King tides, and warning to travelers, coincide with winter holidays

11/26/2019

King tides occur when the earth, the moon and the sun are aligned, exerting the maximum gravitational pull on the tides, and this year they are coinciding with the holidays. The county’s flood control and water conservation district, which includes eight zones managed by voluntary advisory boards, released a notice this week warning residents traveling for Thanksgiving and Christmas in areas notorious for flooding. High tides are projected to reach between 6.3 and 6.8 feet from Nov. 23 to Nov. 28 and again from Dec. 22 to Dec. 27, based on projections published by the National Oceanic and Atmospheric Administration. “Those tides don’t look terribly threatening, unless they happen to coincide with a storm,” explained Gerhard Epke, the senior program coordinator for the county’s flood control district. “When the air pressure lowers during a storm, stopping pushing down the water system as much, the tides can come a foot or a foot and a half higher than those predicted values.” The county urged drivers to allow extra time for trips and to avoid driving through standing water; even six inches of standing water can stall a low-clearance car. It also suggested considering alternative routes. To get a sense of what king tides do to certain spots in West Marin, Mr. Epke pointed to the California King Tides project, an endeavor of the California Coastal Commission and a host of partners. The project maintains a database of photographs taken during the tidal events for the purpose of painting a picture of rising seas; projections show that by 2100, the ocean could rise by around the same number of feet as the inflation during a king tide. The database includes photographs of the iconic Point Reyes boat that typically rests on a sandbar at the shore of Tomales Bay: On Jan. 20, 2019, the boat looked like it was nearly afloat again. Images that show the effects of king tides along the Marin coast can be found on the California Coastal Commission webpage under “King Tides” and the link “King Tides Story Map.”