The U.S. Supreme Court has ruled against the federal government in a wetlands case that could shed light on the justices’ leanings in a broader Clean Water Act case expected to reach the high court in the next few years.

The eight Supreme Court justices on May 31 handed down a unanimous ruling rejecting the government’s argument that jurisdictional determinations—or JDs—are simply advice and cannot be appealed in court by parties that have received a Corps determination that a body of water falls under federal jurisdiction. I

Instead, the court said a company that gets a "negative" Corps determination may appeal in court. The case is U.S. Army Corps of Engineers v. Hawkes Co. Inc.

Hawkes Co. wanted to farm peat on a 530-acre tract of land in Minnesota and sought a Clean Water Act permit from the Corps to develop the site. The Corps told the company that the permitting process could take years because a section of the land had “a significant nexus” to a river about 120 miles away and thus is a federally regulated water.

Hawkes subsequently appealed the Corps’ JD through an administrative process. The Corps told Hawkes that the company could not appeal the JD through formal litigation because the determination was not a final agency action. Hawkes could go ahead without a permit and risk EPA enforcement, the Corps also said.

That alternative was not acceptable, the Supreme Court justices concluded. “As we have long held, parties need not await enforcement proceedings before challenging final agency action where such proceedings carry the risk of ‘serious criminal and civil penalties,’ ” the court wrote.

Writing for the court, Chief Justice John Roberts said that if Hawkes had discharged fill material without a permit "in the mistaken belief that [its] property did not contain jurisdictional waters,” it could face daily Environmental Protection Agency civil penalties of up to $37,500 as well as potential criminal liability. “Respondents need not assume such risks,” he wrote.

As some observers look at the court's ruling in Hawkes, they see possible signs about how it might rule on more wide-ranging challenges to a 2015 Corps-EPA rule redefining what wetlands and streams are "waters of the United States," and thus are under federal permitting authority.

Several states and construction groups, such as the National Association of Home Builders and the American Road and Transportation Builders Association, have filed or supported court challenges to the waters of the U.S., or WOTUS, rule, which, they contend, is a major expansion of which waters require a Clean Water Act construction permit.

Environmental groups generally support the rule, saying it clarifies which U.S. waters need to be protected.

Those lawsuits are making its way through several lower federal courts and at least one of them is expected to come before the high court, though not imminently.

Larry Liebesman, a senior advisor with Dawson and Associates, a Washington, D.C., consulting firm, says the decision by the court bodes well for the broader case challenging the Clean Water rule.

He said: "The fact that the ruling was unanimous shows that even the liberal justices will not automatically defer to the Obama administration's Clean Water Act policy interpretations, which impact property rights. The ruling also suggests that the WOTUS rule will likely face similar scrutiny should it reach the court."