for 

these case-specific significant nexus determinations in the rule, the agencies are 

carefully applying the available science. Consistent with the Clean Water Act, the 

agencies would work with the states in connection with the prevention, reduction and 

elimination of pollution from state waters. The agencies would work with states to more 

closely evaluate state-specific circumstances that may be present within their borders 

and, as appropriate, encourage states to develop rules that reflect their circumstances 

and emerging science to ensure consistent and effective protection for waters in the 

states. As is the case today, nothing in this rule restricts the ability of states to more

broadly protect state waters.

The rule identifies particular waters that are not jurisdictional by rule but are subject to 

case-specific analysis to determine if a significant nexus exists and the water is a “water 

of the United States.” This category of case-specific waters was determined using 
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available science, the law, and in response to public comments received during the 

public comment period that encouraged the agencies to ensure more consistent 

determinations and reduce the complexity of conducting jurisdictional determinations.

Under the significant nexus standard articulated in the Supreme Court opinions, waters 

are “waters of the United States” if they significantly affect the chemical, physical, or 

biological integrity of traditional navigable waters, interstate waters, or the territorial 

seas.

In this final proposed rule, based in particular on the Connectivity Report and the input 

of the EPA science Advisory Board, contained in the administrative record for the rule 

the agencies have identified by rule, five specific types of waters in specific regions that 

should be subject to a significant nexus analysis and are considered similarly situated 

by rule because they perform similar functions and are located sufficiently close 

together in the watershed to function as a single system in affecting downstream 

waters. These five types of waters are prairie potholes, Carolina and Delmarva bays, 

pocosins, western vernal pools in California, and Texas coastal prairie wetlands. As 

explained in the preamble to the final proposed rule and the Technical Support 

document contained in the administrative record for the final proposed rule, the 

agencies determined that such waters should be analyzed “in combination” (as a group, 

rather than individually) in the watershed that drains to the nearest traditional navigable 

water, interstate water, or the territorial seas when making a case-specific analysis of 

whether these waters have a significant nexus to traditional navigable waters, interstate 

waters, or territorial seas. “Connectivity of Streams and Wetlands to Downstream 

Waters: A Review and Synthesis of the Scientific Evidence” was completed by the EPA, 

January 2015 and is incorporated by reference.

The final proposed rule also provides that waters within the 100-year floodplain or 4,000 

feet of the high tide line or the ordinary high water mark of a traditional navigable water, 

interstate water, the territorial seas, impoundments, or covered tributary are subject to 

case specific significant nexus determinations. The science available today would not 

support inclusion of all waters beyond those defined as “adjacent” as jurisdictional by 

rule under the Clean Water Act. The agencies’ experience and expertise have shown

there are waters where the science demonstrates that they often do have a significant 

effect on downstream waters. In establishing the 4,000 feet “bright line the agencies 

have balanced protection of the environment and clarity of the definition of a water of 

the United States, scientific uncertainties and regulatory experience, and established a 

line that is, in their judgment, reasonable and consistent with the statute and its goals 

and objectives. It is the judgment of the agencies that the 4,000 feet bright line would 

capture the vast majority of the waters that have a significant nexus to waters covered 

by the rule and thus should also be subject to jurisdiction under the Clean Water Act.

In circumstances where waters within the 100-year floodplain or 4,000 feet of the high 

tide line or ordinary high water mark are subject to a case-specific significant nexus 

analysis and such waters are to be evaluated as “similarly situated,” it must be first 

demonstrated that these waters function alike and are sufficiently close to function 
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together in affecting downstream waters. The significant nexus analysis must then be 

conducted based on consideration of the functions provided by those waters in 

combination in the point of entry watershed. A “similarly situated” analysis is conducted 

where it is determined that there is a likelihood that there are waters that function as a 

system to affect downstream water integrity. To provide greater clarity and 

transparency in determining what functions would be considered in determining what 

constitutes a significant nexus, the final proposed rule lists specific functions that the 

agencies would consider.

Exclusions

All existing exclusions from the definition of “waters of the United States” are retained, 

and several exclusions reflecting longstanding agency practice are added to the 

regulation for the first time.

Prior converted cropland and waste treatment systems have been excluded from the 

definition of “waters of the United States” definition since 1992 and 1979 respectively, 

and only ministerial changes are made. These two exclusions remain substantively and 

operationally unchanged.

The agencies add exclusions for waters and features previously identified as generally 

exempt (e.g., exclusion for certain ditches that are not located in or drain wetlands) in 

preamble language from Federal Register notices by the USACE on November 13, 

1986, and by EPA on June 6, 1988. This is the first time these exclusions have been 

established by rule. The agencies for the first time also establish by rule that certain 

ditches are excluded from jurisdiction, including ditches with ephemeral flow that are not 

a relocated tributary or excavated in a tributary, and ditches with intermittent flow that 

are not a relocated tributary, or excavated in a tributary, or drain wetlands. The 

agencies add exclusions for groundwater and erosional features, as well as exclusions 

for some waters that were identified in public comments as possibly being found 

jurisdictional under proposed rule language where this was never the agencies’ intent, 

such as stormwater control features constructed to convey, treat, or store stormwater, 

and cooling ponds that are created in dry land. These exclusions reflect the agencies’ 

current practice, and their inclusion in the rule as specifically excluded furthers the 

agencies’ goal of providing greater clarity over what waters are and are not protected 

under the Clean Water Act.

With adoption of the final proposed rule, the definition of waters of the United States

would be changed in the regulation. The new definition would be applicable nationwide 

and utilized by stakeholders and regulators in making jurisdictional determinations 

under Section 404 of the Clean Water Act. The USACE completes jurisdictional 

determinations at the request of a landowner or developer, during processing of a 

Department of the Army permit application, or in conjunction with an enforcement 

action. The jurisdictional determination concludes whether lands for which an action 

may be proposed meet the criteria to be a waters of the United States and therefore 

subject to the Clean Water Act. Because the purpose of the final proposed rule is to 

define a waters of the United States the implementation of the rule would not affect or
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alter the Department of the Army permit application process or the decision-making 

processes in place by the agencies.

The final proposed rule includes eight standalone categories of jurisdictional waters, 

maintains existing exemptions for certain categories of activities and waters, and adds 

additional exclusions for categories of waters that are never covered under the Act. 

Navigable waters as defined by 40 CFR 110.1, means the waters of the United States, 

including the territorial seas. The eight jurisdictional water categories are:

(a) For purposes of the Clean Water Act, 33 U.S.C. 1251 et. seq. and its implementing 

regulations, subject to the exclusions in paragraph (b) of this section, the term 

‘‘waters of the United States’’ means:

(1) All waters which are currently used, 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;

(2) All interstate waters, including interstate wetlands;

(3) The territorial seas;

(4) All impoundments of waters otherwise identified as waters of the United States 

under this section;

(5) All tributaries, as defined in paragraph (c)(3) of the final proposed rule, of 

waters identified in paragraphs (a)(1) through (3) of this section;

(6) All waters adjacent to a water identified in paragraphs (a)(1) through (5) of this 

section, including wetlands, ponds, lakes, oxbows, impoundments, and similar 

waters;

(7) All waters in paragraphs (i) through (v) of this paragraph where they are 

determined, on a case-specific basis, to have a significant nexus to a water 

identified in paragraphs (a)(1) through (3) of this section. The waters identified 

in each of paragraphs (i) through (v) of this paragraph are similarly situated 

and shall be combined, for purposes of a significant nexus analysis, in the 

watershed that drains to the nearest water identified in paragraphs (a)(1) 

through (3) of this section. Waters identified in this paragraph shall not be 

combined with waters identified in paragraph (a)(6) of this section when 

performing a significant nexus analysis. If waters identified in this paragraph 

are also an adjacent water under paragraph (a)(6), they are an adjacent water 

and no case-specific significant nexus analysis is required.

(i) Prairie potholes. Prairie potholes are a complex of glacially formed 

wetlands, usually occurring in depressions that lack permanent natural 

outlets, located in the upper Midwest.

(ii) Carolina bays and Delmarva bays. Carolina bays and Delmarva bays are 

ponded, depressional wetlands that occur along the Atlantic coastal plain.

(iii) Pocosins. Pocosins are evergreen shrub and tree dominated wetlands 

found predominantly along the Central Atlantic coastal plain. 

(iv) Western vernal pools. Western vernal pools are seasonal wetlands 

located in parts of California and associated with topographic depression, 

soils with poor drainage, mild, wet winters and hot, dry summers.
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(v) Texas coastal prairie wetlands. Texas coastal prairie wetlands are 

freshwater wetlands that occur as a mosaic of depressions, ridges, 

intermound flats, and mima mound wetlands located along the Texas 

Gulf Coast.

(8) All waters located within the 100-year floodplain of a water identified in (a)(1) 

through (3) of this section and all waters located within 4,000 feet of the high 

tide line or ordinary high water mark of a water identified in paragraphs (a)(1) 

through (5) of this section where they are determined on a case-specific basis 

to have a significant nexus to a water identified in paragraphs (a)(1) through 

(3) of this section. For waters determined to have a significant nexus, the 

entire water is a water of the United States if a portion is located within the 

100-year floodplain of a water identified in (a)(1) through (3) of this section or 

within 4,000 feet of the high tide line or ordinary high water mark. Waters 

identified in this paragraph shall not be combined with waters identified in 

paragraph (a)(6) of this section when performing a significant nexus analysis. 

If waters identified in this paragraph are also an adjacent water under 

paragraph (a)(6), they are an adjacent water and no case-specific significant 

nexus analysis is required.

The following are not “waters of the United States” even where they otherwise meet the 

terms of paragraphs (iv) through (viii) of the section above.

(b) The following are not waters of the United States” even where they otherwise meet 

the terms of paragraphs (a)(4) through (8) of this section.

(1) Waste treatment systems, including treatment ponds or lagoons designed to 

meet the requirements of the Clean Water Act.

(2) Prior converted cropland. Notwithstanding the determination of an area’s 

status as prior converted cropland by any other Federal agency, for the 

purposes of the Clean Water Act, the final authority regarding Clean Water Act 

jurisdiction remains with EPA.

(3) The following ditches:

(i) Ditches with ephemeral flow that are not a relocated tributary or excavated 

in a tributary.

(ii) Ditches with intermittent flow that are not a relocated tributary, excavated in 

a tributary, or drain wetlands.

(iii) Ditches that do not flow, either directly or through another water, into a 

water identified in paragraphs (a)(1) through (3) of this section.

(4) The following features:

(i) Artificially irrigated areas that would revert to dry land should application of 

water to that area cease;

(ii) Artificial, constructed lakes and ponds created in dry land such as farm and 

stock watering ponds, irrigation ponds, settling basins, fields flooded for 

rice growing, log cleaning ponds, or cooling ponds;

(iii) Artificial reflecting pools or swimming pools created in dry land;

(iv) Small ornamental waters created in dry land;
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(v) Water-filled depressions created in dry land incidental to mining or 

construction activity, including pits excavated for obtaining fill, sand, or 

gravel that fill with water;

(vi) Erosional features, including gullies, rills, and other ephemeral features 

that do not meet the definition of tributary, non-wetland swales, and lawfully 

constructed grassed waterways; and

(vii) Puddles.

(5) Groundwater, including groundwater drained through subsurface drainage 

systems.

(6) Stormwater control features constructed to convey, treat, or store stormwater 

that are created in dry land.

(7) Wastewater recycling structures constructed in dry land; detention and 

retention basins built for wastewater recycling; groundwater recharge basins; 

percolation ponds built for wastewater recycling; and water distributary 

structures built for wastewater recycling.

2.2 NO ACTION ALTERNATIVE

The analysis of the No Action alternative is based upon the existing conditions, rules, 

process, and procedures currently utilized by the agencies in making and enforcing 

jurisdictional determinations on the lands of the United States that are subject to 

protection under the Clean Water Act. The USACE is the lead agency for completing 

jurisdictional determinations. Jurisdictional determinations are the process employed by 

the USACE to complete a formal scientific based evaluation of a parcel of land to 

determine whether lands, for which an action may be proposed, meets the criteria to be 

a waters of the United States and therefore subject to the Clean Water Act. The 

USACE completes jurisdictional determinations at the request of a landowner or 

developer, during processing of a Department of the Army permit application, or in 

conjunction with an enforcement action. Jurisdictional determinations can be completed 

in two ways. If a permit applicant elects to set aside the question of jurisdiction and 

voluntarily opts in to the permitting process, a “preliminary” jurisdictional determination 

is adopted. A preliminary jurisdictional determination can avoid the longer process 

associated with completing an “approved” jurisdictional determination. In Fiscal Year 

2014, 66 percent of jurisdictional determinations completed were preliminary and 34

percent were approved.

The baseline for the No Action alternative analysis is the set of current processes and 

procedures utilized by the agencies of identifying waters that are subject to jurisdiction 

under the Clean Water Act based upon the 1986 regulatory definition, and guidance 

developed as a result of the SWANCC and Rapanos U.S. Supreme Court decisions. 

The analysis of the No Action alternative focuses on the potential impacts to potentially 

impacted environmental resources that are reasonable and foreseeable.

Existing regulations (last codified in 1986) define waters of the United States as 

traditional navigable waters, interstate waters, impoundments of waters of the United 

States, tributaries, the territorial seas, adjacent wetlands, and all other waters that could 

affect interstate or foreign commerce (33 CFR 328.3). Under this definition, the 
13

agencies only have Clean Water Act jurisdictional authority over "isolated" waters under 

the Commerce Clause "if their use, degradation, or destruction could affect interstate or 

foreign commerce." Intrastate waters that could affect interstate commerce solely by 

virtue of their use as habitat for migratory birds are not considered to be waters of the 

United States, in accordance with the SWANCC decision.

In response to the SWANCC decision, approximately 20 million acres of “isolated” 

wetlands were removed from consideration as waters of the United States, and the 

definition of waters of the United States was updated in interagency guidance.

2.3 ALTERNATIVES CONSIDERED BUT ELIMINATED

2.3.1 DRAFT RULE ALTERNATIVE

The agencies developed a draft rule (appendix A) in April 2014 which was published in 

the Federal Register (Vol. 79, No. 76) for a public comment period. Approximately 1.2 

million comments were received. Additionally, approximately 400 stakeholder 

engagements in the form of meetings, webinars, and phone calls were conducted to 

gather input and listen to stakeholders concerns with the draft rule. The substantive 

comments were evaluated and incorporated into the final proposed rule.

The ASA(CW) considered whether to analyze the draft rule in this Environmental 

Assessment, but removed it from further consideration because it is no longer a viable 

option to accomplish the purpose and need for action. The draft rule was modified 

based upon a review of the substantive comments received during the public comment 

period. As a result, and recognizing the myriad components of such a rule, it was 

determined that analyzing the various component elements of the final proposed rule 

was appropriate. Accordingly, this environmental assessment focuses only on 

“Adoption of the Final Proposed Rule” alternative and the No Action alternative 

(baseline).

3.0 ENVIRONMENTAL SETTING

3.1.1 WATERS OF THE UNITED STATES

Wetlands are lands where saturation with water is the dominant factor determining the 

nature of soil development and the types of plant and animal communities living in the 

soil and on its surface. Wetland characteristics can vary widely because of regional and 

local differences in soils, topography, climate, hydrology, water chemistry, vegetation, 

and other factors, including human disturbance. Wetlands are found from the tundra to 

the tropics and on every continent except Antarctica.

For regulatory purposes under the Clean Water Act, the term wetlands means "those 

areas that are inundated or saturated by surface or groundwater at a frequency and 

duration sufficient to support, and that under normal circumstances do support, a 

prevalence of vegetation typically adapted for life in saturated soil conditions. Wetlands 

generally include swamps, marshes, bogs and similar areas." (40 CFR 230.3(t))
14

Wetlands and open waters in non-floodplain landscape settings provide numerous 

functions that benefit downstream water integrity (Connectivity Report). These 

functions include storage of floodwater; recharge of ground water that sustains river 

baseflow; retention and transformation of nutrients, metals, and pesticides; export of 

organisms or reproductive propagules to downstream waters; and habitats needed for 

stream species. This diverse group of wetlands (e.g., many prairie potholes, vernal 

pools, playa lakes) can be connected to downstream waters through surface-water, 

shallow subsurface-water, and ground-water flows and through biological and chemical 

connections.

Streams are the dominant source of water in most rivers, and individually or 

cumulatively, exert a strong influence on the integrity of downstream waters. The 

majority of tributaries are perennial, intermittent, or ephemeral headwater streams. 

Headwater streams convey water into local storage compartments such as ponds, 

shallow aquifers, or stream banks, as well as regional and alluvial aquifers; these local 

storage compartments are important sources of water for maintaining baseflow in rivers.

All tributary streams are physically, chemically, and biologically connected to 

downstream rivers via channels and associated alluvial deposits where water and other 

materials are concentrated, mixed, transformed, and transported. Physical, chemical, 

and biological connections between streams and downstream waters interact via 

integrative processes such as nutrient spiraling, in which stream communities assimilate 

and chemically transform large quantities of nitrogen and other nutrients that otherwise 

would be transported directly downstream, increasing nutrient loads and associated 

impairments due to excess nutrients in downstream waters.

Streams transport water, sediment, wood, organic matter, nutrients, chemical 

contaminants, and many of the organisms found in rivers. They are biologically 

connected to downstream waters by the dispersal and migration of aquatic and 

semiaquatic organisms, including fish, amphibians, plants, microorganisms, and 

invertebrates, that use both upstream and downstream habitats during one or more 

stages of their life cycles, or provide food resources to downstream communities. In 

addition to material transport and biological connectivity, ephemeral, intermittent, and 

perennial flows influence fundamental biogeochemical processes by connecting 

channels and shallow ground water with other landscape elements.

Stream and wetland connections have particularly important consequences for 

downstream water integrity. Most of the materials, in rivers, for example, originate from 

aquatic ecosystems located upstream or elsewhere in the watershed. Longitudinal 

flows through ephemeral, intermittent, and perennial stream channels are much more 

efficient for transport of water, materials, and organisms than diffuse overland flows, 

and areas that concentrate water provide mechanisms for the storage and 

transformation, as well as transport, of materials.
15

In addition to material transport and biological connectivity, ephemeral, intermittent, and 

perennial stream flows influence fundamental biogeochemical processes by connecting 

channels and shallow ground water with other landscape elements.

Connectivity of streams and wetlands to downstream waters occurs along a continuum 

that is described in terms of the frequency, duration, magnitude, timing, and rate of 

change of water, material, and biotic fluxes to downstream waters. Variations in the 

degree of connectivity influence the range of functions provided by streams and 

wetlands, and are critical to the integrity and sustainability of downstream waters.

Human alterations affect the frequency, duration, magnitude, timing, and rate of change 

of connections between headwater streams, including ephemeral and intermittent 

streams, and downstream waters. Human activities and built structures (e.g., 

channelization, dams, groundwater withdrawals) can either enhance or fragment 

longitudinal connections between headwater streams and downstream waters, while 

also constraining lateral and vertical exchanges and tightly controlling the temporal 

dimension of connectivity.

The agencies administer the Clean Water Act Section 404 process and the USACE 

issues four types of permits: standard permits, letters of permission, nationwide permits, 

and regional general permits. All of these permits may require a jurisdictional 

determination (preliminary or approved) to be conducted by the USACE to establish the 

geographic extent of on-site waters and wetlands subject to the Clean Water Act. 

Current practice for the determination of the extent of jurisdictional waters of the United 

States is based upon regulations dated November 16, 1986, and interagency guidance 

documents dated January 15, 2003 and December 2, 2008.

Aquatic resources protected under the Clean Water Act are regulated under Section 

404 of the Act and efforts are made through the regulatory processes to avoid and 

minimize impacts to the fullest extent possible. Compensatory mitigation, in compliance 

with the law, is required for any unavoidable impacts.

3.1.2 CLIMATE CHANGE

The analysis of global climate change related impacts to natural resources and the 

potential responses to those impacts has become a priority as precipitation patterns 

may shift, extreme heat and cold events may become more common, and sea levels 

rise (Flournoy 2013). Because wetlands support a number of migratory birds, 

threatened species, endangered species, interjurisdictional fish, marine mammals, and 

other species of concern and have been linked to water quality and other environmental 

values, their susceptibility to climatic variations is an important consideration. Due in 

part to their limited capacity for adaptation, wetlands have been considered among the 

ecosystems most vulnerable to climate change (Bates et al. 2008).

Global climate change is recognized as a threat to species survival and the health of 

natural systems. Scientists worldwide are looking at the ecological and hydrological 

impacts resulting from climate change. Climate change is projected to make future 
16

efforts to protect, restore, and manage wetlands more complex. Wetland systems are 

vulnerable to changes in quantity and quality of their water supply, and it is expected 

that climate change would have a pronounced effect on wetlands through alterations in 

hydrological regimes with great global variability. Wetland habitat responses to climate 

change and the implications for restoration would be realized differently on a regional 

and mega-watershed level, making it important to recognize that specific restoration and 

management plans would require examination by habitat. Floodplains, mangroves, 

seagrasses, saltmarshes, arctic wetlands, peatlands, freshwater marshes and forests 

are very diverse habitats, with different stressors.

Sea level rose during the 20th century, and observations and projections suggest that it 

would rise at a higher rate during the 21st century. Rising seas increase the risk of 

coastal flooding, storm surge inundation, coastal erosion and shoreline retreat, and 

wetland loss (The National Research Council, 2012). Sea level rise is a major factor in 

sustainability of wetlands and their function. As sea level rises some wetlands would be 

inundated and become open water and some non jurisdictional areas would experience 

hydrologic changes such that they would transition to wetlands. This would result in 

changes in the biota of the United States (wetlands, fish, wildlife, plants) over time. 

Additionally, there would be changes in the Ordinary High Water Mark for some waters 

of the United States as sea level rises.

4.0 RELEVANT RESOURCES

This section contains a description of the relevant resources that could be impacted by 

the proposed action. The principal relevant resource for the purposes of this analysis is 

the set of waters that are subject to a determination under the Clean Water Act as 

waters of the United States. Covered water bodies include oceans, rivers and streams, 

lakes, ponds, impoundments (in some circumstances), wetlands, playa lakes, channels, 

and in some circumstances, various unique ecological features such as 

Carolina/Delmarva Bays, Pocosins, Prairie Potholes, Texas Coastal Wetlands, and 

Vernal Pools. Other relevant resources discussed include fish and wildlife, recreation, 

socio-economic effects and flood risk reduction.

4.1 AFFECTED ENVIRONMENT

4.1.1 WATERS OF THE UNITED STATES

Streams and wetlands provide many functions, including water supply; groundwater 

recharge; sediment trapping; nutrient recycling; pollutant removal; retention and 

attenuation of floodwaters; shoreline stabilization; runoff storage; contribution of flow; 

export of organic matter; export of food resources; and provision of life-cycle dependent 

aquatic habitat (such as foraging, feeding, nesting, breeding, spawning, and nursery 

areas) for fish, shellfish, and wildlife including threatened and endangered species. 

The effect of upstream water can be significant even when a water, alone or in 

combination, is providing a subset, or even just one, of the functions listed.
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Science demonstrates that the aquatic functions provided by smaller streams, ponds, 

wetlands and other waters are important for contributing to the chemical, physical, and 

biological integrity of downstream traditional navigable waters, interstate waters, and 

the territorial seas. For example, States identify sediment and nutrients as the primary 

contaminants in the nation’s waters. Sediment storage and export via streams to 

downstream waters is critical for maintaining the river network, including the formation 

of channel features. Although sediment is essential to river systems, excess sediment 

can impair ecological integrity by filling interstitial spaces, reducing channel capacity, 

blocking sunlight transmission through the water column, and increasing contaminant 

and nutrient concentrations. Streams and wetlands can prevent excess deposits of 

sediment downstream and reduce pollutant concentrations in downstream waters.

Nutrient recycling results in the uptake and transformation of large quantities of nitrogen 

and other nutrients that otherwise would be transported directly downstream, thereby 

decreasing nutrient loads and associated impairments due to excess nutrients in 

downstream waters. Streams, wetlands and open waters improve water quality 

through the assimilation, transformation, or sequestration of pollutants, including 

excess nutrients and chemical contaminants such as pesticides and metals that can 

degrade downstream water integrity. Nutrient transport exports nutrients downstream 

and can degrade water quality and lead to stream impairments. Nutrients are 

necessary to support aquatic life, but excess nutrients lead to excessive plant growth 

and hypoxia, in which over-enrichment causes dissolved oxygen concentrations to fall 

below the level necessary to sustain most aquatic animal life in the downstream waters. 

Nutrient recycling, retention, and export can significantly affect downstream chemical 

integrity by impacting downstream water quality.

