A federal judge on Tuesday rejected an attempt by the US Army Corps of Engineers to dismiss a lawsuit challenging their refusal to protect vulnerable shoreline along the Puget Sound.

The lawsuit deals with tidal jurisdiction boundaries. A key aspect in this dispute is the measurement of high tide along the coast of the Puget Sound in Washington state. The Seattle District of the Corps uses the “mean higher high water” as a high tide line marker, but this level marker is alleged to be out of date according to more recent data. In fact, 25 percent of high tides exceed the current measure of high tide. Additionally, the use of this measurement is inconsistent with other West Coast Corps districts.

The measure of high tide is relevant for the region because of ongoing shoreline armoring. According to the Clean Water Act, shoreline armoring projects require a permit if they are located below the high tide line. Due to the inaccurate tide measurement, armoring projects are being undertaken without proper review.

Improper armoring activities can affect the “health, recreational, environmental, aesthetic, commercial, and/or other interests” of the state and also significantly interfere with the delicate ecosystem of the Sound. The elimination of vegetation and the disruption of spawning habitats for various fish and marine life directly impacts local salmon populations and the Puget Sound orcas.

The Corps sought to dismiss the claim based on a lack of subject matter jurisdiction. It also alleged that the usage of the “high tide line marker is not a ‘final agency action’ and therefore not reviewable under the [Administrative Procedure Act].” The court, though, found sufficient causation for subject matter jurisdiction.

The court’s decision means the lawsuit will go forward.