Catalina Clouthier, Research Fellow
Brigit Rollins, Staff Attorney
In 2024, the United States Fish and Wildlife Service (“FWS”) released a final rule regarding drain tile setbacks for federally-owned wetland easements in the Prairie Pothole Region. The 2024 final Drain Tile Setback rule was developed to provide clarity, transparency, and consistency to both landowners and FWS about the maintenance of these easements. Specifically, the final rule outlines the process that FWS will use to calculate the amount of space that must be left between a protected wetland and drain tiles, also known as the drain tile setback distance. The rule also provides a legal shield to landowners who voluntarily receive and follow setback guidance from FWS. Though the rule seeks to provide clarity, it has prompted some landowners to file lawsuits arguing that the rule misinterprets the terms of their original wetland easements. In response, FWS has sought further feedback from the public, raising the question of whether the 2024 rule will ultimately remain in place.
Background
The Prairie Pothole Region (“PPR”) is a unique area spanning across North Dakota, South Dakota, Iowa, Minnesota, and Montana. Caused by glacial melt, prairie potholes are small depressional wetlands typically less than two feet deep and an acre wide, though can be as small as a tenth of an acre. There are thousands of these wetlands throughout the PPR. Prairie potholes are crucial habitat for waterfowl, with 50-75% percent of the North American duck population breeding in these areas, providing habitat for more than 60% of the breeding population. Noting the ecological significance of the PPR, the federal government began taking action to protect wetlands in the region from activities such as tile drainage starting in the 1950s. Tile drainage is the process of removing water from an area of land to allow for better aeration of the soil. This process is accomplished by the installation of a pipe to draw water away from one area. Tile drainage is often used to convert areas of wetter land into dry land more capable of producing an agricultural crop. However, there are concerns that use of tile drainage in the PPR could drain the region’s small wetlands, potentially reducing the available habitat for waterfowl.
In 1958, Congress created the Small Wetlands Acquisition Program by amending the 1934 Migratory Bird Hunting Stamp Act, also called the Duck Stamp Act. Using funds from the Duck Stamp Act, the federal government worked to protect prairie potholes designated as Waterfowl Production Areas (WPAs). To achieve this goal, the government would purchase land rights to designated WPAs from landowners for the purpose of conservation. In 1959, the federal government purchased the first WPA in South Dakota. In 1961, the Wetlands Loan Act was passed, which appropriated more funds for wetlands easement purchases, accelerating the acquisition of these lands. The purchased easements are part of the National Wildlife Refuge System, administered by the National Wildlife Refuge System Administration Act.
An easement is a type of legal property right that grants the easement holder the right to use another party’s private property. For example, utility companies often purchase easements that give them the right to run pipes or cables through private property. The wetland easements within the PPR are voluntary agreements between landowners and FWS to permanently protect wetlands in exchange for financial compensation. According to FWS, these easements are “minimally restrictive,” meaning that they are intended to have a minimal impact on the property value and on a property owner’s use and enjoyment of the land. Landowners who sell such an easement to FWS agree that the wetlands under the easement cannot be drained, filled, leveled, or burned. If the wetlands naturally dry up, then the land may be farmed, grazed or hayed as though it never was a wetland. Additionally, wetland easements provide that landowners may continue engaging in “normal farming practices” on the areas of their property not impacted by the easement. If a landowner violates the terms of the easement either intentionally or unintentionally, the National Wildlife Refuge System Administration Act allows for financial penalties and the possibility of imprisonment. 16 U.S.C. § 668dd(f).
Wetland easements run with the land “in perpetuity.” This means the wetland easement is permanently part of the land deed, regardless of how many times the land changes hands. For example, if a landowner sold an easement to FWS in the 1960s, and the land is sold in the 1980s, again in the 2000s, and again in 2026, FWS still owns the wetland easement on the property.
A particular challenge regarding the PPR wetland easements is determining which areas are subject to an easement and which are not. Before 1976, FWS did not describe what wetlands on a property were covered when issuing a deed to create an easement. As a result, landowners have faced confusion regarding which areas of their property are subject to the terms of an easement and which areas are not. This uncertainty can present a challenge to landowners who face fines and a possible prison sentence for unknowing violations of the terms of a wetland easement. To address this issue, FWS put forth a guidance document in 2020 that sought to provide landowners with better clarity over the scope of wetland easements in the PPR.
The Final Setback Rule
In 2020, FWS released a guidance memo regarding drain tile setbacks and when the agency would take legal action related to wetland easements in the PPR. In the memo, FWS clarified that it would use a formula known as the van Schilfgaarde equation to determine how far away a drain tile should be from a protected wetland to prevent the wetland from being drained. The distance between the drain tile and the wetland is referred to as a “setback.” There are two measurements taken of the wetland: the “up-gradient,” where water flows to the wetland, and the “down-gradient,” where water flows away from the wetland. The formula FWS uses to determine the setback distance can sometimes over calculates the distance for up-gradient wetlands. When that occurs, FWS caps the setback distance as the upper boundary of the wetland’s “catchment” area. The catchment area is the edge of the land area that drains into the wetland. While the up-gradient setback distance can be set at the edge of the catchment area if the van Schilfgraarde equation over-calculates the distance, the 2020 memo provides that the setback distance for the down-gradient of a wetland is always used according to the formula’s calculation due to groundwater flows and gravity increasing the risk of draining.
Along with describing the method used to calculate drain tile setbacks, the 2020 memo also described when a landowner would be considered in violation of a wetland easement. According to the memo, should a landowner coordinate drain tile planning with FWS and comply with the setback distances determined by the agency, the landowner would be shielded from future legal penalties in the event that the distances do not sufficiently protect wetland areas from drainage. Conversely, if a landowner does not coordinate with FWS on tile installation and protected wetlands are drained as a result, the landowner may be liable for breaking the terms of the easement.
