Congressional Republicans have formally kicked off their campaign to roll back pieces of former President Obama’s environmental agenda — but progressive activists are mounting fierce resistance to their efforts.

Leaders in both the House and Senate on Monday introduced measures that would overturn the Obama administration’s so-called “Stream Protection Rule,” an Interior Department regulation that adds new restrictions to coal development by requiring companies to monitor and test the quality of any waterways that could be affected before, during or after mining operations.

The rule was rolled out in late December, just weeks before Mr. Obama left office. Republicans are taking aim at the rule through the Congressional Review Act (CRA), legislation that allows Congress to revisit and undo recent rules and executive actions by an administration.

Obama administration regulations dating back to June 2016 are subject to the CRA, and the GOP leadership is wasting little time using the measure.

Senate Majority Leader Mitch McConnell and Sen. Shelley Moore Capito of West Virginia on Monday introduced a resolution to reverse the Stream Protection Rule.

“Put into place by the Obama Administration at the 11th hour, the ‘stream buffer’ rule is a harmful regulation that unfairly targets coal jobs,” Mr. McConnell said in a statement. “It is just one example of the former administration’s policies that have jeopardized jobs and taken power away from state and local governments in order to grow the federal bureaucracy. Further, this regulation, like many others of the Obama era does not take into account the negative consequences these policies would have on hardworking Americans and the families they support.”