Why Definitions Matter: The Hidden Systems That Shape Our Rivers and Wetland Protections
- Michael Simpson
- 37 minutes ago
- 27 min read
By Prof. Michael H. Simpson
Antioch University New England
Senior Environmental Scientist, MHS & Associates LLC
At first glance, wetlands don’t seem like places that would decide the fate of a river.
They are easy to overlook—quiet pools in the woods, soggy ground at the edge of a field, a patch of moss that gives slightly underfoot. They don’t roar like rivers or stretch wide like lakes. Most people pass by them without a second thought.
But these unassuming places are doing something extraordinary. They are holding back floodwaters after storms. They are filtering out pollution before it reaches drinking water. They are quietly storing carbon, supporting wildlife, and regulating how water moves across the entire landscape. In fact, much of what we value about healthy rivers—clean water, stable flows, thriving ecosystems—depends on wetlands that many people never notice at all.
And here’s the surprising part, whether these wetlands are protected or left vulnerable often comes down to a single question of definition:
What is a wetland?
That question may sound simple. It is anything but. Scientists, landowners, regulators, and courts have all answered it differently. And over time, those answers have shifted—sometimes dramatically. Today, those shifting definitions are creating a growing gap between how wetlands actually function in the landscape and how they are treated under the law. As that gap widens, many of the wetlands that matter most—small, seasonal, or seemingly isolated—are at risk of falling through the cracks.
This is especially true in places like the Connecticut River watershed, where the most important wetlands are often not the obvious ones, but the hidden network scattered across forests, headwaters, and glacial depressions. Understanding why wetland definitions matter is not just a legal exercise. It is about understanding how a landscape works and what happens when we stop recognizing the systems that quietly hold it together.
An Ecologist’s View of Wetlands
Wetlands rarely call attention to themselves. They lie at the edge of forests, beside rivers, in shallow depressions, and in soggy corners of the landscape where water lingers. But these quiet places do an enormous amount of work.
An ecological definition of wetlands begins with the idea that wetlands are ecosystems shaped by the presence of water. Unlike dry land habitats, wetlands experience repeated or long-lasting soil saturation that influences nearly every aspect of the environment. When soils remain wet for extended periods, oxygen becomes limited, creating special soil conditions known as hydric soils. Only plants and animals adapted to these low-oxygen conditions can survive there. Because of this, wetlands are usually identified by the interaction of three elements: water, wetland soils, and plants adapted to saturated conditions.
Ecologists also understand wetlands as part of a continuum between land and open water, rather than as sharply defined boundaries. Across a landscape, there is often a gradual transition from dry upland forest, to moist soils, to saturated wetland ground, and finally to ponds, streams, or lakes. Wetlands occupy this middle ground. They are often called ecotones—transitional zones where different ecosystems, and the species that inhabit them, meet and interact. Because they sit at this intersection, wetlands receive water, nutrients, sediments, and organic matter from the surrounding land while also influencing nearby streams and lakes.
Another important concept for wetland ecologists is the hydroperiod—the seasonal rhythm of flooding and drying that shapes wetland conditions. Some wetlands remain saturated throughout the year, such as bogs and marshes. Others, like vernal pools, fill with water during spring snowmelt and gradually dry by late summer. Floodplain wetlands follow the natural rise and fall of nearby rivers. These water patterns strongly influence which plants and animals can live in a wetland and help create the rich variety of wetland habitats found across a watershed.
Wetlands are also important biogeochemical systems where water, soils, and living organisms interact to transform materials moving through the landscape. Saturated soils slow decomposition, allowing organic matter to accumulate and store carbon. Microorganisms in wetland soils also convert and remove nutrients such as nitrogen and phosphorus, helping protect water quality downstream. Because of these processes, wetlands filter sediments and pollutants.
Wetlands, especially isolated wetlands, are distributed across the landscape as natural holding areas during rainstorms and snowmelt. When water flows across the land, these depressions capture and store it, slowing its movement and reducing the volume and speed of runoff reaching downstream channels. Over time, this stored water can move downward to recharge groundwater and can be released gradually through seepage and evaporation, helping to spread out flood peaks and reduce erosion. Even though they may appear disconnected, isolated wetlands function collectively as a network, buffering the landscape against sudden pulses of water and quietly reducing the severity of floods downstream.
From this ecological perspective, wetlands are best defined not simply by their appearance, but by how they function within the broader landscape continuum. They are ecosystems created by recurring soil saturation that support specialized plants and animals and perform critical ecological roles. Understanding wetlands as part of a connected landscape helps explain why even small or seasonal wetlands can have large effects on watershed health and water quality.
The Growing Gulf Between Ecologists and Regulators
Ecological definitions are broader than regulatory ones. Understanding wetlands ecologically reveals why small headwater or seasonal systems can have outsized watershed effects—particularly in landscapes like the Connecticut River basin.
But whether a wetland is protected under federal law depends on a legal question that sounds simple and turns out not to be simple at all: Is it a “water of the United States”?
That phrase, at the heart of the Clean Water Act, and how it is interpreted, determines what wetlands are protected within the United States. Over the years, courts and federal agencies have debated what the phrase means and which wetlands it covers. As the legal meaning has changed, so has the reach of federal wetland protection.
