AP Explains: Trump executive order on water protection

President Donald Trump has ordered federal agencies to rewrite an Obama administration rule that would shield many wetlands and small streams from development and pollution.

Under President Barack Obama, the Environmental Protection Agency and the Army Corps of Engineers crafted a regulation that was promptly challenged by more than two dozen states and business groups.

The rule establishes a legal definition of protected tributaries, saying they must have physical features of flowing water such as a bed, bank and ordinary high water mark.

Farm groups say it gives regulators nearly unlimited power over virtually any wet spots, from ditches to farm ponds, leaving producers uncertain about what they can do without obtaining government permits and risking fines.

The president's executive order requires the agencies to follow the guidance of the late conservative Justice Antonin Scalia in producing a new definition of protected waters.

In a 2006 opinion, Scalia interpreted federal jurisdiction narrowly, saying only "relatively permanent, standing or continuously flowing" waters or wetlands with a surface connection to navigable waterways were covered.