Sea Level Rise: Notes on the December 27, 2022 Tide Flood

Back in mid December I visited a dike on the distal Skagit River delta area near Samish Island. The dike holds back high tides from Alice Bay from inundating the low farm fields and road. My site visit took place during high tide. During low tides Alice Bay typically fully drains becoming a broad mud flat.  

Samish Island Road and the dike between the road and Alice Bay.

The road is below sea level

View of the dike looking north. Alice Bay on the right, the east end of Samish Island is in the distance and the Chuckanut Range in the far distance 

View looking south along the dike.

Grassy areas in the near distance are saltwater marsh.

Dike District 5 portion of dike. This section of dike was and lined with with rock last year.

Last February there was a tide surge that caused tidal flooding in Edison. The minimal free board and dike erosion resulted in significant dike raising by the District. However, the district boundary ends between the above shown new work and the high ground to the north at Samish Island.

On December 27, 2022 a very deep and broad area low pressure storm system combined with very high astronomical high tide. The low pressure path and associated wind pattern added to the water levels. At Port Townsend the storm tidal surge was 2.5 feet.

    The result was water overtopping the dikes shown  above. 

Sea water over topping the a low spot in the dike

Multiple over flow locations along dike and water filling the low area behind dike including the road

Tide flood water pouring across road into fields to the west.

Flooded fields viewed from the north

While the above shown flooding covered on the order of 150 acres of fields with sea water, the impact for other areas was more acute. Flooding was reported at multiple locations from this event including Olympia and Port Townsend. 

North shore of Samish Island looking east.

Note that water just reached the top of the slightly elevated area between the homes and Samish Bay.

From the same location above but looking west.

Note here that the berm between the homes and bay is lower allowing flood waters to reach the homes.

Water getting over or around the elevated shoreline berm flooded the whole low area behind the berm. I had some work to do at this area and the water over topped my rubber boots. Not particularly pleasant as the flooding included flooding all the septic systems.  

Sea level rise is pushing what in the past had been a close call tidal flood to full out flood events with a higher frequency.