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When heavy rains drenched the Peninsula on New Year’s Eve in 2022, they didn’t just flood the streets of Crescent Park, Duveneck/St. Francis and other neighborhoods around the volatile San Francisquito Creek.
They also eroded many of the plans that Palo Alto and its partner agencies have had in place to protect these neighborhoods from future flooding, dealing a heavy setback to residents who have been waiting for these improvements for more than 25 years.
With the flood damage exceeding projections, officials from the San Francisquito Creek Joint Powers Authority effectively acknowledged that the projects they had planned for Reach 2 — the agency’s second phase of its major flood-control project — no longer suffice when it comes to flood protection. The creek, it turns out, has less capacity than officials had previously thought. And the variations at the top of its banks have made a larger than expected difference when it comes to water spilling over the top and entering neighborhoods.
More worryingly for residents, the creek authority has concluded that it cannot proceed with the replacement of the flood-prone Pope-Chaucer bridge, a project that area residents have long clamored for, until other improvements are made downstream of the project. And after having its assumptions upended by the Dec. 31, 2022 storm, the creek authority does know at this time what those improvements would be.
Frustrations about the latest delays spilled out during a March 30 town hall meeting, which attracted a crowd of residents from Crescent Park, Duveneck/St. Francis, Community Center and Triple El neighborhoods to Duveneck Elementary School. Many were put off by the latest change of plans from the creek authority, an agency that is headed by elected officials from Palo Alto, Menlo Park, East Palo Alto, Santa Clara Valley Water District and the San Mateo County Flooding and Sea Level Resiliency District and that has been working on flood protection since the devastating flood of February 1998.
“I was flooded in 1998 and I’m very concerned about another flood coming,” said Evan Economos, a De Soto Drive resident.
He was among the residents who pressed the city and the creek authority to be more specific about when they plan to replace the Newell and the Pope-Chaucer bridges. The city is spearheading the Newell Road bridge replacement, which was slated for this year but is now projected to take place in 2025. The Pope-Chaucer bridge replacement, which is being led by the creek authority, is on shakier grounds, according to Margaret Bruce, executive director of the creek authority.
Some improvements have already been made, though they have largely focused on the more vulnerable downstream areas between Newell Road and the U.S. Highway 101. As part of the Reach 1 project that the creek authority completed in 2019, it had fortified these areas by widening channels and building new levees.
But the next phase of planned improvements, known as Reach 2, has not gone according to plans. After the December 2022 storm, engineers from Valley Water flagged the deviation between the creek’s actual activity and the authority’s projections about creek activity, suggesting that the assumptions on which the agency had built its flood-control project may no longer be sufficient.
A review that the consulting firm Schaaf & Wheeler released in February corroborated the Valley Water study and concluded that the creek authority’s prior model has “overestimated creek capacity.” It also found that the “creek geometry and creek roughness are the most important factors to predict overtopping.”
Given the latest information, Bruce said that the earliest that the creek authority can move ahead with replacing the Pope-Chaucer bridge would be in 2027. A key goal is to make sure that any improvements do not place downstream areas at greater risk, she said.
“Figuring out how to remove it or how to change it or how to replace it that doesn’t add to the flood risk of Palo Alto, Menlo Park and East Palo Alto downstream is going to be the hardest thing,” Bruce said.
The Schaaf & Wheeler study, she suggested, underscored the importance of the Pope-Chaucer bridge in protecting other areas from flooding.
“We understand that the slight variations at tops of bank at either side make a big difference about where the water spills and we learned that not only does the Pope-Chaucer bridge cause problems because it’s a choke point and water backs up behind it and spills out, it’s protective of Palo Alto, East Palo Alto and Menlo Park downstream because it retains some of the water,” Bruce said at the Town Hall meeting. “It is illegal for us to transfer risk.”
Not everyone was satisfied with the explanation. Susan Saal, a resident of Forest Avenue, was among those who were frustrated with the bureaucratic impediments to flood improvements. She recalled the anxieties that she and her neighbors experienced during the Dec. 31, 2022, rains.
“We were desperately worried about our neighbors, we were desperately worried about our own property. It was a tremendous crisis,” Saal said. “It is unclear to me what’s holding us up from achieving … what is the right thing to do in balancing these ecological needs with the real problem that we have with the flow of water through this creek.”
The creek authority is also struggling with this question. In March, it went out to bid on a consultant to help it forge a new path forward after the latest setbacks. It expects to hire a firm latest this month and have a new set of alternatives in place for analysis by this fall. It remains to be seen, however, what those improvements would be, how much they will cost, where the funding will come from and whether they will be acceptable to residents around the creek.
Menlo Park City Council member Drew Combs, who chairs the creek authority board of directors, observed in a December meeting that some of the alternatives that had been previously proposed for the Reach 2 segment — including flood walls — had “very visceral and negative reactions from the community.” Bringing these alternatives back could undermine residents’ confidence in the creek authority, he said.
“I’d say we risk a very large loss of trust if we then seem to go back to those alternatives when there was clear public apprehension and say, ‘Well, a new analysis. …’ That’s when trust erodes further,” Combs said.
While major upgrades won’t be coming for some time, the creek authority is preparing for limited creek improvements in the next two summers. This summer, residents should expect to see some site preparation work in the downstream area, she said. The goal is then to widen the channel in the downstream area in 2025 and then augment that work with other projects in 2026 and 2027.
“We have to think very carefully about what is the best solution to remove the problem — to mitigate the problem upstream of the water backing up and spilling — while not adding to the woes of the people of Palo Alto, Menlo Park and East Palo Alto if we were to send all that water down their way,” Bruce said. “We’re looking at that. It may be a while before we have an answer.”