A district court denied a commercial fisherman's motion to preliminarily enjoin the Army Corps of Engineers and EPA from enforcing a 2023 rule that revised the definition of "waters of the United States." The fisherman argued the agencies did not faithfully implement the Sackett v. Environmental Pro...

The U.S. Supreme Court, 5-4, denied two states' motion to enter into a consent decree in a lawsuit concerning a 1938 interstate agreement that apportions the waters of the Rio Grande River among Colorado, New Mexico, and Texas. Texas initially sued Colorado and New Mexico, arguing excessive groundwa...

The Ninth Circuit reversed in part summary judgment for the operators of a marine cargo terminal on Puget Sound in a CWA citizen suit concerning stormwater discharges. An environmental group argued the operators were liable for discharges from the facility's entire footprint, including an area known...

A district court denied the state of Florida's motion for a limited stay of the court's prior ruling vacating EPA's approval of Florida's application to assume permitting authority under §404 of the CWA. Environmental groups initially sued, arguing EPA and FWS violated the ESA because neither the p...

A district court denied summary judgment for Native American tribes in a challenge to EPA's approval of Minnesota's 2021 revised water quality standards. The revisions replaced quantitative standards with qualitative narrative standards that describe the characteristics Minnesota waters must have to...

A district court granted summary judgment for a conservation group in a challenge to the Natural Resource Conservation Service's (NRCS') 2020 rule regarding certification of maps delineating wetlands. The group argued NRCS changed its policy regarding pre-1996 wetland certifications without exercisi...

A district court granted in part environmental groups' motion for summary judgment in a challenge to various agency actions relating to EPA's approval of the state of Florida's application to assume permitting authority under §404 of the CWA. The groups argued EPA and FWS violated the ESA because n...

The Tenth Circuit reversed a district court finding of a CWA violation in a citizen suit brought against the operator of a gold mine in Colorado. Plaintiffs argued the operator violated the CWA because seepage from the mine's settling ponds flowed into the groundwater and then migrated to the Middle...

The Fifth Circuit vacated a district court ruling in a decades-long dispute over whether a property in Louisiana contains federally regulated wetlands. The property owner sued the Army Corps of Engineers, arguing its determination that the property contained federal regulated wetlands was arbitrary ...

The Ninth Circuit affirmed summary judgment for an environmental group in a suit against a California resident who engaged in instream suction dredge mining in Idaho’s South Fork Clearwater River without an NPDES permit. The group argued the resident violated the CWA each time he operated a suctio...