The contribution of flow downstream is an important role, as upstream waters are a 

cumulative source of the majority of the total mean annual flow to bigger downstream 

rivers and waters, in ways that influence the recharge of baseflow. Streams, wetlands, 

and open waters contribute surface and subsurface water downstream, and are the 

dominant sources of water in most rivers.

Small streams and wetlands are particularly effective at retaining and attenuating 

floodwaters. By subsequently releasing (desynchronizing) floodwaters and retaining 

large volumes of stormwater that could otherwise negatively affect the condition or 

function of downstream waters, streams and adjacent wetlands and open waters can 

reduce flood peaks downstream and can also maintain downstream river base flows by 

recharging alluvial aquifers.

Streams, wetlands, and open waters supply downstream waters with dissolved and 

particulate organic matter (e.g., leaves, wood), which support biological activity 

throughout the river network. In addition to organic matter, streams, wetlands, and 

open waters can also export other food resources downstream, such as aquatic insects 

that are the food source for fish in downstream waters. The export of organic matter 

and food resources downstream is important to maintaining the food webs.
18

Streams, wetlands, and open waters provide life-cycle dependent aquatic habitat (such 

as foraging, feeding, nesting, breeding, spawning, and use as a nursery area) for 

species located in traditional navigable waters, interstate waters, or the territorial seas. 

Many species require different habitats for different resources (e.g., food, spawning 

habitat, overwintering habitat), and thus move throughout the river network over their 

life-cycles. For example, headwater streams can provide refuge habitat under adverse 

conditions, enabling fish to persist and recolonize downstream areas once conditions 

have improved. These upstream systems form integral components of downstream 

food webs, providing nursery habitat for breeding fish and amphibians, colonization 

opportunities for stream invertebrates, and maturation habitat for stream insects, 

including for species that are critical to downstream ecosystem function.

The conterminous United States contained an estimated 110.1 million acres of wetlands 

in 2009 (Dahl 2011). An estimated 95 percent of all wetlands were freshwater and 5 

percent were in the marine or estuarine systems. Estuarine emergent (salt marsh) 

wetland was the most prevalent type of all estuarine and marine intertidal wetland. Salt 

marsh made up an estimated 66.7 percent of all estuarine and marine wetland area. 

Forested wetlands made up the single largest category (49.5 percent) of wetland in the 

freshwater system. Freshwater emergent made up an estimated 26.3 percent, shrub 

wetlands 17.8 percent and freshwater ponds 6.3 percent by area (Dahl 2011).

In 1994, an estimated 174 million acres of wetland existed in Alaska (Hall, 1994). 

Hawaii had 52,000 acres as of the 1980s (Dahl, 1990). Next to Alaska, Florida (11.4 

million) (Dahl, 2005), Minnesota (10.6 million) (Klobier, 2010), Louisiana (7.8 million) 

(Caffey, 2003), and Texas (7.6 million) (Dahl 1990) have the largest wetland acreage

(Dahl 2011). The wetlands described above were determined using the Cowardin et al.

system that was adopted as a standard by the U.S. Fish and Wildlife Service and 

subsequently became a Federal Geographic Data Committee (FGDC). This definition 

differs from the Regulatory definition of a wetlands as used in the final proposed rule

Wetland area declined by an estimated 62,300 acres between 2004 and 2009 according 

to the Status and Trends of Wetland in the Conterminous United States 2004 to 2009

(Dahl 2011). The reasons for this loss are complex and reflect economic conditions, 

land use trends, changing wetland regulation and enforcement measures, and climatic 

changes. Certain types of wetland declined while others increased in area. For 

example, between 2004 and 2009, 489,600 acres of former uplands were re-classified 

as wetlands. These increases were attributed to wetland reestablishment and creation 

on agricultural lands and other uplands with undetermined land use including 

undeveloped land, lands in conservation program or idle lands. The rate of wetland 

reestablishment increased by an estimated 17 percent from previous study periods

(1998 and 2004). Conversely, the estimated wetland loss rate increased 140 percent 

during the same time period and as a consequence, national wetland losses have 

outdistanced gains (Dahl 2011).
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4.1.2 FISH AND WILDLIFE

The significance of wildlife resources is demonstrated by the multitude of legislative acts 

that exist to manage and conserve the resource. Pivotal among these are the Coastal 

Zone Management Act; the Estuary Protection Act; the Fish and Wildlife Coordination Act 

of 1958, as amended; the Migratory Bird Conservation Act of 1929 as amended; the 

migratory Bird Treaty Act of 1918; the Endangered Species Act of 1973 (ESA), as 

amended; the Fish and Wildlife Conservation Act of 1980; the North American Wetlands 

Conservation Act; Executive Order 13186 Migratory Bird Habitat Protection; and the 

Magnuson-Stevens Fishery Conservation and Management of 1976, as amended.

Wildlife resources are critical elements of the ecosystem and important indicators of the 

health of the ecosystem. Wetlands provide habitat for waterfowl and other wildlife, 

habitat for rare and endangered species, food production, and plant production. 

Wetlands provide valuable habitat for recreational and commercial fishing and nursery 

areas for a wide variety of finfish and shellfish.

Fish and wildlife resources are important because of the high priority that the public 

places on their esthetic, recreational, and commercial value. Living marine resources 

constitute valuable and renewable resources that contribute to the food supply, 

economy, welfare, health, and recreational opportunities of the Nation (MagnusonStevens Act, 1996). Wildlife serve as agents of pollination, are a food source, control 

the rate and extent by which nutrients are distributed in an ecosystem, contain 

compounds that are the basis of some medicines, and can provide a safe, effective and 

less expensive alternative to chemical pest control.

Threatened and endangered fish, wildlife, and plant species “are of esthetic, ecological, 

educational, historical, recreational, and scientific value to the Nation and its people.” 

Biodiversity is essential for a healthy and functional ecosystem. There are currently 678 

fish and wildlife species listed as threatened and endangered in the United States. 

Since passage of the Endangered Species Act in 1973, over 1,300 endangered and 

threatened species have been protected in the United States and its territories. Male 

and Bean (Male, 2005), in a review of 1988 to 2002 Federal agency reports to the 

United States Congress, “found that 52 percent of species showed repeated 

improvements or were not declining over this time. Species status improved over time, 

with only 35 percent still declining 13 years or more after protection.”

4.1.3 RECREATION

Wetlands have recreational value to the Nation. More than half of all U.S. adults (98 

million) hunt, fish, bird watching or photograph wildlife (EPA). While individual 

significance or value of recreation may differ greatly, nationally it is very significant. A 

1999 report drafted by the National Recreation Lakes Study Commission, states 

“recreation constitutes 10.5 percent of all consumer spending and contributes more than 

$350 billion annually to the Gross Domestic Product” (1999). The 2011 National Survey 

of Fishing, Hunting, and Wildlife-Associated Recreation revealed that over 90 million 

U.S. residents 16 years old and older participated in wildlife-related recreation. During 

that year, 33.1 million people fished, 13.7 million hunted, and 71.8 million participated in 
20

at least one type of wildlife-watching activity including observing, feeding, or 

photographing fish and other wildlife in the United States.

4.2 SOCIO-ECONOMIC

Wetlands have a socio-economic value to the Nation and its residents and visitors, 

especially in providing positive ecosystem services that contribute to human well-being. 

Some of these services include preservation of food supply (i.e. rice farming);

preservation of habitats and food supply for a variety of species including fish, migratory 

birds and other organisms; increasing water supply, purification, and quality; providing 

additional resiliency in coastal protection and flood regulation (per Section 4.3) and 

increasing recreational opportunities and tourism (per Section 4.1.3).

These services are difficult to quantify as monetized values, because they are not 

market goods with a direct dollar value, but instead are qualitative and can be derived 

by noting in addition to their services, their preventative contribution to flooding and 

general environmental degradation. Waters of the United States contribute to a 

desirable quality of life and sustainability of that quality of life. The EPA estimates that 

wetlands could have a value of up to $15 trillion (The Millennium Ecosystem 

Assessment, 1997) and studies of the role of coastal wetlands in reducing the severity 

of impacts from hurricanes in the United States found that they provided storm damage 

reduction services with an estimated value of $23.2 billion per year (Costanza 2008).

4.3 FLOOD RISK REDUCTION 

Wetlands serve a vital role in temporarily storing storm water during flooding events. 

Wetlands function as natural sponges that trap and slowly release surface water, rain, 

snowmelt, groundwater and flood waters. Trees, root mats, and other wetland 

vegetation also slow the speed of flood waters and distributes them more slowly over 

the floodplain. This combined water storage and braking action lowers flood heights 

and reduces erosion. As discussed in the connectivity Report wetlands within and 

downstream of urban areas are particularly valuable, counteracting the greatly 

increased rate and volume of surface- water runoff from pavement and buildings.

A one-acre wetland can typically store about three-acre feet of water, or up to one and 

half million gallons. The holding capacity of wetlands helps control floods and prevents 

water logging of crops. Preserving and restoring wetlands, together with other water 

retention, can often provide the level of flood risk reduction otherwise provided by 

expensive dredge operations and levees.

Coastal wetlands can have an impact on storm surge associated with coastal storms. 

Wetland plants help retard shoreline erosion by holding the soil in place with their roots 

and absorbing the energy of waves.
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5.0 ENVIRONMENTAL CONSEQUENCES

5.1 WATERS OF THE UNITED STATES

5.1.1 ADOPTION OF THE FINAL PROPOSED RULE ALTERNATIVE (Proposed Action)

Adoption of the final proposed rule would have no direct effect on the environment. 

Indirect effects under NEPA are those caused by an action that are later in time or 

farther removed in distance but are still reasonably foreseeable. See 40 C.F.R. 

1508.8(b). Compared to a baseline of the existing regulations and historic practice,

prior to the SWANCC case, the adoption of the final proposed rule results in a decrease 

in Clean Water Act jurisdiction because the scope of regulatory jurisdiction in this rule is 

narrower than that under the existing regulation. However, when compared to the No 

Action alternative, the set of current processes and procedures utilized by the agencies

of identifying waters that are subject to jurisdiction under the Clean Water Act based 

upon the 1986 regulatory definition, and guidance developed as a result of the 

SWANCC and Rapanos U.S. Supreme Court decisions, this rule is projected to result in 

a incremental increase in Clean Water Act jurisdiction because the uncertainty caused 

by the efforts to implement the Supreme Court cases, and the resulting caution in 

asserting jurisdiction, would be resolved by the rule which provides clarity about which 

waters are covered by the Clean Water Act.

Based upon an analysis performed as a part of the economic analysis, a random 

selection of 188 negative jurisdictional determinations made in Fiscal Years 2013 and 

2014 covering 32 states, in which waters were found to not be subject to jurisdiction

under the Clean Water Act, were reviewed and a determination was made if the waters 

in those jurisdictional determinations would be determined to be positive with adoption 

of the final proposed rule. The analysis used negative jurisdiction determinations from 

the three categories of waters of the United States: streams, wetlands, and other 

waters. Of the 188 jurisdictional determinations 65 percent were streams, 29 percent 

were wetlands, and 6 percent were other waters. Based upon that analysis it was 

determined that there would be an increase of between 2.8 and 4.6 percent in the 

waters found to be jurisdictional with adoption of the rule. The majority of the change 

occurring in the determinations would be in the category for waters that fit the “Other 

Waters” category.

A positive jurisdictional determination is a determination made by the USACE 

that finds the waters/wetlands to be waters of the United States.

Negative jurisdictional determination is a determination made by the USACE 

that finds the waters/wetlands to not be waters of the United States.

Upon request the USACE evaluates a parcel of land for jurisdiction, as such, a 

jurisdictional determination may include jurisdictional areas as well as nonjurisdictional areas. Additionally, in many cases a single jurisdictional 

determination evaluates all waters the on the parcel of property, thus, one or 

more waters may be included in a single jurisdictional determination and those 

water may fall into different categories of waters of the United States.
22

For the purposes of the analysis preformed in this EA, a subsample of the total number 

of jurisdictional determinations made were examined. Based upon that analysis a 

determination was made that there would be an incremental increase in the number of 

waters found to be subject to jurisdiction under the Clean Water Act. No analysis was 

made to determine the actual number of acres of waters that would be and for this 

reason it is not possible to estimate the number of acres that would be captured by this 

increase in positive jurisdictional determinations. As described below, the majority of 

the incremental change in jurisdiction would occur in the category of “Other Waters.” 

Other Waters are those waters that do not fit within the categories of waters 

jurisdictional by rule and would only be jurisdictional upon a case-specific determination 

that those waters have a significant nexus to a water which is currently used, was 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; all interstate waters, including 

interstate wetlands; and the territorial seas. Based upon the analysis of the negative 

jurisdictional determinations that would be found to be positive with adoption of the rule 

the following impacts could be expected to occur:

Streams - the estimated percentage of positive jurisdictional determinations for 

streams would go from 99.3 percent to 100 percent (tributaries) under the new rule. 

(a)(1)

Adjacent Wetlands - the estimated percentage of positive jurisdictional determinations 

for wetlands would go from 98.9 percent to 100 percent under the new rule. (a)(6)

The estimated change in positive jurisdictional determinations for Other Waters is 

estimated at 34.5 percent. ((a)(6), (a)(7), and (a)(8))

Other Waters (adjacent waters) – estimated that there would be up to a 17.1 

percent increase in positive jurisdictional determinations for "other waters," 

based on the assumption that they are "adjacent waters." (a)(6)

Other Waters (significant nexus) - estimated that there would be up to a 15.7

percent increase in positive jurisdictional determinations for "other waters," 

based on the assumption that there is a significant nexus to a nearby water of 

the United States. (a)(7)

Other Waters (Bright Line) - estimated that there would be up to a 1.7 percent

increase in positive jurisdictional determinations for “other waters,” based on 

the assumption that there is a significant nexus to a (a)(1) to (a)(5) waters of 

the United States within the 100-year floodplain or 4,000 feet of a high tide line 

or ordinary high water mark of a waters of the United States. (a)(8)

As discussed above, estimates are that under paragraph (a)(8) of the final proposed 

rule there could be a 1.7 percent increase in positive jurisdictional determinations, there 

is also the possibility that some wetlands that might have been found jurisdictional as 

“adjacent” under current rules and practice, would no longer be jurisdictional under the 

final proposed rule. Specifically, in a few instances in the past the USACE has 

determined that there were jurisdictional wetlands based on a surface or subsurface 

hydrologic connection to regulated waters, but those wetlands would fall outside either 
23

the 100-year floodplain or 4,000 feet from the high tide line or ordinary high water mark. 

These wetlands would have been considered “adjacent” under the current regulation, 

but would not be “adjacent” based on the definition of neighboring in the final proposed

rule. However, in the agencies experience the vast majority of wetlands with a 

significant nexus are located within the 4,000 foot boundary. It is anticipated that the 

incremental decrease in jurisdictional determinations for wetlands outside the 100 year 

floodplain or 4,000 feet of the high tide line or ordinary high water mark of jurisdictional 

waters would correspondingly be small. It is also speculative and hypothetical as to 

what the environmental consequences would be for such waters beyond the 100-year 

floodplain or 4,000 feet if they are not subject to the Section 404 permitting process. 

The consequences would depend on other factors not related to this rule, such as the 

nature of any activity proposed for such waters and the waters affected, and any other 

requirements (e.g., Section 9 of the Endangered Species Act, or state and local law) 

that may be applicable.

With adoption of the final proposed rule there would be an incremental increase in the 

amount of waters of the United States subject to jurisdiction under the Clean Water Act, 

and any proposals that would impact jurisdictional areas would be subject to review 

under the USACE public interest analysis, the section 404(b)(1) Guidelines and any 

other applicable federal requirements (e.g., NEPA, section 7 of the ESA) that would not 

occur if areas were not subject to jurisdiction (No Action). Under the Section 404(b)(1) 

guidelines, some impacts to waters may be avoided or minimized as a result of the 

implementation of the proposed action and for areas that are impacted due to 

unavoidable actions the expectation is that the functional losses would be offset by 

compensatory mitigation.

5.1.2 NO ACTION ALTERNATIVE

Between 2004 and 2009, an estimated 62,300 acres of wetlands were lost in the 

conterminous United States. Various factors have contributed to the decline in the loss 

rate including implementation and enforcement of wetland protection measures and 

elimination of some incentives of wetland drainage. Certain types of wetland declined 

while others increased in area. For example, between 2004 and 2009, 489,600 acres of 

uplands were re-classified as wetlands. These increases were attributed to wetland 

reestablishment and creation on agricultural lands and other uplands with undetermined 

land use including undeveloped land, lands in conservation program or idle lands. The 

rate of wetland reestablishment increased by an estimated 17 percent from previous 

study period (1998 and 2004). Conversely, the estimated wetland loss rate increased 

140 percent during the same time period and as a consequence, national wetland 

losses have outdistanced gains (Dahl 2011).

Under the No Action Alternative, the current procedures, processes, and definitions 

used by the USACE to complete jurisdictional determinations would continue to be 

utilized and the process and procedures would not be impacted by the changes to 

jurisdiction with the adoption of the final proposed rule. However, as discussed in 

Section 5.1.1, under this alternative, the scope of Clean Water Act jurisdiction and 

permitting would be incrementally smaller than under the final proposed rule alternative.
24

5.2 FISH AND WILDLIFE

5.2.1 ADOPTION OF THE FINAL PROPOSED RULE ALTERNATIVE (Proposed Action)

The reasonable and foreseeable future for the biota of the United States (wetlands, fish, 

wildlife, plants) would primarily be changes associated with the effects of climate 

change and continued pressure from parties interested in development. Low lying 

wetlands would be completely inundated as waters rise, while some of the land at 

higher elevations would experience hydrologic changes such that they would transition 

to wetland habitats.

Under the final proposed rule there would be an incremental increase in the amount of 

waters of the United States subject to jurisdiction under the Clean Water Act, and any 

proposals that would impact jurisdictional areas would be subject to review under the 

USACE public interest analysis, the Section 404(b)(1) Guidelines and any other 

applicable federal requirements (e.g. NEPA, Section 7 of the ESA) that would not occur 

if areas were not subject to jurisdiction (No Action). Under the Section 404(b)(1)

guidelines (40 C.F.R. part 230), some impacts to biota may be avoided or minimized as 

a result of the implementation of the proposed action and for areas that are impacted 

due to unavoidable actions the expectation is that the functional losses would be offset 

by compensatory mitigation. The additional protections associated with the incremental 

increase in the amount of waters subject to Clean Water Act jurisdiction is expected to 

have a beneficial impact on fish and wildlife for which the protected waters provide 

habitat.

5.2.2 NO ACTION ALTERNATIVE

Impacts to fish and wildlife would continue to occur as a result of climate change and 

development. Existing wetlands would be impacted negatively as waters rise and other 

areas would experience hydrologic changes and transition into wetland habitats. 

Impacts to areas as a result of development, would continue in accordance with existing 

practice and areas not subject to jurisdiction under the Clean Water Act would occur 

and not be subject to requirements related to mitigation (avoid, minimize, or 

compensatory mitigation) required in the Section 404 program.

Impacts to Threatened and Endangered Species would be similar in nature and scope 

to those discussed above for Fish and Wildlife. Potential impacts from takings on nonjurisdictional lands would continue.

5.3 RECREATION

5.3.1 ADOPTION OF THE FINAL PROPOSED RULE ALTERNATIVE (Proposed Action)

Under the proposed action, there would be an incremental increase in the amount of 

waters of the United States subject to jurisdiction and therefore protected under the 

Clean Water Act. Thus, any proposed projects that would impact the areas subject to 

jurisdiction would be subject to review under the USACE public interest analysis, the 

section 404(b)(1) Guidelines and any other applicable federal requirements (e.g., 

NEPA, Section 7 of the ESA) that would not occur if the areas were not subject to 
25

jurisdiction. Under the section 404(b)(1) Guidelines, some impacts to biota may be 

avoided or minimized as a result of the implementation of the proposed action and for 

areas that are impacted due to unavoidable actions the expectation is that the functional 

losses would be offset by compensatory mitigation. The additional protections 

associated with the incremental increase in the amount of waters subject to Clean 

Water Act jurisdiction is expected to have a beneficial impact on recreation, based on 

the increase in wildlife available for hunting, fishing, bird watching, and photography.

5.3.2 NO ACTION ALTERNATIVE

The Nation’s wetlands provide visitors with opportunities to experience unique and 

rewarding adventures in a natural environment. Recreation opportunities would 

continue along existing trends under this alternative.

5.4 SOCIO-ECONOMIC

5.4.1 ADOPTION OF THE FINAL PROPOSED RULE ALTERNATIVE (Proposed Action)

There would be an incremental increase in the amount of waters of the United States 

subject to jurisdiction and therefore protected under the Clean Water Act. Based upon 

the information available there would be approximately a 2.8 to 4.6 percent increase in 

jurisdictional waters with adoption of the rule. This increase in jurisdiction expected to 

impact several aspects of the regulatory program; specifically Sections 410, 402 and 

404, and each program could be impacted in different ways.

An economic analysis was prepared to estimate the incremental costs and benefits that 

may result from any change in the number of positive jurisdictional determinations 

associated with Clean Water Act programs relying on the definition of waters of the 

United States. The economic report entitled: “Economic Analysis of the EPA-Army 

Clean Water Rule” – May 2015 is incorporated by reference into this Environmental 

Assessment. The agencies concluded that adoption of the new rule would result in an 

increase in the number of positive jurisdictional determinations and an associated 

increase in both costs and benefits that derive from conducting of Clean Water Act 

programs, based on an approximate 2.8 to 4.6 percent increase in positive jurisdictional 

determinations for waters annually, due to adoption of the new rule when compared with 

current process and procedures.

To estimate annual costs and benefits, the agencies uniformly applied the 2.8 and 4.6 

percent incremental change in jurisdiction to the total costs and benefits for the Sections 

311, 401, 402 (stormwater, pesticide general permit, Confined Animal Feeding 

Operation permits (CAFO)) and 404 programs to account for an estimated increase in 

permitting and regulatory activities that would result. The increase varies across 

programs and is based upon varying assumptions about the number of permits and the 

cost of permits involved for each program. To estimate costs, the agencies relied on 

existing annual administrative and compliance cost information, and updated cost 

figures to 2014 dollars. On the benefits side, the focus of the benefits analysis is based 

on an anticipated increase in Clean Water Act 404 permits that would result in 

ecological benefits from those permitted losses being offset through compensatory 
26

mitigation acres. The agency estimated the potential benefits from Clean Water Act 404 

compensatory mitigation based upon a benefits transfer analysis from approximately 12 

studies across the United States that used a contingent valuation survey method to 

measure willingness to pay for the preservation of wetlands similar to the type likely to 

be protected by adoption of this rule. There are several costs and benefits that the 

agencies were unable to monetize, including permitting time and project redesign costs 

under Section 404, as well as the benefits of Section 404 stream mitigation, benefits of 

the 402 pesticide general permit, and benefits of the 401 certification program. The 

agencies assumed, however, that costs and benefits associated with each of these 

programs would be relatively small.

The table below summarizes the range of costs and benefits that the agencies

estimated for each program, given an assumed positive 2.8 to 4.6 percent change in the 

number of waters affected by new jurisdictional determinations.

Estimated Annual Indirect Costs and Benefits

Annual Costs

(FY14$ millions)

Annual Benefits

(FY14$ millions)

Clean Water Action Section Low High Low High

402 CAFO Administration $0.3 $0.3 $6.2 $10.8 402 CAFO Implementation $9.9 $9.9

402 Stormwater Administration $0.5 $0.5 $47.5 $60.2 402 Stormwater Implementation $47.8 $59.6

404 Permit Application $47.0 $80.3 $501.2 $501.2 404 Mitigation – Wetlands $89.0 $249.4

SUBTOTAL $194.5 $400.0 $554.9 $572.3

311 Compliance $12.7 $12.7 not quantified

401 Administration $1.3 $1.3 not quantified

402 Pesticide General Permit 

Implementation $5.4 $5.9 not quantified

404 Mitigation – Streams $22.8 $45.2 not quantified

TOTAL $236.8 $465.1 $554.9 $572.3

Implementation of the rule is expected, based upon past experience in implementing 

rules, to have a lag time for policy and rules change to occur, such that permitting and 

other resource regulatory programs could show a temporary impact in terms of 

increased cost and realized benefits.
27

5.4.2 NO ACTION ALTERNATIVE

If No Action is taken jurisdictional determinations would continue to be completed 

according to the process and procedures in place today. The ambiguity that exists 

under current regulations and practices following recent Supreme Court decisions, 

under which virtually all waters and wetlands across the country theoretically could be 

subject to a case-specific jurisdictional determination would continue to be an issue for 

landowners, developers and regulators.

