IDEM Reviewing Which Waterways Fall Under State Protection After Court Revokes Trump Water Rule

September 2, 2021

The Indiana Department of Environmental Management said it is reviewing how a federal court ruling revoking a Trump water rule will affect state waterways.

The U.S. District Court for the District of Arizona struck down the Navigable Waters Protection Rule, a 2020 rule that narrowed the definition of “waters of the United States,” the legal phrase in the Clean Water Act which determines which waterways are protected by federal law.

The court said the rule contained serious errors and could potentially cause “serious environmental harm” if left in place.

In Indiana, the ruling could restore protection for some of the state’s wetlands, while disappointing some farm and trade groups that oppose stricter environmental regulations.

The ruling could be appealed, but for now the decision returns jurisdiction over some waterways in Indiana to the more stringent control of the federal government. The scope of the change and how that would be implemented by state agencies remains unclear.


The Trump rule restricted the waterways protected by the Clean Water Act to four categories: territorial seas and navigable waters; perennial and intermittent tributaries; certain lakes, ponds and impoundments; and wetlands adjacent to jurisdictional waters.

Waterways that did not fall under those categories fell under state or tribal jurisdiction.

Indiana lawmakers and lobbyists used the Trump rule to justify eliminating state protections for wetlands and ephemeral streams, saying the protections put Indiana at a disadvantage compared to states without such legislation.

U.S. District Judge Rosemary Marquez, an Obama appointee, ruled that the Trump administration ignored advice from the U.S. Environmental Protection Agency’s Science Advisory Board and a 2015 report when it excluded certain hydrologic features from the rule, including isolated wetlands and temporary, rain-dependent waterways known as ephemeral streams.

Marquez said the Trump administration’s exclusion of those water features would cause “significant, actual environmental harms.”

“Impacts to ephemeral streams, wetlands, and other aquatic resources could have ‘cascading and cumulative downstream effects,’ and the [EPA and U.S. Army Corps of Engineers] ‘have heard concerns from a broad array of stakeholders . . . that the reduction in the jurisdictional scope of the CWA is resulting in significant, actual environmental harms,” Marquez wrote.

“The seriousness of the agencies’ errors in enacting the NWPR, the likelihood that the agencies will alter the NWPR’s definition of ‘waters of the United States,’ and the possibility of serious environmental harm if the NWPR remains in place upon remand, all weigh in favor of remand with vacatur.”

Marquez vacated the Navigable Waters Protection Rule and sent it back to the EPA and Army Corps of Engineers for reconsideration.


The repeal restores, for now, the regulations defining “waters of the United States” that were in place from 1986 until 2015. The court’s ruling could also revive an Obama-era rule repealed by the Trump administration.

The Obama administration’s Clean Water Rule expanded the WOTUS definition to include case-specific waters that required analysis to determine whether they were jurisdictional waters.

A coalition of states, including Indiana, sued to stop its implementation, and the rule was stuck in legal limbo until the Trump administration repealed it in 2019.

As part of the court’s ruling, all the parties involved in the lawsuit were given 30 days to submit proposals about the repeal of the Obama WOTUS rule.

The possibility remains that the court could also vacate the Trump administration’s repeal of the WOTUS rule, allowing it to survive and resume its legal battles.


The EPA and IDEM said they are reviewing the court’s ruling, so it is unclear how and when federal protections will be restored to waterways that lost federal protection during the Trump administration.

Groups like the Hoosier Environmental Council told the Indiana Environmental Reporter the likely result of the ruling is that fewer waterways in the state will fall under state jurisdiction.

The ruling is expected to reduce the impact of a law that weakened state protections for isolated wetlands and ephemeral streams.

Wetlands trap and slowly release water, filtering it through sediment and vegetation before it reaches surface and groundwater systems. They can reduce or prevent flooding and are home to many species of wildlife. Ephemeral streams have similar hydrologic functions.

State lawmakers in 2003 decided to protect wetlands that did not fall under federal protection with the bipartisan Isolated Wetlands Law.

Under the 2003 law, state wetlands were categorized into three wetland classes.

Class I, which included ephemeral streams, was defined as having “minimum” wildlife or hydrologic function. Class III is defined as having “more than minimal” wildlife or hydrologic function. Class II is vaguely defined as being an isolated wetland “that is not a Class I or Class III wetland.”

Senate Bill 389, introduced in January by State Sens. Chris Garten, Mark Messmer and Linda Rogers, sought to repeal all state protections for isolated wetlands, including ephemeral streams, not under federal jurisdiction.

SB 389 ultimately repealed protections for all Class I wetlands, which make up 425,000 acres of Indiana’s remaining 800,000 acres wetlands and weakened protections for the state’s 250,000 acres of Class II wetlands, wetlands.

The law was estimated to cost cities and farmers millions of dollars in water management and treatment costs due to a loss in natural filtration and storage, as well as increase the risk of flooding over time.

The EPA and IDEM’s interpretation of the federal court’s repeal of the NWPR could restore federal protection to some of those wetland acres.

The Biden administration has said it will present its own WOTUS definition, possibly later this year.

Farm groups like the Indiana Farm Bureau and American Farm Bureau Federation and trade organizations like the Indiana Builders Association said an update is unwelcome.

IBA CEO Rick Wajda provided public comments to the EPA, saying the NWPR allowed states to set regulations, like SB 389, to meet local needs.

“We heard the calls from members of our organization who thought they were going to see regulatory relief last year when the new WOTUS rule went into effect, only to find out that they would still have to get an isolated wetlands permit from the state of Indiana for their project,” Wajda said.

“We know that 4,300 Hoosier households are priced out of the market. This is why the current WOTUS rule and definition should remain in effect. Each state has the ability to tailor their program to fit the needs of their constituents. The existing WOTUS rule provides a framework without jeopardizing the protection of wetlands already provided for in federal regulations.”

Water quality in Indiana’s streams and other waterways has significantly decreased over the past decade.

The number of miles of streams impaired by E. coli has nearly doubled in the last decade, jumping from 12,716 miles in 2010 to 24,001 in 2020. State streams have also experienced rises in the number of miles of streams facing biological integrity impairments, more PCBs found in fish tissue, oxygen depletion, excess nutrients, pH impairments and other issues.

IDEM Reviewing Which Waterways Fall Under State Protection After Court Revokes Trump Water Rule