## Facts

- Riverside Bayview Homes, Inc. owned low-lying, marshy property near Lake St. Clair, Michigan.
- The Clean Water Act prohibits discharging dredged or fill material into “navigable waters,” defined as “waters of the United States,” without a permit under § 404.
- The U.S. Army Corps of Engineers defined “waters of the United States” by regulation to include freshwater wetlands adjacent to other covered waters, identified by saturation sufficient to support vegetation adapted to saturated soil.
- Riverside Bayview began placing fill material on the property without seeking a § 404 permit.
- The United States brought an enforcement action seeking to enjoin further filling absent a permit.
- The district court found the property met the regulatory wetland definition due to groundwater saturation supporting wetland vegetation and adjacency to Lake St. Clair, and held the Corps had § 404 jurisdiction.
- The Sixth Circuit reversed, reading the regulation to exclude wetlands not frequently flooded by adjacent navigable waters and construing jurisdiction narrowly to avoid potential Fifth Amendment takings problems.

## Issues

1. Whether the Clean Water Act must be narrowly construed to limit the Corps’ wetlands jurisdiction to avoid potential Fifth Amendment takings concerns.
2. Whether the Corps may reasonably interpret “waters of the United States” to include freshwater wetlands adjacent to navigable waters even if the wetlands are not regularly flooded by those waters.

## Decision

- The Supreme Court unanimously reversed the Sixth Circuit.
- The Court held that the Corps reasonably interpreted the Clean Water Act to cover wetlands adjacent to other waters of the United States and to require § 404 permits for discharges of fill into such wetlands.
- The Court rejected using constitutional-avoidance reasoning to narrow the statute because a permit requirement or permit denial is not necessarily a taking, and compensation would remain available if a taking occurred.
- The Court upheld the district court’s factual findings that the property was an adjacent wetland under the regulation.

## Legal Principles

- The Clean Water Act’s use of “waters of the United States” reflects broad federal authority to protect water quality, supporting regulation beyond traditionally navigable waters.
- The Corps may treat adjacent wetlands as within “waters of the United States” where ecological and hydrological connections make the boundary between water and land difficult to draw.
- Agency line-drawing in technically complex environmental regulation is reviewed for reasonableness; courts should not substitute narrower jurisdictional limits absent statutory command.
- Requiring a permit for land development affecting regulated waters does not, by itself, constitute a Fifth Amendment taking, and denial of a permit is not necessarily a taking.
- Potential takings concerns do not justify narrowing an otherwise reasonable statutory interpretation where compensation remedies remain available if a taking is later established.

## Conclusion

The Court sustained federal § 404 permitting authority over wetlands adjacent to navigable waters, confirming that the Corps may reasonably include such wetlands within “waters of the United States” and rejecting a takings-based rationale for constricting Clean Water Act jurisdiction.


United States v. Riverside Bayview Homes, Inc., 474 U.S. 121 (1985)