5.5 FLOOD RISK REDUCTION

5.5.1 ADOPTION OF THE FINAL PROPOSED RULE ALTERNATIVE (Proposed Action)

Under the proposed action, there would be an incremental increase in the amount of 

waters of the United States subject to jurisdiction and therefore protected under the 

Clean Water Act. Thus, any proposed projects that would impact the areas subject to 

jurisdiction would be subject to review under the USACE public interest analysis, the 

Section 404(b)(1) Guidelines and any other applicable federal requirements (e.g., 

NEPA, Section 7 of the ESA) that would not occur if the areas were not subject to 

jurisdiction (No Action).

Under the Section 404(b(1) Guidelines, potential reduction in flood storage capacity 

would be avoided or minimized as a result of the adoption of the proposed action and 

for areas that are impacted due to unavoidable actions the expectation is that the losses 

would be offset by compensatory mitigation. The additional protections associated with 

the incremental increase in the amount of waters subject to Clean Water Act jurisdiction 

is expected to have a beneficial impact on flood risk reduction, based on the increase in

wetland capacity for storage and slow release of snowmelt, groundwater, and flood 

waters.

5.5.2 NO ACTION ALTERNATIVE

As discussed in Section 5.1.2, between 2004 and 2009, an estimated 62,300 acres of 

wetlands were lost in the conterminous US. Certain types of wetland declined while 

others increased in area. For example, between 2004 and 2009, 489,600 acres of 

uplands were re-classified as wetlands (Dahl 2011). These increases were attributed to 

wetland reestablishment and creation on agricultural lands and other uplands with 

undetermined land use including undeveloped land, lands in conservation program or 

idle lands. These trends and associated impacts on flood storage capacity would be 

expected to continue as a result of natural and manmade factors.

5.6 CUMULATIVE IMPACT

“Cumulative impact” is defined by the Council on Environmental Quality regulation as 

the impact on the environment resulting from the incremental impact of the action when 

added to other past, present, and reasonably foreseeable future federal or non-federal 

actions. 40 C.F.R. 1508.7.

The effects of adopting the rule would be added to a multitude of past, present, and 

reasonably foreseeable federal and non-federal activities that have or may benefit or 
28

adversely affect these waters. This includes environmental regulation, development, 

agriculture, and other activities and climate change.

The incremental impact of the rule when added to these other actions do not differ in a 

measurable (quantitative) way from the indirect effects of the rule discussed qualitatively 

throughout Section 5. The anticipated incremental increase in jurisdiction would not 

have any unique or reasonably foreseeable cumulative impact beyond the application of 

the Section 404 permitting program. Similarly, no cumulative impact is anticipated for 

waters that may no longer be subject to Section 404 permitting.

6.0 COORDINATION AND PUBLIC INVOLVEMENT IN SHAPING THE PROPOSED RULE

The public was provided with significant environmental information about the proposed 

rule in order to allow members of the public to provide their views and inform agency 

decision-making. The draft rule was published in the Federal Register (Vol. 79, No. 76) 

on April 21, 2014 for public comment through July 21, 2014 and extended at the request 

of stakeholders until November 14, 2014. After publication of the draft rule 

approximately 400 stakeholder engagements in the form of meetings, webinars, and 

phone calls were conducted.

Of the approximately 1.2 million comments received, the vast majority of the comments 

were form letters from mass letter writing campaigns. A subset of the 1.2 million 

comments, 20,567 were identified as unique and evaluated further to determine if the 

comments were substantive. Responses to the substantive comments have been 

developed by the Environmental Protection Agency and the U.S. Army Corps of 

Engineers and are contained in the rulemaking. Docket EPA-HQ-OW-2011-0880.

7.0 CONCLUSION

With adoption of the proposed action, there would be an incremental increase in the 

amount of waters of the United States subject to jurisdiction and therefore protected 

under the Clean Water Act. Thus, any proposed projects that would impact the areas 

subject to jurisdiction would be subject to review under the USACE public interest 

analysis, the Section 404(b)(1) Guidelines and any other applicable federal 

requirements (e.g., NEPA, Section 7 of the ESA) that would not occur if the areas were 

not subject to jurisdiction (No Action). Some adverse impacts to the aquatic 

environment would be avoided or minimized as a result of the adoption of the proposed 

action. For areas that are impacted due to unavoidable actions, the assumption is that 

the functional losses would be addressed through compensatory mitigation.

In respect to the Socio-Economic analysis of the costs and benefits conducted by the

EPA, indications are that indirect incremental benefits exceed indirect incremental 

costs. The analysis acknowledges that there is a possibility that costs (and benefits) 

may be overstated because each new jurisdictional water may not be affected by all 

Clean Water Act programs simultaneously, and in some cases a particular activity 

affecting a waters of the United States may be exempt from permitting under the Clean 
29

Water Act. The water in the “other waters” category represents the greatest potential 

for changes in jurisdictional determinations as a result of adoption of the rule. However, 

it is likely that the benefits may be understated because the benefits are based primarily 

on compensatory mitigation acres (from the Section 404 program) and that the 

willingness to pay analysis used to value these acres are from existing studies 

conducted between 1986 and 2000. In recent years the public has become more aware 

of the value of wetlands and updated studies might show a significant increase in 

willingness to pay associated with preserving wetlands, particularly when wetlands are 

tied to a concrete utility, such as improved water quality, hunting and fishing habitat, 

general recreation, or flood control.

8.0 PREPARED BY

Gib Owen US. Army, Office of the Assistant Secretary of the Army for 

Civil Works

Marianne Matheny-Katz US. Army, Office of the Assistant Secretary of the Army for 

Civil Works

Tom Hughes US. Army, Office of the Assistant Secretary of the Army for 

Civil Works

Sandra Stiles US. Army Corps of Engineers, Mississippi Valley Division, 

New Orleans District

Elizabeth Behrens US. Army Corps of Engineers, Mississippi Valley Division, 

New Orleans District
30

9.0 REFERENCES

Bates, B.C., Z.W. Kundzewicz, S. Wu, and J.P. Palutikof (eds.). 2008. Climate Change 

and Water. Technical Paper of the Intergovernmental Panel on Climate Change, 

IPCC Secretariat, Geneva, 210 p

Caffey, R.H. and M. Schexnayder. 2003. "Coastal Louisiana and South Florida: A 

Comparative Wetland Inventory," Interpretive Topic Series on Coastal Wetland 

Restoration in Louisiana, Coastal Wetland Planning, Protection, and Restoration 

Act (eds.), National Sea Grant Library. 8 pp. 

http://lacoast.gov/new/Data/Reports/ITS/Florida.pdf

Costanza, Robert, Octavio Pérez-Maqueo, M. Luisa Martinez, Paul Sutton, Sharolyn J. 

Anderson, and Kenneth Mulder. 2008. "The Value of Coastal Wetlands for 

Hurricane Protection." AMBIO: A Journal of the Human Environment 37 (4):241-

248.

Dahl, T.E. 2011. Status and Trends of Wetlands in the Conterminous United States 

2004 to 2009. U.S. Department of the Interior, Fish and Wildlife Service, 

Washington, D.C. 108 pp. http://www.fws.gov/wetlands/Status-And-Trends2009/index.html

Dahl, T.E. 1990. Wetlands Losses in the United States 1780's to 1980's. U.S. 

Department of the Interior, Fish and Wildlife Service, Washington, D.C. 13 pp. 

http://www.fws.gov/wetlands/Documents/Wetlands-Losses-in-the-United-States1780s-to-1980s.pdf

Dahl, T.E. 2005. Florida's Wetlands: An Update on Status and Trends 1985 to 1996. 

U.S. Department of the Interior, Fish and Wildlife Service, Washington, D.C. 80 

pp. http://www.fws.gov/wetlands/Documents/Floridas-Wetlands-An-Update-onStatus-and-Trends-1985-to-1996.pdf

Federal Geographic Data Committee. 1996. On-line resource: http:// 

www.fgdc.gov/standards/projects/ FGDC-standards-projects/ wetlands/

Flournoy, Alyson C and A. Fischman. 2013. Wetlands Regulation in an Era of Climate 

Change: Can Section 404 Meet the Challenge? Geo. Wash. J. Energy & Envtl. 

L., Summer 2013, at 67, available at http://scholarship.law.ufl.edu/facultypub/368

Hall, Jonathan V., W.E. Frayer, and Bill O. Wilen. 1994. Status of Alaska Wetlands. U.S. 

Department of the Interior, Fish and Wildlife Service, Washington, D.C. 36 pp. 

http://www.fws.gov/wetlands/Documents/Status-of-Alaska-Wetlands.pdf

Klobier, Steven M. 2010. Status and Trends of Wetlands in Minnesota: Wetland 

Quantity Baseline. Minnesota Department of Natural Resources. Ecological and 
31

Water Resources Report, Saint Paul, MN. 28 pp 

http://files.dnr.state.mn.us/eco/wetlands/wstmp_report_final_121410.pdf

Male, Timothy D. and Michael J. Bean. 2005. Measuring Progress in US Endangered 

Species Conservation. 7 pp., available at

http://www.esf.edu/efb/gibbs/efb413/Male-Bean.2005.pdf

National Research Council. 2012. Sea-Level Rise for the Coasts of California, Oregon,

and Washington: Past, Present, and Future, Washington, DC: The National 

Academies Press. 201 pp

National Atlas. Average Annual Precipitation, 1961-1990

U.S. Department of the Interior, U.S. Geological Survey. URL: 

http://geomaps.wr.usgs.gov/parks/province/index.htmlFlournoy, Alyson C and A. 

Fischman. 2013. Wetlands Regulation in an Era of Climate Change: Can Section 

404 Meet the Challenge? Geo. Wash. J. Energy & Envtl. L., Summer 2013, at 67, 

available at http://scholarship.law.ufl.edu/facultypub/368

U.S. Environmental Protection Agency. 2015. Connectivity of Streams and Wetlands to 

Downstream Waters: A Review and Synthesis of the Scientific Evidence (Final 

Report). EPA/600/R-14/475F. U.S. Environmental Protection Agency, Washington, 

D.C.

Upon request hard copies of any materials or reports reference in this report can be 

obtained at any USACE District and Division offices and EPA regional and field offices
1

FINAL

ENVIRONMENTAL ASSESSMENT

ADOPTION OF

THE CLEAN WATER RULE: DEFINITION OF WATERS OF THE UNITED STATES

APPENDIX A

PROPOSED DRAFT RULE (APRIL 2014)

26 May 2015
2
3

Appendix A – Proposed Rule

(a) For purposes of all sections of the Clean Water Act, 33 U.S.C. 1251 et. seq. and its 

implementing regulations, subject to the exclusions in subsection (b) of this section, 

the term “waters of the United States” means:

(1) All waters which are currently used, 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;

(2) All interstate waters, including interstate wetlands;

(3) The territorial seas;

(4) All impoundments of waters otherwise defined as waters of the United States 

under this definition;

(5) All tributaries of waters identified in paragraphs (1) through (3) of this section;

(6) All waters, including wetlands, adjacent to a water identified in paragraphs (1) 

through (5) of this section; and 

(7) On a case-specific basis, other waters, including wetlands, provided that those 

waters alone, or in combination with other similarly situated waters, including 

wetlands, located in the same region, have a significant nexus to a water 

identified in paragraphs (1) through (3) of this section.

(b) The following are not “waters of the United States”

(1) Waste treatment systems, including treatment ponds or lagoons, designed to 

meet the requirements of the Clean Water Act.

(2) Prior converted cropland. Notwithstanding the determination of an area’s status 

as prior converted cropland by any other federal agency, for the purposes of the 

Clean Water Act, the final authority regarding Clean Water Act jurisdiction 

remains with EPA; and,

(3) Artificially irrigated areas that would revert to upland should application of 

irrigation water to that area 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; gullies and rills; non-wetland 

swales; and puddles; 

(4) Ditches that are excavated wholly in uplands, drain only uplands or nonjurisdictional waters, and have no more than ephemeral flow; and 

(5) Ditches that do not contribute flow, either directly or through other waterbodies, 

to a water identified in paragraphs (a)(1) through (a)(3) of this section.

(c) Definitions

Adjacent: The term adjacent means bordering, contiguous or neighboring. Waters, 

including wetlands, separated from other waters of the United States by man-
4

made dikes or barriers, natural river berms, beach dunes and the like are 

“adjacent waters.”

Neighboring: The term neighboring, for purposes of the term “adjacent” in this 

section, includes waters located within the riparian area or floodplain of a water 

identified in paragraphs (a)(1) through (a)(5) of this section, or waters with a 

surface or shallow subsurface hydrologic connection to such a jurisdictional 

water.

Riparian area: The term riparian area means an area bordering a water where 

surface or subsurface hydrology influence the ecological processes and plant 

and animal community structure in that area. Riparian areas are transitional 

areas between aquatic and terrestrial ecosystems that influence the exchange of 

energy and materials between those ecosystems.

Floodplain: The term floodplain means an area bordering inland or coastal waters 

that was formed by sediment deposition from such water under present climatic 

conditions and is inundated during periods of moderate to high water flows.

Tributary: The term tributary means a water body physically characterized by the 

presence of a bed and banks and ordinary high water mark, which contributes 

flow, either directly or through other water bodies, to a water identified in 

paragraphs (a)(1) through (a)(3) of this section. A water body that otherwise 

qualifies as a tributary under this definition does not lose its status as a tributary 

if, for any length, there are one or more man-made breaks (such as bridges, 

culverts, pipes, or dams), or one or more natural breaks (such as wetlands at the 

head of or along the run of a stream, debris piles, boulder fields, or a stream that 

flows underground) so long as a bed and banks and an ordinary high water mark 

can be identified upstream or downstream of the break. In addition, wetlands are 

tributaries (even if they lack a bed and banks and ordinary high water mark) if 

they contribute flow, either directly or through other water bodies to a water 

identified in paragraphs (a)(1) through (a)(3) of this section. A tributary, including 

wetlands, can be a natural, man-altered, or man-made water body and includes 

waters such as rivers, streams, lakes, impoundments, canals, and ditches not 

excluded in paragraph (b)(4) and (b)(5) of this section.

Wetlands: The term wetlands means those areas that are inundated or saturated 

by surface or groundwater at a frequency and duration sufficient to support, and 

that under normal circumstances do support, a prevalence of vegetation typically 

adapted for life in saturated soil conditions. Wetlands generally include swamps, 

marshes, bogs and similar areas.

Significant nexus: The term significant nexus means a more than speculative or 

insubstantial effect that a water, including wetlands, either alone or in 

combination with other similarly situated waters in the region (i.e., the watershed 

that drains to a water identified in paragraphs (a)(1) through (3) of this section), 
5

has on the chemical, physical or biological integrity of a water identified in 

paragraphs (a)(1) through (3) of this section. Other waters, including wetlands, 

are similarly situated when they perform similar functions and are located 

sufficiently close together or close to a “water of the U.S.” so that they can be 

evaluated as a single landscape unit with regard to their effect on the chemical, 

physical, or biological integrity of a water identified in paragraphs (a)(1) through 

(a)(3) of this section.
1

FINAL

ENVIRONMENTAL ASSESSMENT

ADOPTION OF

THE CLEAN WATER RULE: DEFINITION OF WATERS OF THE UNITED STATES

APPENDIX B

FINAL PROPOSED RULE

26 May 2015
2
3

Appendix B – Final Proposed Rule

Title 33—Navigation and Navigable Waters

For the reasons set out in the preamble, title 33, chapter I of the Code of Federal 

Regulations is amended as follows:

PART 328—DEFINITION OF WATERS OF THE UNITED STATES

1. The authority citation for part 328 continues to read as follows:

Authority: The Clean Water Act, 33 U.S.C. 1251 et.seq.

2. Section 328.3 is amended by removing the introductory text, redesignating paragraph 

(f) as paragraph (d), and revising paragraphs (a)—(e), to read as follows:

§ 328.3 Definitions.

(a) For purposes of the Clean Water Act, 33 U.S.C. 1251 et. seq. and its 

implementing regulations, subject to the exclusions in paragraph (b) of this 

section, the term ‘‘waters of the United States’’ means:

(1) All waters which are currently used, 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;

(2) All interstate waters, including interstate wetlands;

(3) The territorial seas;

(4) All impoundments of waters otherwise identified as waters of the United 

States under this section;

(5) All tributaries, as defined in paragraph (c)(3) of this section, of waters 

identified in paragraphs (a)(1) through (3) of this section;

(6) All waters adjacent to a water identified in paragraphs (a)(1) through (5) of 

this section, including wetlands, ponds, lakes, oxbows, impoundments, and 

similar waters; 

(7) All waters in paragraphs (i) through (v) of this paragraph where they are 

determined, on a case-specific basis, to have a significant nexus to a water 

identified in paragraphs (a)(1) through (3) of this section. The waters 

identified in each of paragraphs (i) through (v) of this paragraph are similarly 

situated and shall be combined, for purposes of a significant nexus analysis, 

in the watershed that drains to the nearest water identified in paragraphs 

(a)(1) through (3) of this section. Waters identified in this paragraph shall not 

be combined with waters identified in paragraph (a)(6) of this section when 

performing a significant nexus analysis. If waters identified in this paragraph 

are also an adjacent water under paragraph (a)(6), they are an adjacent water 

and no case-specific significant nexus analysis is required.

(i) Prairie potholes. Prairie potholes are a complex of glacially formed 

wetlands, usually occurring in depressions that lack permanent natural 

outlets, located in the upper Midwest.

(ii) Carolina bays and Delmarva bays. Carolina bays and Delmarva bays are 

ponded, depressional wetlands that occur along the Atlantic coastal plain.

(iii) Pocosins. Pocosins are evergreen shrub and tree dominated wetlands 

found predominantly along the Central Atlantic coastal plain.
4

(iv) Western vernal pools. Western vernal pools are seasonal wetlands 

located in parts of California and associated with topographic depression, 

soils with poor drainage, mild, wet winters and hot, dry summers.

(v) Texas coastal prairie wetlands. Texas coastal prairie wetlands are 

freshwater wetlands that occur as a mosaic of depressions, ridges, 

intermound flats, and mima mound wetlands located along the Texas 

Gulf Coast.

(8) All waters located within the 100-year floodplain of a water identified in (a)(1) 

through (3) of this section and all waters located within 4,000 feet of the high 

tide line or ordinary high water mark of a water identified in paragraphs (a)(1) 

through (5) of this section where they are determined on a case-specific basis 

to have a significant nexus to a water identified in paragraphs (a)(1) through 

(3) of this section. For waters determined to have a significant nexus, the 

entire water is a water of the United States if a portion is located within the 

100-year floodplain of a water identified in (a)(1) through (3) of this section or 

within 4,000 feet of the high tide line or ordinary high water mark. Waters 

identified in this paragraph shall not be combined with waters identified in 

paragraph (a)(6) of this section when performing a significant nexus analysis. 

If waters identified in this paragraph are also an adjacent water under 

paragraph (a)(6), they are an adjacent water and no case-specific significant 

nexus analysis is required.

(b) The following are not “waters of the United States” even where they otherwise 

meet the terms of paragraphs (a)(4) through (8) of this section.

(1) Waste treatment systems, including treatment ponds or lagoons designed to 

meet the requirements of the Clean Water Act.

(2) Prior converted cropland. Notwithstanding the determination of an area’s 

status as prior converted cropland by any other Federal agency, for the 

purposes of the Clean Water Act, the final authority regarding Clean Water 

Act jurisdiction remains with EPA.

(3) The following ditches:

(i) Ditches with ephemeral flow that are not a relocated tributary or 

excavated in a tributary.

(ii) Ditches with intermittent flow that are not a relocated tributary, excavated 

in a tributary, or drain wetlands.

(iii) Ditches that do not flow, either directly or through another water, into a 

water identified in paragraphs (a)(1) through (3) of this section.

(4) The following features:

(i) Artificially irrigated areas that would revert to dry land should application 

of water to that area cease;

(ii) Artificial, constructed lakes and ponds created in dry land such as farm 

and stock watering ponds, irrigation ponds, settling basins, fields flooded 

for rice growing, log cleaning ponds, or cooling ponds;

(iii) Artificial reflecting pools or swimming pools created in dry land;

(iv) Small ornamental waters created in dry land;
5

(v) Water-filled depressions created in dry land incidental to mining or 

construction activity, including pits excavated for obtaining fill, sand, or 

gravel that fill with water;

(vi) Erosional features, including gullies, rills, and other ephemeral features 

that do not meet the definition of tributary, non-wetland swales, and 

lawfully constructed grassed waterways; and

(vii) Puddles.

(5) Groundwater, including groundwater drained through subsurface drainage 

systems.

(6) Stormwater control features constructed to convey, treat, or store stormwater 

that are created in dry land.

(7) Wastewater recycling structures constructed in dry land; detention and 

retention basins built for wastewater recycling; groundwater recharge basins; 

percolation ponds built for wastewater recycling; and water distributary 

structures built for wastewater recycling.

(c) Definitions—In this section, the following definitions apply:

(1) Adjacent. The term adjacent means bordering, contiguous, or neighboring a 

water identified in paragraphs (a)(1) through (5) of this section, including 

waters separated by constructed dikes or barriers, natural river berms, beach

dunes, and the like. For purposes of adjacency, an open water such as a 

pond or lake includes any wetlands within or abutting its ordinary high water 

mark. Adjacency is not limited to waters located laterally to a water identified 

in paragraphs (a)(1) through (5) of this section. Adjacent waters also include 

all waters that connect segments of a water identified in paragraphs (a)(1) 

through (5) or are located at the head of a water identified in paragraphs 

(a)(1) through (5) of this section and are bordering, contiguous, or 

neighboring such water. Waters being used for established normal farming, 

ranching, and silviculture activities (33 USC § 1344(f)) are not adjacent.

(2) Neighboring. The term neighboring means:

(i) All waters located within 100 feet of the ordinary high water mark of a 

water identified in paragraphs (a)(1) through (5) of this section. The 

entire water is neighboring if a portion is located within 100 feet of the 

ordinary high water mark;

(ii) All waters located within the 100-year floodplain of a water identified in 

paragraphs (a)(1) through (5) of this section and not more than 1,500 feet 

from the ordinary high water mark of such water. The entire water is 

neighboring if a portion is located within 1,500 feet of the ordinary high 

water mark and within the 100-year floodplain;

(iii) all waters located within 1,500 feet of the high tide line of a water 

identified in paragraphs (a)(1) or (a)(3) of this section, and all waters 

within 1,500 feet of the ordinary high water mark of the Great Lakes. The 

entire water is neighboring if a portion is located within 1,500 feet of the 

high tide line or within 1,500 feet of the ordinary high water mark of the 

Great Lakes.
6

(3) Tributary and tributaries. The terms tributary and tributaries each mean a 

water that contributes flow, either directly or through another water (including 

an impoundment identified in paragraph (a)(4) of this section), to a water 

identified in paragraphs (a)(1) through (3) of this section that is characterized 

by the presence of the physical indicators of a bed and banks and an ordinary 

high water mark. These physical indicators demonstrate there is volume, 

frequency, and duration of flow sufficient to create a bed and banks and an 

ordinary high water mark, and thus to qualify as a tributary. A tributary can be 

a natural, man-altered, or man-made water and includes waters such as 

rivers, streams, canals, and ditches not excluded under paragraph (b) of this 

section. A water that otherwise qualifies as a tributary under this definition 

does not lose its status as a tributary if, for any length, there are one or more 

constructed breaks (such as bridges, culverts, pipes, or dams), or one or 

more natural breaks (such as wetlands along the run of a stream, debris piles, 

boulder fields, or a stream that flows underground) so long as a bed and 

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

break. A water that otherwise qualifies as a tributary under this definition does 

not lose its status as a tributary if it contributes flow through a water of the 

United States that does not meet the definition of tributary or through a nonjurisdictional water to a water identified in paragraphs (a)(1) through (3) of this

section.

(4) Wetlands. The term wetlands means those areas that are inundated or

saturated by surface or groundwater at a frequency and duration sufficient to

support, and that under normal circumstances do support, a prevalence of 

vegetation typically adapted for life in saturated soil conditions. Wetlands

generally include swamps, marshes, bogs, and similar areas.

(5) Significant nexus. The term significant nexus means that a water, including 

wetlands, either alone or in combination with other similarly situated waters in 

the region, significantly affects the chemical, physical, or biological integrity of 

a water identified in paragraphs (a)(1) through (3) of this section. The term “in 

the region” means the watershed that drains to the nearest water identified in 

paragraphs (a)(1) through (3) of this section. For an effect to be significant, it 

must be more than speculative or insubstantial. Waters are similarly situated 

when they function alike and are sufficiently close to function together in 

affecting downstream waters. For purposes of determining whether or not a 

water has a significant nexus, the water’s effect on downstream (a)(1) through 

(3) waters shall be assessed by evaluating the aquatic functions identified in 

paragraphs (i) through (ix) of this paragraph. A water has a significant nexus 

when any single function or combination of functions performed by the water, 

alone or together with similarly situated waters in the region, contributes 

significantly to the chemical, physical, or biological integrity of the nearest 

water identified in paragraphs (a)(1) through (3) of this section. Functions 

relevant to the significant nexus evaluation are the following:

(i) sediment trapping,

(ii) nutrient recycling,

(iii) pollutant trapping, transformation, filtering, and transport,
7

(iv)retention and attenuation of flood waters,

(v) runoff storage,

(vi) contribution of flow,

(vii) export of organic matter,

(viii) export of food resources, and

(ix) provision of life cycle dependent aquatic habitat (such as foraging, 

feeding, nesting, breeding, spawning, or use as a nursery area) for 

species located in a water identified in paragraphs (a)(1) through (3) of 

this section.