The 2020 memo was initially an internal agency document to which FWS officials could refer for guidance on how to interpret the law, but was not legally obligated to rely on. Ultimately, FWS sought to turn the document into law in an effort to bring “consistency, transparency, and clarity” to both easement landowners and the agency. Following a period of public comment, FWS issued the final Drain Tile Setback rule in 2024, formally codifying the 2020 memo into regulation. Like the 2020 document, the 2024 Drain Tile Setback rule establishes that landowners within the PPR may voluntarily request that FWS provide them with setback distances for the placement of drain tiles on lands covered by wetland easements. The final rule then requires FWS to provide requested setback distances and clarifies that landowners who comply with the setback distances will be immune from legal action should the setbacks fail to protect a wetland from drainage.
Although the 2024 final rule is broadly similar to the 2020 memo, there are a couple of key differences. First, the rule provides that FWS will use the “best available science” to calculate setback distances, not specifically the van Schilfgraarde equation. Next, the preamble for the rule – the section of the rulemaking document that explains the agency’s reasons for taking action but does not carry the force of law – specifically differentiates the PPR wetland easements from other federal wetlands protections found in the so-called “Swampbuster” provisions of the 1985 Farm Bill. Under Swampbuster, agricultural landowners throughout the United States are prohibited from converting designated wetlands into land capable of producing an agricultural commodity or they risk losing access to certain federal program benefits. However, Swampbuster allows drain tile to have a “minimal effect” on wetlands without a landowner being in violation of the law. According to the 2024 Drain Tile Setback rule, wetland easements in the PPR require drain tile to have “no effect” to covered wetlands. This difference in standards between Swampbuster and the PPR wetland easements was not included in the original 2020 memo.
Landowner Lawsuits & Further Agency Action
Following the final 2024 Drain Tile Setback rule, some landowners in the PPR expressed concern that the regulation conflicted with the original terms of their wetland easement contracts. This has prompted some landowners to file lawsuits and spurred FWS to seek additional information on how best to calculate drain tile setbacks in the PPR.
Several lawsuits have been filed by plaintiffs seeking to challenge either the 2024 Drain Tile Setback rule itself or setback distances calculated pursuant to the rule. For example, the plaintiff in Ellingson Drainage v. U.S. Fish & Wildlife Serv., No. 1:25-cv-00541 (D. D.C., February 24, 2025) is a Minnesota company that provides drain tile installation services to farms in the Midwest. In its lawsuit, the plaintiff alleged that the 2024 Drain Tile Setback rule misinterpreted the scope of the original wetland easements. According to the plaintiff, the original easement contracts apply only to the covered wetlands themselves and do not extend to the non-wetland portions of a property. The plaintiff also noted that the original easement contracts typically allowed landowners to continue engaging in “normal farming activities” on the non-wetland portions of their properties. The plaintiff argued that the 2024 rule exceeds the scope of the original easements by prohibiting the installation of drain tiles within the designated setback area even if that area is not considered part of the actual wetland covered by an easement. Additionally, the plaintiff claimed that the 2024 misinterpreted the scope of the wetland easements by stating that a landowner may have “no effect” on protected wetlands despite the original easement contracts allowing landowners to continue normal farming activities on other portions of their property.
Ultimately, the court dismissed Ellingson Drainage v. U.S. Fish & Wildlife Serv. after finding that the court could not hear a challenge regarding something an agency included in the preamble of a rule because preambles only provide context to an agency’s reasoning and are not legally enforceable. Additionally, the court concluded that the plaintiff had failed to show that it had personally suffered an injury sufficient to bring a lawsuit because the plaintiff itself was not subject to a wetland easement. However, the plaintiff in Peterson v. United States, No. 3:25-cv-00078 (D. N.D., April 8, 2025) is a landowner within the PPR who’s property is encumbered by a wetland easement. He raises arguments largely similar to those raised in Ellingson Drainage v. U.S. Fish & Wildlife Serv., but instead of challenging the 2024 rule itself, he argues that the setback distances FWS calculated for his property pursuant to the rule should not be enforced because they include land not covered by the original easement contract. As of late October 2026, the case remains ongoing.
In the meantime, on July 24, 2026, FWS opened a fourteen-day request for information seeking public feedback on the overall efficacy of the 2024 rule and what changes, if any, FWS should make regarding drain tile setbacks. Often, agencies will seek this kind of feedback when they are considering a policy or regulatory change. During a two-week public comment period, 219, 428 comments were submitted. As of this publication, FWS has not taken any further action in response to the public comments from the request for information. However, the door remains open for FWS to take action in the future in response to the comments.
Going Forward
For landowners in the PPR, the 2024 final Drain Tile Setback rule is currently the law. Should FWS take action in response to the information gathered through its formal request and changes or amends the rule in the future, affected landowners may face new standards they must adhere to in order to remain in compliance with the terms of a wetland easement. Additionally, should any of the currently ongoing lawsuits result in a ruling that the 2024 rule exceeds the scope of original wetland easements, that would likely require FWS to reconsider its setback policy. For landowners with property encumbered by a PPR wetland easement, staying up to date with any FWS changes regarding the PPR rules will be important to ensure individuals are aware of the status of their wetlands, and are able to plan agricultural and other land uses according to the newest information and regulations.
To read the complaint in Ellingson Drainage v. U.S. Fish & Wildlife Serv., click here.
To read the complaint in Peterson v. United States, click here.
For more information on wetland easements from FWS, click here.