With rising tides threatening to submerge the Palo Alto Baylands by mid-century, city officials agreed on Monday that they need to explore new barriers — both physical and legislative — to protect coastal area from sea level rise.
These measures will be approved as part of a new Sea Level Rise Implementation Plan, a document that Public Works staff are in the process of putting together and that could have significant ramification for properties around the Baylands. The plan will evaluate, among other measures, zone changes in high-risk areas and new conditions for approving projects in these areas. It will also consider new Baylands structures to reduce the impacts of sea level rise, including horizontal levees.
The new plan aims to address what city officials have identified as a glaring weakness in their recent drive toward environmental sustainability. While the council had recently adopted a new sustainability plan and selected "climate change" as a top 2019 priority, its planning on sea level rise has until recently been relatively minimal. Some council members, including former Councilman Cory Wolbach, have repeatedly advocated for more planning for sea level rise, prompting staff to proceed more aggressively on the topic.
This includes the creation of a new sea-level-rise policy, which the City Council unanimously approved Monday night. The policy, in and of itself, does not create any new restrictions or propose new infrastructure. Rather, it recognizes that the best way to avoid long-term impacts from some of the most severe sea-level-rise projects is to continue to reduce greenhouse-gas emissions. It also commits the city to work with neighbors to coordinate a response to this expected calamity.
The policy also represents a bridge between the city's broad sustainability goals and specific policies that the council will start debating next year, including zone changes and building standards. Public Works Director Brad Eggleston called the policy a "critical first step for responding to future rising tides caused by climate change that we'll be experiencing over the foreseeable future."
"More importantly, it will be the springboard for developing a climate-adaptation plan that will protect Palo Alto," Eggleston said.
The city also plans to conduct a vulnerability assessment to identify possible threats to critical infrastructure through the year 2100. According to California's Fourth Climate Change Assessment, a state study published in January, sea level in the Bay Area has risen by more than 0.6 feet over the past century. The assessment projects a sea level rise of up to 1.9 feet by 2050 and between 5.7 and 6.9 feet by 2100. At that level, tides would spread through the Baylands and threaten critical city facilities, including the Municipal Services Center, the animal shelter, the Elwell Court offices of the Utilities Department and the Regional Water Quality Control Plant.
A map of projected sea levels in 2100 that the council saw Monday showed several neighborhoods on the east part of Palo Alto, including Duveneck/St. Francis and parts of Midtown, under between 2 and 4 feet of water.
"We do know it is going on and we do know it's going on at an accelerating rate," Jeremy Lowe, a senior environmental scientist with the San Francisco Estuary Institute, told the council Monday.
Lowe noted that there is inherent uncertainty in trying to project sea level rise, which depends in part on such factors as melting glaciers and failing ice sheets in south Antarctica. The situation, he said, could be a lot worse than what current estimates show. He also told the council that as sea levels continue to rise, so will the frequency with which extreme water events occur, such that 100-year floods (those that have a 1 percent chance of happening in a given year) become 50-year floods, which in turn becomes 20-year floods.
"Sea level rise will continue and we must think that is now business as usual and we should plan accordingly," Lowe said.
The council enthusiastically supported the policy, which calls for enhanced community engagement on sea level rise and an economic assessment of sea-level-rise vulnerability for public and private property (including cost estimates for inaction). But while there were no objections to the broad policy, city officials acknowledged that conditions will likely get more contentious in the future, when council members consider zone changes and other specific regulations for properties in flood-prone zones.
"There could be zoning requirements on where new developments could occur at all. There could be requirements on heights at which new developments could occur," Assistant Public Works Director Phil Bobel said.
Esther Nigenda, a member of the citizens group Save Palo Alto's Groundwater, was one of several residents who turned out to support the policy. She urged the city to go beyond the policy's long-term goals and adopt some of the near-term strategies that are included in the state guidelines. This includes ensuring that new developments are sited properly, prohibiting underground construction in expected flood zones and requiring electrical outlets to be placed above expected flood levels, she said.
"There are a lot of small things we can start doing now so we can make sure the projects coming up in the next two years are able to withstand impacts of sea level rise," Nigenda said.
The council agreed that the city should move with some urgency on the topic. Councilwoman Liz Kniss encouraged staff to move faster on the plan, with the goal of completing a draft by June 2020. Councilwoman Alison Cormack called the new policy an important development.
"This isn't about panicking now," Cormack said. "This is about understanding. Every time we look to build something in this area, let's think about how long this particular asset is going to last and we'll base our decisions on that."