Posted on December 3, 2009 by Karen Aldridge Crawford
United States v. Milner, Nos. 05-35802, -36126, 39 ELR 20232 (9th Cir. Oct. 9, 2009)
In a suit brought by the United States against homeowners for common law trespass to tidelands held in trust for a Native American tribe, the Ninth Circuit held that waterfront homeowners who built shoreline defense structures on this property are liable for common law trespass and for violating the Rivers and Harbors Appropriations Act of 1899 (RHA).
Between 1963 and 1988, the homeowners leased the tidelands from the tribe, giving them the right to erect shore defense structures on the tidelands. After the lease expired, the homeowners refused to remove the structures or enter into a new lease agreement. The homeowners argued that they cannot be liable for trespass, despite the movement of the tideland boundary, because their structures were lawfully built on the homeowners’ property landward of the mean high water (MHW) line.
The court disagreed. Under common law, however, the boundary between the tidelands and the uplands is ambulatory, changing when the water body shifts course or changes in volume. Because both the upland and tideland owners have a vested right to gains from the ambulation of the boundary, the homeowners cannot permanently fix the property boundary, thereby depriving the tribe of tidelands that they would otherwise gain. And although the structures may have been legal as they were initially erected, the court found that this is not a defense against the trespass action nor does it justify denying the tribe land that would otherwise accrue to them.
The court also determined the homeowners are liable under the RHA because they have maintained at least part of their shore defense structures below the MHW line and because the structures alter the course, location, condition, or capacity of a navigable U.S. water. Addressing whether the homeowners had also violated the Clean Water Act (CWA), the court held that it was unclear from the evidence whether the high tide line actually reached the area where the homeowners discharged fill material during their maintenance of the structures. The court emphasized that although the jurisdictional reach of the CWA is generally broader than that of the RHA, the RHA is concerned with preventing obstructions, whereas the CWA is focused on discharges into water. Since the two laws serve different purposes, their regulatory powers will diverge in some circumstances, such as this one.