San Mateo County gearing up for Wednesday storm

From late Thursday to Sunday, most areas of San Mateo County saw at least 4 to 6 inches of rain, with San Francisco International Airport getting 4.62 and Redwood City 5.12 inches. New Year’s Eve saw 4.47 inches of rain in the county, the third-highest rain total in a single day, according to the National Weather Service. Major roads like Highway 101 closed for several hours during the weekend because of the flooding. Wednesday will likely see substantial rainfall and gusty winds, with a flood watch in place until Thursday afternoon.

Parts of the Sunnybrae neighborhood in San Mateo flooded over the weekend, along with 42nd Avenue near El Camino Real. The San Mateo Police Department said on Facebook, on Sunday, that a vehicle became submerged after turning right onto 42nd Avenue from El Camino Real, ignoring cones and warning signs. The submerging led to the San Mateo Consolidated Fire Department and police officers having to get the woman trapped out of her vehicle. According to the police, four officers jumped into the water to help, taking the woman to a hospital for treatment. Police urged residents to be careful and turn around if they encounter a flooded road.

San Mateo city spokesperson Samantha Weigel said the 42nd Avenue intersection near El Camino Real closed Saturday morning and reopened Monday morning. San Mateo work crews are out clearing stormwater catch basins throughout the city to reduce flooding in vulnerable areas. Debris from across the city often gets caught in the storm drains and can clog the sewage system. The city advised residents to get any grocery shopping done before the storm and to avoid the roads during the storm. The city is testing stormwater pump stations and lowering the Marina Lagoon even further below typical winter levels. It will also open its emergency operations center to coordinate a city response.

“In areas that are more prone to flooding, we are preparing and warning residents we may proactively have to close some roads or provide detours for safety reasons,” Weigel said.

The city is working on several infrastructure projects to replace aging wastewater infrastructure and reduce flooding issues in the future, like the Underground Flow Equalization System project, which will build an underground 5.3-million-gallon structure to eliminate overflows.

“That is really going to help us in extreme storms like this to help capture that water instead of it flowing out into the street and treated,” Weigel said.

San Mateo County Sheriff’s Office Lt. Eamonn Allen said there were no injuries or deaths because of the flooding but urged people to be safe on the roads. The Sheriff’s Office is now preparing for the upcoming storm on Wednesday, planning to deploy search and rescue vehicles out to the coast in preparation for debris removal.

“We are expecting a severe storm, not as bad as the Saturday one, but still a good amount of rainfall,” Allen said.

Ray Mueller, who will be sworn in as San Mateo County supervisor Tuesday, said people should contact the county and their local city governments for support and resources if their homes are flooded, such as finding hotel stays.

The San Mateo Corporation Yard at 1949 Pacific Blvd. will have a sandbag station for residents, with the potential for a second location if needed. The city of San Mateo asked people to bring their own heavy-duty trash bags because supplies of bags are gone. The city of Foster City set up a free sandbag filling station in the City Hall parking lot for residents Monday. However, most supplies were gone by early afternoon, with plans to bring more in Tuesday, Foster City police Lt. Mark Lee said. Lee said there was no flooding or outages in Foster City as of Monday afternoon. The city of San Carlos said on social media that it ran out of sandbags on Monday but would have more on Tuesday at the Corporation Yard at 1000 Bransten Road. Sandbags are available in Redwood City at the Public Works yard at 1400 Broadway.