(6) Ordinary high water mark. The term ordinary high water mark means 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.

(7) High tide line. The term high tide line means the line of intersection of the land 

with the water's surface at the maximum height reached by a rising tide. The 

high tide line may be determined, in the absence of actual data, by a line of oil 

or scum along shore objects, a more or less continuous deposit of fine shell 

or debris on the foreshore or berm, other physical markings or characteristics, 

vegetation lines, tidal gages, or other suitable means that delineate the 

general height reached by a rising tide. The line encompasses spring high 

tides and other high tides that occur with periodic frequency but does not 

include storm surges in which there is a departure from the normal or 

predicted reach of the tide due to the piling up of water against a coast by 

strong winds such as those accompanying a hurricane or other intense storm.
8

Title 40—Protection of the Environment

For reasons set out in the preamble, title 40, chapter I of the Code of Federal 

Regulations is proposed to be amended as follows:

PART 110—DISCHARGE OF OIL

3. The authority citation for part 110 continues to read as follows:

Authority: The Clean Water Act, 33 U.S.C. 1321 et.seq.

4. Section 110.1 is amended by revising the definition of “navigable waters” to read as 

follows:

§ 110.1 Definitions.

Navigable waters means waters of the United States, including the territorial seas.

(1) For purposes of the Clean Water Act, 33 U.S.C. 1251 et. seq. and its 

implementing regulations, subject to the exclusions in paragraph (2) of this 

section, the term ‘‘waters of the United States’’ means:

(i) All waters which are currently used, 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;

(ii) All interstate waters, including interstate wetlands;

(iii) The territorial seas;

(iv) All impoundments of waters otherwise identified as waters of the United 

States under this section;

(v) All tributaries, as defined in paragraph (3)(iii) of this section, of waters 

identified in paragraphs (1)(i) through (iii) of this section;

(vi) All waters adjacent to a water identified in paragraphs (1)(i) through (v) of this 

section, including wetlands, ponds, lakes, oxbows, impoundments, and 

similar waters;

(vii) All waters in paragraphs (A) through (E) of this paragraph where they are 

determined, on a case-specific basis, to have a significant nexus to a water 

identified in paragraphs (1)(i) through (iii) of this section. The waters 

identified in each of paragraphs (A) through (E) of this paragraph are 

similarly situated and shall be combined, for purposes of a significant nexus 

analysis, in the watershed that drains to the nearest water identified in 

paragraphs (1)(i) through (iii) of this section. Waters identified in this 

paragraph shall not be combined with waters identified in paragraph (1)(vi) of 

this section when performing a significant nexus analysis. If waters identified 

in this paragraph are also an adjacent water under paragraph (1)(vi), they 

are an adjacent water and no case-specific significant nexus analysis is 

required.

(A) Prairie potholes. Prairie potholes are a complex of glacially formed 

wetlands, usually occurring in depressions that lack permanent natural 

outlets, located in the upper Midwest.

(B) Carolina bays and Delmarva bays. Carolina bays and Delmarva bays 

are ponded, depressional wetlands that occur along the Atlantic 

coastal plain.
9

(C) Pocosins. Pocosins are evergreen shrub and tree dominated wetlands 

found predominantly along the Central Atlantic coastal plain.

(D) Western vernal pools. Western vernal pools are seasonal wetlands 

located in parts of California and associated with topographic 

depression, soils with poor drainage, mild, wet winters and hot, dry 

summers.

(E) Texas coastal prairie wetlands. Texas coastal prairie wetlands are 

freshwater wetlands that occur as a mosaic of depressions, ridges, 

intermound flats, and mima mound wetlands located along the Texas 

Gulf Coast.

(viii) All waters located within the 100-year floodplain of a water identified in (1)(i) 

through (iii) of this section and all waters located within 4,000 feet of the high 

tide line or ordinary high water mark of a water identified in paragraphs (1)(i) 

through (v) of this section where they are determined on a case-specific 

basis to have a significant nexus to a water identified in paragraphs (1)(i) 

through (iii) of this section. For waters determined to have a significant 

nexus, the entire water is a water of the United States if a portion is located 

within the 100-year floodplain of a water identified in (1)(i) through (iii) of this 

section or within 4,000 feet of the high tide line or ordinary high water mark. 

Waters identified in this paragraph shall not be combined with waters 

identified in paragraph (1)(vi) of this section when performing a significant 

nexus analysis. If waters identified in this paragraph are also an adjacent 

water under paragraph (1)(vi), they are an adjacent water and no casespecific significant nexus analysis is required.

(2) The following are not “waters of the United States” even where they otherwise 

meet the terms of paragraphs (1)(iv) through (viii) of this section.

(i) Waste treatment systems, including treatment ponds or lagoons designed to 

meet the requirements of the Clean Water Act.

(ii) Prior converted cropland. Notwithstanding the determination of an area’s 

status as prior converted cropland by any other Federal agency, for the 

purposes of the Clean Water Act, the final authority regarding Clean Water 

Act jurisdiction remains with EPA.

(iii) The following ditches:

(A) Ditches with ephemeral flow that are not a relocated tributary or 

excavated in a tributary.

(B) Ditches with intermittent flow that are not a relocated tributary, 

excavated in a tributary, or drain wetlands.

(C) Ditches that do not flow, either directly or through another water, into a 

water identified in paragraphs (1)(i) through (iii) of this section.

(iv) The following features:

(A) Artificially irrigated areas that would revert to dry land should 

application of water to that area cease;

(B) Artificial, constructed lakes and ponds created in dry land such as farm 

and stock watering ponds, irrigation ponds, settling basins, fields 

flooded for rice growing, log cleaning ponds, or cooling ponds;
10

(C) Artificial reflecting pools or swimming pools created in dry land;

(D) Small ornamental waters created in dry land;

(E) Water-filled depressions created in dry land incidental to mining or 

construction activity, including pits excavated for obtaining fill, sand, or 

gravel that fill with water;

(F) Erosional features, including gullies, rills, and other ephemeral features 

that do not meet the definition of tributary, non-wetland swales, and 

lawfully constructed grassed waterways; and

(G) Puddles.

(v) Groundwater, including groundwater drained through subsurface drainage 

systems.

(vi) Stormwater control features constructed to convey, treat, or store stormwater 

that are created in dry land.

(vii) Wastewater recycling structures constructed in dry land; detention and 

retention basins built for wastewater recycling; groundwater recharge basins; 

percolation ponds built for wastewater recycling; and water distributary 

structures built for wastewater recycling.

(3) Definitions—In this section, the following definitions apply:

(i) Adjacent. The term adjacent means bordering, contiguous, or neighboring a 

water identified in paragraphs (1)(i) through (v) of this section, including 

waters separated by constructed dikes or barriers, natural river berms, beach

dunes, and the like. For purposes of adjacency, an open water such as a 

pond or lake includes any wetlands within or abutting its ordinary high water 

mark. Adjacency is not limited to waters located laterally to a water identified 

in paragraphs (1)(i) through (v) of this section. Adjacent waters also include 

all waters that connect segments of a water identified in paragraphs (1)(i) 

through (v) or are located at the head of a water identified in paragraphs 

(1)(i) through (v) of this section and are bordering, contiguous, or 

neighboring such water. Waters being used for established normal farming, 

ranching, and silviculture activities (33 USC § 1344(f)) are not adjacent.

(ii) Neighboring. The term neighboring means:

(A) all waters located within 100 feet of the ordinary high water mark of a 

water identified in paragraphs (1)(i) through (v) of this section. The 

entire water is neighboring if a portion is located within 100 feet of the 

ordinary high water mark;

(B) all waters located within the 100-year floodplain of a water identified in 

paragraphs (1)(i) through (v) of this section and not more than 1,500 

feet from the ordinary high water mark of such water. The entire water 

is neighboring if a portion is located within 1,500 feet of the ordinary 

high water mark and within the 100-year floodplain;

(C) all waters located within 1,500 feet of the high tide line of a water 

identified in paragraphs (1)(i) or (1)(iii) of this section, and all waters 

within 1,500 feet of the ordinary high water mark of the Great Lakes. 

The entire water is neighboring if a portion is located within 1,500 feet 
11

of the high tide line or within 1,500 feet of the ordinary high water mark 

of the Great Lakes.

(iii) Tributary and tributaries. The terms tributary and tributaries each mean a 

water that contributes flow, either directly or through another water (including 

an impoundment identified in paragraph (1)(iv) of this section), to a water 

identified in paragraphs (1)(i) through (iii) of this section that is characterized 

by the presence of the physical indicators of a bed and banks and an

ordinary high water mark. These physical indicators demonstrate there is 

volume, frequency, and duration of flow sufficient to create a bed and banks 

and an ordinary high water mark, and thus to qualify as a tributary. A 

tributary can be a natural, man-altered, or man-made water and includes 

waters such as rivers, streams, canals, and ditches not excluded under 

paragraph (2) of this section. A water that otherwise qualifies as a tributary 

under this definition does not lose its status as a tributary if, for any length, 

there are one or more constructed breaks (such as bridges, culverts, pipes, 

or dams), or one or more natural breaks (such as wetlands along the run of a 

stream, debris piles, boulder fields, or a stream that flows underground) so

long as a bed and banks and an ordinary high water mark can be identified

upstream of the break. A water that otherwise qualifies as a tributary under

this definition does not lose its status as a tributary if it contributes flow 

through a water of the United States that does not meet the definition of 

tributary or through a non-jurisdictional water to a water identified in 

paragraphs (1)(i1) through (iii) of this section.

(iv) Wetlands. The term wetlands means those areas that are inundated or

saturated by surface or groundwater at a frequency and duration sufficient to

support, and that under normal circumstances do support, a prevalence of 

vegetation typically adapted for life in saturated soil conditions. Wetlands

generally include swamps, marshes, bogs, and similar areas.

(v) Significant nexus. The term significant nexus means that a water, including 

wetlands, either alone or in combination with other similarly situated waters 

in the region, significantly affects the chemical, physical, or biological 

integrity of a water identified in paragraphs (1)(i) through (iii) of this section. 

The term “in the region” means the watershed that drains to the nearest 

water identified in paragraphs (1)(i) through (iii) of this section. For an effect 

to be significant, it must be more than speculative or insubstantial. Waters 

are similarly situated when they function alike and are sufficiently close to 

function together in affecting downstream waters. For purposes of 

determining whether or not a water has a significant nexus, the water’s effect 

on downstream (1)(i) through (iii) waters shall be assessed by evaluating the 

aquatic functions identified in paragraphs (A) through (I) of this paragraph. A 

water has a significant nexus when any single function or combination of 

functions performed by the water, alone or together with similarly situated 

waters in the region, contributes significantly to the chemical, physical, or 

biological integrity of the nearest water identified in paragraphs (1)(i) through 

(iii) of this section. Functions relevant to the significant nexus evaluation are 

the following:
12

(A) sediment trapping,

(B) nutrient recycling,

(C) pollutant trapping, transformation, filtering, and transport,

(D) retention and attenuation of flood waters,

(E) runoff storage,

(F) contribution of flow,

(G) export of organic matter,

(H) export of food resources, and

(I) provision of life cycle dependent aquatic habitat (such as foraging, 

feeding, nesting, breeding, spawning, or use as a nursery area) for 

species located in a water identified in paragraphs (a)(1) through (3) of 

this section.

(vi) Ordinary high water mark. The term ordinary high water mark means 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.

(vii) High tide line. The term high tide line means the line of intersection of the 

land with the water's surface at the maximum height reached by a rising tide. 

The high tide line may be determined, in the absence of actual data, by a line 

of oil or scum along shore objects, a more or less continuous deposit of fine 

shell or debris on the foreshore or berm, other physical markings or 

characteristics, vegetation lines, tidal gages, or other suitable means that 

delineate the general height reached by a rising tide. The line encompasses 

spring high tides and other high tides that occur with periodic frequency but 

does not include storm surges in which there is a departure from the normal 

or predicted reach of the tide due to the piling up of water against a coast by 

strong winds such as those accompanying a hurricane or other intense 

storm.
13

PART 112 –OIL POLLUTION PREVENTION

5. The authority citation for part 112 continues to read as follows:

Authority: The Clean Water Act, 33 U.S.C. 1321 et.seq.

6. Section 112.2 is amended by revising the definition of “navigable waters” to read as 

follows:

§ 112.2 Definitions

Navigable waters means waters of the United States, including the territorial seas.

(1) For purposes of the Clean Water Act, 33 U.S.C. 1251 et. seq. and its implementing 

regulations, subject to the exclusions in paragraph (2) of this section, the term 

‘‘waters of the United States’’ means:

(i) All waters which are currently used, 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;

(ii) All interstate waters, including interstate wetlands;

(iii) The territorial seas;

(iv) All impoundments of waters otherwise identified as waters of the United 

States under this section;

(v) All tributaries, as defined in paragraph (3)(iii) of this section, of waters 

identified in paragraphs (1)(i) through (iii) of this section;

(vi) All waters adjacent to a water identified in paragraphs (1)(i) through (v) of 

this section, including wetlands, ponds, lakes, oxbows, impoundments, and 

similar waters;

(vii) All waters in paragraphs (A) through (E) of this paragraph where they are 

determined, on a case-specific basis, to have a significant nexus to a water 

identified in paragraphs (1)(i) through (iii) of this section. The waters 

identified in each of paragraphs (A) through (E) of this paragraph are 

similarly situated and shall be combined, for purposes of a significant nexus 

analysis, in the watershed that drains to the nearest water identified in 

paragraphs (1)(i) through (iii) of this section. Waters identified in this 

paragraph shall not be combined with waters identified in paragraph (1)(vi) of 

this section when performing a significant nexus analysis. If waters identified 

in this paragraph are also an adjacent water under paragraph (1)(vi), they 

are an adjacent water and no case-specific significant nexus analysis is 

required.

(A) Prairie potholes. Prairie potholes are a complex of glacially formed 

wetlands, usually occurring in depressions that lack permanent natural 

outlets, located in the upper Midwest.

(B) Carolina bays and Delmarva bays. Carolina bays and Delmarva bays 

are ponded, depressional wetlands that occur along the Atlantic 

coastal plain.

(C) Pocosins. Pocosins are evergreen shrub and tree dominated wetlands 

found predominantly along the Central Atlantic coastal plain.

(D) Western vernal pools. Western vernal pools are seasonal wetlands 

located in parts of California and associated with topographic 
14

depression, soils with poor drainage, mild, wet winters and hot, dry 

summers.

(E) Texas coastal prairie wetlands. Texas coastal prairie wetlands are 

freshwater wetlands that occur as a mosaic of depressions, ridges, 

intermound flats, and mima mound wetlands located along the Texas 

Gulf Coast.

(viii) All waters located within the 100-year floodplain of a water identified in 

(1)(i) through (iii) of this section and all waters located within 4,000 feet of the 

high tide line or ordinary high water mark of a water identified in paragraphs 

(1)(i) through (v) of this section where they are determined on a case-specific 

basis to have a significant nexus to a water identified in paragraphs (1)(i) 

through (iii) of this section. For waters determined to have a significant 

nexus, the entire water is a water of the United States if a portion is located 

within the 100-year floodplain of a water identified in (1)(i) through (iii) of this 

section or within 4,000 feet of the high tide line or ordinary high water mark. 

Waters identified in this paragraph shall not be combined with waters 

identified in paragraph (1)(vi) of this section when performing a significant 

nexus analysis. If waters identified in this paragraph are also an adjacent 

water under paragraph (1)(vi), they are an adjacent water and no casespecific significant nexus analysis is required.

(2) The following are not “waters of the United States” even where they otherwise 

meet the terms of paragraphs (1)(iv) through (viii) of this section.

(i) Waste treatment systems, including treatment ponds or lagoons designed to 

meet the requirements of the Clean Water Act.

(ii) Prior converted cropland. Notwithstanding the determination of an area’s 

status as prior converted cropland by any other Federal agency, for the 

purposes of the Clean Water Act, the final authority regarding Clean Water 

Act jurisdiction remains with EPA.

(iii) The following ditches:

(A) Ditches with ephemeral flow that are not a relocated tributary or 

excavated in a tributary.

(B) Ditches with intermittent flow that are not a relocated tributary, 

excavated in a tributary, or drain wetlands.

(C) Ditches that do not flow, either directly or through another water, into a 

water identified in paragraphs (1)(i) through (iii) of this section.

(iv) The following features:

(A) Artificially irrigated areas that would revert to dry land should 

application of water to that area cease;

(B) Artificial, constructed lakes and ponds created in dry land such as farm 

and stock watering ponds, irrigation ponds, settling basins, fields 

flooded for rice growing, log cleaning ponds, or cooling ponds;

(C) Artificial reflecting pools or swimming pools created in dry land;

(D) Small ornamental waters created in dry land;
15

(E) Water-filled depressions created in dry land incidental to mining or 

construction activity, including pits excavated for obtaining fill, sand, or 

gravel that fill with water;

(F) Erosional features, including gullies, rills, and other ephemeral features 

that do not meet the definition of tributary, non-wetland swales, and 

lawfully constructed grassed waterways; and

(G) Puddles.

(v) Groundwater, including groundwater drained through subsurface drainage 

systems.

(vi) Stormwater control features constructed to convey, treat, or store 

stormwater that are created in dry land.

(vii) Wastewater recycling structures constructed in dry land; detention and 

retention basins built for wastewater recycling; groundwater recharge basins; 

percolation ponds built for wastewater recycling; and water distributary 

structures built for wastewater recycling.

(3) Definitions—In this section, the following definitions apply:

(i) Adjacent. The term adjacent means bordering, contiguous, or neighboring a 

water identified in paragraphs (1)(i) through (v) of this section, including 

waters separated by constructed dikes or barriers, natural river berms, beach

dunes, and the like. For purposes of adjacency, an open water such as a 

pond or lake includes any wetlands within or abutting its ordinary high water 

mark. Adjacency is not limited to waters located laterally to a water identified 

in paragraphs (1)(i) through (v) of this section. Adjacent waters also include 

all waters that connect segments of a water identified in paragraphs (1)(i) 

through (v) or are located at the head of a water identified in paragraphs 

(1)(i) through (v) of this section and are bordering, contiguous, or 

neighboring such water. Waters being used for established normal farming, 

ranching, and silviculture activities (33 USC § 1344(f)) are not adjacent.

(ii) Neighboring. The term neighboring means:

(A) all waters located within 100 feet of the ordinary high water mark of a 

water identified in paragraphs (1)(i) through (v) of this section. The 

entire water is neighboring if a portion is located within 100 feet of the 

ordinary high water mark;

(B) all waters located within the 100-year floodplain of a water identified in 

paragraphs (1)(i) through (v) of this section and not more than 1,500 

feet from the ordinary high water mark of such water. The entire water 

is neighboring if a portion is located within 1,500 feet of the ordinary 

high water mark and within the 100-year floodplain;

(C) all waters located within 1,500 feet of the high tide line of a water 

identified in paragraphs (1)(i) or (1)(iii) of this section, and all waters 

within 1,500 feet of the ordinary high water mark of the Great Lakes. 

The entire water is neighboring if a portion is located within 1,500 feet 

of the high tide line or within 1,500 feet of the ordinary high water mark 

of the Great Lakes.
16

(iii) Tributary and tributaries. The terms tributary and tributaries each mean a 

water that contributes flow, either directly or through another water (including 

an impoundment identified in paragraph (1)(iv) of this section), to a water 

identified in paragraphs (1)(i) through (iii) of this section that is characterized 

by the presence of the physical indicators of a bed and banks and an

ordinary high water mark. These physical indicators demonstrate there is 

volume, frequency, and duration of flow sufficient to create a bed and banks 

and an ordinary high water mark, and thus to qualify as a tributary. A 

tributary can be a natural, man-altered, or man-made water and includes 

waters such as rivers, streams, canals, and ditches not excluded under 

paragraph (2) of this section. A water that otherwise qualifies as a tributary 

under this definition does not lose its status as a tributary if, for any length, 

there are one or more constructed breaks (such as bridges, culverts, pipes, 

or dams), or one or more natural breaks (such as wetlands along the run of a 

stream, debris piles, boulder fields, or a stream that flows underground) so

long as a bed and banks and an ordinary high water mark can be identified

upstream of the break. A water that otherwise qualifies as a tributary under

this definition does not lose its status as a tributary if it contributes flow 

through a water of the United States that does not meet the definition of 

tributary or through a non-jurisdictional water to a water identified in 

paragraphs (1)(i1) through (iii) of this section.

(iv) Wetlands. The term wetlands means those areas that are inundated or

saturated by surface or groundwater at a frequency and duration sufficient to

support, and that under normal circumstances do support, a prevalence of 

vegetation typically adapted for life in saturated soil conditions. Wetlands

generally include swamps, marshes, bogs, and similar areas.

(v) Significant nexus. The term significant nexus means that a water, including 

wetlands, either alone or in combination with other similarly situated waters 

in the region, significantly affects the chemical, physical, or biological 

integrity of a water identified in paragraphs (1)(i) through (iii) of this section. 

The term “in the region” means the watershed that drains to the nearest 

water identified in paragraphs (1)(i) through (iii) of this section. For an effect 

to be significant, it must be more than speculative or insubstantial. Waters 

are similarly situated when they function alike and are sufficiently close to 

function together in affecting downstream waters. For purposes of 

determining whether or not a water has a significant nexus, the water’s effect 

on downstream (1)(i) through (iii) waters shall be assessed by evaluating the 

aquatic functions identified in paragraphs (A) through (I) of this paragraph. A 

water has a significant nexus when any single function or combination of 

functions performed by the water, alone or together with similarly situated 

waters in the region, contributes significantly to the chemical, physical, or 

biological integrity of the nearest water identified in paragraphs (1)(i) through 

(iii) of this section. Functions relevant to the significant nexus evaluation are 

the following:

(A) sediment trapping,

(B) nutrient recycling,
17

(C) pollutant trapping, transformation, filtering, and transport,

(D) retention and attenuation of flood waters,

(E) runoff storage,

(F) contribution of flow,

(G) export of organic matter, 

(H) export of food resources, and

(I) provision of life cycle dependent aquatic habitat (such as foraging, 

feeding, nesting, breeding, spawning, or use as a nursery area) for 

species located in a water identified in paragraphs (a)(1) through (3) of 

this section.

(vi) Ordinary high water mark. The term ordinary high water mark means 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.

(vii) High tide line. The term high tide line means the line of intersection of the 

land with the water's surface at the maximum height reached by a rising tide. 

The high tide line may be determined, in the absence of actual data, by a line 

of oil or scum along shore objects, a more or less continuous deposit of fine 

shell or debris on the foreshore or berm, other physical markings or 

characteristics, vegetation lines, tidal gages, or other suitable means that 

delineate the general height reached by a rising tide. The line encompasses 

spring high tides and other high tides that occur with periodic frequency but 

does not include storm surges in which there is a departure from the normal 

or predicted reach of the tide due to the piling up of water against a coast by 

strong winds such as those accompanying a hurricane or other intense 

storm.
18

Part 116—DESIGNATION OF HAZARDOUS SUBSTANCE

7. The authority citation for part 116 continues to read as follows:

Authority: The Clean Water Act, 33 U.S.C. 1321 et.seq.

8. Section 116.3 is amended by revising the definition of “navigable waters” to read as 

follows:

Navigable waters is defined in section 502(7) of the Act to mean “waters of the United 

States, including the territorial seas.”

