Wetlands play a critical role in protecting water quality and watershed health by filtering pollutants, buffering downstream areas from floods, providing habitat for wildlife, and supporting recreation and tourism for local economies in Colorado. Given their essential role in our watersheds, wetlands have long been a focus of water protection laws, most notably the federal Clean Water Act. However, the scope of wetland protections has changed over time, creating new questions about which wetlands are regulated and what that means for working in wetlands. Whether you are restoring a wetland or planning a project that may impact wetland habitat, understanding the current regulatory landscape is key to protecting and minimizing adverse impacts to Colorado’s wetlands.
The Clean Water Act (CWA) was created in 1972 in response to widespread water pollution problems in the United States. Before the CWA, many rivers, lakes, and coastal waters were heavily contaminated by waste, sewage, and chemicals, making them unsafe for drinking, recreation, and wildlife. High-profile events, like the Cuyahoga River catching fire due to oil and industrial pollutants, combined with growing public concern over environmental health, pushed Congress to act.
The CWA was created to stop unchecked pollution and protect the nation’s waters for health, recreation, and ecosystems. While Congress used the term “navigable waters”, they defined the phrase broadly as “waters of the United States” (WOTUS). The intent was to cover more than just big rivers and lakes because pollution in small streams and wetlands can flow downstream and harm larger waters.
The main goals of the CWA were to “restore and maintain the chemical, physical, and biological integrity of the nation’s waters, eliminate the discharge of pollutants into navigable waters, and ensure waters were safe for fishing and swimming.” The CWA funded wastewater treatment plants, established a system to permit dredging or placing fill material into WOTUS, and gave the federal government authority to regulate water quality standards. Essentially, it marked a turning point from uncontrolled pollution to a structured approach for protecting water resources.
The CWA originally aimed to protect “navigable waters,” but over time the meaning of WOTUS has shifted through court cases, agency rules, and administration changes. For decades, agencies like Environmental Protection Agency (EPA) and the U.S. Army Corps of Engineers (USACE) included not just rivers and lakes but also wetlands and other waters connected to interstate commerce.
- In the 1980s, courts confirmed that wetlands next to navigable waters were covered and USACE and EPA issued revised regulations.
- In the 2000s, two Supreme Court cases, SWANCC (2001) and Rapanos (2006), limited federal authority over isolated waters and introduced two tests: “significant nexus” (connection to larger waters) and “relatively permanent” (lasting water presence).
- In 2015, the Obama administration issued the Clean Water Rule, clarifying the interpretation of WOTUS based on science showing connectivity between streams and wetlands.
- In 2020, the Trump administration repealed the Clean Water Rule and replaced it with the Navigable Waters Protection Rule, which narrowed coverage and excluded many ephemeral streams. Courts struck down that rule in 2021, reverting to older definitions while new rules were proposed.
- In 2023, the Supreme Court’s Sackett decision eliminated the “significant nexus” test, leaving only the “relatively permanent” standard. EPA and the Army Corps quickly updated regulations to reflect this change.
Today, the definition varies by state: some follow the revised 2023 rule; others use the pre-2015 approach modified by Sackett.
Overall, the legislative trend has been a tug-of-war between broader and narrower interpretations of the intent of the CWA. The latest shift favors a more limited federal role focused on WOTUS with continuous surface connections to Traditional Navigable Waters.
Sackett removed federal protection from large portions of Colorado’s wetlands and streams, leaving no permitting requirement for dredge-and-fill activities in those waters. Colorado had no equivalent to the federal Section 404 program, To account for the lack of federal protections for waterbodies that do not meet the new definition of WOTUS, the State of Colorado passed House Bill 24-1379 in May 2024, which creates a state dredge and fill permitting program for “state waters” that are not regulated by the federal CWA. State waters include any surface or subsurface waters in Colorado, explicitly adding wetlands to the definition, including isolated wetlands.
The Colorado Department of Public Health and Environment (CDPHE) Water Quality Control Division (WQCD) led the effort to establish and adopt rules under Regulation No. 87, which were adopted on December 10, 2025, requiring permits for activities that discharge dredged or fill material into state waters.