That matters everywhere, but it matters especially in New England. Many wetlands here are not broad marshes along major rivers. They are small forest pools, headwater wetlands, beaver wetlands, and soggy depressions left behind by glaciers. They may not look connected to a river on the surface, but they still play an important role in how water moves through the landscape.
Today, because of several major Supreme Court decisions (CRC has previously written about the Sackett vs. EPA decision when that ruling was issued), many of these wetlands may receive less federal protection than they once did. That means states, towns, land trusts, and watershed groups are becoming more important than ever.
From Navigation to Wetlands Protection
Federal water law did not begin with environmental protection; one of its foundations began with navigation. In the early years of the United States, rivers were the nation’s highways. Moving goods, people, and commerce depended on keeping waterways open and unobstructed. Because of this, federal authority over water was rooted in the Commerce Clause of the Constitution [1], which gives Congress the power to regulate interstate commerce. If a river could be used for trade, it fell under federal oversight.
This early focus was reflected in laws like the Rivers and Harbors Act of 1899 [2] which prohibited activities that would block or alter “navigable waters.” At the time, the concern was straightforward: prevent obstructions to boats and shipping. Wetlands were not the focus—they were often seen as obstacles to be drained or filled.
But over time, a deeper understanding began to emerge. Water does not stay in one place. Pollution released upstream does not remain there. Sediment, nutrients, and contaminants move through entire river systems. And the landscapes surrounding rivers—especially wetlands—play a critical role in shaping what happens downstream.
By the mid-20th century, it had become clear that protecting only the main channels of rivers was not enough. When Congress passed the Clean Water Act (CWA) in 1972, it marked a fundamental shift in thinking. The goal was no longer just to keep waterways open for navigation, but to restore and maintain the chemical, physical, and biological integrity of the nation’s waters. This broader purpose recognized that water quality, ecosystem health, and human well-being are tightly connected.
To achieve this, the law needed to reach beyond large rivers. It needed to address tributaries, wetlands, and headwater systems—places where water is stored, filtered, and transformed before it ever reaches a navigable river. Wetlands, once dismissed as marginal land were increasingly understood as essential parts of the aquatic system: slowing floodwaters, trapping sediment, cycling nutrients, and supporting biodiversity.
And yet, the CWA retained a key phrase from its earlier roots in the Rivers and Harbors Act: navigable waters.
At first glance, the term seems clear. But in practice, it hinges on a deeper and more difficult question: What counts as “navigable”? Does it mean waters that are literally navigable by boat? Or does it include smaller streams, wetlands, and seasonal waters that influence those navigable rivers? This question has shaped decades of legal debate. Because while science points to a connected system where wetlands and headwaters influence downstream waters, law has often struggled to define how far that connection must extend to justify federal protection.
Over time, the meaning of “navigable waters” has expanded and contracted through court decisions, regulatory changes, and shifting interpretations. Each change has redrawn the boundary of federal authority—sometimes including wetlands as part of a larger system, and sometimes excluding them if their connection is not obvious on the surface.
By the late 20th century, it had become clear that a navigation-based definition of waters of the United States was no longer sufficient. The Clean Water Act of 1972 was Congress’s attempt to reconcile this gap between law and ecological reality.
Clean Water Act (CWA): The Arbiter
By the early 1970s, it was becoming clear that clean water could not be achieved without maintaining the ecological integrity of the landscapes through which it flows. Congress passed the Clean Water Act [3] in 1972 to protect the nation’s waters from pollution. The law was meant to do more than protect shipping routes or major rivers. It was written broadly so that pollution could be addressed across entire water systems.
The stated goal of the Act is:
“…water quality which provides for the protection and propagation of fish, shellfish, and wildlife and provides for recreation in and on the water...[4]”
One of the most important parts of the CWA is Section 404, which regulates the filling or dredging of wetlands and streams. If someone wants to fill a wetland for development, build a road across it, or alter a stream channel, federal permits may be required. Whether those permits apply depends on where the wetland is and thus, determines whether the CWA applies and protects it.
Section 401 has also provided an important basis for protecting wetlands that not are not directly connected to navigable waters, due to their role in improving downstream water quality. By requiring states to ensure water quality standards under section 401, wetland integrity could be considered where federal permitting is required, such as the relicensing of hydroelectric dams on the Connecticut River.
The Clean Water Act expanded the federal focus from navigation to water quality and ecosystem health. That broader purpose raised a central question: How far should federal wetland protection reach?
At the center of the Clean Water Act is a short definition: “The term navigable waters mean the waters of the United States, including the territorial seas.”
These few words carry a great deal of weight informing four major cases brought before the Supreme Court. If a wetland qualifies as a water of the United States, it may be protected under federal law. If it does not, that protection may fall away.
Supreme Court Steps In
Although the Clean Water Act set out a broad vision for protecting water quality and ecological integrity, it left one critical question unresolved: how far that protection should extend across the landscape. Over time, that question has been answered not by Congress alone, but by the Supreme Court. In a series of landmark cases—Riverside Bayview (1985), SWANCC (2001), Rapanos (2006), and Sackett (2023)—the Court has interpreted what qualifies as “waters of the United States,” shaping the boundary between federally protected and unprotected wetlands. As the following section shows, each decision has shifted that boundary, at times recognizing the ecological connections that tie wetlands to downstream waters, and at other times narrowing protection to those with more visible, surface connections.