(1) For purposes of the Clean Water Act, 33 U.S.C. 1251 et. seq. and its implementing 

regulations, subject to the exclusions in paragraph (2) of this section, the term 

‘‘waters of the United States’’ means:

(i) All waters which are currently used, 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;

(ii) All interstate waters, including interstate wetlands;

(iii) The territorial seas;

(iv) All impoundments of waters otherwise identified as waters of the United 

States under this section;

(v) All tributaries, as defined in paragraph (3)(iii) of this section, of waters 

identified in paragraphs (1)(i) through (iii) of this section;

(vi) All waters adjacent to a water identified in paragraphs (1)(i) through (v) of this 

section, including wetlands, ponds, lakes, oxbows, impoundments, and 

similar waters;

(vii) All waters in paragraphs (A) through (E) of this paragraph where they are 

determined, on a case-specific basis, to have a significant nexus to a water 

identified in paragraphs (1)(i) through (iii) of this section. The waters 

identified in each of paragraphs (A) through (E) of this paragraph are similarly 

situated and shall be combined, for purposes of a significant nexus analysis, 

in the watershed that drains to the nearest water identified in paragraphs (1)(i) 

through (iii) of this section. Waters identified in this paragraph shall not be 

combined with waters identified in paragraph (1)(vi) of this section when 

performing a significant nexus analysis. If waters identified in this paragraph 

are also an adjacent water under paragraph (1)(vi), they are an adjacent 

water and no case-specific significant nexus analysis is required.

(A) Prairie potholes. Prairie potholes are a complex of glacially formed 

wetlands, usually occurring in depressions that lack permanent natural 

outlets, located in the upper Midwest.

(B) Carolina bays and Delmarva bays. Carolina bays and Delmarva bays 

are ponded, depressional wetlands that occur along the Atlantic coastal 

plain.

(C) Pocosins. Pocosins are evergreen shrub and tree dominated wetlands 

found predominantly along the Central Atlantic coastal plain.

(D) Western vernal pools. Western vernal pools are seasonal wetlands 

located in parts of California and associated with topographic 
19

depression, soils with poor drainage, mild, wet winters and hot, dry 

summers.

(E) Texas coastal prairie wetlands. Texas coastal prairie wetlands are 

freshwater wetlands that occur as a mosaic of depressions, ridges, 

intermound flats, and mima mound wetlands located along the Texas 

Gulf Coast.

(viii) All waters located within the 100-year floodplain of a water identified in (1)(i) 

through (iii) of this section and all waters located within 4,000 feet of the high 

tide line or ordinary high water mark of a water identified in paragraphs (1)(i) 

through (v) of this section where they are determined on a case-specific basis 

to have a significant nexus to a water identified in paragraphs (1)(i) through 

(iii) of this section. For waters determined to have a significant nexus, the 

entire water is a water of the United States if a portion is located within the 

100-year floodplain of a water identified in (1)(i) through (iii) of this section or 

within 4,000 feet of the high tide line or ordinary high water mark. Waters 

identified in this paragraph shall not be combined with waters identified in 

paragraph (1)(vi) of this section when performing a significant nexus analysis. 

If waters identified in this paragraph are also an adjacent water under 

paragraph (1)(vi), they are an adjacent water and no case-specific significant 

nexus analysis is required.

(2) The following are not “waters of the United States” even where they otherwise 

meet the terms of paragraphs (1)(iv) through (viii) of this section.

(i) Waste treatment systems, including treatment ponds or lagoons designed to 

meet the requirements of the Clean Water Act.

(ii) Prior converted cropland. Notwithstanding the determination of an area’s 

status as prior converted cropland by any other Federal agency, for the 

purposes of the Clean Water Act, the final authority regarding Clean Water 

Act jurisdiction remains with EPA.

(iii) The following ditches:

(A) Ditches with ephemeral flow that are not a relocated tributary or 

excavated in a tributary.

(B) Ditches with intermittent flow that are not a relocated tributary, 

excavated in a tributary, or drain wetlands.

(C) Ditches that do not flow, either directly or through another water, into a 

water identified in paragraphs (1)(i) through (iii) of this section.

(iv) The following features:

(A) Artificially irrigated areas that would revert to dry land should application 

of water to that area cease;

(B) Artificial, constructed lakes and ponds created in dry land such as farm 

and stock watering ponds, irrigation ponds, settling basins, fields 

flooded for rice growing, log cleaning ponds, or cooling ponds;

(C) Artificial reflecting pools or swimming pools created in dry land;

(D) Small ornamental waters created in dry land;
20

(E) Water-filled depressions created in dry land incidental to mining or 

construction activity, including pits excavated for obtaining fill, sand, or 

gravel that fill with water;

(F) Erosional features, including gullies, rills, and other ephemeral features 

that do not meet the definition of tributary, non-wetland swales, and 

lawfully constructed grassed waterways; and

(G) Puddles.

(v) Groundwater, including groundwater drained through subsurface drainage 

systems.

(vi) Stormwater control features constructed to convey, treat, or store stormwater 

that are created in dry land.

(vii) Wastewater recycling structures constructed in dry land; detention and 

retention basins built for wastewater recycling; groundwater recharge basins; 

percolation ponds built for wastewater recycling; and water distributary 

structures built for wastewater recycling.

(3) Definitions—In this section, the following definitions apply:

(i) Adjacent. The term adjacent means bordering, contiguous, or neighboring a 

water identified in paragraphs (1)(i) through (v) of this section, including 

waters separated by constructed dikes or barriers, natural river berms, beach

dunes, and the like. For purposes of adjacency, an open water such as a 

pond or lake includes any wetlands within or abutting its ordinary high water 

mark. Adjacency is not limited to waters located laterally to a water identified 

in paragraphs (1)(i) through (v) of this section. Adjacent waters also include 

all waters that connect segments of a water identified in paragraphs (1)(i) 

through (v) or are located at the head of a water identified in paragraphs (1)(i) 

through (v) of this section and are bordering, contiguous, or neighboring such 

water. Waters being used for established normal farming, ranching, and 

silviculture activities (33 USC § 1344(f)) are not adjacent.

(ii) Neighboring. The term neighboring means:

(A) all waters located within 100 feet of the ordinary high water mark of a 

water identified in paragraphs (1)(i) through (v) of this section. The 

entire water is neighboring if a portion is located within 100 feet of the 

ordinary high water mark;

(B) all waters located within the 100-year floodplain of a water identified in 

paragraphs (1)(i) through (v) of this section and not more than 1,500 

feet from the ordinary high water mark of such water. The entire water 

is neighboring if a portion is located within 1,500 feet of the ordinary

high water mark and within the 100-year floodplain;

(C) all waters located within 1,500 feet of the high tide line of a water 

identified in paragraphs (1)(i) or (1)(iii) of this section, and all waters 

within 1,500 feet of the ordinary high water mark of the Great Lakes. 

The entire water is neighboring if a portion is located within 1,500 feet of 

the high tide line or within 1,500 feet of the ordinary high water mark of 

the Great Lakes.
21

(iii) Tributary and tributaries. The terms tributary and tributaries each mean a 

water that contributes flow, either directly or through another water (including 

an impoundment identified in paragraph (1)(iv) of this section), to a water 

identified in paragraphs (1)(i) through (iii) of this section that is characterized 

by the presence of the physical indicators of a bed and banks and an

ordinary high water mark. These physical indicators demonstrate there is 

volume, frequency, and duration of flow sufficient to create a bed and banks 

and an ordinary high water mark, and thus to qualify as a tributary. A 

tributary can be a natural, man-altered, or man-made water and includes 

waters such as rivers, streams, canals, and ditches not excluded under 

paragraph (2) of this section. A water that otherwise qualifies as a tributary 

under this definition does not lose its status as a tributary if, for any length, 

there are one or more constructed breaks (such as bridges, culverts, pipes, 

or dams), or one or more natural breaks (such as wetlands along the run of a 

stream, debris piles, boulder fields, or a stream that flows underground) so

long as a bed and banks and an ordinary high water mark can be identified

upstream of the break. A water that otherwise qualifies as a tributary under

this definition does not lose its status as a tributary if it contributes flow 

through a water of the United States that does not meet the definition of 

tributary or through a non-jurisdictional water to a water identified in 

paragraphs (1)(i) through (iii) of this section.

(iv) Wetlands. The term wetlands means those areas that are inundated or

saturated by surface or groundwater at a frequency and duration sufficient to

support, and that under normal circumstances do support, a prevalence of 

vegetation typically adapted for life in saturated soil conditions. Wetlands

generally include swamps, marshes, bogs, and similar areas.

(v) Significant Nexus. The term significant nexus means that a water, including 

wetlands, either alone or in combination with other similarly situated waters 

in the region, significantly affects the chemical, physical, or biological 

integrity of a water identified in paragraphs (1)(i) through (iii) of this section. 

The term “in the region” means the watershed that drains to the nearest 

water identified in paragraphs (1)(i) through (iii) of this section. For an effect 

to be significant, it must be more than speculative or insubstantial. Waters 

are similarly situated when they function alike and are sufficiently close to 

function together in affecting downstream waters. For purposes of 

determining whether or not a water has a significant nexus, the water’s effect 

on downstream (1)(i) through (iii) waters shall be assessed by evaluating the 

aquatic functions identified in paragraphs (A) through (I) of this paragraph. A 

water has a significant nexus when any single function or combination of 

functions performed by the water, alone or together with similarly situated 

waters in the region, contributes significantly to the chemical, physical, or 

biological integrity of the nearest water identified in paragraphs (1)(i) through 

(iii) of this section. Functions relevant to the significant nexus evaluation are 

the following:

(A) sediment trapping,

(B) nutrient recycling,
22

(C) pollutant trapping, transformation, filtering, and transport,

(D) retention and attenuation of flood waters, 

(E) runoff storage,

(F) contribution of flow,

(G) export of organic matter,

(H) export of food resources, and

(I) provision of life cycle dependent aquatic habitat (such as foraging, 

feeding, nesting, breeding, spawning, or use as a nursery area) for 

species located in a water identified in paragraphs (a)(1) through (3) of 

this section.

(vi) Ordinary high water mark. The term ordinary high water mark means 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.

(vii) High tide line. The term high tide line means the line of intersection of the 

land with the water's surface at the maximum height reached by a rising tide. 

The high tide line may be determined, in the absence of actual data, by a line 

of oil or scum along shore objects, a more or less continuous deposit of fine 

shell or debris on the foreshore or berm, other physical markings or 

characteristics, vegetation lines, tidal gages, or other suitable means that 

delineate the general height reached by a rising tide. The line encompasses 

spring high tides and other high tides that occur with periodic frequency but 

does not include storm surges in which there is a departure from the normal 

or predicted reach of the tide due to the piling up of water against a coast by 

strong winds such as those accompanying a hurricane or other intense 

storm.
23

PART 117—DETERMINATION OF REPORTABLE QUANTITIES FOR HAZARDOUS 

SUBSTANCES

9. The authority citation for part 119 continues to read as follows:

Authority: The Clean Water Act, 33 U.S.C. 1321 et.seq.

10. Section 117.1 is amended by revising the definition of “navigable waters” to read as 

follows:

§ 117.1 Definitions

(i) Navigable waters is defined in section 502(7) of the Act to mean “waters of the United 

States, including the territorial seas.”

(1) For purposes of the Clean Water Act, 33 U.S.C. 1251 et. seq. and its 

implementing regulations, subject to the exclusions in paragraph (2) of this 

section, the term ‘‘waters of the United States’’ means:

(i) All waters which are currently used, 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;

(ii) All interstate waters, including interstate wetlands;

(iii) The territorial seas;

(iv) All impoundments of waters otherwise identified as waters of the United 

States under this section;

(v) All tributaries, as defined in paragraph (3)(iii) of this section, of waters 

identified in paragraphs (1)(i) through (iii) of this section;

(vi) All waters adjacent to a water identified in paragraphs (1)(i) through (v) of this 

section, including wetlands, ponds, lakes, oxbows, impoundments, and similar 

waters;

(vii) All waters in paragraphs (A) through (E) of this paragraph where they are 

determined, on a case-specific basis, to have a significant nexus to a water 

identified in paragraphs (1)(i) through (iii) of this section. The waters identified 

in each of paragraphs (A) through (E) of this paragraph are similarly situated 

and shall be combined, for purposes of a significant nexus analysis, in the 

watershed that drains to the nearest water identified in paragraphs (1)(i) 

through (iii) of this section. Waters identified in this paragraph shall not be 

combined with waters identified in paragraph (1)(vi) of this section when 

performing a significant nexus analysis. If waters identified in this paragraph 

are also an adjacent water under paragraph (1)(vi), they are an adjacent water 

and no case-specific significant nexus analysis is required.

(A) Prairie potholes. Prairie potholes are a complex of glacially formed 

wetlands, usually occurring in depressions that lack permanent natural 

outlets, located in the upper Midwest.

(B) Carolina bays and Delmarva bays. Carolina bays and Delmarva bays 

are ponded, depressional wetlands that occur along the Atlantic coastal 

plain.

(C) Pocosins. Pocosins are evergreen shrub and tree dominated wetlands 

found predominantly along the Central Atlantic coastal plain.
24

(D) Western vernal pools. Western vernal pools are seasonal wetlands 

located in parts of California and associated with topographic depression, 

soils with poor drainage, mild, wet winters and hot, dry summers.

(E) Texas coastal prairie wetlands. Texas coastal prairie wetlands are 

freshwater wetlands that occur as a mosaic of depressions, ridges, 

intermound flats, and mima mound wetlands located along the Texas 

Gulf Coast.

(viii) All waters located within the 100-year floodplain of a water identified in (1)(i) 

through (iii) of this section and all waters located within 4,000 feet of the high 

tide line or ordinary high water mark of a water identified in paragraphs (1)(i) 

through (v) of this section where they are determined on a case-specific basis 

to have a significant nexus to a water identified in paragraphs (1)(i) through (iii) 

of this section. For waters determined to have a significant nexus, the entire 

water is a water of the United States if a portion is located within the 100-year 

floodplain of a water identified in (1)(i) through (iii) of this section or within 

4,000 feet of the high tide line or ordinary high water mark. Waters identified 

in this paragraph shall not be combined with waters identified in paragraph 

(1)(vi) of this section when performing a significant nexus analysis. If waters 

identified in this paragraph are also an adjacent water under paragraph (1)(vi), 

they are an adjacent water and no case-specific significant nexus analysis is 

required.

(2) The following are not “waters of the United States” even where they otherwise 

meet the terms of paragraphs (1)(iv) through (viii) of this section.

(i) Waste treatment systems, including treatment ponds or lagoons designed to 

meet the requirements of the Clean Water Act.

(ii) Prior converted cropland. Notwithstanding the determination of an area’s 

status as prior converted cropland by any other Federal agency, for the 

purposes of the Clean Water Act, the final authority regarding Clean Water Act 

jurisdiction remains with EPA.

(iii) The following ditches:

(A) Ditches with ephemeral flow that are not a relocated tributary or 

excavated in a tributary.

(B) Ditches with intermittent flow that are not a relocated tributary, excavated 

in a tributary, or drain wetlands.

(C) Ditches that do not flow, either directly or through another water, into a 

water identified in paragraphs (1)(i) through (iii) of this section.

(iv) The following features:

(A) Artificially irrigated areas that would revert to dry land should application 

of water to that area cease;

(B) Artificial, constructed lakes and ponds created in dry land such as farm 

and stock watering ponds, irrigation ponds, settling basins, fields flooded 

for rice growing, log cleaning ponds, or cooling ponds;

(C) Artificial reflecting pools or swimming pools created in dry land;

(D) Small ornamental waters created in dry land;
25

(E) Water-filled depressions created in dry land incidental to mining or 

construction activity, including pits excavated for obtaining fill, sand, or 

gravel that fill with water;

(F) Erosional features, including gullies, rills, and other ephemeral features 

that do not meet the definition of tributary, non-wetland swales, and 

lawfully constructed grassed waterways; and

(G) Puddles.

(v) Groundwater, including groundwater drained through subsurface drainage 

systems.

(vi) Stormwater control features constructed to convey, treat, or store stormwater 

that are created in dry land.

(vii) Wastewater recycling structures constructed in dry land; detention and 

retention basins built for wastewater recycling; groundwater recharge basins; 

percolation ponds built for wastewater recycling; and water distributary 

structures built for wastewater recycling.

(3) Definitions—In this section, the following definitions apply:

(i) Adjacent. The term adjacent means bordering, contiguous, or neighboring a 

water identified in paragraphs (1)(i) through (v) of this section, including 

waters separated by constructed dikes or barriers, natural river berms, beach

dunes, and the like. For purposes of adjacency, an open water such as a 

pond or lake includes any wetlands within or abutting its ordinary high water 

mark. Adjacency is not limited to waters located laterally to a water identified 

in paragraphs (1)(i) through (v) of this section. Adjacent waters also include 

all waters that connect segments of a water identified in paragraphs (1)(i) 

through (v) or are located at the head of a water identified in paragraphs (1)(i) 

through (v) of this section and are bordering, contiguous, or neighboring such 

water. Waters being used for established normal farming, ranching, and 

silviculture activities (33 USC § 1344(f)) are not adjacent.

(ii) Neighboring. The term neighboring means:

(A) All waters located within 100 feet of the ordinary high water mark of a 

water identified in paragraphs (1)(i) through (v) of this section. The 

entire water is neighboring if a portion is located within 100 feet of the 

ordinary high water mark;

(B) All waters located within the 100-year floodplain of a water identified in 

paragraphs (1)(i) through (v) of this section and not more than 1,500 feet 

from the ordinary high water mark of such water. The entire water is 

neighboring if a portion is located within 1,500 feet of the ordinary high 

water mark and within the 100-year floodplain;

(C) All waters located within 1,500 feet of the high tide line of a water 

identified in paragraphs (1)(i) or (1)(iii) of this section, and all waters 

within 1,500 feet of the ordinary high water mark of the Great Lakes. The 

entire water is neighboring if a portion is located within 1,500 feet of the 

high tide line or within 1,500 feet of the ordinary high water mark of the 

Great Lakes.
26

(iii) Tributary and tributaries. The terms tributary and tributaries each mean a 

water that contributes flow, either directly or through another water (including 

an impoundment identified in paragraph (1)(iv) of this section), to a water 

identified in paragraphs (1)(i) through (iii) of this section that is characterized 

by the presence of the physical indicators of a bed and banks and an ordinary 

high water mark. These physical indicators demonstrate there is volume, 

frequency, and duration of flow sufficient to create a bed and banks and an 

ordinary high water mark, and thus to qualify as a tributary. A tributary can be 

a natural, man-altered, or man-made water and includes waters such as 

rivers, streams, canals, and ditches not excluded under paragraph (2) of this 

section. A water that otherwise qualifies as a tributary under this definition 

does not lose its status as a tributary if, for any length, there are one or more 

constructed breaks (such as bridges, culverts, pipes, or dams), or one or 

more natural breaks (such as wetlands along the run of a stream, debris piles, 

boulder fields, or a stream that flows underground) so long as a bed and 

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

break. A water that otherwise qualifies as a tributary under this definition does 

not lose its status as a tributary if it contributes flow through a water of the 

United States that does not meet the definition of tributary or through a nonjurisdictional water to a water identified in paragraphs (1)(i1) through (iii) of 

this section.

(iv) Wetlands. The term wetlands means those areas that are inundated or

saturated by surface or groundwater at a frequency and duration sufficient to

support, and that under normal circumstances do support, a prevalence of 

vegetation typically adapted for life in saturated soil conditions. Wetlands

generally include swamps, marshes, bogs, and similar areas.

(v) Significant nexus. The term significant nexus means that a water, including 

wetlands, either alone or in combination with other similarly situated waters in 

the region, significantly affects the chemical, physical, or biological integrity of 

a water identified in paragraphs (1)(i) through (iii) of this section. The term “in 

the region” means the watershed that drains to the nearest water identified in 

paragraphs (1)(i) through (iii) of this section. For an effect to be significant, it 

must be more than speculative or insubstantial. Waters are similarly situated 

when they function alike and are sufficiently close to function together in 

affecting downstream waters. For purposes of determining whether or not a 

water has a significant nexus, the water’s effect on downstream (1)(i) through 

(iii) waters shall be assessed by evaluating the aquatic functions identified in 

paragraphs (A) through (I) of this paragraph. A water has a significant nexus 

when any single function or combination of functions performed by the water, 

alone or together with similarly situated waters in the region, contributes 

significantly to the chemical, physical, or biological integrity of the nearest 

water identified in paragraphs (1)(i) through (iii) of this section. Functions 

relevant to the significant nexus evaluation are the following:

(A) sediment trapping,

(B) nutrient recycling,

(C) pollutant trapping, transformation, filtering, and transport,
27

(D) retention and attenuation of flood waters,

(E) runoff storage,

(F) contribution of flow,

(G) export of organic matter, 

(H) export of food resources, and

(I) provision of life cycle dependent aquatic habitat (such as foraging, 

feeding, nesting, breeding, spawning, or use as a nursery area) for 

species located in a water identified in paragraphs (a)(1) through (3) of 

this section.

(vi) Ordinary high water mark. The term ordinary high water mark means 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.

(vii) High tide line. The term high tide line means the line of intersection of the 

land with the water's surface at the maximum height reached by a rising tide. 

The high tide line may be determined, in the absence of actual data, by a line 

of oil or scum along shore objects, a more or less continuous deposit of fine 

shell or debris on the foreshore or berm, other physical markings or 

characteristics, vegetation lines, tidal gages, or other suitable means that 

delineate the general height reached by a rising tide. The line encompasses 

spring high tides and other high tides that occur with periodic frequency but 

does not include storm surges in which there is a departure from the normal 

or predicted reach of the tide due to the piling up of water against a coast by 

strong winds such as those accompanying a hurricane or other intense storm.
28

PART 122—EPA ADMINISTERED PERMIT PROGRAMS: THE NATIONAL 

POLLUTANT DISCHARGE ELIMINATION SYSTEM

11. The authority citation for part 122 continues to read as follows:

Authority: The Clean Water Act, 33 U.S.C. 1251 et.seq.

12. Section 122.2 is amended by revising the definition of “Waters of the United States” 

and removing the note and editorial note at the end of the section. The revision 

reads as follows:

§ 122.2 Definitions. 

Waters of the United States or waters of the U.S. means:

(a) For purposes of the Clean Water Act, 33 U.S.C. 1251 et. seq. and its implementing 

regulations, subject to the exclusions in paragraph (b) of this section, the term 

‘‘waters of the United States’’ means:

(1) All waters which are currently used, 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;

(2) All interstate waters, including interstate wetlands;

(3) The territorial seas;

(4) All impoundments of waters otherwise identified as waters of the United 

States under this section;

(5) All tributaries, as defined in paragraph (c)(3) of this section, of waters 

identified in paragraphs (a)(1) through (3) of this section;

(6) All waters adjacent to a water identified in paragraphs (a)(1) through (5) of 

this section, including wetlands, ponds, lakes, oxbows, impoundments, and 

similar waters;

(7) All waters in paragraphs (i) through (v) of this paragraph where they are 

determined, on a case-specific basis, to have a significant nexus to a water 

identified in paragraphs (a)(1) through (3) of this section. The waters 

identified in each of paragraphs (i) through (v) of this paragraph are similarly 

situated and shall be combined, for purposes of a significant nexus analysis, 

in the watershed that drains to the nearest water identified in paragraphs 

(a)(1) through (3) of this section. Waters identified in this paragraph shall not 

be combined with waters identified in paragraph (a)(6) of this section when 

performing a significant nexus analysis. If waters identified in this paragraph 

are also an adjacent water under paragraph (a)(6), they are an adjacent 

water and no case-specific significant nexus analysis is required.

(i) Prairie potholes. Prairie potholes are a complex of glacially formed 

wetlands, usually occurring in depressions that lack permanent natural 

outlets, located in the upper Midwest.

(ii) Carolina bays and Delmarva bays. Carolina bays and Delmarva bays 

are ponded, depressional wetlands that occur along the Atlantic coastal 

plain.

(iii) Pocosins. Pocosins are evergreen shrub and tree dominated wetlands 

found predominantly along the Central Atlantic coastal plain.
29

(iv) Western vernal pools. Western vernal pools are seasonal wetlands 

located in parts of California and associated with topographic 

depression, soils with poor drainage, mild, wet winters and hot, dry 

summers.

(v) Texas coastal prairie wetlands. Texas coastal prairie wetlands are 

freshwater wetlands that occur as a mosaic of depressions, ridges, 

intermound flats, and mima mound wetlands located along the Texas 

Gulf Coast.

(8) All waters located within the 100-year floodplain of a water identified in (a)(1) 

through (3) of this section and all waters located within 4,000 feet of the high 

tide line or ordinary high water mark of a water identified in paragraphs (a)(1) 

through (5) of this section where they are determined on a case-specific 

basis to have a significant nexus to a water identified in paragraphs (a)(1) 

through (3) of this section. For waters determined to have a significant 

nexus, the entire water is a water of the United States if a portion is located 

within the 100-year floodplain of a water identified in (a)(1) through (3) of this 

section or within 4,000 feet of the high tide line or ordinary high water mark. 

Waters identified in this paragraph shall not be combined with waters 

identified in paragraph (a)(6) of this section when performing a significant 

nexus analysis. If waters identified in this paragraph are also an adjacent 

water under paragraph (a)(6), they are an adjacent water and no casespecific significant nexus analysis is required.

