The Cost of Sea-Level Rise Measured in Tens of Billions in California

A new report summarizes the impact rising sea levels would have on California residents, businesses, and infrastructure. The effects would be catastrophic for the San Francisco Bay Area.

2 minute read

August 20, 2020, 9:00 AM PDT

By James Brasuell @CasualBrasuell


King Tides

Rae Allen / Flickr

Roxy Bonafont shares news of a new report from the California State Legislative Analyst’s office that quantifies the risk to property, public and private, in the state of California as a result of expected sea-level rise.

"Sea levels on the California coast could rise as much as seven feet by 2100 and put tens of thousands of vulnerable San Franciscans at risk of daily flooding, according to the climate change that informs the new report.

The effects for the state of California would be catastrophic, according to Bonafont's explanation for he report's findings:

Between $8 billion and $10 billion worth of existing property in California will likely be underwater by 2050, the report states, and an additional $6 billion to $10 billion will be at risk at high tide. A six-foot sea level rise, combined with recurring annual storms, would put over 480,000 California residents and $119 billion in property value. Five feet of sea level rise would put 55 percent of coastal habitats in California at high risk of flooding and damage. Rising sea levels could also contaminate drinking water with saltwater or toxic materials.

The news isn't any better for the Bay Area, either:

A four-foot increase in sea levels would put a significant amount of Bay Area infrastructure at risk of flooding, including 59 miles of highways and bridges, 48 miles of freight rail lines, 20 miles of passenger rail lines, 11 acres of ferry terminals, 780 acres of seaports, and 4,670 acres of airports. A six-foot increase would put 30 San Francisco wastewater treatment plants at risk of flooding — far more plants than in any other part of the state — which could cause toxic sewage leaks that endanger the health of the surrounding community.

The San Francisco Bay Area's economy, already hampered by the pandemic, would also lose some of its clout, as 104,000 existing jobs in the Bay Area would be forced to relocate in the event of four feet of sea-level rise.

Saturday, August 15, 2020 in San Francisco Weekly

Young Professional

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching. Mary G., Urban and Environmental Planner

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching.

Mary G., Urban and Environmental Planner

Get top-rated, practical training for planners

"Planetizen federal action tracker" logo superimposed over black and white image of US Capitol dome.

Planetizen Federal Action Tracker

A weekly monitor of how Trump’s orders and actions are impacting planners and planning in America.

7 hours ago - Zachary Whalen

Overlapping highways

The state-sanctioned urbicide of Austin

People don’t kill cities. Freeways do.

September 8, 2026 - Benjamin Schneider

The Hoover Dam blocking the Colorado River. The river's water level is noticeably low. The cliffs surrounding the blue water are brown and jagged.

US to reduce Colorado River water deliveries to Mexico

A new Colorado Treaty amendment reduces Mexico’s Colorado River water allocation by 250,000 acre feet.

September 11, 2026 - The Arizona Republic

A cluster of wind turbines beneath a stormy sky, above a forest where the leaves are beginning to change colors.

5 New England states march closer to 800 megawatt wind energy project

Securing federal approval for the project may be complicated under the Trump administration, which has historically been hostile towards domestic wind power.

3 hours ago - Inside Climate News

People boarding a bus on Maryland's Orange Route.

Baltimore to break ground on $50 million Transit Priority Project

The project will bring faster bus trips, safer streets and better bike connections to Baltimore.

4 hours ago - Mass Transit

A brick building with a circular sign with the Airbnb logo hanging off of it.

Airbnb launches $250 million 'last-dollar financing' housing accelerator, makes first investment in Austin

The company will put $6.4 million towards affordable housing development in Texas’ capital.

5 hours ago - Smart Cities Dive

FREE Course: Walkable City 1: Why Walkability?

After describing his path towards focusing on walkability as the essence of good planning, Jeff Speck marches through his five principal reasons for making more walkable places.

Reinventing Malls: Planning Alchemy—Turning Gray Fields Into Gold

The course focuses on the opportunities and imperatives that shape reinvention of mall sites.