In the 65 years that Tommy Calvert has grown hay and raised cattle in Denton County, he’s never applied for a federal permit. But with a new national clean water rule in effect, he’s not sure if it’s something he needs to think about. After heavy rains, runoff from his fields sometimes reaches a creek near his 300-acre farm, and Calvert doesn’t know if that tenuous connection to the drinking water supply might be enough to bring him under federal purview.

Calvert’s confusion reflects wider uncertainty as the U.S. Environmental Protection Agency’s new Waters of the U.S. rule kicks in, extending the agency’s regulatory power to smaller bodies of water, including some streams that only flow after heavy precipitation. 

The changes mean more landowners may need to apply for permits for work affecting water that now falls under federal jurisdiction. But some environmental law experts say the rule is so broad that it’s unclear whether farmers like Calvert will be affected.

The environmental agency says the rule — meant to clear up ambiguities in the 1972 federal Clean Water Act — only expands the agency’s jurisdiction by about three percent, and is needed to protect drinking water supplies. It won’t add economic burdens to farmers and maintains exemptions for agricultural practices, the agency says. Texas farmers won’t need permits to plow, cultivate, conduct minor drainage or harvest crops

But Texas Attorney General Ken Paxton has claimed the change means “virtually every river, stream and creek in the U.S. will come under the oversight of bureaucrats from the EPA.”

The rule is already in muddy legal waters. Hours before it took effect Friday, U.S. District Court Judge Ralph Erickson of North Dakota granted a request from 13 states — not including Texas — to temporarily block the regulation. But the EPA said it would continue to enforce it in the 37 others states not affected by the suit. 

Much of the anger comes from a dispute over whether the rule enlarges the EPA’s jurisdiction. The Clean Water Act made it illegal to pollute “navigable waters of the United States,” and the agency always believed its jurisdiction stretched beyond traditional navigable waters — like rivers and seas — to smaller bodies of water and wetlands that can affect them. The updated definition is intended to formally establish that authority.

When the EPA first introduced the proposed rule in March 2014, Texas politicians, agencies and business groups were quick to label it as federal overreach. More than half the states have sued, claiming the rule wrenches power away from states and threatens farmers and industries with red tape.

The Texas Farm Bureau, the Texas and Southwestern Cattle Raisers Association and local county farm organizations said they haven’t been able to give members clear guidance on how to prepare for the rule because they don’t fully understand how strictly it will be enforced, or if it will be upheld in court. Concern is high in Texas, where most land is privately owned and the state leads the nation in the number of farms and ranches.

Under federal law, landowners can’t pollute or dredge land near any water under federal jurisdiction without obtaining a permit, a process they say will be costly and time-consuming.

“Farmers and ranchers, we just have to watch our bottom lines because of the prices that we go by with cattle and with commodities, they’re always fluctuating,” said Calvert, president of the Denton County Farm Bureau. “The cost factor of that permit, that could be huge.” The stakes are potentially high — the fine for dredging near protected water without a permit can go as high as $16,000 per day.

Particularly troubling to some critics is language in the rule giving the agency authority over ephemeral water sources, streams that flow only seasonally. One in three Americans get drinking water from streams that only flow seasonally or after heavy rain, according to the EPA.

The agency’s rationale is that protecting drinking water requires protecting all the water sources that flow into drinking water. And in Texas, environmentalists point to an example to illustrate the rule’s importance. In 2007, crude oil spilled in Edwards Creek, a seasonally flowing stream in Titus County. The EPA wanted to demand a cleanup, but couldn’t prove its jurisdiction over a creek that only sometimes has flowing water.

But critics say the regulation creates backdoors that will allow the agency to creep in and claim authority over private property in the name of clean water. For example, provisions in the rule allow the EPA to regulate any water body if it has a “significant nexus” to water already under federal jurisdiction and if it’s less than 4,000 feet from the high water mark of water already under federal jurisdiction or it falls in a floodplain.

“If you go into a farm field or pasture and you see there’s a river that goes into a creek that goes into a stream and it keeps getting smaller, almost all of that is covered now” said Jim Bradbury, a Fort Worth-based environmental attorney. “It’s a big regulatory change.”

Landowners can request a jurisdictional determination — to see if they will need a permit to move soil or emit pollutants — from the U.S. Army Corps of Engineers. But the Texas Farm Bureau is not encouraging farmers or ranchers to seek that determination yet, said Regan Beck, the bureau’s government affairs director.

“This is a fluid situation,” Beck said. “The rule has been challenged by numerous other states including Texas and its not settled how this will end up.”

“It’s very vague, it’s very broad. There’s no way that you can prepare for this and be certain that you’re going to be unaffected,” he added.

When Texas filed a suit with Louisiana and Mississippi, it described a lengthy seven-step process for landowners to determine whether they had water features that fall under federal jurisdiction. The state alleged this determination required Texans to measure a high water mark, a high tide line and have knowledge of floodplains, areas prone to flooding in the last 100 years.

“It is unrealistic for the Federal Agencies to expect that landowners will possess the expertise, patience, and resources to employ this onerous test,” the states claimed in the suit.

Disclosure: The Texas and Southwestern Cattle Raisers Association and Texas Farm Bureau are corporate sponsors of The Texas Tribune. A complete list of Tribune donors and sponsors can be viewed here.