(b) The following are not “waters of the United States” even where they otherwise 

meet the terms of paragraphs (a)(4) through (8) of this section.

(1) Waste treatment systems, including treatment ponds or lagoons, designed to 

meet the requirements of the Clean Water Act. This exclusion applies only to 

manmade bodies of water which neither were originally created in waters of 

the United States (such as disposal area in wetlands) nor resulted from the 

impoundment of waters of the United States.1

(2) Prior converted cropland. Notwithstanding the determination of an area’s 

status as prior converted cropland by any other Federal agency, for the 

purposes of the Clean Water Act, the final authority regarding Clean Water 

Act jurisdiction remains with EPA.

(3) The following ditches:

(i) Ditches with ephemeral flow that are not a relocated tributary or excavated 

in a tributary.

(ii) Ditches with intermittent flow that are not a relocated tributary, excavated 

in a tributary, or drain wetlands.

(iii) Ditches that do not flow, either directly or through another water, into a 

water identified in paragraphs (a)(1) through (3) of this section.

(4) The following features:

 

1

At 45 FR 48620, July 21, 1980, the Environmental Protection Agency suspended until further notice in § 

122.2, the last sentence, beginning “This exclusion applies...” in the definition of “Waters of the United 

States.” This revision (48 FR 14153, Apr. 1, 1983) continues that suspension.
30

(i) Artificially irrigated areas that would revert to dry land should application of 

water to that area cease;

(ii) Artificial, constructed lakes and ponds created in dry land such as farm 

and stock watering ponds, irrigation ponds, settling basins, fields flooded 

for rice growing, log cleaning ponds, or cooling ponds;

(iii) Artificial reflecting pools or swimming pools created in dry land;

(iv) Small ornamental waters created in dry land;

(v) Water-filled depressions created in dry land incidental to mining or 

construction activity, including pits excavated for obtaining fill, sand, or 

gravel that fill with water;

(vi) Erosional features, including gullies, rills, and other ephemeral features 

that do not meet the definition of tributary, non-wetland swales, and 

lawfully constructed grassed waterways; and

(vii) Puddles.

(5) Groundwater, including groundwater drained through subsurface drainage 

systems.

(6) Stormwater control features constructed to convey, treat, or store stormwater 

that are created in dry land.

(7) Wastewater recycling structures constructed in dry land; detention and 

retention basins built for wastewater recycling; groundwater recharge basins; 

percolation ponds built for wastewater recycling; and water distributary 

structures built for wastewater recycling.

(c) Definitions—In this section, the following definitions apply:

(1) Adjacent. The term adjacent means bordering, contiguous, or neighboring a 

water identified in paragraphs (a)(1) through (5) of this section, including waters 

separated by constructed dikes or barriers, natural river berms, beach dunes, 

and the like. For purposes of adjacency, an open water such as a pond or lake 

includes any wetlands within or abutting its ordinary high water mark. 

Adjacency is not limited to waters located laterally to a water identified in 

paragraphs (a)(1) through (5) of this section. Adjacent waters also include all 

waters that connect segments of a water identified in paragraphs (a)(1) through 

(5) or are located at the head of a water identified in paragraphs (a)(1) through 

(5) of this section and are bordering, contiguous, or neighboring such water. 

Waters being used for established normal farming, ranching, and silviculture 

activities (33 USC § 1344(f)) are not adjacent.

(2) Neighboring. The term neighboring means:

(i) All waters located within 100 feet of the ordinary high water mark of a water 

identified in paragraphs (a)(1) through (5) of this section. The entire water is 

neighboring if a portion is located within 100 feet of the ordinary high water 

mark;

(ii) All waters located within the 100-year floodplain of a water identified in 

paragraphs (a)(1) through (5) of this section and not more than 1,500 feet 

from the ordinary high water mark of such water. The entire water is 

neighboring if a portion is located within 1,500 feet of the ordinary high 

water mark and within the 100-year floodplain;
31

(iii) All waters located within 1,500 feet of the high tide line of a water identified 

in paragraphs (a)(1) or (a)(3) of this section, and all waters within 1,500 feet 

of the ordinary high water mark of the Great Lakes. The entire water is 

neighboring if a portion is located within 1,500 feet of the high tide line or 

within 1,500 feet of the ordinary high water mark of the Great Lakes.

(3) Tributary and tributaries. The terms tributary and tributaries each mean a water 

that contributes flow, either directly or through another water (including an 

impoundment identified in paragraph (a)(4) of this section), to a water identified 

in paragraphs (a)(1) through (3) of this section that is characterized by the 

presence of the physical indicators of a bed and banks and an ordinary high 

water mark. These physical indicators demonstrate there is volume, frequency, 

and duration of flow sufficient to create a bed and banks and an ordinary high 

water mark, and thus to qualify as a tributary. A tributary can be a natural,

man-altered, or man-made water and includes waters such as rivers, streams,

canals, and ditches not excluded under paragraph (b) of this section. A water 

that otherwise qualifies as a tributary under this definition does not lose its 

status as a tributary if, for any length, there are one or more constructed breaks 

(such as bridges, culverts, pipes, or dams), or one or more natural breaks (such 

as wetlands along the run of a stream, debris piles, boulder fields, or a stream 

that flows underground) so long as a bed and banks and an ordinary high water 

mark can be identified upstream of the break. A water that otherwise qualifies 

as a tributary under this definition does not lose its status as a tributary if it 

contributes flow through a water of the United States that does not meet the 

definition of tributary or through a non-jurisdictional water to a water identified in 

paragraphs (a)(1) through (3) of this section.

(4) Wetlands. The term wetlands means those areas that are inundated or

saturated by surface or groundwater at a frequency and duration sufficient to

support, and that under normal circumstances do support, a prevalence of 

vegetation typically adapted for life in saturated soil conditions. Wetlands

generally include swamps, marshes, bogs, and similar areas.

(5) Significant nexus. The term significant nexus means that a water, including 

wetlands, either alone or in combination with other similarly situated waters in 

the region, significantly affects the chemical, physical, or biological integrity of a 

water identified in paragraphs (a)(1) through (3) of this section. The term “in 

the region” means the watershed that drains to the nearest water identified in 

paragraphs (a)(1) through (3) of this section. For an effect to be significant, it 

must be more than speculative or insubstantial. Waters are similarly situated 

when they function alike and are sufficiently close to function together in 

affecting downstream waters. For purposes of determining whether or not a 

water has a significant nexus, the water’s effect on downstream (a)(1) through 

(3) waters shall be assessed by evaluating the aquatic functions identified in 

paragraphs (A) through (I) of this paragraph. A water has a significant nexus 

when any single function or combination of functions performed by the water, 

alone or together with similarly situated waters in the region, contributes 

significantly to the chemical, physical, or biological integrity of the nearest water 
32

identified in paragraphs (a)(1) through (3) of this section. Functions relevant to 

the significant nexus evaluation are the following:

(i) sediment trapping,

(ii) nutrient recycling,

(iii) pollutant trapping, transformation, filtering, and transport,

(iv) retention and attenuation of flood waters,

(v) runoff storage,

(vi) contribution of flow,

(vii) export of organic matter,

(viii) export of food resources, and

(ix) provision of life cycle dependent aquatic habitat (such as foraging, feeding, 

nesting, breeding, spawning, or use as a nursery area) for species located 

in a water identified in paragraphs (a)(1) through (3) of this section. 

(6) Ordinary high water mark. The term ordinary high water mark means 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.

(7) High tide line. The term high tide line means the line of intersection of the land 

with the water's surface at the maximum height reached by a rising tide. The 

high tide line may be determined, in the absence of actual data, by a line of oil 

or scum along shore objects, a more or less continuous deposit of fine shell or 

debris on the foreshore or berm, other physical markings or characteristics, 

vegetation lines, tidal gages, or other suitable means that delineate the general 

height reached by a rising tide. The line encompasses spring high tides and 

other high tides that occur with periodic frequency but does not include storm 

surges in which there is a departure from the normal or predicted reach of the 

tide due to the piling up of water against a coast by strong winds such as those 

accompanying a hurricane or other intense storm.
33

PART 230—SECTION 404(b)(1) GUIDELINES FOR SPECIFICATION OF DISPOSAL 

SITES FOR DREDGED OR FILL MATERIAL.

13. The authority citation for part 230 continues to read as follows:

Authority: The Clean Water Act, 33 U.S.C. 1251 et.seq.

14. Section 230.3 is amended by revising paragraphs (s) and (t) and adding paragraph 

(u) to read as follows:

§ 230.3 Definitions.

(s) For purposes of the Clean Water Act, 33 U.S.C. 1251 et. seq. and its implementing 

regulations, subject to the exclusions in paragraph (b) of this section, the term 

‘‘waters of the United States’’ means:

(1) All waters which are currently used, 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;

(2) All interstate waters, including interstate wetlands;

(3) The territorial seas;

(4) All impoundments of waters otherwise identified as waters of the United 

States under this section;

(5) All tributaries, as defined in paragraph (c)(3) of this section, of waters 

identified in paragraphs (a)(1) through (3) of this section;

(6) All waters adjacent to a water identified in paragraphs (a)(1) through (5) of 

this section, including wetlands, ponds, lakes, oxbows, impoundments, and 

similar waters; 

(7) All waters in paragraphs (i) through (v) of this paragraph where they are 

determined, on a case-specific basis, to have a significant nexus to a water 

identified in paragraphs (a)(1) through (3) of this section. The waters 

identified in each of paragraphs (i) through (v) of this paragraph are similarly 

situated and shall be combined, for purposes of a significant nexus analysis, 

in the watershed that drains to the nearest water identified in paragraphs 

(a)(1) through (3) of this section. Waters identified in this paragraph shall not 

be combined with waters identified in paragraph (a)(6) of this section when

performing a significant nexus analysis. If waters identified in this paragraph 

are also an adjacent water under paragraph (a)(6), they are an adjacent water 

and no case-specific significant nexus analysis is required.

(i) Prairie potholes. Prairie potholes are a complex of glacially formed 

wetlands, usually occurring in depressions that lack permanent natural 

outlets, located in the upper Midwest.

(ii) Carolina bays and Delmarva bays. Carolina bays and Delmarva bays 

are ponded, depressional wetlands that occur along the Atlantic coastal 

plain.

(iii) Pocosins. Pocosins are evergreen shrub and tree dominated wetlands 

found predominantly along the Central Atlantic coastal plain.

(iv) Western vernal pools. Western vernal pools are seasonal wetlands 

located in parts of California and associated with topographic 
34

depression, soils with poor drainage, mild, wet winters and hot, dry 

summers.

(v) Texas coastal prairie wetlands. Texas coastal prairie wetlands are 

freshwater wetlands that occur as a mosaic of depressions, ridges, 

intermound flats, and mima mound wetlands located along the Texas 

Gulf Coast.

(8) All waters located within the 100-year floodplain of a water identified in (a)(1) 

through (3) of this section and all waters located within 4,000 feet of the high 

tide line or ordinary high water mark of a water identified in paragraphs (a)(1) 

through (5) of this section where they are determined on a case-specific basis 

to have a significant nexus to a water identified in paragraphs (a)(1) through 

(3) of this section. For waters determined to have a significant nexus, the 

entire water is a water of the United States if a portion is located within the 

100-year floodplain of a water identified in (a)(1) through (3) of this section or 

within 4,000 feet of the high tide line or ordinary high water mark. Waters 

identified in this paragraph shall not be combined with waters identified in 

paragraph (a)(6) of this section when performing a significant nexus analysis. 

If waters identified in this paragraph are also an adjacent water under 

paragraph (a)(6), they are an adjacent water and no case-specific significant 

nexus analysis is required.

(t) The following are not “waters of the United States” even where they otherwise meet 

the terms of paragraphs (a)(4) through (8) of this section.

(1) Waste treatment systems, including treatment ponds or lagoons designed to 

meet the requirements of the Clean Water Act.

(2) Prior converted cropland. Notwithstanding the determination of an area’s 

status as prior converted cropland by any other Federal agency, for the 

purposes of the Clean Water Act, the final authority regarding Clean Water 

Act jurisdiction remains with EPA.

(3) The following ditches:

(i) Ditches with ephemeral flow that are not a relocated tributary or 

excavated in a tributary.

(ii) Ditches with intermittent flow that are not a relocated tributary, excavated 

in a tributary, or drain wetlands.

(iii) Ditches that do not flow, either directly or through another water, into a 

water identified in paragraphs (a)(1) through (3) of this section.

(4) The following features:

(i) Artificially irrigated areas that would revert to dry land should application 

of water to that area cease;

(ii) Artificial, constructed lakes and ponds created in dry land such as farm 

and stock watering ponds, irrigation ponds, settling basins, fields flooded 

for rice growing, log cleaning ponds, or cooling ponds;

(iii) Artificial reflecting pools or swimming pools created in dry land;

(iv) Small ornamental waters created in dry land;
35

(v) Water-filled depressions created in dry land incidental to mining or 

construction activity, including pits excavated for obtaining fill, sand, or 

gravel that fill with water;

(vi) Erosional features, including gullies, rills, and other ephemeral features 

that do not meet the definition of tributary, non-wetland swales, and 

lawfully constructed grassed waterways; and

(vii) Puddles.

(viii) Groundwater, including groundwater drained through subsurface 

drainage systems. 

(ix) Stormwater control features constructed to convey, treat, or store 

stormwater that are created in dry land.

(7) Wastewater recycling structures constructed in dry land; detention and 

retention basins built for wastewater recycling; groundwater recharge basins; 

percolation ponds built for wastewater recycling; and water distributary 

structures built for wastewater recycling.

(u) Definitions—In this section, the following definitions apply:

(1) Adjacent. The term adjacent means bordering, contiguous, or neighboring a 

water identified in paragraphs (a)(1) through (5) of this section, including waters 

separated by constructed dikes or barriers, natural river berms, beach dunes, 

and the like. For purposes of adjacency, an open water such as a pond or lake 

includes any wetlands within or abutting its ordinary high water mark. Adjacency 

is not limited to waters located laterally to a water identified in paragraphs (a)(1) 

through (5) of this section. Adjacent waters also include all waters that connect 

segments of a water identified in paragraphs (a)(1) through (5) or are located at 

the head of a water identified in paragraphs (a)(1) through (5) of this section and 

are bordering, contiguous, or neighboring such water. Waters being used for 

established normal farming, ranching, and silviculture activities (33 USC § 

1344(f)) are not adjacent.

(2) Neighboring. The term neighboring means:

(A) All waters located within 100 feet of the ordinary high water mark of a water 

identified in paragraphs (a)(1) through (5) of this section. The entire water is 

neighboring if a portion is located within 100 feet of the ordinary high water 

mark;

(B) All waters located within the 100-year floodplain of a water identified in 

paragraphs (a)(1) through (5) of this section and not more than 1,500 feet 

from the ordinary high water mark of such water. The entire water is 

neighboring if a portion is located within 1,500 feet of the ordinary high water 

mark and within the 100-year floodplain;

(C) All waters located within 1,500 feet of the high tide line of a water identified 

in paragraphs (a)(1) or (a)(3) of this section, and all waters within 1,500 feet 

of the ordinary high water mark of the Great Lakes. The entire water is 

neighboring if a portion is located within 1,500 feet of the high tide line or 

within 1,500 feet of the ordinary high water mark of the Great Lakes.

(3) Tributary and tributaries. The terms tributary and tributaries each mean a water 

that contributes flow, either directly or through another water (including an 
36

impoundment identified in paragraph (a)(4) of this section), to a water identified in

paragraphs (a)(1) through (3) of this section that is characterized by the presence 

of the physical indicators of a bed and banks and an ordinary high water mark. 

These physical indicators demonstrate there is volume, frequency, and duration 

of flow sufficient to create a bed and banks and an ordinary high water mark, and 

thus to qualify as a tributary. A tributary can be a natural, man-altered, or manmade water and includes waters such as rivers, streams, canals, and ditches not 

excluded under paragraph (b) of this section. A water that otherwise qualifies as 

a tributary under this definition does not lose its status as a tributary if, for any 

length, there are one or more constructed breaks (such as bridges, culverts, 

pipes, or dams), or one or more natural breaks (such as wetlands along the run 

of a stream, debris piles, boulder fields, or a stream that flows underground) so

long as a bed and banks and an ordinary high water mark can be identified

upstream of the break. A water that otherwise qualifies as a tributary under this 

definition does not lose its status as a tributary if it contributes flow through a 

water of the United States that does not meet the definition of tributary or through 

a non-jurisdictional water to a water identified in paragraphs (a)(1) through (3) of 

this section.

(4) Wetlands. The term wetlands means those areas that are inundated or saturated 

by surface or groundwater at a frequency and duration sufficient to support, and 

that under normal circumstances do support, a prevalence of vegetation typically 

adapted for life in saturated soil conditions. Wetlands generally include swamps, 

marshes, bogs, and similar areas.

(5) Significant nexus. The term significant nexus means that a water, including 

wetlands, either alone or in combination with other similarly situated waters in the 

region, significantly affects the chemical, physical, or biological integrity of a 

water identified in paragraphs (a)(1) through (3) of this section. The term “in the

region” means the watershed that drains to the nearest water identified in 

paragraphs (a)(1) through (3) of this section. For an effect to be significant, it 

must be more than speculative or insubstantial. Waters are similarly situated 

when they function alike and are sufficiently close to function together in affecting 

downstream waters. For purposes of determining whether or not a water has a 

significant nexus, the water’s effect on downstream (a)(1) through (3) waters 

shall be assessed by evaluating the aquatic functions identified in paragraphs (A) 

through (I) of this paragraph. A water has a significant nexus when any single 

function or combination of functions performed by the water, alone or together 

with similarly situated waters in the region, contributes significantly to the 

chemical, physical, or biological integrity of the nearest water identified in 

paragraphs (a)(1) through (3) of this section. Functions relevant to the significant 

nexus evaluation are the following:

(i) sediment trapping,

(ii) nutrient recycling,

(iii) pollutant trapping, transformation, filtering, and transport,

(iv) retention and attenuation of flood waters, 

(v) runoff storage,

(vi) contribution of flow,
37

(vii) export of organic matter,

(viii) export of food resources, and

(ix) provision of life cycle dependent aquatic habitat (such as foraging, feeding, 

nesting, breeding, spawning, or use as a nursery area) for species located in 

a water identified in paragraphs (a)(1) through (3) of this section.

(6) Ordinary high water mark. The term ordinary high water mark means 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.

(7) High tide line. The term high tide line means the line of intersection of the land 

with the water's surface at the maximum height reached by a rising tide. The 

high tide line may be determined, in the absence of actual data, by a line of oil or 

scum along shore objects, a more or less continuous deposit of fine shell or 

debris on the foreshore or berm, other physical markings or characteristics, 

vegetation lines, tidal gages, or other suitable means that delineate the general 

height reached by a rising tide. The line encompasses spring high tides and 

other high tides that occur with periodic frequency but does not include storm 

surges in which there is a departure from the normal or predicted reach of the 

tide due to the piling up of water against a coast by strong winds such as those 

accompanying a hurricane or other intense storm.
38

PART 232—404 PROGRAMS DEFINITIONS; EXEMPT ACTIVITIES NOT REQUIRING 

404 PERMITS

15. The authority citation for part 230 continues to read as follows:

Authority: The Clean Water Act, 33 U.S.C. 1251 et.seq.

16. Section 232.2 is amended by revising the definition of “Waters of the United States” 

to read as follows:

§ 232.2 Definitions.

Waters of the United States or waters means:

(1) For purposes of the Clean Water Act, 33 U.S.C. 1251 et. seq. and its implementing 

regulations, subject to the exclusions in paragraph (2) of this section, the term 

‘‘waters of the United States’’ means:

(i) All waters which are currently used, 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;

(ii) All interstate waters, including interstate wetlands;

(iii) The territorial seas;

(iv) All impoundments of waters otherwise identified as waters of the United 

States under this section;

(v) All tributaries, as defined in paragraph (3)(iii) of this section, of waters 

identified in paragraphs (1)(i) through (iii) of this section;

(vi) All waters adjacent to a water identified in paragraphs (1)(i) through (v) of this 

section, including wetlands, ponds, lakes, oxbows, impoundments, and 

similar waters; 

(vii) All waters in paragraphs (A) through (E) of this paragraph where they are 

determined, on a case-specific basis, to have a significant nexus to a water 

identified in paragraphs (1)(i) through (iii) of this section. The waters 

identified in each of paragraphs (A) through (E) of this paragraph are similarly 

situated and shall be combined, for purposes of a significant nexus analysis, 

in the watershed that drains to the nearest water identified in paragraphs (1)(i)

through (iii) of this section. Waters identified in this paragraph shall not be 

combined with waters identified in paragraph (1)(vi) of this section when 

performing a significant nexus analysis. If waters identified in this paragraph 

are also an adjacent water under paragraph (1)(vi), they are an adjacent 

water and no case-specific significant nexus analysis is required.

(A) Prairie potholes. Prairie potholes are a complex of glacially formed 

wetlands, usually occurring in depressions that lack permanent natural 

outlets, located in the upper Midwest.

(B) Carolina bays and Delmarva bays. Carolina bays and Delmarva bays 

are ponded, depressional wetlands that occur along the Atlantic coastal 

plain.

(C) Pocosins. Pocosins are evergreen shrub and tree dominated wetlands 

found predominantly along the Central Atlantic coastal plain.
39

(D) Western vernal pools. Western vernal pools are seasonal wetlands 

located in parts of California and associated with topographic depression, 

soils with poor drainage, mild, wet winters and hot, dry summers.

(E) Texas coastal prairie wetlands. Texas coastal prairie wetlands are 

freshwater wetlands that occur as a mosaic of depressions, ridges, 

intermound flats, and mima mound wetlands located along the Texas 

Gulf Coast.

(viii) All waters located within the 100-year floodplain of a water identified in (1)(i) 

through (iii) of this section and all waters located within 4,000 feet of the high 

tide line or ordinary high water mark of a water identified in paragraphs (1)(i) 

through (v) of this section where they are determined on a case-specific basis 

to have a significant nexus to a water identified in paragraphs (1)(i) through 

(iii) of this section. For waters determined to have a significant nexus, the 

entire water is a water of the United States if a portion is located within the 

100-year floodplain of a water identified in (1)(i) through (iii) of this section or 

within 4,000 feet of the high tide line or ordinary high water mark. Waters 

identified in this paragraph shall not be combined with waters identified in 

paragraph (1)(vi) of this section when performing a significant nexus analysis. 

If waters identified in this paragraph are also an adjacent water under 

paragraph (1)(vi), they are an adjacent water and no case-specific significant 

nexus analysis is required.

(2) The following are not “waters of the United States” even where they otherwise meet 

the terms of paragraphs (1)(iv) through (viii) of this section.

(i) Waste treatment systems, including treatment ponds or lagoons designed to 

meet the requirements of the Clean Water Act.

(ii) Prior converted cropland. Notwithstanding the determination of an area’s 

status as prior converted cropland by any other Federal agency, for the 

purposes of the Clean Water Act, the final authority regarding Clean Water 

Act jurisdiction remains with EPA.

(iii) The following ditches:

(A) Ditches with ephemeral flow that are not a relocated tributary or 

excavated in a tributary.

(B) Ditches with intermittent flow that are not a relocated tributary, excavated 

in a tributary, or drain wetlands.

(C) Ditches that do not flow, either directly or through another water, into a 

water identified in paragraphs (1)(i) through (iii) of this 

section.

(iv) The following features:

(A) Artificially irrigated areas that would revert to dry land should application 

of water to that area cease;

(B) Artificial, constructed lakes and ponds created in dry land such as farm 

and stock watering ponds, irrigation ponds, settling basins, fields flooded 

for rice growing, log cleaning ponds, or cooling ponds;

(C) Artificial reflecting pools or swimming pools created in dry land;

(D) Small ornamental waters created in dry land;
40

(E) Water-filled depressions created in dry land incidental to mining or 

construction activity, including pits excavated for obtaining fill, sand, or 

gravel that fill with water;

(F) Erosional features, including gullies, rills, and other ephemeral features 

that do not meet the definition of tributary, non-wetland swales, and 

lawfully constructed grassed waterways; and

(G) Puddles.

(v) Groundwater, including groundwater drained through subsurface drainage 

systems.

(vi) Stormwater control features constructed to convey, treat, or store stormwater 

that are created in dry land.

(vii) Wastewater recycling structures constructed in dry land; detention and 

retention basins built for wastewater recycling; groundwater recharge basins; 

percolation ponds built for wastewater recycling; and water distributary 

structures built for wastewater recycling.

