The Trump administration on Tuesday began the process of formally rescinding the highly controversial “Waters of the U.S.” rule, an Obama-era regulation that gave Washington broad powers over streams and other small bodies of water across the country. The rule, put forth in 2015 but subsequently stayed by the Supreme Court before going into effect, was one of EPA Administrator Scott Pruitt’s top targets when he took the helm at the agency. President Trump earlier this year signed an executive order directing Mr. Pruitt to review the rule, and with Tuesday’s action, the EPA says it’s finalized that review and...