Riverside Case (1985)
States v. Riverside Bayview Homes (1985) [5] was the first major Supreme Court case that put the protection of wetlands under the purview of the Clean water Act to the test. A developer in Michigan filled wetlands next to Lake St. Clair without a federal permit. The defendant’s argument was straightforward: wetlands were not listed by name in the statute, so they were not covered under the CWA.
The Supreme Court disagreed. The justices recognized that wetlands next to rivers and lakes are often part of the same aquatic system. They store water, filter runoff, and help protect water quality.
This Court decision established what became known as the adjacency standard [6].
Essentially, it meant that wetlands could be federally protected if they were next to, bordering, or closely located to neighboring rivers, lakes, or streams. The wetland did not have to be connected by surface water or hold water the entire year. For years, this provided a fairly broad basis for wetland protection.
SWANCC CASE (2001)
The next major change came in Solid Waste Agency of Northern Cook County v. U.S. Army Corps of Engineers (2001)[7] usually called SWANCC. This case involved abandoned sand and gravel pits that had been excavated down to the water table, and had subsequently developed a wetland that was used by migratory birds [8].
The U.S. Army Corps of Engineers (ACOE), in coordination with the Environmental Protection Agency, developed the Migratory Bird Rule [9] in the 1980s as an administrative interpretation of “waters of the United States” under the Clean Water Act to include certain isolated wetlands whose ecological functions extended beyond state boundaries. The legal basis for this interpretation rested on the Commerce Clause [10], which grants Congress authority to regulate activities affecting interstate commerce; the ACOE reasoned that wetlands used by migratory birds—species that move across state and national borders—support interstate economic activities such as hunting, recreation, and birdwatching, thereby justifying federal jurisdiction.
The Supreme Court said no. The SWANCC decision held that the Clean Water Act does not extend to isolated, non-navigable wetlands based solely on their use by migratory birds, thereby limiting federal jurisdiction and signaling a more constrained interpretation of “waters of the United States.” This was a major shift. It meant that many wetlands without proximity, or obvious connection to navigable waters, might no longer be federally protected. Due to this Court decision, an estimated tens of millions of acres of wetlands could potentially fall outside federal jurisdiction nationwide, dependent upon how narrowly the ruling was interpreted within the revised regulations promulgated by federal environmental agencies.
Rapanos Case (2006)
Then came Rapanos v. United States (2006) [11], one of the most confusing cases in modern wetland environmental law.
The Court split badly, and no single opinion clearly controlled how wetlands were federally protected. Two different tests emerged.
Justice Scalia’s opinion said federal jurisdiction should reach only relatively permanent waters and wetlands with a continuous surface connection to them, harkening back to the strict definition of navigable waters of the United States.
Justice Kennedy proposed a different test, the significant nexus [12] test. Under that approach, wetlands could be protected if they significantly affected the health of downstream navigable waters, even if the connection was less obvious, which gave a nod to the adjacency standard.
For years after Rapanos, federal environmental agencies mostly relied on the significant nexus interpretation. That allowed protection for wetlands connected through groundwater, flood pulses, seasonal overflow, or other ecological relationships. In practice, the Rapanos decision did not provide clarity. It created years of uncertainty.
Sackett (2023)
The most recent and most significant definition was a result of the case Sackett v. Environmental Protection Agency (2023) [13]. In Sackett, the Court rejected the significant nexus approach and adopted a narrower standard. Under the new rule, wetlands must have a continuous surface-water connection [14] to relatively permanent waters so that the wetlands would be hard to distinguish from those waters.
That sounds technical, but the effect is easy to understand: if a wetland is not visibly and directly connected to a river, stream, or lake, it is less likely to be federally protected. Wetlands connected only through subsurface flow or deeper groundwater, intermittent streams, or seasonal flooding, may no longer qualify. For sure, isolated wetlands in the Connecticut River’s watershed, such as vernal pools, bogs, fens, headwater wetlands, and maybe some beaver impoundments, would fall out of federal jurisdictional protection.
Depending on how the Sackett ruling is interpreted, recent studies suggest that up to 90 million acres [15] of non-tidal wetlands could fall outside federal protection due to the Sackett decision. This translates to approximately 80% of the wetland acreage in the lower 48 states.
Sackett Decision: Death Knell for Wetlands?
The wetlands most likely to lose federal protection are often the ones that matter most at the watershed scale. These wetlands may not sit right beside a major river, or have water flowing through them year-round, but they still hold water, store nutrients, support biodiversity, and shape streamflow downstream.
For watershed managers, the narrowing of federal wetland jurisdiction does not change the ecological importance of wetlands, but it does change the policy framework governing their protection. Many wetlands that support watershed health—particularly vernal pools, headwater wetlands, forested depressional wetlands, and beaver wetlands—may increasingly depend on state law and local land-use planning rather than federal regulation. In regards to federal protection, the current status is summarized in the following table.
All of the wetland types listed above, and no longer protected by the Clean Water Act, are classified by the federal government as Palustrine [16] wetlands. These are the wetlands in the states along Connecticut River that do not directly bound a lake or a river.
