Trump begins dismantling Obama’s EPA rules today. First up: the Clean Water Rule

At first glance, it’s hard to see why the Clean Water Rule (also known as the “Waters of the US rule”) inspires such fury. It’s a technical regulation from the Environmental Protection Agency meant to clarify which streams and wetlands fall under federal clean water protections — a question that had been causing legal confusion for years.

But when the rule was published in June 2015, it triggered fierce blowback from farm and industry groups across the country. “Opponents condemn it as a massive power grab by Washington,” Politico reported, “saying it will give bureaucrats carte blanche to swoop in and penalize landowners every time a cow walks through a ditch.” Many of those criticisms were overblown, but the rule was widely cited by conservatives as a prime example of EPA overreach under President Obama. (The regulation is currently being tied up in court and hasn’t taken effect yet.)

Now Donald Trump wants to get rid of the rule — a first step in his ongoing efforts to dismantle Obama-era EPA protections. On Tuesday, he signed an executive order that asks new EPA Administrator Scott Pruitt to begin the long process of repealing the rule and replacing it with... something else.

Except here’s the catch: Rolling back this rule won’t be easy to do. By law, Pruitt has to go through the formal federal rulemaking process and replace Obama’s regulation with his own version — and then defend it in court as legally superior. And, as Pruitt’s about to find out, figuring out which bodies of water deserve protection is a maddeningly complex task that could take years.