Nearly a third of Florida's streams will gain federal protection under new rules aimed at smaller streams, tributaries and wetlands.
The rules clarify which of the waterways are protected under the Clean Water Act.
The confusion stems from two Supreme Court rulings, which had left the law's reach uncertain.
Jennifer Rubiello of Environment Florida says the protection is important because major waterways like the St. Johns River are only as healthy as their tributaries.
"The streams that gain protection today supply the drinking water for nearly 2 million Floridians, many of which are in Central Florida."
The Environmental Protection Agency and U.S. Army Corps of Engineers issued the rules.
Farm groups and the Republican-led Congress are opposing them. They say the rules amount to overreach.