The Supreme Court appears ready to narrow the scope of the Clean Water Act, eliminating protections for many inland streams and wetlands that feed rivers, lakes and bays. But California is also ready, thanks to former President Donald Trump.

When Trump tried to roll back federal regulation of inland waterways toward the end of his term, California stepped in with new pollution controls designed to protect those waters within the state’s borders — regulations that would largely fill the gap the Supreme Court seems poised to create by mid-2023.