Update from Kate - High Tides Through the Holidays

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High Tides Predicted Through Holiday Season

Travel plans could be affected, including on Thanksgiving

High-tide flooding is expected in Marin County starting this week, and the County of Marin's Department of Public Works and the Marin County Flood Control District are teaming with the California Department of Transportation (Caltrans) to urge residents and visitors to stay informed of changing conditions and understand how high tides might affect travel plans.

Drivers are encouraged to:

  • consider using alternative routes
  • avoid driving through ponded water
  • allow extra time for trips, especially during peak times of holiday and commuter travel
  • alert your visitors about possible flooding
  • check 511.org for the latest traffic and transit information

Caltrans plans to close the lower half of the Manzanita Park and Ride Lot and all nearby Shoreline Highway street parking in the Tam Junction area starting Friday, November 20. Here is an information sheet about Manzanita Tidal Flooding for further detailed information.

According to the National Oceanic and Atmospheric Association (NOAA), the following are predicted high tides at or above 6.5 feet Mean Lower Low Water (MLLW) through December 31 at the San Francisco gauge.

(KT = king tide)

Monday, November 23, 8:52 AM

6.6 ft.

Tuesday, November 24, 9:34 AM

6.8 ft.

Wednesday, November 25, 10:16 AM

6.9 ft.

Thursday, November 26, 10:59 AM

6.8 ft.

Friday, November 27, 11:42 AM

6.6 ft.<

Monday, December 21, 7:38 AM (KT)

6.5 ft.

Tuesday, December 22, 8:25 AM (KT)

6.7 ft.

Wednesday, December 23, 9:11 AM (KT)

6.9 ft.

Thursday, December 24, 9:56 AM

6.9 ft.

Friday, December 25, 10:41 AM

6.8 ft.

Saturday, December 26, 11:24 AM

6.6 ft.


King tides occur when the earth is closest to the sun and when the moon's orbit is closest to the earth, thereby causing a strong gravitational pull on surface water. Normal tides can still be significant even when king tide conditions are not present.

Southern Marin has a number of known tidal flood-prone locations where tidal water impacts roadways.

Mill Valley

  • Shoreline Highway at Highway 101, including Manzanita lot
  • Miller Avenue at Richardson Bay
  • Camino Alto at Miller Avenue
  • Redwood Highway Frontage Road (West)

During extreme high tide events, tidal flooding is also known to occur at the Marin City freeway ramp.

Marin City

  • West of Highway 101 and east of the ramp, approximately 850 feet north of Donahue Street

The National Weather Service has advised that El Niño conditions are already present and are likely to continue through this winter. The latest precipitation outlook for December through March indicates that Marin has a greater than 40 percent chance of receiving above normal precipitation. El Niño may increase the frequency of nuisance flooding.

Flood control zone-specific updates regarding maintenance, storm preparedness and responses are provided at the Marin Watersheds webpage. Learn about how you can prepare for flooding on the Flood Control District’s flood preparedness webpage.

Please stay in touch and feel welcome to write to me at ksears@marincounty.org. Share this information with friends and urge them to subscribe to my news and information by signing up. Have a safe and enjoyable Thanksgiving holiday.