Individually the loss of these particular wetland types may appear minor, but these Palustrine wetlands are by far the most numerous wetland type found within the Connecticut River watershed. Collectively they have a major role in regulating watershed processes such as: flood attenuation, groundwater recharge nutrient retention and sediment trapping.
Now, just as the previous mention estimates for loss of wetland protection across the country, most being Palustrine designated wetlands. This impact will also be seen in the states bounding the Connecticut River.
By using a rapid, albeit coarse, visual-assessment approach that categorizes Palustrine wetlands associated with perennial flow versus those that don’t, a rough estimate can be made of the percentage of wetlands in a watershed that would fall out of being federally protected. This approach assumes that wetlands, which are not perennial flowing water and not directly touching what the Sackett decision determined were the wasters of the United States are assumed to be Palustrine and thus fall out of federal protection under the Clean Water Act.
Using a visual method [17] approach for four sub-watersheds, it provides some hint of what the potential impact that the Sackett decision may have on the entire in the Connecticut River Basin.
The loss of such Palustrine wetlands from federal protection under the Clean Water Act will negatively impact the ecosystem services [18] which not only support, but provide an economic benefit, to the communities within the Connecticut River watershed.
Examples of ecosystem services provided by the Connecticut River watershed uplands wetlands includes:
Headwater Wetlands: Wetlands at the top of a watershed influence what happens downstream. These wetlands help regulate streamflow due to bedrock groundwater being discharged at many of these locations. They can also remove nitrogen and phosphorus before these pollutants enter larger streams and rivers. Protecting these upper-watershed wetlands helps maintain water quality throughout the entire river system.
Isolated Wetlands: These are depressions scattered across the landscape, often surrounded by forest or upland soils. They provide important habitat that increases species diversity and richness. They also help slow flood waves in downstream tributaries and improve water quality by capturing sediment from heavy precipitation flows of water, followed by a slow release of that water over time. Concurrently, these wetlands trap sediments and nutrients such as phosphorus that can trigger algal and cyanobacteria blooms downstream.
Vernal Pools: New England’s vernal pools support wood frogs, spotted salamanders, and Jefferson salamanders. These small seasonal pools are often easy to overlook, but they provide irreplaceable breeding habitat for amphibians. Because they often lack visible surface connections to streams, many most likely fall outside federal jurisdiction.
Beaver-Created Wetland: Wetlands created by beavers are increasingly recognized as natural climate-impact mitigation infrastructure. Beaver impoundments slow runoff, spread water across floodplains, reduce erosion, and hold water on the landscape during dry periods. However, under narrow jurisdictional definitions, some of these wetlands may not qualify for federal protection.
Peatlands: Bogs are peat-forming wetlands that receive most of their water from rainfall rather than flowing groundwater or streams. Because they are low in nutrients and often acidic, they support rare and endangered species adapted to this specialized habitat. Over time, peat accumulates and stores large amounts of carbon, making bogs important for long-term climate regulation.
Fens are fed primarily by groundwater moving slowly through mineral soils. Like bogs they provide a mitigating impact on a changing climate by accumulating peat. But unlike bogs, they slowly release groundwater and filtering nutrients which help regulate streamflow and protect downstream water quality.
Riparian Wetlands
For riparian wetlands that lie within the broader floodplain, where groundwater, seasonal flooding, and overbank flows periodically saturate the soil, the outlook is unsure. They may not be protected due to the Sackett decision, even if they hydrologically and ecologically remain closely tied to river processes. Beneficially, they do store water across the floodplain, slow the movement of runoff, and trap sediments and nutrients before they return to the river. Thus, these threatened wetland systems moderate floods, improve water quality, and provide important habitat for wildlife moving along river and stream corridors.
No-Net Loss: States to the Rescue?
The idea of no-net- loss of wetlands - maintaining the total extent and function of wetlands despite development - is more of a policy to influence decision-making rather than a uniformly adopted legal standard. The roots of this policy targeting wetlands is primarily federal [19] rather than at the state level. However, this federal framework - centered on avoiding, minimizing, and compensating for wetland impacts - has strongly influenced how New England states structure their own regulations, even where the phrase itself does not appear in statute.
Among the Connecticut River states, Massachusetts comes closest to fully implementing this concept through its Wetlands Protection Act (M.G.L. c.131 §40; 310 CMR 10.00), which requires replacement of lost flood storage and often mandates compensatory mitigation, effectively operating as a no-net-loss system.
Vermont applies a similar avoid–minimize–mitigate framework under its Vermont Wetland Rules (10 V.S.A. Chapter 37). But with recent legislation [20] there is more of an emphasis on restoration and enhancement, moving toward a “net gain” of wetland functions rather than simply maintaining existing levels.
New Hampshire, through its Wetlands statutes (RSA 482-A), regulates dredge and fill activities within wetlands and may require mitigation as a requirement of a permit. Although, there is no formal statewide no-net-loss standard in the statutes, the State has set up the Aquatic Resource Mitigation Fund (ARM), dedicated to restoring or creating wetland acreage using monies paid by developers who have ben unable to avoid a negative environmental impact to a wetland.