Regulation No. 87 uses federal Section 404(b)(1) guidelines as a baseline but allows Colorado to go further to protect water quality. It includes general permits for isolated wetlands and exemptions for normal farming, emergency repairs, and voluntary stream restoration.
Colorado’s law essentially fills the regulatory gap left by Sackett, restoring protections for wetlands and streams critical to water supply and ecosystem health. It allows Colorado to lead on wetland protection, maintains water integrity in a post-Sackett landscape, and provides a model for other states around the country.
With the rules of Regulation No. 87 now in place, any activity involving impacts to State Waters must go through CDPHEs notification and permitting process.
Current Status of the State's Program Implementation:
- January 1, 2025: The division started issuing Temporary Authorizations for dredge and fill activities into state waters.
- February 6, 2026: General Authorization for Discharge of Dredged and Fill Materials into Isolated State Waters went into effect.
- April 2026: The division will begin noticing General Authorizations for public comment.
In November 2025, the EPA released a new Proposed Rule with the intention of “revising the regulations defining the scope of waters federally covered” under the CWA in response to the Sackett ruling. The Proposed Rule “provides greater regulatory certainty and increases CWA program predictability and consistency by clarifying the definition of WOTUS.” Under the Proposed Rule, WOTUS would include:
- Traditional navigable waters and the territorial seas,
- Most impoundments of WOTUS,
- Relatively permanent tributaries of traditional navigable waters, the territorial seas, and impoundments,
- Wetlands adjacent (i.e., having a continuous surface connection) to traditional navigable waters, impoundments, and tributaries, and
- Lakes and ponds that are relatively permanent and have a continuous surface connection to a traditional navigable water, the territorial seas, or a tributary.
The biggest implications of the Proposed Rule come from the new definitions of “relatively permanent” and “continuous surface connection”, and the incorporation of a “wet season” to gauge relative permanence. These terms were not explicitly defined previously.
A continuous surface connection would now be defined as abutting or touching a jurisdictional water. Relatively permanent waters would now be defined as “standing or continuously flowing bodies of surface water that are standing or continuously flowing year-round or at least during the wet season.” The includes “extended periods of predictable, continuous surface hydrology occurring in the same geographic feature year after year in response to the wet season, such as when the average monthly precipitation exceeds average monthly evapotranspiration.” The proposed rule includes potential methods for determining the wet season.
In Colorado, these definitions remove ephemeral waters from federal jurisdiction and protection. Wetlands and intermittent waterways lacking a relatively permanent and continuous surface connection to traditionally navigable waters (i.e., major perennial rivers like the Colorado River or South Platte) would also no longer be covered under federal protections. These changes could remove many acres of wetlands in Colorado from federal jurisdiction, leaving them under the purview of the new state regulatory program.
The 45-day comment period for the Proposed Rule closed on January 5, 2026, with the release of a final rule pending.
Most Colorado wetlands are only regulated at the federal level, but some cities and counties have stricter wetland regulations and policies. The City of Boulder currently has the strongest local wetland protections in the State, and other counties such as Larimer and Park have wetland protections in their land use code and zoning regulations. Park County’s regulations require a 50 ft buffer between wetlands and most types of land use, and the City of Boulder and Larimer County require a 50-100 ft buffer depending on the size, condition, and/or surrounding land use of a wetland. Contact your local government for information pertaining to wetland regulation in your area.
See Wetland Best Management Practices for more details on how to protect wetlands from construction and other types of disturbance.
Federal Links:
- EPA WOTUS Homepage
- EPA's Current Implementation of WOTUS and Guidance
- Updated Definition of WOTUS and Resources for the EPA’s Proposed Rule
Colorado State Links:
- Colorado General Assembly House Bill 24-1379
- CDPHE Discharges of Dredge and Fill Website
- Background on CDPHE’s Regulation No. 87
- CDPHE’s Regulation No. 87 Text
- CDPHE's Isolated State Waters General Authorization
- CDPHE List of Helpful Links for Applicants