(3) Definitions—In this section, the following definitions apply:

(i) Adjacent. The term adjacent means bordering, contiguous, or neighboring a 

water identified in paragraphs (1)(i) through (v) of this section, including 

waters separated by constructed dikes or barriers, natural river berms, beach

dunes, and the like. For purposes of adjacency, an open water such as a 

pond or lake includes any wetlands within or abutting its ordinary high water 

mark. Adjacency is not limited to waters located laterally to a water identified 

in paragraphs (1)(i) through (v) of this section. Adjacent waters also include 

all waters that connect segments of a water identified in paragraphs (1)(i) 

through (v) or are located at the head of a water identified in paragraphs (1)(i) 

through (v) of this section and are bordering, contiguous, or neighboring such 

water. Waters being used for established normal farming, ranching, and 

silviculture activities (33 USC § 1344(f)) are not adjacent.

(ii) Neighboring. The term neighboring means:

(A) All waters located within 100 feet of the ordinary high water mark of a 

water identified in paragraphs (1)(i) through (v) of this section. The 

entire water is neighboring if a portion is located within 100 feet of the 

ordinary high water mark;

(B) All waters located within the 100-year floodplain of a water identified in 

paragraphs (1)(i) through (v) of this section and not more than 1,500 feet 

from the ordinary high water mark of such water. The entire water is 

neighboring if a portion is located within 1,500 feet of the ordinary high 

water mark and within the 100-year floodplain;

(C) All waters located within 1,500 feet of the high tide line of a water 

identified in paragraphs (1)(i) or (1)(iii) of this section, and all waters 

within 1,500 feet of the ordinary high water mark of the Great Lakes. 

The entire water is neighboring if a portion is located within 1,500 feet of 

the high tide line or within 1,500 feet of the ordinary high water mark of 

the Great Lakes.
41

(iii) Tributary and tributaries. The terms tributary and tributaries each mean a 

water that contributes flow, either directly or through another water (including 

an impoundment identified in paragraph (1)(iv) of this section), to a water 

identified in paragraphs (1)(i) through (iii) of this section that is characterized 

by the presence of the physical indicators of a bed and banks and an ordinary 

high water mark. These physical indicators demonstrate there is volume, 

frequency, and duration of flow sufficient to create a bed and banks and an 

ordinary high water mark, and thus to qualify as a tributary. A tributary can be 

a natural, man-altered, or man-made water and includes waters such as 

rivers, streams, canals, and ditches not excluded under paragraph (2) of this 

section. A water that otherwise qualifies as a tributary under this definition 

does not lose its status as a tributary if, for any length, there are one or more 

constructed breaks (such as bridges, culverts, pipes, or dams), or one or 

more natural breaks (such as wetlands along the run of a stream, debris piles, 

boulder fields, or a stream that flows underground) so long as a bed and 

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

break. A water that otherwise qualifies as a tributary under this definition 

does not lose its status as a tributary if it contributes flow through a water of 

the United States that does not meet the definition of tributary or through a 

non-jurisdictional water to a water identified in paragraphs (1)(i1) through (iii) 

of this section.

(iv) Wetlands. The term wetlands means those areas that are inundated or

saturated by surface or groundwater at a frequency and duration sufficient to

support, and that under normal circumstances do support, a prevalence of 

vegetation typically adapted for life in saturated soil conditions. Wetlands

generally include swamps, marshes, bogs, and similar areas.

(v) Significant Nexus. The term significant nexus means that a water, including 

wetlands, either alone or in combination with other similarly situated waters in 

the region, significantly affects the chemical, physical, or biological integrity of 

a water identified in paragraphs (1)(i) through (iii) of this section. The term “in 

the region” means the watershed that drains to the nearest water identified in 

paragraphs (1)(i) through (iii) of this section. For an effect to be significant, it 

must be more than speculative or insubstantial. Waters are similarly situated 

when they function alike and are sufficiently close to function together in 

affecting downstream waters. For purposes of determining whether or not a 

water has a significant nexus, the water’s effect on downstream (1)(i) through 

(iii) waters shall be assessed by evaluating the aquatic functions identified in 

paragraphs (A) through (I) of this paragraph. A water has a significant nexus 

when any single function or combination of functions performed by the water, 

alone or together with similarly situated waters in the region, contributes 

significantly to the chemical, physical, or biological integrity of the nearest 

water identified in paragraphs (1)(i) through (iii) of this section. Functions 

relevant to the significant nexus evaluation are the following:

(A) sediment trapping,

(B) nutrient recycling,

(C) pollutant trapping, transformation, filtering, and transport,
42

(D retention and attenuation of flood waters,

(E) runoff storage,

(F) contribution of flow,

(G) export of organic matter,

(H) export of food resources, and

(I) provision of life cycle dependent aquatic habitat (such as foraging, 

feeding, nesting, breeding, spawning, or use as a nursery area) for 

species located in a water identified in paragraphs (a)(1) through (3) of 

this section.

(vi) Ordinary high water mark. The term ordinary high water mark means 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.

(vii) High tide line. The term high tide line means the line of intersection of the 

land with the water's surface at the maximum height reached by a rising tide. 

The high tide line may be determined, in the absence of actual data, by a line 

of oil or scum along shore objects, a more or less continuous deposit of fine 

shell or debris on the foreshore or berm, other physical markings or 

characteristics, vegetation lines, tidal gages, or other suitable means that 

delineate the general height reached by a rising tide. The line encompasses 

spring high tides and other high tides that occur with periodic frequency but 

does not include storm surges in which there is a departure from the normal 

or predicted reach of the tide due to the piling up of water against a coast by 

strong winds such as those accompanying a hurricane or other intense storm.
43

PART 300—NATIONAL OIL AND HAZARDOUS SUBSTANCES POLLUTION 

CONTINTENCY PLAN

17. The authority citation for part 300 continues to read as follows:

Authority: The Clean Water Act, 33 U.S.C. 1251 et.seq.

18. Section 300.5 is amended by revising the definition of “navigable waters” to read as 

follows:

§ 300.5 Definitions.

Navigable waters as defined by 40 CFR 110.1, means the waters of the United States, 

including the territorial seas.

(1) For purposes of the Clean Water Act, 33 U.S.C. 1251 et. seq. and its implementing 

regulations, subject to the exclusions in paragraph (2) of this section, the term 

‘‘waters of the United States’’ means:

(i) All waters which are currently used, 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;

(ii) All interstate waters, including interstate wetlands;

(iii) The territorial seas;

(iv) All impoundments of waters otherwise identified as waters of the United 

States under this section;

(v) All tributaries, as defined in paragraph (3)(iii) of this section, of waters 

identified in paragraphs (1)(i) through (iii) of this section;

(vi) All waters adjacent to a water identified in paragraphs (1)(i) through (v) of this 

section, including wetlands, ponds, lakes, oxbows, impoundments, and 

similar waters; 

(vii) All waters in paragraphs (A) through (E) of this paragraph where they are 

determined, on a case-specific basis, to have a significant nexus to a water 

identified in paragraphs (1)(i) through (iii) of this section. The waters 

identified in each of paragraphs (A) through (E) of this paragraph are similarly 

situated and shall be combined, for purposes of a significant nexus analysis, 

in the watershed that drains to the nearest water identified in paragraphs (1)(i)

through (iii) of this section. Waters identified in this paragraph shall not be 

combined with waters identified in paragraph (1)(vi) of this section when 

performing a significant nexus analysis. If waters identified in this paragraph 

are also an adjacent water under paragraph (1)(vi), they are an adjacent 

water and no case-specific significant nexus analysis is required.

(A) Prairie potholes. Prairie potholes are a complex of glacially formed 

wetlands, usually occurring in depressions that lack permanent natural 

outlets, located in the upper Midwest.

(B) Carolina bays and Delmarva bays. Carolina bays and Delmarva bays 

are ponded, depressional wetlands that occur along the Atlantic coastal 

plain.

(C) Pocosins. Pocosins are evergreen shrub and tree dominated wetlands 

found predominantly along the Central Atlantic coastal plain.
44

(D) Western vernal pools. Western vernal pools are seasonal wetlands 

located in parts of California and associated with topographic 

depression, soils with poor drainage, mild, wet winters and hot, dry 

summers.

(E) Texas coastal prairie wetlands. Texas coastal prairie wetlands are 

freshwater wetlands that occur as a mosaic of depressions, ridges, 

intermound flats, and mima mound wetlands located along the Texas 

Gulf Coast.

(viii) All waters located within the 100-year floodplain of a water identified in (1)(i) 

through (iii) of this section and all waters located within 4,000 feet of the high 

tide line or ordinary high water mark of a water identified in paragraphs (1)(i) 

through (v) of this section where they are determined on a case-specific basis 

to have a significant nexus to a water identified in paragraphs (1)(i) through 

(iii) of this section. For waters determined to have a significant nexus, the 

entire water is a water of the United States if a portion is located within the 

100-year floodplain of a water identified in (1)(i) through (iii) of this section or 

within 4,000 feet of the high tide line or ordinary high water mark. Waters 

identified in this paragraph shall not be combined with waters identified in 

paragraph (1)(vi) of this section when performing a significant nexus analysis. 

If waters identified in this paragraph are also an adjacent water under 

paragraph (1)(vi), they are an adjacent water and no case-specific significant 

nexus analysis is required.

(2) The following are not “waters of the United States” even where they otherwise meet 

the terms of paragraphs (1)(iv) through (viii) of this section.

(i) Waste treatment systems, including treatment ponds or lagoons designed to 

meet the requirements of the Clean Water Act.

(ii) Prior converted cropland. Notwithstanding the determination of an area’s 

status as prior converted cropland by any other Federal agency, for the 

purposes of the Clean Water Act, the final authority regarding Clean Water 

Act jurisdiction remains with EPA.

(iii) The following ditches:

(A) Ditches with ephemeral flow that are not a relocated tributary or 

excavated in a tributary.

(B) Ditches with intermittent flow that are not a relocated tributary, 

excavated in a tributary, or drain wetlands.

(C) Ditches that do not flow, either directly or through another water, into a 

water identified in paragraphs (1)(i) through (iii) of this section.

(iv) The following features:

(A) Artificially irrigated areas that would revert to dry land should application 

of water to that area cease;

(B) Artificial, constructed lakes and ponds created in dry land such as farm 

and stock watering ponds, irrigation ponds, settling basins, fields flooded 

for rice growing, log cleaning ponds, or cooling ponds;

(C) Artificial reflecting pools or swimming pools created in dry land;

(D) Small ornamental waters created in dry land;
45

(E) Water-filled depressions created in dry land incidental to mining or 

construction activity, including pits excavated for obtaining fill, sand, or 

gravel that fill with water;

(F) Erosional features, including gullies, rills, and other ephemeral features 

that do not meet the definition of tributary, non-wetland swales, and 

lawfully constructed grassed waterways; and

(G) Puddles.

(v) Groundwater, including groundwater drained through subsurface drainage 

systems. 

(vi) Stormwater control features constructed to convey, treat, or store stormwater 

that are created in dry land.

(vii) Wastewater recycling structures constructed in dry land; detention and 

retention basins built for wastewater recycling; groundwater recharge basins; 

percolation ponds built for wastewater recycling; and water distributary 

structures built for wastewater recycling.

(3) Definitions—In this section, the following definitions apply:

(i) Adjacent. The term adjacent means bordering, contiguous, or neighboring a 

water identified in paragraphs (1)(i) through (v) of this section, including 

waters separated by constructed dikes or barriers, natural river berms, beach

dunes, and the like. For purposes of adjacency, an open water such as a 

pond or lake includes any wetlands within or abutting its ordinary high water 

mark. Adjacency is not limited to waters located laterally to a water identified 

in paragraphs (1)(i) through (v) of this section. Adjacent waters also include 

all waters that connect segments of a water identified in paragraphs (1)(i) 

through (v) or are located at the head of a water identified in paragraphs (1)(i) 

through (v) of this section and are bordering, contiguous, or neighboring such 

water. Waters being used for established normal farming, ranching, and 

silviculture activities (33 USC § 1344(f)) are not adjacent.

(ii) Neighboring. The term neighboring means:

(A) All waters located within 100 feet of the ordinary high water mark of a water 

identified in paragraphs (1)(i) through (v) of this section. The entire water is 

neighboring if a portion is located within 100 feet of the ordinary high water 

mark;

(B) All waters located within the 100-year floodplain of a water identified in 

paragraphs (1)(i) through (v) of this section and not more than 1,500 feet from 

the ordinary high water mark of such water. The entire water is neighboring if 

a portion is located within 1,500 feet of the ordinary high water mark and 

within the 100-year floodplain;

(C) All waters located within 1,500 feet of the high tide line of a water identified in 

paragraphs (1)(i) or (1)(iii) of this section, and all waters within 1,500 feet of 

the ordinary high water mark of the Great Lakes. The entire water is 

neighboring if a portion is located within 1,500 feet of the high tide line or 

within 1,500 feet of the ordinary high water mark of the Great Lakes.

(iii) Tributary and tributaries. The terms tributary and tributaries each mean a 

water that contributes flow, either directly or through another water (including 
46

an impoundment identified in paragraph (1)(iv) of this section), to a water 

identified in paragraphs (1)(i) through (iii) of this section that is characterized 

by the presence of the physical indicators of a bed and banks and an ordinary 

high water mark. These physical indicators demonstrate there is volume, 

frequency, and duration of flow sufficient to create a bed and banks and an 

ordinary high water mark, and thus to qualify as a tributary. A tributary can be 

a natural, man-altered, or man-made water and includes waters such as 

rivers, streams, canals, and ditches not excluded under paragraph (2) of this 

section. A water that otherwise qualifies as a tributary under this definition 

does not lose its status as a tributary if, for any length, there are one or more 

constructed breaks (such as bridges, culverts, pipes, or dams), or one or

more natural breaks (such as wetlands along the run of a stream, debris piles, 

boulder fields, or a stream that flows underground) so long as a bed and 

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

break. A water that otherwise qualifies as a tributary under this definition 

does not lose its status as a tributary if it contributes flow through a water of 

the United States that does not meet the definition of tributary or through a 

non-jurisdictional water to a water identified in paragraphs (1)(i1) through (iii) 

of this section.

(iv) Wetlands. The term wetlands means those areas that are inundated or

saturated by surface or groundwater at a frequency and duration sufficient to

support, and that under normal circumstances do support, a prevalence of 

vegetation typically adapted for life in saturated soil conditions. Wetlands

generally include swamps, marshes, bogs, and similar areas.

(v) Significant nexus. The term significant nexus means that a water, including 

wetlands, either alone or in combination with other similarly situated waters in 

the region, significantly affects the chemical, physical, or biological integrity of 

a water identified in paragraphs (1)(i) through (iii) of this section. The term “in 

the region” means the watershed that drains to the nearest water identified in 

paragraphs (1)(i) through (iii) of this section. For an effect to be significant, it 

must be more than speculative or insubstantial. Waters are similarly situated 

when they function alike and are sufficiently close to function together in 

affecting downstream waters. For purposes of determining whether or not a 

water has a significant nexus, the water’s effect on downstream (1)(i) through 

(iii) waters shall be assessed by evaluating the aquatic functions identified in 

paragraphs (A) through (I) of this paragraph. A water has a significant nexus 

when any single function or combination of functions performed by the water, 

alone or together with similarly situated waters in the region, contributes 

significantly to the chemical, physical, or biological integrity of the nearest 

water identified in paragraphs (1)(i) through (iii) of this section. Functions 

relevant to the significant nexus evaluation are the following:

(A) sediment trapping,

(B) nutrient recycling,

(C) pollutant trapping, transformation, filtering, and transport,

(D) retention and attenuation of flood waters,

(E) runoff storage,
47

(F) contribution of flow,

(G) export of organic matter,

(H) export of food resources, and

(I) provision of life cycle dependent aquatic habitat (such as foraging, 

feeding, nesting, breeding, spawning, or use as a nursery area) for 

species located in a water identified in paragraphs (a)(1) through (3) of 

this section.

(vi) Ordinary high water mark. The term ordinary high water mark means 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.

(vii) High tide line. The term high tide line means the line of intersection of the 

land with the water's surface at the maximum height reached by a rising tide. 

The high tide line may be determined, in the absence of actual data, by a line 

of oil or scum along shore objects, a more or less continuous deposit of fine 

shell or debris on the foreshore or berm, other physical markings or 

characteristics, vegetation lines, tidal gages, or other suitable means that 

delineate the general height reached by a rising tide. The line encompasses 

spring high tides and other high tides that occur with periodic frequency but 

does not include storm surges in which there is a departure from the normal 

or predicted reach of the tide due to the piling up of water against a coast by 

strong winds such as those accompanying a hurricane or other intense storm.
48

19. In appendix E to part 300, section 1.5 Definitions is amended by revising the 

definition of “navigable waters” to read as follows:

Appendix E to Part 300—Oil Spill Response.

1.5 Definitions

Navigable waters as defined by 40 CFR 110.1, means the waters of the United States, 

including the territorial seas.

(1) For purposes of the Clean Water Act, 33 U.S.C. 1251 et. seq. and its implementing 

regulations, subject to the exclusions in paragraph (2) of this section, the term 

‘‘waters of the United States’’ means:

(i) All waters which are currently used, 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;

(ii) All interstate waters, including interstate wetlands;

(iii) The territorial seas;

(iv) All impoundments of waters otherwise identified as waters of the United 

States under this section;

(v) All tributaries, as defined in paragraph (3)(iii) of this section, of waters 

identified in paragraphs (1)(i) through (iii) of this section;

(vi) All waters adjacent to a water identified in paragraphs (1)(i) through (v) of this 

section, including wetlands, ponds, lakes, oxbows, impoundments, and similar 

waters;

(vii) All waters in paragraphs (A) through (E) of this paragraph where they are 

determined, on a case-specific basis, to have a significant nexus to a water 

identified in paragraphs (1)(i) through (iii) of this section. The waters identified 

in each of paragraphs (A) through (E) of this paragraph are similarly situated 

and shall be combined, for purposes of a significant nexus analysis, in the 

watershed that drains to the nearest water identified in paragraphs (1)(i)

through (iii) of this section. Waters identified in this paragraph shall not be 

combined with waters identified in paragraph (1)(vi) of this section when 

performing a significant nexus analysis. If waters identified in this paragraph 

are also an adjacent water under paragraph (1)(vi), they are an adjacent water 

and no case-specific significant nexus analysis is required.

(A) Prairie potholes. Prairie potholes are a complex of glacially formed 

wetlands, usually occurring in depressions that lack permanent natural 

outlets, located in the upper Midwest.

(B) Carolina bays and Delmarva bays. Carolina bays and Delmarva bays are 

ponded, depressional wetlands that occur along the Atlantic coastal plain.

(C) Pocosins. Pocosins are evergreen shrub and tree dominated wetlands 

found predominantly along the Central Atlantic coastal plain.

(D) Western vernal pools. Western vernal pools are seasonal wetlands 

located in parts of California and associated with topographic depression, 

soils with poor drainage, mild, wet winters and hot, dry summers.

(E) Texas coastal prairie wetlands. Texas coastal prairie wetlands are 

freshwater wetlands that occur as a mosaic of depressions, ridges, 
49

intermound flats, and mima mound wetlands located along the Texas Gulf 

Coast.

(viii) All waters located within the 100-year floodplain of a water identified in (1)(i) 

through (iii) of this section and all waters located within 4,000 feet of the high 

tide line or ordinary high water mark of a water identified in paragraphs (1)(i) 

through (v) of this section where they are determined on a case-specific basis 

to have a significant nexus to a water identified in paragraphs (1)(i) through (iii) 

of this section. For waters determined to have a significant nexus, the entire 

water is a water of the United States if a portion is located within the 100-year 

floodplain of a water identified in (1)(i) through (iii) of this section or within 

4,000 feet of the high tide line or ordinary high water mark. Waters identified 

in this paragraph shall not be combined with waters identified in paragraph 

(1)(vi) of this section when performing a significant nexus analysis. If waters 

identified in this paragraph are also an adjacent water under paragraph (1)(vi), 

they are an adjacent water and no case-specific significant nexus analysis is 

required.

(2) The following are not “waters of the United States” even where they otherwise meet 

the terms of paragraphs (1)(iv) through (viii) of this section.

(i) Waste treatment systems, including treatment ponds or lagoons designed to 

meet the requirements of the Clean Water Act.

(ii) Prior converted cropland. Notwithstanding the determination of an area’s 

status as prior converted cropland by any other Federal agency, for the 

purposes of the Clean Water Act, the final authority regarding Clean Water Act 

jurisdiction remains with EPA.

(iii) The following ditches:

(A) Ditches with ephemeral flow that are not a relocated tributary or 

excavated in a tributary.

(B) Ditches with intermittent flow that are not a relocated tributary, excavated 

in a tributary, or drain wetlands.

(C) Ditches that do not flow, either directly or through another water, into a 

water identified in paragraphs (1)(i) through (iii) of this section.

(iv) The following features:

(A) Artificially irrigated areas that would revert to dry land should application 

of water to that area cease;

(B) Artificial, constructed lakes and ponds created in dry land such as farm 

and stock watering ponds, irrigation ponds, settling basins, fields flooded 

for rice growing, log cleaning ponds, or cooling ponds;

(C) Artificial reflecting pools or swimming pools created in dry land;

(D) Small ornamental waters created in dry land;

(E) Water-filled depressions created in dry land incidental to mining or 

construction activity, including pits excavated for obtaining fill, sand, or 

gravel that fill with water;

(F) Erosional features, including gullies, rills, and other ephemeral features 

that do not meet the definition of tributary, non-wetland swales, and 

lawfully constructed grassed waterways; and
50

(G) Puddles.

(v) Groundwater, including groundwater drained through subsurface drainage 

systems.

(vi) Stormwater control features constructed to convey, treat, or store stormwater 

that are created in dry land.

(vii) Wastewater recycling structures constructed in dry land; detention and 

retention basins built for wastewater recycling; groundwater recharge basins; 

percolation ponds built for wastewater recycling; and water distributary 

structures built for wastewater recycling.

(3) Definitions—In this section, the following definitions apply:

(i) Adjacent. The term adjacent means bordering, contiguous, or neighboring a water 

identified in paragraphs (1)(i) through (v) of this section, including waters 

separated by constructed dikes or barriers, natural river berms, beach dunes, and 

the like. For purposes of adjacency, an open water such as a pond or lake 

includes any wetlands within or abutting its ordinary high water mark. Adjacency 

is not limited to waters located laterally to a water identified in paragraphs (1)(i) 

through (v) of this section. Adjacent waters also include all waters that connect 

segments of a water identified in paragraphs (1)(i) through (v) or are located at the 

head of a water identified in paragraphs (1)(i) through (v) of this section and are 

bordering, contiguous, or neighboring such water. Waters being used for 

established normal farming, ranching, and silviculture activities (33 USC § 

1344(f)) are not adjacent.

(ii) Neighboring. The term neighboring means:

(A) All waters located within 100 feet of the ordinary high water mark of a water 

identified in paragraphs (1)(i) through (v) of this section. The entire water is 

neighboring if a portion is located within 100 feet of the ordinary high water 

mark;

(B) All waters located within the 100-year floodplain of a water identified in 

paragraphs (1)(i) through (v) of this section and not more than 1,500 feet from 

the ordinary high water mark of such water. The entire water is neighboring if 

a portion is located within 1,500 feet of the ordinary high water mark and within 

the 100-year floodplain;

(C) All waters located within 1,500 feet of the high tide line of a water identified in 

paragraphs (1)(i) or (1)(iii) of this section, and all waters within 1,500 feet of 

the ordinary high water mark of the Great Lakes. The entire water is 

neighboring if a portion is located within 1,500 feet of the high tide line or 

within 1,500 feet of the ordinary high water mark of the Great Lakes.

(iii) Tributary and tributaries. The terms tributary and tributaries each mean a water 

that contributes flow, either directly or through another water (including an 

impoundment identified in paragraph (1)(iv) of this section), to a water identified in

paragraphs (1)(i) through (iii) of this section that is characterized by the presence 

of the physical indicators of a bed and banks and an ordinary high water mark. 

These physical indicators demonstrate there is volume, frequency, and duration of 

flow sufficient to create a bed and banks and an ordinary high water mark, and 

thus to qualify as a tributary. A tributary can be a natural, man-altered, or man-
51

made water and includes waters such as rivers, streams, canals, and ditches not 

excluded under paragraph (2) of this section. A water that otherwise qualifies as 

a tributary under this definition does not lose its status as a tributary if, for any 

length, there are one or more constructed breaks (such as bridges, culverts, 

pipes, or dams), or one or more natural breaks (such as wetlands along the run of 

a stream, debris piles, boulder fields, or a stream that flows underground) so long 

as a bed and banks and an ordinary high water mark can be identified upstream 

of the break. A water that otherwise qualifies as a tributary under this definition 

does not lose its status as a tributary if it contributes flow through a water of the 

United States that does not meet the definition of tributary or through a nonjurisdictional water to a water identified in paragraphs (1)(i1) through (iii) of this

section.