In Connecticut, wetlands are regulated under the Inland Wetlands and Watercourses Act (Conn. Gen. Stat. §§ 22a-36 to 22a-45), which focuses on controlling activities that may impact wetlands. But the State does not have an explicit no-net-loss mandate. Instead, Connecticut’s program relies on its strong, locally administered, regulatory framework.
State Oversight, Uneven Ground
As federal jurisdiction has narrowed, state wetland laws become more important. The states that border the Connecticut River have already developed some of the stronger wetland protection programs in the country. These laws, and the resultant regulations, often protect wetlands based on ecological importance, whether or not federal law happens to apply.
In many environmental laws, the federal government sets a basic level of protection—a kind of minimum standard that applies across the country. But states are often allowed to go further. This is sometimes described as a “floor, not a ceiling,” meaning the federal law is an established baseline, but states can adopt stronger rules if they choose. In practice, this allows states to protect specific types of wetlands, which may require wider buffer zones, or apply stricter permitting standards than found under federal law.
This is especially important for the protection isolated Palustrine wetlands, including vernal pools. Particular to vernal pools, the most overt regulations protecting isolated wetlands is seen within the State of Massachusetts. If a formal state-mandated certification has been completed, vernal pools become highly protected. Also, Massachusetts’ 100 ft buffer around such a certified wetland, helps protect the habitat of migrating vernal pool amphibian species that spend most of the year in the surrounding upland.
Connecticut reflects an ecological approach to wetland protection, but does so indirectly by relying on a definition of hydric soils as the key indicator for whether a wetland is present. The ecological reasoning for this field metric assumes that the presence of water drives what is considered a wetland. When soil stays saturated for long periods, air can’t easily reach the it. Saturated soils have soil oxygen significantly reduced. In this low oxygen (anerobic) state, saturated soil changes color, texture, and chemistry, forming what scientists call hydric soils [21] which have very specific observable field-based characteristics.
It is then assumed that these identified hydric soil conditions can stress most plants, except for hydrophytes (wetland plants) adapted to survive in low oxygen soil. These hydrophytes will out-compete typical “dry-land” plants, shaping the unique plant communities we see in wetlands. In short, if hydric soil conditions are identified, the attest to the existence, or subsequent development, of a robust wetland ecosystem.
Vermont’s regulations are clearly function-based for the protection of wetlands. For vernal pools and isolated wetlands, protection occurs if the waterbody meets a metric for “ecological significance”. Through this lens, the State has created a classification system for the State’s wetlands based on the richness of the wetland community, presence of rare or endangered species, flood storage potential, and water quality. They even consider the potential of such systems for education and recreation.
New Hampshire’s wetland protection is activity-based. The regulations are triggered based on actively dredging and filling in, or near, a wetland. Once the process is triggered, the wetland boundary is delineated by a state certified wetland scientist, who uses hydrological, hydric soils and wetland plants to determine what is in and out of the wetland regarding dredge and fill activities. Crucially, under State regulations there is an additional protection for those wetlands that have been declared significant to protect by local municipalities.
Where Protection Really Happens
Local governments matter too. Municipal wetland ordinances, a planning board's Master Plan and associated regulations, conservation commissions oversight, and land trust protection decisions may determine the fate of wetlands that are no longer clearly covered by federal law.
Local (municipal) laws can be stricter than state laws, depending on how much authority the State gives to its towns and cities. In many cases, states allow local governments to adopt more protective regulations, especially for land use and natural resources. This is why some towns have stronger wetland buffer requirements or additional protections for vernal pools.
How much local governments can go beyond State wetland laws varies by states along the Connecticut River, creating a mix of strong local authority in some places and more state-controlled systems in others.
In Massachusetts and Connecticut, local conservation or local conservation commissions play a central role. These towns often have the authority to adopt stricter protections than the State baseline, such as wider buffer zones or additional safeguards for vernal pools and isolated wetlands. As a result, protection can be quite strong—but it may also vary from town to town.
In Vermont, wetland regulation is more state-centered with the State setting the primary standards through its wetland rules and classification system. While municipalities can support protection through zoning and planning, they generally have less direct regulatory authority to exceed state wetland permitting requirements.
New Hampshire falls somewhere in between. The state runs the core permitting program, but towns can adopt local ordinances that add an extra layer of protection designate. Also, a town can opt to establish a Prime Wetlands [22] ordinance, where specific wetlands have been formally identified by a municipality as having exceptional value and significance and as such receives greater protection under state statutes.
Where Small Decisions Shape Big Outcomes
For river conservancies, watershed groups, and local conservation organizations, this is a moment for needed transition. Federal law still matters, and state law matters greatly, but the future of many wetlands is increasingly shaped closer to home. Decisions made at the local and regional level - often subtly, in planning meetings, site visits, and community discussions - are becoming the determining factor in whether these threatened wetland ecosystems persist or are altered. That may sound like a burden, but it also creates an opportunity. It means organizations like the Connecticut River Conservancy could play a larger role in shaping the future not only of their rivers but the integrity of a healthy watershed.
This shift places greater importance on everyday decisions, such as whether a town chooses to protect or strengthen wetland buffer zones; whether a land trust prioritizes the conservation of a small headwater wetland that may not appear significant at first glance; whether a watershed group restores a floodplain to reconnect a river with its natural storage capacity; or whether a community recognizes the ecological and hydrological value of a beaver complex rather than viewing it as a nuisance to be removed.
