The Trump administration’s proposal to limit the Clean Water Act’s reach over wetlands and waterways would likely complicate efforts to protect and manage the parched West’s most important and imperiled source of water. At risk: the Colorado River — water provider for 40 million people and vast swaths of cropland — which is already reeling from a crippling drought and rising water demands. Trump’s proposed waters of the U.S. (WOTUS) rule would strip federal protections for ephemeral streams that only flow after rain or snow and wetlands without continuous surface water connections to waterways. That’s particularly important in the Colorado River Basin.