Texas, Louisiana and Mississippi have sued the U.S. Environmental Protection Agency and Army Corps of Engineers in Houston federal court over a rule that they say strips them of jurisdiction over water.
In a separate case filed Monday, 13 states are also seeking to have the rule overturned.
The May rule would greatly expand federal authority under the Clean Air Act over the bodies of water the EPA can legally regulate, restoring protections to tributaries and wetlands.
In a Monday statement, Texas Attorney General Ken Paxton said the rule is overly broad and potentially could include "everything from ditches and dry creek beds, to gullies, to isolated ponds formed after a big rain."
The latest news from around North Texas.
The rule was published in the Federal Register on Monday and takes effect Aug. 28.