Individually, these decisions may seem small. Taken together, they shape how water moves through the landscape, how nutrients are filtered, how floods are moderated, and how wildlife persists. In this way, local stewardship is no longer simply complementary to federal and state protections—it is becoming essential to sustaining the health and resilience of the watershed.
Wetland definitions matter because legal definitions now determine whether many ecologically important wetlands receive protection at all. If federal coverage continues to narrow, the future of these wetlands will increasingly depend on state laws, local ordinances, land trusts, conservation commissions, and watershed groups.
The Connecticut River Conservancy, and the Connecticut River states, each provide important backstops in different ways, but it is also clear that local stewardship is becoming indispensable. The stewards of the Connecticut River should realize the law may change how wetlands are classified, but it does not change how much they matter to the health, resilience, and economy of the watershed.
Seeing What Matters: A Call to Stewardship
Wetlands have not changed. They still slow floodwaters after heavy rains. They still filter pollutants before they reach our rivers. They still provide habitat for amphibians, birds, and countless unseen organisms. They still shape the health, stability, and resilience of entire watersheds. What has changed is whether we choose to see them—and protect them.
As federal definitions narrow, many of the wetlands that quietly sustain the Connecticut River watershed are no longer guaranteed protection. The small forest pools, the headwater seeps, the beaver-shaped wetlands, the peatlands accumulating carbon over centuries—these are the systems now most at risk. Not because they have lost their value, but because they may no longer fit within a legal definition.
That shift places the future of wetlands closer to home. It now rests in decisions made by states, towns, conservation commissions, land trusts, and watershed organizations. It lives in local zoning bylaws, buffer protections, restoration projects, and land conservation priorities. It depends on whether communities recognize that the “insignificant” wetland down the road may be doing essential work for the river miles away.
This is not just a regulatory gap—it is an opportunity. An opportunity to align how we manage the landscape with how it actually functions. An opportunity to protect wetlands not because they meet a narrow legal test, but because we understand their role in sustaining clean water, reducing flood risk, and supporting life. An opportunity for local stewardship to become the driving force behind watershed resilience.
The question is no longer simply What is a wetland under the law? The question should be: What kind of landscape do we want to live in—and are we willing to protect the systems that make it possible? Because in the end, wetlands do not need us to define them. But they do need us to recognize their value. And now, more than ever, the future – and the future of the Connecticut River watershed – depends on whether we act.
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[1] The Commerce Clause of the U.S. Constitution gives Congress the power “to regulate Commerce with foreign Nations, and among the several States…” (U.S. Const. art. I, § 8, cl. 3). This authority has historically provided the constitutional foundation for federal regulation of navigable waters and, over time, broader water resource protections.
[2] Rivers and Harbors Appropriation Act of 1899, 33 U.S.C. §§ 401–413. This law prohibited the obstruction or alteration of navigable waters without federal authorization and represents one of the earliest federal statutes asserting control over activities affecting the nation’s waterways.
[3] United States Congress. (1972). Federal Water Pollution Control Act Amendments of 1972 (Clean Water Act), 33 U.S.C. §§ 1251–1387
[4] Clean Water Act §101(a)(2)
[5] United States v. Riverside Bayview Homes, 474 U.S. 121 (1985).
[6] Following this decision, federal regulatory agencies—primarily the U.S. Army Corps of Engineers and the Environmental Protection Agency—interpreted “adjacent wetlands” broadly when implementing Clean Water Act §404 permitting. In practice, adjacency did not require a continuous surface-water connection; wetlands could be considered jurisdictional if they were bordering, contiguous, or neighboring jurisdictional waters, including those separated by natural features (e.g., berms, dunes) or man-made barriers (e.g., roads, levees).
[7] Solid Waste Agency of Northern Cook County v. U.S. Army Corps of Engineers, 531 U.S. 159 (2001).https://www.law.cornell.edu/supct/html/99-1178.ZS.html
[8] Clean Water Act §502(7)
[9] U.S. Army Corps of Engineers. (1986). Final rule for regulatory programs of the Corps of Engineers (51 Fed. Reg. 41,206). https://www.govinfo.gov/content/pkg/FR-1986-11-13/pdf/FR-1986-11-13.pdf
[10] U.S. Constitution, Article I, Section 8, Clause 3 (Commerce Clause). https://constitution.congress.gov/browse/article-1/section-8/clause-3/
[11] Rapanos v. United States, 547 U.S. 715 (2006).https://www.epa.gov/wotus/rapanos-v-united-states-carabell-v-united-states
[12] The significant nexus test originated in Justice Anthony Kennedy’s opinion in Rapanos v. United States (2006). Under this approach, wetlands could fall under federal jurisdiction if they significantly affect the chemical, physical, or biological integrity of downstream navigable waters. This test allowed federal protection of wetlands connected through ecological processes such as floodplain flow, groundwater exchange, or nutrient transport, even if they lacked a continuous surface-water connection.
[13] Sackett v. Environmental Protection Agency, 598 U.S. (2023).
