13 inches of rain, with break in sight for San Mateo County

“The next system is coming in with a cold front and should be a fairly quick moving storm that should produce anywhere from a tenth to a quarter inch of rain. After that, a high pressure moves in and there should be clear skies for the rest of the week,” Goatley said.

This past weekend, the county saw 3 to 4 1/2 inches of rain, which totaled 13 inches of rain since the New Year’s Eve storm. Temperatures throughout the week will be in the mid-50s and overnight lows in the high 30s to low 40s. However, Goatley said the rain was a little too much in a short period of time.

“If the rain was spread out over a long period it would have been far more beneficial that way,” Goatley said. “When you get the ground so saturated, water can’t build up so it starts to run off in excess and it is not retainable.”

The Bay Area accumulated more than 20 inches of rain this water year, which is 244% compared to normal as of Tuesday, Goatley said.

Additionally, Steven Ritchie, assistant general manager of water enterprise at the San Francisco Public Utilities Commission, said the rain is on track with 1983’s record high, during a meeting Tuesday.

On Tuesday, the Calaveras Reservoir reached its capacity spilling over for the first time since the new dam was built in 2019. Also, Crystal Springs Reservoir has reached 58,806 acre feet, surpassing its operating capacity by 500 acre feet. Ritchie added the reservoir’s total capacity is around 68,000 acre feet and operates lower to preserve endangered species in the area but it sometimes will flow over. The reservoir is on the fuller side as the officials closed pipelines from the Hetch Hetchy Reservoir in Yosemite for maintenance, leaving the county to consume what water is currently stored in the Crystal Springs and San Andreas reservoirs. 

Flooding issues

Creeks overflowed in various parts of the county throughout the series of storms and Pescadero was devastated by last week’s storm when Stagecoach Road and North Street completely flooded. That forced some residents to evacuate and Cal Fire had to rescue three vehicles from flooded muddy water.

The Belmont Trailer Park also had severe flooding issues, which forced its residents to evacuate. That, ultimately, prompted Caltrans to assess how the influx of water can be better mitigated during future storms. Pedro Quintana, Office of Public Affairs branch chief for Caltrans, said the agency responded to the flooding at the trailer park and is monitoring the situation closely with a hydraulics expert expected to visit the site late last week.

“Caltrans crews are working 12-hour shifts on a 24/7 basis on cleanup and repair for the extreme weather events in the Bay Area, as well as preventative measures as the rain continues,” Quintana said in an email.

Landslides and sinkholes

The storms caused serious damage to roads and infrastructure causing sinkholes and landslides in various locations around the county from the oversaturated grounds. A large sinkhole developed on State Route 92 west of Skyline Boulevard on the westbound lane. Quintana said engineers and safety specialists were able to fill the hole and address a rock slope protection to protect vehicles and the road from further debris. A one-way traffic from the Highway 35 juncture Pilarcitos Creek Road, 3.2 miles east of Highway 1. Quintana said while the road is being worked on travelers should consider alternative routes or prepare for delays.

“We have crews working on this 24/7, Caltrans’ main priority is safety and we want to make sustainable repairs, to make sure it is safe for travelers and from future storms,” said Quintana, adding travelers can use northbound Highway 1 toward Pacifica to reach Interstate 280 if they want to avoid the traffic congestion.

Once Caltrans finishes the westbound side, it will switch traffic over and work on the eastbound side for additional precautionary repairs.

On Monday, a large boulder fell onto the southbound side of Highway 1 near the entrance of the Tom Lantos Tunnels near Devil’s Slide in Half Moon Bay. Quintana said California Highway Patrol reported the incident and Caltrans crews were able to move the debris over.

“Crews were able to clear the road and called a geologist to examine the slope, however, the San Mateo County Parks owns the land and Caltrans is working closely with the Parks Department to ensure we can support them to make sure the slope is safe and no other debris will fall from the area,” Quintana said.

On Highway 1 near Pescadero Creek in Pescadero, one-way controlled traffic is in place due to a portion of the road sinking. A Caltrans geologist was sent to the scene and crews are working toward stabilizing the slope near the guard rail, Quintana said.

The 4100 block of Stagecoach Road is closed due to a partial collapse of the road near Pescadero that occurred last Saturday, according to the Cal Fire CZU Twitter page.

Two homes in Belmont were compromised by the storm after a large mudslide occurred in the 2800 block of San Juan Boulevard on Jan. 14. The city announced the road will likely be closed for another two weeks while it evaluates options for debris removal. A portion of San Juan Boulevard near the mudslide remains closed and the two homes red tagged.