The swath of land between Indian and Marrowstone Islands was historically comprised of tidal channels and salt marsh. Tidal waters exchanged freely between Oak Bay and Kilisut Harbor, flushing cold water, moving sediment, and allowing juvenile salmon to migrate northward from Oak Bay into the shallow, productive waters of Kilisut Harbor. The installation of the causeway in between Kilisut Harbor and Oak Bay eased transportation between the Islands, but choked the flow of water and sediment, eventually creating an artificial beach berm, a filled channel, and increased water temperatures in Kilisut Harbor. The Kilisut Harbor Restoration Project will restore the historic tidal connection between southern Kilisut Harbor and Oak Bay by removing the earthen causeway containing two undersized culverts and replacing it with a 440-foot bridge.
This project benefits many species including salmon, shorebirds, waterfowl, shellfish and eelgrass, while also providing transport between the two islands. The bridge will be built to withstand earthquakes and storm surges where the current causeway is not. The completion of this project will reconnect the large numbers of Hood Canal and Puget Sound migrating juvenile salmon that converge at Oak Bay with immense foraging opportunities available within Kilisut Harbor. Restoring the connection between Kilisut Harbor and Oak Bay through salt marsh habitat will help filter contaminants and improve nutrient flushing and dissolved oxygen levels in Kilisut Harbor, thus improving overall water quality and conditions for shellfish.
Photo Credit: Monte Reinders