(iv) Wetlands. The term wetlands means those areas that are inundated or saturated 

by surface or groundwater at a frequency and duration sufficient to support, and 

that under normal circumstances do support, a prevalence of vegetation typically 

adapted for life in saturated soil conditions. Wetlands generally include swamps, 

marshes, bogs, and similar areas.

(v) Significant nexus. The term significant nexus means that a water, including 

wetlands, either alone or in combination with other similarly situated waters in the 

region, significantly affects the chemical, physical, or biological integrity of a water 

identified in paragraphs (1)(i) through (iii) of this section. The term “in the region” 

means the watershed that drains to the nearest water identified in paragraphs 

(1)(i) through (iii) of this section. For an effect to be significant, it must be more 

than speculative or insubstantial. Waters are similarly situated when they function 

alike and are sufficiently close to function together in affecting downstream 

waters. For purposes of determining whether or not a water has a significant 

nexus, the water’s effect on downstream (1)(i) through (iii) waters shall be 

assessed by evaluating the aquatic functions identified in paragraphs (A) through 

(I) of this paragraph. A water has a significant nexus when any single function or 

combination of functions performed by the water, alone or together with similarly

situated waters in the region, contributes significantly to the chemical, physical, or 

biological integrity of the nearest water identified in paragraphs (1)(i) through (iii) 

of this section. Functions relevant to the significant nexus evaluation are the

following:

(A) sediment trapping,

(B) nutrient recycling,

(C) pollutant trapping, transformation, filtering, and transport,

(D) retention and attenuation of flood waters,

(E) runoff storage,

(F) contribution of flow,

(G) export of organic matter,

(H) export of food resources, and

(I) provision of life cycle dependent aquatic habitat (such as foraging, feeding, 

nesting, breeding, spawning, or use as a nursery area) for species located in a 

water identified in paragraphs (a)(1) through (3) of this section.
52

(vi) Ordinary high water mark. The term ordinary high water mark means 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.

(vii) High tide line. The term high tide line means the line of intersection of the land 

with the water's surface at the maximum height reached by a rising tide. The high 

tide line may be determined, in the absence of actual data, by a line of oil or scum 

along shore objects, a more or less continuous deposit of fine shell or debris on 

the foreshore or berm, other physical markings or characteristics, vegetation lines, 

tidal gages, or other suitable means that delineate the general height reached by 

a rising tide. The line encompasses spring high tides and other high tides that 

occur with periodic frequency but does not include storm surges in which there is 

a departure from the normal or predicted reach of the tide due to the piling up of 

water against a coast by strong winds such as those accompanying a hurricane or 

other intense storm.
53

PART 302—DESIGNATION, REPORTABLE QUANTITIES, AND NOTIFICATION

20. The authority citation for part 302 continues to read as follows:

Authority: The Clean Water Act, 33 U.S.C. 1251 et.seq.

21. Section 302.3 is amended by revising the definition of “navigable waters” to read as 

follows:

§ 302.3 Definitions.

Navigable waters as defined by 40 CFR 110.1, means the waters of the United States, 

including the territorial seas.

(1) For purposes of the Clean Water Act, 33 U.S.C. 1251 et. seq. and its 

implementing regulations, subject to the exclusions in paragraph (2) of this 

section, the term ‘‘waters of the United States’’ means:

(i) All waters which are currently used, 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;

(ii) All interstate waters, including interstate wetlands;

(iii) The territorial seas;

(iv) All impoundments of waters otherwise identified as waters of the United 

States under this section;

(v) All tributaries, as defined in paragraph (3)(iii) of this section, of waters 

identified in paragraphs (1)(i) through (iii) of this section;

(vi) All waters adjacent to a water identified in paragraphs (1)(i) through (v) of 

this section, including wetlands, ponds, lakes, oxbows, impoundments, and 

similar waters;

(vii) All waters in paragraphs (A) through (E) of this paragraph where they are 

determined, on a case-specific basis, to have a significant nexus to a water 

identified in paragraphs (1)(i) through (iii) of this section. The waters 

identified in each of paragraphs (A) through (E) of this paragraph are 

similarly situated and shall be combined, for purposes of a significant nexus 

analysis, in the watershed that drains to the nearest water identified in 

paragraphs (1)(i) through (iii) of this section. Waters identified in this 

paragraph shall not be combined with waters identified in paragraph (1)(vi) 

of this section when performing a significant nexus analysis. If waters 

identified in this paragraph are also an adjacent water under paragraph 

(1)(vi), they are an adjacent water and no case-specific significant nexus 

analysis is required.

(A) Prairie potholes. Prairie potholes are a complex of glacially formed 

wetlands, usually occurring in depressions that lack permanent 

natural outlets, located in the upper Midwest.

(B) Carolina bays and Delmarva bays. Carolina bays and Delmarva bays 

are ponded, depressional wetlands that occur along the Atlantic 

coastal plain.

(C) Pocosins. Pocosins are evergreen shrub and tree dominated 

wetlands found predominantly along the Central Atlantic coastal plain.

(D) Western vernal pools. Western vernal pools are seasonal wetlands 

located in parts of California and associated with topographic 
54

depression, soils with poor drainage, mild, wet winters and hot, dry 

summers.

(E) Texas coastal prairie wetlands. Texas coastal prairie wetlands are 

freshwater wetlands that occur as a mosaic of depressions, ridges, 

intermound flats, and mima mound wetlands located along the Texas 

Gulf Coast.

(viii) All waters located within the 100-year floodplain of a water identified in 

(1)(i) through (iii) of this section and all waters located within 4,000 feet of 

the high tide line or ordinary high water mark of a water identified in 

paragraphs (1)(i) through (v) of this section where they are determined on a 

case-specific basis to have a significant nexus to a water identified in 

paragraphs (1)(i) through (iii) of this section. For waters determined to have 

a significant nexus, the entire water is a water of the United States if a 

portion is located within the 100-year floodplain of a water identified in (1)(i) 

through (iii) of this section or within 4,000 feet of the high tide line or 

ordinary high water mark. Waters identified in this paragraph shall not be 

combined with waters identified in paragraph (1)(vi) of this section when 

performing a significant nexus analysis. If waters identified in this 

paragraph are also an adjacent water under paragraph (1)(vi), they are an 

adjacent water and no case-specific significant nexus analysis is required.

(2) The following are not “waters of the United States” even where they otherwise 

meet the terms of paragraphs (1)(iv) through (viii) of this section.

(i) Waste treatment systems, including treatment ponds or lagoons designed to 

meet the requirements of the Clean Water Act.

(ii) Prior converted cropland. Notwithstanding the determination of an area’s 

status as prior converted cropland by any other Federal agency, for the 

purposes of the Clean Water Act, the final authority regarding Clean Water 

Act jurisdiction remains with EPA.

(iii) The following ditches:

(A) Ditches with ephemeral flow that are not a relocated tributary or 

excavated in a tributary.

(B) Ditches with intermittent flow that are not a relocated tributary, 

excavated in a tributary, or drain wetlands.

(C) Ditches that do not flow, either directly or through another water, into 

a water identified in paragraphs (1)(i) through (iii) of this section.

(iv) The following features:

(A) Artificially irrigated areas that would revert to dry land should 

application of water to that area cease;

(B) Artificial, constructed lakes and ponds created in dry land such as 

farm and stock watering ponds, irrigation ponds, settling basins, fields 

flooded for rice growing, log cleaning ponds, or cooling ponds;

(C) Artificial reflecting pools or swimming pools created in dry land;

(D) Small ornamental waters created in dry land;
55

(E) Water-filled depressions created in dry land incidental to mining or 

construction activity, including pits excavated for obtaining fill, sand, or 

gravel that fill with water;

(F) Erosional features, including gullies, rills, and other ephemeral 

features that do not meet the definition of tributary, non-wetland 

swales, and lawfully constructed grassed waterways; and

(G) Puddles.

(v) Groundwater, including groundwater drained through subsurface drainage 

systems.

(vi) Stormwater control features constructed to convey, treat, or store 

stormwater that are created in dry land.

(vii) Wastewater recycling structures constructed in dry land; detention and 

retention basins built for wastewater recycling; groundwater recharge 

basins; percolation ponds built for wastewater recycling; and water 

distributary structures built for wastewater recycling.

(3) Definitions—In this section, the following definitions apply:

(i) Adjacent. The term adjacent means bordering, contiguous, or neighboring 

a water identified in paragraphs (1)(i) through (v) of this section, including 

waters separated by constructed dikes or barriers, natural river berms, 

beach dunes, and the like. For purposes of adjacency, an open water such 

as a pond or lake includes any wetlands within or abutting its ordinary high 

water mark. Adjacency is not limited to waters located laterally to a water 

identified in paragraphs (1)(i) through (v) of this section. Adjacent waters 

also include all waters that connect segments of a water identified in 

paragraphs (1)(i) through (v) or are located at the head of a water identified 

in paragraphs (1)(i) through (v) of this section and are bordering, 

contiguous, or neighboring such water. Waters being used for established 

normal farming, ranching, and silviculture activities (33 USC § 1344(f)) are 

not adjacent.

(ii) Neighboring. The term neighboring means:

(A) All waters located within 100 feet of the ordinary high water mark of a 

water identified in paragraphs (1)(i) through (v) of this section. The

entire water is neighboring if a portion is located within 100 feet of the 

ordinary high water mark;

(B) All waters located within the 100-year floodplain of a water identified 

in paragraphs (1)(i) through (v) of this section and not more than 

1,500 feet from the ordinary high water mark of such water. The 

entire water is neighboring if a portion is located within 1,500 feet of 

the ordinary high water mark and within the 100-year floodplain;

(C) All waters located within 1,500 feet of the high tide line of a water 

identified in paragraphs (1)(i) or (1)(iii) of this section, and all waters 

within 1,500 feet of the ordinary high water mark of the Great Lakes. 

The entire water is neighboring if a portion is located within 1,500 feet 

of the high tide line or within 1,500 feet of the ordinary high water 

mark of the Great Lakes.
56

(iii) Tributary and tributaries. The terms tributary and tributaries each mean a 

water that contributes flow, either directly or through another water 

(including an impoundment identified in paragraph (1)(iv) of this section), to 

a water identified in paragraphs (1)(i) through (iii) of this section that is 

characterized by the presence of the physical indicators of a bed and 

banks and an ordinary high water mark. These physical indicators 

demonstrate there is volume, frequency, and duration of flow sufficient to 

create a bed and banks and an ordinary high water mark, and thus to 

qualify as a tributary. A tributary can be a natural, man-altered, or manmade water and includes waters such as rivers, streams, canals, and 

ditches not excluded under paragraph (2) of this section. A water that

otherwise qualifies as a tributary under this definition does not lose its 

status as a tributary if, for any length, there are one or more constructed 

breaks (such as bridges, culverts, pipes, or dams), or one or more natural 

breaks (such as wetlands along the run of a stream, debris piles, boulder 

fields, or a stream that flows underground) so long as a bed and banks and 

an ordinary high water mark can be identified upstream of the break. A 

water that otherwise qualifies as a tributary under this definition does not 

lose its status as a tributary if it contributes flow through a water of the 

United States that does not meet the definition of tributary or through a 

non-jurisdictional water to a water identified in paragraphs (1)(i1) through 

(iii) of this section.

(iv) Wetlands. The term wetlands means those areas that are inundated or

saturated by surface or groundwater at a frequency and duration sufficient 

to support, and that under normal circumstances do support, a prevalence

of vegetation typically adapted for life in saturated soil conditions.

Wetlands generally include swamps, marshes, bogs, and similar areas.

(v) Significant nexus. The term significant nexus means that a water, including 

wetlands, either alone or in combination with other similarly situated waters 

in the region, significantly affects the chemical, physical, or biological 

integrity of a water identified in paragraphs (1)(i) through (iii) of this section. 

The term “in the region” means the watershed that drains to the nearest 

water identified in paragraphs (1)(i) through (iii) of this section. For an 

effect to be significant, it must be more than speculative or insubstantial. 

Waters are similarly situated when they function alike and are sufficiently 

close to function together in affecting downstream waters. For purposes of 

determining whether or not a water has a significant nexus, the water’s 

effect on downstream (1)(i) through (iii) waters shall be assessed by 

evaluating the aquatic functions identified in paragraphs (A) through (I) of 

this paragraph. A water has a significant nexus when any single function 

or combination of functions performed by the water, alone or together with 

similarly situated waters in the region, contributes significantly to the 

chemical, physical, or biological integrity of the nearest water identified in 

paragraphs (1)(i) through (iii) of this section. Functions relevant to the 

significant nexus evaluation are the following:

(A) sediment trapping,
57

(B) nutrient recycling,

(C) pollutant trapping, transformation, filtering, and transport,

(D) retention and attenuation of flood waters,

(E) runoff storage,

(F) contribution of flow,

(G) export of organic matter,

(H) export of food resources, and

(I) provision of life cycle dependent aquatic habitat (such as foraging, 

feeding, nesting, breeding, spawning, or use as a nursery area) for 

species located in a water identified in paragraphs (a)(1) through (3) 

of this section.

(vi) Ordinary high water mark. The term ordinary high water mark means 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.

(vii) High tide line. The term high tide line means the line of intersection of the 

land with the water's surface at the maximum height reached by a rising 

tide. The high tide line may be determined, in the absence of actual data, 

by a line of oil or scum along shore objects, a more or less continuous 

deposit of fine shell or debris on the foreshore or berm, other physical 

markings or characteristics, vegetation lines, tidal gages, or other suitable 

means that delineate the general height reached by a rising tide. The line 

encompasses spring high tides and other high tides that occur with 

periodic frequency but does not include storm surges in which there is a 

departure from the normal or predicted reach of the tide due to the piling 

up of water against a coast by strong winds such as those accompanying 

a hurricane or other intense storm.
58

Part 401—GENERAL PROVISIONS

22. The authority citation for part 401 continues to read as follows:

Authority: The Clean Water Act, 33 U.S.C. 1251 et.seq.

23. Section 401.11 is amended by revising the definition of “navigable waters” to read 

as follows:

§ 401.11 General definitions.

(l) The term navigable waters as defined by 40 CFR 110.1, means the waters of the 

United States, including the territorial seas.

(1) For purposes of the Clean Water Act, 33 U.S.C. 1251 et. seq. and its 

implementing regulations, subject to the exclusions in paragraph (2) of this 

section, the term ‘‘waters of the United States’’ means:

(i) All waters which are currently used, 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;

(ii) All interstate waters, including interstate wetlands;

(iii) The territorial seas;

(iv) All impoundments of waters otherwise identified as waters of the United 

States under this section;

(v) All tributaries, as defined in paragraph (3)(iii) of this section, of waters 

identified in paragraphs (1)(i) through (iii) of this section;

(vi) All waters adjacent to a water identified in paragraphs (1)(i) through (v) of 

this section, including wetlands, ponds, lakes, oxbows, impoundments, 

and similar waters;

(vii) All waters in paragraphs (A) through (E) of this paragraph where they are 

determined, on a case-specific basis, to have a significant nexus to a

water identified in paragraphs (1)(i) through (iii) of this section. The waters 

identified in each of paragraphs (A) through (E) of this paragraph are 

similarly situated and shall be combined, for purposes of a significant 

nexus analysis, in the watershed that drains to the nearest water identified 

in paragraphs (1)(i) through (iii) of this section. Waters identified in this 

paragraph shall not be combined with waters identified in paragraph (1)(vi) 

of this section when performing a significant nexus analysis. If waters 

identified in this paragraph are also an adjacent water under paragraph 

(1)(vi), they are an adjacent water and no case-specific significant nexus 

analysis is required.

(A) Prairie potholes. Prairie potholes are a complex of glacially formed 

wetlands, usually occurring in depressions that lack permanent 

natural outlets, located in the upper Midwest.

(B) Carolina bays and Delmarva bays. Carolina bays and Delmarva 

bays are ponded, depressional wetlands that occur along the Atlantic 

coastal plain.

(C) Pocosins. Pocosins are evergreen shrub and tree dominated 

wetlands found predominantly along the Central Atlantic coastal 

plain.
59

(D) Western vernal pools. Western vernal pools are seasonal wetlands 

located in parts of California and associated with topographic 

depression, soils with poor drainage, mild, wet winters and hot, dry 

summers.

(E) Texas coastal prairie wetlands. Texas coastal prairie wetlands are 

freshwater wetlands that occur as a mosaic of depressions, ridges, 

intermound flats, and mima mound wetlands located along the Texas 

Gulf Coast.

(viii) All waters located within the 100-year floodplain of a water identified in 

(1)(i) through (iii) of this section and all waters located within 4,000 feet of 

the high tide line or ordinary high water mark of a water identified in 

paragraphs (1)(i) through (v) of this section where they are determined on 

a case-specific basis to have a significant nexus to a water identified in 

paragraphs (1)(i) through (iii) of this section. For waters determined to 

have a significant nexus, the entire water is a water of the United States if 

a portion is located within the 100-year floodplain of a water identified in 

(1)(i) through (iii) of this section or within 4,000 feet of the high tide line or 

ordinary high water mark. Waters identified in this paragraph shall not be 

combined with waters identified in paragraph (1)(vi) of this section when 

performing a significant nexus analysis. If waters identified in this 

paragraph are also an adjacent water under paragraph (1)(vi), they are an 

adjacent water and no case-specific significant nexus analysis is required.

(2) The following are not “waters of the United States” even where they otherwise 

meet the terms of paragraphs (1)(iv) through (viii) of this section.

(i) Waste treatment systems, including treatment ponds or lagoons designed 

to meet the requirements of the Clean Water Act.

(ii) Prior converted cropland. Notwithstanding the determination of an area’s 

status as prior converted cropland by any other Federal agency, for the 

purposes of the Clean Water Act, the final authority regarding Clean Water 

Act jurisdiction remains with EPA.

(iii) The following ditches:

(A) Ditches with ephemeral flow that are not a relocated tributary or 

excavated in a tributary.

(B) Ditches with intermittent flow that are not a relocated tributary, 

excavated in a tributary, or drain wetlands.

(C) Ditches that do not flow, either directly or through another water, into 

a water identified in paragraphs (1)(i) through (iii) of this section.

(iv) The following features:

(A) Artificially irrigated areas that would revert to dry land should 

application of water to that area cease;

(B) Artificial, constructed lakes and ponds created in dry land such as 

farm and stock watering ponds, irrigation ponds, settling basins, 

fields flooded for rice growing, log cleaning ponds, or cooling ponds;

(C) Artificial reflecting pools or swimming pools created in dry land;

(D) Small ornamental waters created in dry land;
60

(E) Water-filled depressions created in dry land incidental to mining or 

construction activity, including pits excavated for obtaining fill, sand, 

or gravel that fill with water;

(F) Erosional features, including gullies, rills, and other ephemeral 

features that do not meet the definition of tributary, non-wetland 

swales, and lawfully constructed grassed waterways; and

(G) Puddles.

(v) Groundwater, including groundwater drained through subsurface drainage 

systems. 

(vi) Stormwater control features constructed to convey, treat, or store 

stormwater that are created in dry land.

(vii) Wastewater recycling structures constructed in dry land; detention and 

retention basins built for wastewater recycling; groundwater recharge 

basins; percolation ponds built for wastewater recycling; and water 

distributary structures built for wastewater recycling.

(3) Definitions—In this section, the following definitions apply:

(i) Adjacent. The term adjacent means bordering, contiguous, or neighboring 

a water identified in paragraphs (1)(i) through (v) of this section, including 

waters separated by constructed dikes or barriers, natural river berms, 

beach dunes, and the like. For purposes of adjacency, an open water such 

as a pond or lake includes any wetlands within or abutting its ordinary high 

water mark. Adjacency is not limited to waters located laterally to a water 

identified in paragraphs (1)(i) through (v) of this section. Adjacent waters 

also include all waters that connect segments of a water identified in 

paragraphs (1)(i) through (v) or are located at the head of a water identified 

in paragraphs (1)(i) through (v) of this section and are bordering, 

contiguous, or neighboring such water. Waters being used for established 

normal farming, ranching, and silviculture activities (33 USC § 1344(f)) are 

not adjacent.

(ii) Neighboring. The term neighboring means:

(A) All waters located within 100 feet of the ordinary high water mark of a 

water identified in paragraphs (1)(i) through (v) of this section. The 

entire water is neighboring if a portion is located within 100 feet of the 

ordinary high water mark;

(B) All waters located within the 100-year floodplain of a water identified 

in paragraphs (1)(i) through (v) of this section and not more than 

1,500 feet from the ordinary high water mark of such water. The 

entire water is neighboring if a portion is located within 1,500 feet of 

the ordinary high water mark and within the 100-year floodplain;

(C) All waters located within 1,500 feet of the high tide line of a water 

identified in paragraphs (1)(i) or (1)(iii) of this section, and all waters 

within 1,500 feet of the ordinary high water mark of the Great Lakes. 

The entire water is neighboring if a portion is located within 1,500 feet 

of the high tide line or within 1,500 feet of the ordinary high water 

mark of the Great Lakes.
61

(iii) Tributary and tributaries. The terms tributary and tributaries each mean a 

water that contributes flow, either directly or through another water 

(including an impoundment identified in paragraph (1)(iv) of this section), to 

a water identified in paragraphs (1)(i) through (iii) of this section that is 

characterized by the presence of the physical indicators of a bed and 

banks and an ordinary high water mark. These physical indicators 

demonstrate there is volume, frequency, and duration of flow sufficient to 

create a bed and banks and an ordinary high water mark, and thus to 

qualify as a tributary. A tributary can be a natural, man-altered, or manmade water and includes waters such as rivers, streams, canals, and 

ditches not excluded under paragraph (2) of this section. A water that

otherwise qualifies as a tributary under this definition does not lose its 

status as a tributary if, for any length, there are one or more constructed 

breaks (such as bridges, culverts, pipes, or dams), or one or more natural 

breaks (such as wetlands along the run of a stream, debris piles, boulder 

fields, or a stream that flows underground) so long as a bed and banks and 

an ordinary high water mark can be identified upstream of the break. A 

water that otherwise qualifies as a tributary under this definition does not 

lose its status as a tributary if it contributes flow through a water of the 

United States that does not meet the definition of tributary or through a 

non-jurisdictional water to a water identified in paragraphs (1)(i1) through 

(iii) of this section.

(iv) Wetlands. The term wetlands means those areas that are inundated or

saturated by surface or groundwater at a frequency and duration sufficient 

to support, and that under normal circumstances do support, a prevalence

of vegetation typically adapted for life in saturated soil conditions. 

Wetlands generally include swamps, marshes, bogs, and similar areas.

(v) Significant nexus. The term significant nexus means that a water, including 

wetlands, either alone or in combination with other similarly situated waters 

in the region, significantly affects the chemical, physical, or biological 

integrity of a water identified in paragraphs (1)(i) through (iii) of this section. 

The term “in the region” means the watershed that drains to the nearest 

water identified in paragraphs (1)(i) through (iii) of this section. For an 

effect to be significant, it must be more than speculative or insubstantial. 

Waters are similarly situated when they function alike and are sufficiently 

close to function together in affecting downstream waters. For purposes of 

determining whether or not a water has a significant nexus, the water’s 

effect on downstream (1)(i) through (iii) waters shall be assessed by 

evaluating the aquatic functions identified in paragraphs (A) through (I) of 

this paragraph. A water has a significant nexus when any single function 

or combination of functions performed by the water, alone or together with 

similarly situated waters in the region, contributes significantly to the 

chemical, physical, or biological integrity of the nearest water identified in 

paragraphs (1)(i) through (iii) of this section. Functions relevant to the 

significant nexus evaluation are the following:

(A) sediment trapping,
62

(B) nutrient recycling,

(C) pollutant trapping, transformation, filtering, and transport,

(D) retention and attenuation of flood waters,

(E) runoff storage,

(F) contribution of flow,

(G) export of organic matter,

(H) export of food resources, and

(I) provision of life cycle dependent aquatic habitat (such as foraging, 

feeding, nesting, breeding, spawning, or use as a nursery area) for 

species located in a water identified in paragraphs (a)(1) through (3) 

of this section.

(vi) Ordinary high water mark. The term ordinary high water mark means 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.

(vii) High tide line. The term high tide line means the line of intersection of the 

land with the water's surface at the maximum height reached by a rising 

tide. The high tide line may be determined, in the absence of actual data, 

by a line of oil or scum along shore objects, a more or less continuous 

deposit of fine shell or debris on the foreshore or berm, other physical 

markings or characteristics, vegetation lines, tidal gages, or other suitable 

means that delineate the general height reached by a rising tide. The line 

encompasses spring high tides and other high tides that occur with periodic 

frequency but does not include storm surges in which there is a departure 

from the normal or predicted reach of the tide due to the piling up of water 

against a coast by strong winds such as those accompanying a hurricane 

or other intense storm.