Author: Stephanie Lau

Jurisdictions across the San Francisco Bay Area are experiencing climate change impacts that extend beyond city boundaries. Working collaboratively allows jurisdictions to pool resources and implement projects more effectively.

For example, OneShoreline helped bring together Redwood City, Menlo Park, Atherton, and San Mateo County to advance the Bayfront Canal and Atherton Channel Flood Protection and Ecosystem Restoration Project. This partnership improved regional flood resilience and reduced flooding in nearby mobile home parks.

Read more about OneShoreline’s role in coordinating multi-jurisdictional projects here: https://www.kneedeeptimes.org/regional-climate-adaptation-coordination/

Come join OneShoreline and County of San Mateo’s Public Works and Sustainability Department to pick up trash and create a healthier and more beautiful environment.

When: Saturday, March 14, 2026 at 9 am – 12 pm

Great opportunity for student volunteer hours! Help clean up Colma Creek! Scan the QR code in the flyer below for meetup location.

The flooding that occurred in Marin County on January 3–4, 2026 demonstrates the increasing impacts of sea level rise on shoreline communities in the Bay Area. With extensive coastline, low-lying development, and reduced funding available to protect communities and infrastructure, Marin County faces complex near- and long-term challenges that other Bay Area cities and counties are also confronting. These shared challenges highlight the value of a countywide agency like OneShoreline in coordinating stakeholders and advancing multi-jurisdictional shoreline resilience projects.

Join OneShoreline, San Mateo County Parks, and the City of San Mateo for a walk along San Francisco Bay to learn more about king tides, sea level rise, and the solutions that are currently being implemented to protect our shoreline.

When: Saturday, January 3, 2026 at 10:00 am-12:00 pm

Where: Coyote Point Recreation Area in San Mateo

The hike will meet at the Eastern Promenade (second left after entering the park) by the restroom with the mural. Hike attendees will not need to pay the $6 vehicle entrance fee.

Registration link: https://www.eventbrite.com/e/king-tides-guided-hike-tickets-1976673698242?aff=oddtdtcreator

Please Note: Heavy rain (more than 0.25 inch) will cancel this event.

A new article published in Western City, a magazine of the League of California Cities, highlights OneShoreline’s role facilitating and leveraging regional collaboration across all San Mateo County jurisdictions to address flooding and sea level rise.

Read more about how OneShoreline is working to help cities, agencies, and developers plan for a changing climate here: San Mateo County cities band together to improve climate resilience.

Help us clean the Bay! Join South San Francisco’s Environmental Compliance Program, OneShoreline, and the Town of Colma for our Volunteer Creek Cleanup.

When: Saturday, September 20, 2025 at 9 am – 12 pm

Where: Meet at the Utah Ave bridge in South San Francisco , at the intersection of Utah and Harbor Way, near 180 Utah

Refreshments will be provided, so please register for the event using this form.

For more information, visit http://www.smchealth.org/ccdcoastalcleanupday.org

Earlier this week, U.S. Representative Kevin Mullin (CA) held a press conference along the San Francisco Bay to announce new legislation he is advancing through Congress on shallow groundwater and sea level rise, co-led with Rep. Andrew Garbarino (NY). The Groundwater Rise and Infrastructure Preparedness Act would direct the U.S. Geological Survey (USGS) to map projected groundwater rise through 2100, assess potential impacts on public infrastructure and public health, and recommend mitigation strategies for at-risk communities.

“In San Mateo County, migrating groundwater already affects private property and public infrastructure, said Len Materman, CEO of the San Mateo County Flood and Sea Level Rise Resiliency District, or OneShoreline. ‘To overcome these hurdles and build protection, we need the best tools at our disposal, and in regard to groundwater, we do not yet have this,’ Materman said of areas in the county where groundwater is already close to the surface.” (from KQED’s coverage of the press conference)

Full articles about the press conference:

• Lawmakers Push to Map Groundwater Before It Swamps America’s Infrastructure (KQED)
• Mullin takes on groundwater rise in San Mateo County (San Mateo Daily Journal)

Groundwater levels are projected to rise in low-lying areas around the San Francisco Bay as sea levels rise. Learn more about groundwater rise here: Shallow Groundwater and Sea-Level Rise

Coastside News has published a new article on OneShoreline’s efforts to expand the Countywide Flood Early Warning System to include Pilarcitos Creek in Half Moon Bay.

Len Materman, OneShoreline’s CEO, said “the goal is for the city or county to be able to issue an alert to give residents enough time to move belongings off the ground and relocate vehicles. This would allow city officials to close roads and warn the wastewater treatment plant of incoming floodwaters.“

Read the full article here: https://oneshoreline.org/wp-content/uploads/2025/07/Coastsidenews-re-Flood-Early-Warning-System-7.16.25.pdf

The San Mateo Daily Journal has published an article about OneShoreline’s recent efforts to expand the Countywide Flood Early Warning System.

“There’s a lot of factors that are involved, but basically, what we’re trying to do is consolidate in one place, in real time, information for people throughout the county that are in flood-prone areas,” said Len Materman, CEO of OneShoreline.

Read the full article here: https://oneshoreline.org/wp-content/uploads/2025/07/San-Mateo-Daily-Journal-Flood-Early-Warning-System.pdf

Since last fall, OneShoreline has been partnering with ISeeChange to gather real-time reports of flooding throughout San Mateo County. As the rainy season comes to a close, we’re now also seeking historic flood photos to help us better understand where flooding has occurred over the years.

ISeeChange is a community-driven platform that enables residents to document and share how climate change affects their neighborhoods. Their team will analyze both current and past flood photos to gather insights that will support future flood resilience efforts and guide planning across San Mateo County.

Share your photos of flooding here: https://www.iseechange.com/campaigns/san-mateo