In this episode, we're joined by Wayne Rosenbaum of the Environmental Law Group in San Diego to unpack Waters of the United States (WOTUS). Wayne reviews where the definition came from, how it changed over time, and what it looks like today after the Supreme Court’s 2023 Sackett v. EPA decision and subsequent federal implementation actions. Together, they walk through practical, real-world questions that come up in project planning and compliance: the difference between ephemeral features and intermittent tributaries, what “continuous surface connection” means in wetland jurisdiction, and how changes to hydrology (like berms, dikes, or dams) can affect a site’s regulatory posture. The conversation also tackles a few common scenarios such as wetland fill for development, mostly-dry drainages that ultimately reach jurisdictional waters, agricultural ditches and stormwater, and California’s proposed SB 601 concept of “nexus waters.”