The EPA has proposed a new rule clarifying which American streams and wetlands are subject to Clean Water Act protections, intending to resolve long-standing confusion over the proper regulation of seasonal and rain-dependent streams.
The question of which particular streams and wetlands qualify for protection under the Clean Water Act has been unresolved for over a decade. There have been two major Supreme Court decisions on the matter, but neither gave EPA clear authority to regulate the 60% of US stream-miles that flow only seasonally, or after rain. All ephemeral and intermittent streams, and the wetlands that are connected or next to them, will be subject to federal oversight under the proposed rule.
A link to the EPA site with more detailed information on the proposed rule can be found here.