Cottonwood tree shoots sprout in a channel leading to the Santa Cruz River on the Tohono O’odham Nation. A new tribal lawsuit claims relaxed Clean Water Act rules will allow pollutants to be discharged into small streams, where they will find their way to larger rivers.

PHOENIX — Two Arizona tribes, the Tohono O’odham and the Pascua Yaqui, are suing the federal government over the Trump administration’s decision to dilute water quality rules.

The lawsuit filed in federal court here says the Environmental Protection Agency and the Army Corps of Engineers, at the direction of President Trump, repealed Obama-era regulations defining the scope of the protections of the Clean Water Act.

The net effect of this revised Navigable Waters Rule, which technically took effect Monday, would eliminate federal oversight of pollution into small and ephemeral streams and washes as well as adjacent properties.

The lawsuit says pollutants that will now be dischargeable into these small streams eventually will wind up in the larger rivers that clearly are covered by the rule.

Attorneys for the tribes said the effects would be immediate in the arid Southwest.

“The Navigable Waters Rule would strip away protections for thousands of miles of ephemeral streams, including the vast majority of surface water that crisscross the Pascua Yaqui Tribe and Tohono O’odham Nation reservations and provide a critical source of surface flows,” the lawsuit states.

“The rule would also exclude headwater ephemeral streams, such as those in the Santa Rita Mountains that Pascua Yaqui and Tohono O’odham members visit to gather traditional materials and offer prayers for their ancestors.”

The lawsuit asks a federal judge to set aside the new changes.

The EPA is reviewing the filing, said agency spokeswoman Molly Block. She defended the changes.

“EPA and the Army (Corps of Engineers) developed the rule to protect the navigable waters and their core tributary systems for the entire country while respecting our statutory authority,” she said. “The rule strikes the proper balance between state and federal jurisdiction and is designed to end the confusion that has existed for decades.”

Block also noted that a federal court in California last week denied a request by 17 states to block the rule from being implemented as scheduled while that case is litigated.

Conversely, a federal judge in Colorado enjoined enforcement of the rule, but only in that state.

While the tribes are trying to have the changes voided, David Godlewski, president of the Southern Arizona Home Builders Association, said his members and the national organization support the Trump administration’s actions. He said the prior regulations were unnecessary and expensive.

“There are a number of local environmental ordinances that prevent you from building in washes,” he said. “There comes a point at which you’re regulating for the sake of regulation.”

Required steps include hiring consultants and setting aside land, Godlewski said. “And that drives up the cost of land development and, ultimately, the cost of housing,” he said. “And it makes housing less affordable.”

The Clean Water Act, adopted originally in 1972, established the basic structure for regulating the discharge of pollutants into “navigable waters,” which are considered “waters of the United States.”

Attorneys for Earthjustice, which filed the lawsuit for the two Arizona tribes and three others elsewhere in the country, said that when Congress adopted the law it intended to provide the “broadest possible” definition of “navigable” waters to provide the broadest protection.

They concede that the U.S. Supreme Court has ruled that the law does not protect every wet area, like water-filled abandoned gravel mining pits. But they said the justices have consistently affirmed that both the EPA and the Corps have broad authority to protect not just navigable streams but also “non-navigable waters that are adjacent, connected, or have a significant nexus to navigable waters.”

In 2014 the two federal agencies published a rule to define “waters of the United States.” Those rules, the lawsuit states, were based on an EPA-commissioned science report that found “all tributaries, including perennial, intermittent and ephemeral streams, exert a strong influence on the integrity of downstream waters.”

The rules protected tributaries and had what the challengers say is a broad definition of “adjacent wetlands” that also would be protected.

Attorney Stuart Gillespie said the rules are designed to carry out the intent of Congress.

“It recognized that waterways are hydrologically connected,” he said. “In order to protect the navigable waters of the United States you needed to protect the tributaries, the headwater streams that support and provide the lifeblood that sustains our downstream waters. It’s critical that Clean Water Act protections extend not just to rivers that flow year-round but also all the ephemeral streams.”

The president ordered the agencies to replace the regulations. That resulted in what is called the repeal rule. What’s wrong with that, the lawsuit states, is that neither the EPA nor the Corps provided any explanation or analysis.


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