San Mateo County experts prep for sea-level rise

OneShoreline’s Planning Guidance Policy to Protect and Enhance Bay Shoreline Areas of San Mateo County, crafted by OneShoreline staff and consultants with Good City Company, is meant to be a resource for the 12 cities either directly lining the Bay or affected by it and those who are interested in engaging in discussions around sea-level rise and resiliency. 

The 54-page document includes actionable template language for general plans, specific plans and zoning ordinance amendments — the key ways decision-makers enact land use policy — a project review checklist, implementation and an interagency development review tools and an interactive map showing future expected flooding and sea-level rise conditions. 

It solely focuses on the county’s Bayside, an area at high risk of sea-level rise but also greatly vulnerable to other side effects of extreme weather conditions like flooding as seen during recent winter storms. Historic levels of rain fell in the area and, paired with high tides, left cities scrambling to respond to downed trees, flooding creeks and streets and extended power outages. 

“We see this as the new normal,” said OneShoreline CEO Len Materman during the April 24 meeting. “Obviously, every year will be slightly different, but we should at least plan for this eventuality on an ongoing basis from now on.” 

Substantial development, largely from large commercial developers, has been proposed on the Bayside, underscoring the need for strong planning tools around how that new development will be expected to be built with sea-level rise resiliency in mind to protect the property being developed and those nearby. 

The document focuses on planning recommendations that put more responsibility on private developers to play a key role in building out environmental resiliency, largely excluding public facilities and small residential buildings including single-family homes, duplexes and triplexes. 

But Materman noted jurisdictions are facing immense pressure to build more housing by the state through its housing element process with many cities looking to build thousands of new homes in the next eight years. As part of that process, jurisdictions have also had to update their environmental justice and safety elements, which staff said presented an opportunity for integrating some of OneShoreline’s recommended policies into existing guiding documents. 

“Our core planning documents — general plans, specific plans, zoning ordinances — don’t take into account this new normal or any real aspect of the new normal and we think that they should because if that doesn’t change, then new developments that are intended to function for several decades under this regime of the environment won’t be resilient to those conditions and we’ll need to retrofit them to both protect those developments but to protect areas around them,” Materman said. 

Burlingame Vice Mayor Donna Colson noted developers interested in building in her city have offered to harden the shoreline against sea-level rise and other mitigation work as a community benefit despite needing that work to take place to protect their own properties for decades to come. 

By adopting policies like those proposed in the document, she said cities could remove climate resiliency improvements out of “the realm” of community benefits packages, a notion for which San Carlos Mayor Adam Rak shared strong support. Both cities, along with San Mateo and South San Francisco, have already begun working with OneShoreline on implementing climate resiliency measures into city planning documents. 

OneShoreline also plans to offer technical assistance to other cities looking to implement the plan and have developed a guideline for how to best go about doing so. They were also encouraged by board members to provide presentations to other counties that also border the Bay to encourage a regional response. 

The plan is also meant to evolve as new scientific information like projects on storms, sea-level rise and groundwater rise becomes available and lessons are learned as the guidance is implemented. 

Two areas already known to need more study include stormwater drainage and shallow groundwater rise. The public has also stressed the need for more consideration of environmental equity, recommendations for existing development, capital project planning and low-density residential development, among other areas. 

“We tapped into a lot of resources throughout the country to sort of pull together the recommendations in this document and we hope this document adds to that literature and pushes the conversation forward in how we can incorporate these requirements in a really tangible, meaningful way with our land use decisions,” said Project Manager Makena Wong. 

OneShoreline will hold an information and feedback session on the document at noon May 9 over Zoom. Email comments can also be submitted to planning@oneshoreline.org through May 19. Comments will be shared with the board during a meeting on May 22 with the final draft presented to the board on June 26 for approval. 

Visit https://oneshoreline.org/planning-guidance/ to learn more about OneShoreline’s Planning Guidance Policy and feedback opportunities. 

sierra@smdailyjournal.com 

(650) 344-5200 ext. 106