After a years-long tussle with Congress and other stakeholders, the Obama Administration last week issued a regulation that spells out which U.S. waterways are protected under the Clean Water Act, the federal law that controls water pollution and aims to conserve wetlands. The detailed rule defines and clarifies federal protections for tributaries as well as streams that are intermittent or perennial. For example, it specifically excludes from regulation ditches that have seasonal flows of water, EPA says. The rule came under immediate fire from industry groups and congressional Republicans representing agricultural states. The U.S. Chamber of Commerce, a powerful business lobby, says the rule will “significantly broaden federal regulatory jurisdiction over private activities on land and in waterways, wetlands, and drainage ditches.” Bills moving through Congress—including H.R. 1732 and S. 1140—would force EPA to scrap the regulation and require the agency to rewrite the rule with broader input from stakeholders. In addition, the rule is expected to be challenged in federal court.