WHY CLEAN WATER IS IMPORTANT

Clean water is vital to our health, communities, and economy. We need clean water upstream to have 

healthy communities downstream. The health of rivers, lakes, bays, and coastal waters depend on the 

streams and wetlands where they begin. Streams and wetlands provide many benefits to communities 

by trapping floodwaters, recharging groundwater supplies, filtering pollution, and providing habitat for 

fish and wildlife. People depend on clean water for their health: About 117 million Americans -- one in 

three people – get drinking water from streams that were vulnerable to pollution before the Clean 

Water Rule. Our cherished way of life depends on clean water: healthy ecosystems provide wildlife 

habitat and places to fish, paddle, surf, and swim. Our economy depends on clean water: 

manufacturing, farming, tourism, recreation, energy production, and other economic sectors need clean 

water to function and flourish.

WHAT IS THE CLEAN WATER RULE

Protection for about 60 percent of the nation’s streams and 

millions of acres of wetlands has been confusing and complex as 

the result of Supreme Court decisions in 2001 and 2006. The Clean 

Water Rule protects streams and wetlands that are scientifically 

shown to have the greatest impact on downstream water quality 

and form the foundation of our nation’s water resources. EPA and 

the U.S. Army are ensuring that waters protected under the Clean 

Water Act are more precisely defined, more predictable, easier for 

businesses and industry to understand, and consistent with the 

law and the latest science. The Clean Water Rule:

• Clearly defines and protects tributaries that impact the health of downstream waters. The 

Clean Water Act protects navigable waterways and their tributaries. The rule says that a 

tributary must show physical features of flowing water – a bed, bank, and ordinary high water 

mark – to warrant protection. The rule provides protection for headwaters that have these 

features and science shows can have a significant connection to downstream waters.

• Provides certainty in how far safeguards extend to nearby waters. The rule protects waters 

that are next to rivers and lakes and their tributaries because science shows that they impact 

downstream waters. The rule sets boundaries on covering nearby waters for the first time that 

are physical and measurable.

• Protects the nation’s regional water treasures. Science shows that specific water features can 

function like a system and impact the health of downstream waters. The rule protects prairie 

potholes, Carolina and Delmarva bays, pocosins, western vernal pools in California, and Texas 

coastal prairie wetlands when they impact downstream waters.

• Focuses on streams, not ditches. The rule limits protection to ditches that are constructed out 

of streams or function like streams and can carry pollution downstream. So ditches that are not 

constructed in streams and that flow only when it rains are not covered.

• Maintains the status of waters within Municipal Separate Storm Sewer Systems. The rule does 

not change how those waters are treated and encourages the use of green infrastructure.

The Clean Water Act 

protects the nation’s 

waters. A Clean Water Act 

permit is only needed if 

these waters are going to 

be polluted or destroyed.

www.epa.gov/cleanwaterrule Clear Protection for Clean Water
• Reduces the use of case-specific analysis of waters. Previously, almost any water could be put 

through a lengthy case-specific analysis, even if it would not be subject to the Clean Water Act. 

The rule significantly limits the use of case-specific analysis by creating clarity and certainty on 

protected waters and limiting the number of similarly situated water features. 

The rule protects clean water without getting in the way of farming, ranching, and forestry. Farms

across America depend on clean and reliable water for livestock, crops, and irrigation. Activities like

planting, harvesting, and moving livestock have long been exempt from Clean Water Act regulation, and

the Clean Water Rule doesn’t change that. The Clean Water Rule provides greater clarity and certainty

to farmers and does not add any new requirements or economic burden on agriculture.

The rule only protects waters that have historically been covered by the Clean Water Act. It does not

interfere with or change private property rights, or address land use. It does not regulate most ditches 

or regulate groundwater, shallow subsurface flows or tile drains. It does not change policy on irrigation 

or water transfers. It does not apply to rills, gullies, or erosional features.

Subject Old Rule Proposed Rule Final Rule

Navigable Waters Jurisdictional Same Same

Interstate Waters Jurisdictional Same Same

Territorial Seas Jurisdictional Same Same

Impoundments Jurisdictional Same Same

Tributaries to the 

Traditionally

Navigable Waters

Did not define tributary Defined tributary for the 

first time as water features 

with bed, banks and 

ordinary high water mark, 

and flow downstream.

Same as proposal except 

wetlands and open waters 

without beds, banks and high 

water marks will be evaluated 

for adjacency.

Adjacent 

Wetlands/Waters

Included wetlands 

adjacent to traditional 

navigable waters, 

interstate waters, the 

territorial seas, 

impoundments or 

tributaries.

Included all waters

adjacent to jurisdictional 

waters, including waters in 

riparian area or floodplain, 

or with surface or shallow 

subsurface connection to 

jurisdictional waters. 

Includes waters adjacent to

jurisdictional waters within a 

minimum of 100 feet and

within the 100-year floodplain 

to a maximum of 1,500 feet of 

the ordinary high water mark.

Isolated or “Other” 

Waters

Included all other waters 

the use, degradation or 

destruction of which 

could affect interstate or 

foreign commerce.

Included “other waters” 

where there was a 

significant nexus to 

traditionally navigable 

water, interstate water or 

territorial sea. 

Includes specific waters that 

are similarly situated: Prairie 

potholes, Carolina & Delmarva 

bays, pocosins, western 

vernal pools in California, & 

Texas coastal prairie wetlands

when they have a significant 

nexus. 

Includes waters with a 

significant nexus within the

100-year floodplain of a 

traditional navigable water, 

interstate water, or the 

territorial seas, as well as

waters with a significant nexus 

within 4,000 feet of

jurisdictional waters.

Exclusions to the 

definition of 

“Waters of the 

U.S.”

Excluded waste 

treatment systems and 

prior converted cropland.

Categorically excluded 

those in old rule and added 

two types of ditches, 

groundwater, gullies, rills 

and non-wetland swales. 

Includes proposed rule 

exclusions, expands exclusion 

for ditches, and also excludes 

constructed components for 

MS4s and water 

delivery/reuse and erosional 

features.

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www.epa.gov/cleanwaterrule Clear Protection for Clean Water