Kilisut Harbor Restoration Project

Kilisut Harbor Resoration Project at high tide, image by John Gussman

Kilisut in the news!

Project Update: We are excited to announce that the Kilisut Harbor Restoration project reached the milestone we’ve all been working toward since 2011 – Oak Bay is now reconnected to Kilisut Harbor! The land bridge connecting the two islands was built in the 1940s making it almost 75 years since these two water bodies have been connected. There are fish and crab in the newly constructed tidal channels and the water quality improvements to Kilisut Harbor are already apparent. The first weekend the channel was reopened, community members paddled back and forth between the two bays and we are reminded again that our nearshore projects are not only good for fish and ecosystems, but also our local communities. Hope to see you out there soon!

Project Details

The area 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 restores tidal connection between southern Kilisut Harbor (Scow Bay) and Oak Bay by removing the earthen causeway that contained two culverts. The causeway was replaced with a 440-foot bridge. These actions on WA State Route 116, restore natural processes and biological responses to 27 acres of marine intertidal habitat and tidal-fringe salt marsh that have been severely impacted by the construction of the earthen causeway.

This project benefits many species including salmon, shorebirds, waterfowl, shellfish and eelgrass, while also providing transportation between the two islands. The bridge is being built to withstand earthquakes and storm surges where the causeway could not. The successful completion of this project will reconnect the large numbers of Hood Canal and Puget Sound out-migrating juvenile salmon that converge at Oak Bay with immense foraging opportunities available within Kilisut Harbor. The project will also restore and enhance important staging and foraging habitat for multiple coastal dependent and migratory birds. The greater Kilisut Harbor and Oak Bay areas have been identified as Important Bird Areas by the Washington Audubon Society, supporting up to 13,500 wintering shorebirds and waterfowl. Restoring the tidal flow between Kilisut Harbor and Oak Bay through salt marsh habitat will improve dissolved oxygen levels in Kilisut Harbor, thus improving overall water quality and conditions for shellfish.

Click here for a 360-degree view of the project at high tide, image by John Gussman.

Click here for a 360-degree view of the project at low tide, image by John Gussman.

Recent aerial images from the Kilisut Harbor Restoration Project, click on an image and scroll through! All images by John Gussman.

Panorama of the Kilisut Harbor Restoration Project at high tideThe reestablished channel between Oak Bay, at the bottom of the image, with Kilisut Harbor to the north of the bridge is clearly visible in this panorama.

Panorama of the Kilisut Harbor Resoration Project at low tidePanorama of the Kilisut Harbor Resoration Project at low tide, showing the newly constructed bridge from Indian Island on the left to Marrowstone Island on the right. The newly opened channel follows the same path as the historical channel. Oak Bay is in the lower left of the image, and Kilisut Harbor/Scow Bay is in the upper right.

High tide looking south from Kilisut HarborThe lower reach of Kilisut Harbor is called Scow Bay. This image is shot from Scow Bay looking towards Oak Bay beyond the bridge.

Facing south towards Oak Bay from Kilisut HarborLow tide with Marrowstone Island on the left and Indian Island on the right.

The bridge from aboveCloser detail of the bridge from above, seen at high tide.

Facing east at low tideSouthern approach to the Kilisut Harbor Restoration Project at low tide, Oak Bay is on the right.

If you’re taking a walk along the tidal channel, please be mindful of Navy property.

See below a list of funders and partners for the Kilisut Harbor Restoration Project.