President Donald Trump speaks to the media before meeting with Senate Minority Leader Chuck Schumer, D-N.Y., and House Minority Leader Nancy Pelosi, D-Calif., in the Oval Office of the White House, Tuesday, Dec. 11, 2018, in Washington. Credit: Evan Vucci | AP

The Trump administration on Tuesday proposed to sharply limit the federal government’s authority to regulate the pollution of wetlands and tributaries that run into the nation’s largest rivers, a move that could ease development by home builders, farmers and shale oil and gas drillers.

The administration said it would introduce a “new construct,” limiting regulation to streams that held water in a “typical year” as measured against the past 30 years of precipitation.

“This will be a significant retreat from how jurisdiction has been defined for decades,” said Ann Navaro, who worked at the Army Corps of Engineers and at the Interior and Justice Departments. “This will significantly reduce the regulatory burden on land owners, developers and industry.”

The new scaled-back regulation was one of President Donald Trump’s top priorities when he took office, and he issued an executive order in February 2017 ordering the Environmental Protection Agency to carry out “the elimination of this very destructive and horrible rule.”

The Obama administration, under the Waters of the United States rule issued in 2015, had unambiguously asserted federal oversight of a variety of ditches, storm water controls, lakes, streams and wetlands that feed into larger waterways that are clearly protected under the Clean Water Act of 1972. Many experts believed that the 1972 law already gave EPA and the Army Corps of Engineers control over smaller U.S. waterways and tributaries, but a series of court rulings had left the extent of that regulatory power ambiguous.

Acting EPA Adminstrator Andrew Wheeler said in a briefing with reporters Monday night that the Obama administration’s approach had imposed undue regulatory burdens and that it had “further expanded Washington’s reach into privately-owned lands” under the guise of protecting water. He said that the Obama regulations had required permits that were often costly and time-consuming to obtain.

Wheeler said the Trump administration’s new proposal would eliminate federal protections for areas that contain water only after rainfall. It would no longer regulate groundwater, storm water, waste water and land already converted for crops. It would eliminate regulation of ditches other than canals, such as the Erie Canal, used for commercial shipping or affected by tides. And it would only regulate wetlands or waterways that are clearly adjacent to navigable waterways above ground or through “direct subsurface connection.”

State agencies can still regulate Clean Water Act violations, but many experts said that would create the sort of “patchwork” that Wheeler said he wanted to abolish.

The new proposal, which will be open for a 60-day comment period, is a victory for businesses, farmers and ranchers. It would, for example, prevent federal officials from ordering changes in the handling of fertilizers that might spill into small waterways. The changes could also benefit coal mining companies that lop off the top of mountains and fill in valleys with waste, often creating ponds. In many cases, Navaro said, Clean Water Act permits were the only ones those companies needed.

The new proposal would also drop federal oversight of gravel and sand pits, commonly used in the fracking industry, and old quarries that fill up with water.

The fracking of shale oil or gas involves large amounts of gravel to build drilling pads and sand to fracture underground oil and gas-bearing rock. The American Petroleum Institute last year said that the 2015 rule “would have imposed burdensome and costly regulations, and stifled energy production with little to no environmental benefit.” The National Association of Home Builders said in a recent web posting that any new rule should “not encompass man-made systems or remote features with marginal ecologic value.” And the Farm Bureau’s senior director of congressional relations said Monday that “we want to see some common-sense approaches.”

Wheeler also said that the administration would distinguish between “intermittent” streams, which have defined stream channels, and “ephemeral” streams, which have a swale or depression. Intermittent streams, which would remain regulated, disappear from view when the water table dips below the stream bed. Ephemeral streams, which would not be regulated any longer, appear only after heavy rainfall.

“The distinction I think is bogus,” said Chris Wood, president of Trout Unlimited, a nonprofit group devoted to the conservation of clean rivers and streams. “You can’t distinguish between the two. Everything is going to find its way downstream.”

“Folks will no longer need a Clean Water Act permit to discharge pollutants into ephemeral streams even though once full with storm water they will flow into navigable waters,” said Navaro, now a partner at the firm Bracewell.

Protection of wetlands and head waters are “critically important areas for the health of rivers and drinking water supplies for Americans all over the country,” said Bob Irvin, president of American Rivers, a nonprofit advocacy group seeking to protect and restore waterways. He said that even though the connection between bodies of water may not appear on the surface, “there may be connections through groundwater.”

The Clean Water Act made it unlawful to pollute a “water of the United States” without a permit, but what constitutes a water of the United States has been the subject of political debate and lengthy litigation culminating at the Supreme Court.

In the Rapanos v. United States decision, the court split three ways. Its four most conservative justices at the time offered a very constrained view that only “navigable waters” met this test. But Justice Anthony Kennedy, who refused to join either the conservatives or the liberals, said in a concurring opinion that the government could intervene when there was a “significant nexus” between large water bodies and smaller, as well as intermittent, ones.

The ruling was important because many intermittent streams and wetlands are connected beneath the surface.

Trump’s executive order said that federal officials should rely on the dissenting opinion of the late Justice Antonin Scalia, who argued the law should only apply to “navigable waters.” No court has ever ruled that this test is the single decisive threshold for triggering Clean Water Act protections.

The administration’s new proposal likely conflicts with the Rapanos case. Legal experts said that the administration might be betting that the newly constituted court would look favorably on the new rule. But it could take two to three years of litigation before a case reaches the high court, and by then there could be a different administration.

Dave Ross, assistant administrator of the Office for Water at EPA, said the administration had chosen to “weave together between the commonalities in those decisions.”

Before issuing the new rule, the Trump administration had already encountered choppy seas in its effort to undo the Waters of the United States. In August, David Norton, a federal judge in South Carolina, struck down the Trump administration’s effort to strip away clean water protections from rivers, lakes, streams and other waters that provide drinking supplies across the South in a case led by the Southern Environmental Law Center.

Norton said that the administration was violating the Administrative Procedure Act by halting enforcement of the Obama regulation, which is still in effect. “As administrations change, so do regulatory priorities,” he wrote. “But the requirements of the APA remain the same.”

“This will be a huge fight,” Navaro said. “There will be huge pushback from a number of states and even Congress and certainly from environmental groups. I think folks are ready to do battle. We have a lot of complicated litigation to look forward to.”