San Mateo to spend on flood prevention

A city staff report noted flooding was primarily due to the overwhelmed capacity of the city’s storm drain system, with Chuck Anderson from Schaaf and Wheeler saying that, based on simulations of storm results, most street flooding came from inadequate storm draining and creek overflow rather than higher than expected lagoon levels. The Marina Lagoon pumping station saw multiple pump engines failing in the early morning, which caused higher water levels and prevented the Marina Lagoon from being drawn down. The station receives stormwater drainage from approximately two-thirds of the city. The engine failures resulted in lagoon levels rapidly rising and being 1 foot higher than if all the engines and pumps had operated as intended. The day saw multiple pump operation problems between 5-8 a.m., with replacement pumps not called on during failures. One engine had issues all day, and the alarms did not call out. Anderson noted the best preventative measure for flooding was to ensure all pumps were operational. Had all pumps worked, there still would have been flooding along the 16th Avenue channel upstream of Highway 101, with some flooding around 19th Avenue. There would have been isolated other flooding, primarily in streets downstream of Highway 101.

To help address some of the flooding issues at the lagoon and with the city’s stormwater system, the council agreed to a city staff three-phased approach aimed at short-term moves to address flooding issues. The city will start maintenance on all five diesel engines costing around $500,000, have five sandbag stations in the city during the rainy season and clean all catch basins before the rainy season and during high-risk times. The council agreed to use $1.9 million from the city’s general fund and $1.1 million from its rainy day reserve, with confirmation expected at the Sept. 5 meeting. The council unanimously agreed to the funding requests, with Mayor Amourence Lee noting the issue was a priority that needed direction as soon as possible.

“There’s a real sense of urgency to act,” Lee said at the council meeting.

Other improvements the city will work on include small lagoon maintenance dredging, small-scale drainage improvements, camera monitoring of priority creeks, and an aerial survey of the creek and lagoon. Longer term options include a storm drain master plan update costing around $2.4 million and more substantial planning for Marina Lagoon dredging of debris at $1.4 million. Dredging would require a long permit process from the U.S. Army Corps of Engineers, the Department of Fish and Wildlife and others to determine the best method of dredging and approval. The total costs for all the short-term improvements suggested at the council meeting would be around $8.5 million. However, city staff is not requesting the full funding yet because of staff capacity restrictions on completing the tasks.

Councilmember Rich Hedges wanted to see more money initially allocated from city funding for the improvements, suggesting a minimum of $4 million from the city’s reserve fund and $1.9 million from the general fund. He noted he had talked to the city’s finance director about more funding and believes it could work under the current restraints. However, the council decided on $3 million based on staff recommendation.

“I think the money is light,” Hedges said.

Full funding for infrastructure improvements still needs to be allocated. The city has previously said upstream infrastructure improvements to prevent flooding, like increasing pipe sizes and small culverts near highways, would require around $68 million in funding. The council is exploring an $8 monthly stormwater property fee for a November ballot measure following reports showing narrow support for it. However, it is still less than half of what is needed for full funding, which is $18.87 a month.

The push for funding comes following public mobilization to advocate for further investment and changes, with the Shoreview neighborhood a key driver in asking for more from the city. Danielle Cwirko-Godycki, a leader in organizing whose Shoreview home flooded, spoke at the council meeting to call for funding to reduce the flooding threats. She helped form the Shoreview Parkside Association and is part of Future Ready San Mateo, a community organization of people throughout the city working to address problems.

“We need to fix the infrastructure because we can’t keep up with climate change, and it’s really critical we do this now,” Cwirko-Godycki said.

Several public speakers, like Rick Sakuda, called for continuing dialogue with the city to help prepare for future storms and to ensure people’s concerns were being addressed, noting the city had improved in the last few months.

“We need open communication with our Department of Public Works,” Sakuda said. “We can provide knowledgeable members from our community who have practical knowledge of the operations of the lagoon,” Sakuda said.

“I think it’s clear that the community has been united in its feeling,” Deputy Mayor Lisa Diaz Nash said, “and I think it’s clear we have heard you.”