[14] The continuous surface connection test was adopted by the U.S. Supreme Court in Sackett v. EPA (2023). Under this interpretation, wetlands fall under federal jurisdiction only when they are adjacent to relatively permanent waters and have an ongoing surface-water connection that makes them difficult to distinguish from the adjacent waterbody. Wetlands separated from rivers or lakes by uplands, banks, berms, roads, or other barriers generally fall outside federal jurisdiction under this standard.
[15] The range from difference sources is 30 million to 90 million acres.
[16] Palustrine wetlands are inland wetlands that are not part of rivers, or lakes They include marshes, swamps, bogs, fens, and many forested wetlands where water is usually shallow and slow-moving or temporarily present. In the classification system used by the U.S. Fish and Wildlife Service National Wetlands Inventory, palustrine wetlands are typically smaller than about 20 acres and lack strong wave action or deep open water, thus, distinguishing them from lake (lacustrine) or river (riverine) wetlands.
[17] A visual method compares the apparent share of mapped wetlands that lie directly along perennial-flow corridors versus wetlands that occur as depressional, headwater, pond-fringe, beaver, floodplain-backwater, or other off-channel settings. Analysis of the four tributaries within the CT River Watershed are documented by the boundaries of USGS’ Hydrologic Unit (HUC-8 level), combined with USFWS’ National Wetland Inventory ((NWI) maps that identify palustrine Wetlands within such a boundary not adjacent to streams, lakes or rivers. For a better estimation of the loss of protection of the palustrine wetlands in the Connecticut River Valley would be a task for a GIS polygon analysis using layers from NWI maps, USGS HUCs, soil overlays and land-use codes polygons. But even then, the NWI maps often miss the smaller isolated wetlands situated on the landscape.
[18] Ecosystem services (are the natural benefits that wetlands provide to people and the environment through their normal biological and hydrological functions. These include storing floodwaters, filtering pollutants from water, recharging groundwater, supporting fish and wildlife habitat, and storing carbon. In effect, wetlands perform many of the same functions as built infrastructure—such as flood control and water treatment—but they do so naturally as part of a healthy ecosystem.
[19] At the national level, the concept was formalized in 1989 under President George H. W. Bush, who established “no net loss” as a guiding goal for federal agency wetland policy under the Clean Water Act §404 program.
[20] Vermont’s recently passed Flood Safety Act (2024). By using a watershed-wide approach to mitigating flood risk across the state, the Act takes a watershed-wide approach to mitigating flood risk across the state, by mandating the increase in statewide flood resilience and protection public safety from flood damage. A particular section of this act[1] specifically targets increasing floodwater storage by establishing for every acre of wetland loss, there must be 2 acres of wetlands restored.
[21] Hydric soils are identified by looking for physical and chemical signs that the soil has been saturated long enough to develop low-oxygen conditions. One of the most noticeable indicators is color. When soils remain wet, iron in the soil is reduced and leached away, leaving behind gray or bluish colors known as gleying. You may also see mottling—patches of orange, red, or brown—where oxygen occasionally re-enters the soil and iron re-oxidizes. Another key indicator is the presence of organic matter. In saturated conditions, decomposition slows, allowing dark, mucky material—sometimes called muck or peat.
[22] In New Hampshire, Prime Wetlands are locally designated under RSA 482-A as wetlands of exceptional ecological and community value. Municipalities identify and map them through scientific review and public input, with state approval required. Once designated, these wetlands receive stronger protection—proposed impacts such as dredging or filling face stricter review by the New Hampshire Department of Environmental Services and are rarely approved without clear public benefit and no reasonable alternatives. This process allows communities to strengthen protection within the state framework.
Selected References
Adler, R. W. (2015). The Clean Water Act and the Constitution: The commerce clause and the limits of federal authority. Environmental Law Reporter. https://www.eli.org/eli-press-books/clean-water-act-and-constitution-legal-structure-and-publics-right-clean-and
Brinson, M. M. (1993). A hydrogeomorphic classification for wetlands. U.S. Army Corps of Engineers. https://usace.contentdm.oclc.org/digital/collection/p266001coll1/id/7194
Calhoun, A. J. K., & deMaynadier, P. (2008). Science and conservation of vernal pools in northeastern North America. CRC Press.
Clean Water Act, 33 U.S.C. §1251 et seq. https://www.epa.gov/laws-regulations/summary-clean-water-act
Clean Water Act Section 404, 33 U.S.C. §1344. https://www.epa.gov/cwa-404
Clean Water Act Section 401, 33 U.S.C. §1341. https://www.epa.gov/cwa-401
Cohen, M. J., Creed, I. F., Alexander, L., Basu, N., Calhoun, A. J. K., Craft, C., D’Amico, E., DeKeyser, E., Fowler, L., Golden, H. E., Jawitz, J. W., Kalla, P., Kirkman, L., Lane, C. R., Lang, M., Leibowitz, S. G., Lewis, D. B., Marton, J., McLaughlin, D., & Walls, S. C. (2016). Do geographically isolated wetlands influence landscape functions? Proceedings of the National Academy of Sciences, 113(8), 1978–1986.
Connecticut Inland Wetlands and Watercourses Act. (2024). Conn. Gen. Stat. §§ 22a-36 to 22a-45.https://www.cga.ct.gov/2021/pub/chap_440.htm
Dahl, T. E., & Stedman, S. (2013). Status and trends of wetlands in the conterminous United States 2004–2009. U.S. Fish and Wildlife Service.
