High-tide flooding coming to Marin County

High-tide flooding in Marin County is expected in December and January starting Sunday, the Marin County Department of Public Works said Monday.

Flooded roads are expected in parts of Marin County between Dec.

10-16 and Jan. 8-14. Drivers are encouraged to use alternate routes and avoid driving through water.

Caltrans plans to close the lower half of the flood-prone Manzanita Park and Ride lot at the junction of U.S. Highway 101 and state Highway 1 near Mill Valley. The area floods when tide levels exceed 6.2 feet.

The Department of Public Works constructed a 175-foot long sandbag wall along Highway 1 adjacent to the Caltrans maintenance yard where the road floods, but the risk of flooding is still high at other locations in the area with the predicted tide levels.

Extreme high tides, known as king tides, just over seven feet are expected on Dec. 13 and 14 and Jan. 11, according to the Department of Public Works. King tides occur annually when the earth is closest to the sun and the moon’s orbit is closest to the earth causing a strong gravitational pull on the water surface.

The lowest tides will be 6.36 feet on Dec. 10 and 6.34 feet on Jan. 14. The highest tides will be 7.09 feet on Dec. 13, 7.06 feet on Dec. 14 and 7.01 feet on Jan. 11.