The exceptionally high tides recorded along the Oregon coast last weekend – referred to as “King Tides” – are nothing new. The alignment of the earth to the sun and the moon that causes the abnormally high tides has happened since the beginning of time. But with the development of global climate change and sea-level rise has pushed this annual tidal event to the forefront of many coastal communities.
Many coastal towns that only a couple of decades ago were high and dry, now see significant flooding and coastal beach erosion on a regular basis. When coupled with other weather events like high winds and heavy rainfall, the annual extra high tides and the flooding has become increasingly severe.
On our eastern seaboard, where the coastal plain extends inland for miles, the same King Tide conditions caused extensive flooding of lowland and a number of coastal towns. In Myrtle Beach, S.C., where the King Tides came with a drenching rainstorm, portions of its community were temporarily cut off by the combination of high river flows and the relentless tides that rose over roads and causeways, isolating the community for several hours.
The high tide swept across town, flooding neighborhoods and temporarily put the municipality at a standstill. No doubt there will be flood-related damages still to be assessed.
On the Lane County coast the King Tides came on a relatively pleasant and mild weekend. But the effects of the abnormally high tides were hard to miss. All the beaches were inundated with sea water as waves pushed all the way to the sand dunes and protective jetties. This made beaches inaccessible and dangerous to visit throughout the weekend. In the Siuslaw River Bay, water backed up far past Mapleton and nearly to Brickerville. Lower in the bay, Cushmen historically has always been prone to high tides that can be made much worse when the Siuslaw nears or reaches flood stages. Fortunately the river, while the flow has gone up a bit in recent days, was not high enough to worsen what in general was a mild flooding event.
It will be a few days before we begin to understand the effects the recent King Tide had on the Oregon coast. Some beach erosion was already visible and there likely will be reports of minor flooding in our other river bay communities too. Which was the case around Florence, where a few bayfront homes and businesses had minor flooding, along with several bayfront parks that had water cover their parking lots and picnic areas. And a couple of small boats that apparently had broken away from their moorage, could be seen floating unmanned on the bay.
Bender County Park
At Heceta State Park, the beach had eroded away, the waves were crashing up against the riprap that holds the parking lot up and it could be awhile before the beach builds back up. Although the path to the lighthouse is fully intact, last weekend plenty of people were making the short trek to the lighthouse level to get a better view.
The complete flooding of the Siuslaw River Bay and estuary was quite dramatic and something not seen every day. The “King Tides” return in early December and again in January 2022 before subsiding until next fall.