Environmental Protection Agency. (n.d.). Waters of the United States (WOTUS). https://www.epa.gov/wotus
Federal Water Pollution Control Act (Clean Water Act), 33 U.S.C. §§ 1251–1387. https://www.law.cornell.edu/uscode/text/33/chapter-26
Gold, A. C. (2024). How wet must a wetland be to have federal protections in the post-Sackett United States? Science.
Golden, H. E., Lane, C. R., Amatya, D. M., Bandilla, K. W., Raanan-Kiperwas, H., Knightes, C. D., & Ssegane, H. (2014). Hydrologic connectivity between geographically isolated wetlands and surface water systems: A review of select modeling methods. Journal of the American Water Resources Association, 50(2), 291–310.
Intergovernmental Panel on Climate Change (IPCC). (2021). Climate change 2021: The physical science basis. https://www.ipcc.ch/report/ar6/wg1/
Lang, M. W., Ingebritsen, S., & Griffin, R. (2024). Status and trends of wetlands in the conterminous United States 2009–2019. U.S. Fish and Wildlife Service. https://www.fws.gov/sites/default/files/documents/2024-03/wetlands-status-and-trends-2009-to-2019.pdf
Leibowitz, S. G., Mushet, D. M., Newton, W. E., Alexander, L. C., Cohen, M. J., Creed, I. F., Golden, H. E., Jawitz, J. W., Kalla, P., Lane, C. R., & McLaughlin, D. L. (2018). Connectivity of streams and wetlands to downstream waters: An integrated systems framework. Journal of the American Water Resources Association.
Massachusetts Wetlands Protection Act. (2025). 310 CMR 10.00: Wetlands Protection Act Regulations.https://www.mass.gov/regulations/310-CMR-1000-wetlands-protection-act-regulations
Meltz, R. (2015). The wetlands coverage of the Clean Water Act: Rapanos and beyond. Congressional Research Service.
Mitsch, W. J., & Gosselink, J. G. (2015). Wetlands (5th ed.). Wiley.
National Research Council. (1995). Wetlands: Characteristics and boundaries. National Academy Press.
Natural Resources Defense Council. (2025). New report reveals massive loss of wetland protections after Sackett.
RSA 482-A Fill and Dredge in Wetlands Act. (2024). N.H. Rev. Stat. Ann. § 482-A.https://law.justia.com/codes/new-hampshire/title-l/chapter-482-a/
Odum, E. P. (1971). Fundamentals of Ecology. Saunders. https://archive.org/details/fundamentalsofec0000odum
Pollock, M. M., Beechie, T. J., & Jordan, C. E. (2014). The beaver restoration guidebook: Working with beaver to restore streams, wetlands, and floodplains. U.S. Fish and Wildlife Service.
Rapanos v. United States, 547 U.S. 715 (2006).
Rivers and Harbors Act of 1899, 33 U.S.C. §403. https://www. https://www.govinfo.gov/content/pkg/COMPS-5399/pdf/COMPS-5399.pdf.
Sackett v. Environmental Protection Agency, 598 U.S. (2023). https://www.supremecourt.gov/opinions/22pdf/21-454_4g15.pdf
Solid Waste Agency of Northern Cook County v. U.S. Army Corps of Engineers, 531 U.S. 159 (2001).
Union of Concerned Scientists. (2024). Sackett decision puts wetlands at risk. https://www.ucs.org/about/news/sackett-decision-puts-30-million-acres-wetlands-risk
United States v. Riverside Bayview Homes, 474 U.S. 121 (1985). https://www.law.cornell.edu/supremecourt/text/474/121
U.S. Army Corps of Engineers. (1987). Corps of Engineers wetlands delineation manual. https://www.sac.usace.army.mil/portals/43/docs/regulatory/1987_wetland_delineation_manual_reg.pdf
U.S. Army Corps of Engineers. (2012). Regional supplement to the Corps of Engineers wetlands delineation manual: Northcentral and Northeast region.
U.S. Army Corps of Engineers & U.S. Environmental Protection Agency (Adjacency Standard). (1986). Final rule for regulatory programs of the Corps of Engineers and EPA (33 CFR Parts 323 and 328; 40 CFR Part 230). Federal Register, 51(219), 41206–41260. https://www.govinfo.gov/content/pkg/FR-1986-11-13/pdf/FR-1986-11-13.pdf
U.S. Constitution, Article I, Section 8, Clause 3 (Commerce Clause). https://constitution.congress.gov/browse/article-1/section-8/clause-3/
U.S. Environmental Protection Agency. (2015). Connectivity of streams and wetlands to downstream waters.
U.S. Fish and Wildlife Service. (n.d.). National wetlands inventory. https://www.fws.gov/program/national-wetlands-inventory
U.S. Fish and Wildlife Service. (2024). Status and trends of wetlands in the conterminous United States 2009–2019. U.S. Department of the Interior. https://www.fws.gov/sites/default/files/documents/2024-03/wetlands-status-and-trends-2009-2019-signed.pdf
Vermont Department of Environmental Conservation. (2020). Vermont wetland rules. https://www.law.cornell.edu/regulations/vermont/12-056-Code-Vt-R-12-004-056-X
