California report urges new flood modeling rules to boost resilience and insurance incentives

A California Ocean Science Trust report developed with Scripps Institution of Oceanography lays out eight recommendations to better reflect flood mitigation in catastrophe models and insurance pricing. The goal is to help coastal counties reduce risk, improve transparency and make resilience investments more financially rewarding as flood danger rises.

Why it matters: - California faces growing flood exposure from sea level rise, stronger rainfall, storm tides and ocean waves. - Better catastrophe modeling could help insurers reward flood mitigation with improved pricing and availability. - The report aims to make resilience investments more visible in insurance markets, which could support public and private spending on flood defenses. - The recommendations could help California better protect consumers as coastal flooding becomes more costly and more frequent.

What happened: - California Ocean Science Trust released a new report in partnership with Scripps Institution of Oceanography and under the oversight of a Technical Steering Committee. - The report was developed for the California Department of Insurance. - The report assesses current flood modeling practices and offers eight recommendations to improve how mitigation infrastructure is reflected in catastrophe models. - The effort builds on OST’s ongoing partnership with the California Department of Insurance, first formalized through a Memorandum of Understanding in 2023. - Insurance Commissioner Ricardo Lara welcomed the report and said the work shows how regulators can move toward proactive leadership on coastal flooding.

The details: - The report is titled “Strengthening Incentives for Flood Risk Reduction in Catastrophe Modeling and Insurance: Recommendations for California Coastal Counties.” - Scripps Institution of Oceanography scientists authored the report. - Dr. Brett Sanders of UC Irvine, Dr. Michael Beck of UC Santa Cruz, and Tim Farrell of the National Association of Insurance Commissioners served on the Technical Steering Committee. - Flood-related property damage in California is estimated at $8 billion per year on average, according to the California Earthquake Authority. - The National Oceanic and Atmospheric Administration warns that the strengthening “super El Niño” could bring more frequent, widespread and deeper flooding in coastal communities this winter. - Scientists at the U.S. Geological Survey estimate that an abnormal year with a catastrophic 1-in-1,000-year flood event in California could cause $725 billion in damage and business disruption, or more than $1 trillion in present-day dollars. - The report highlights the need for more information exchange, including stronger baseline measurement, better model inputs and more transparency in how risk reduction shows up in insurance outcomes. - The authors point to statewide flood insurance protection gap analysis, comprehensive data sets on flood-risk and defense structures, and a California Public Flood Risk Model as key next steps. - Dr. Tom Corringham of Scripps said insurance could help California prepare for rising flood risk by rewarding mitigation with better pricing and availability. - Dr. Liz Whiteman, executive director of OST, said state leaders need actionable guidance so insurance tools capture the value of both nature-based and traditional flood defenses.

Between the lines: - The report pushes California beyond counting flood losses and toward modeling how mitigation lowers risk. - That shift could influence underwriting, pricing and oversight, not just engineering or infrastructure planning. - The emphasis on transparency suggests the authors see current insurance models as too opaque to fully credit resilience investments. - The report also frames flood defenses as having multiple benefits, including stormwater capture, if they are planned well.

What's next: - California can use the report’s recommendations to improve mitigation planning across public investment, private risk-reduction decisions, insurance pricing and underwriting. - The report says those steps could position California as a national and global model for flood-risk understanding. - OST’s partnership with the California Department of Insurance is likely to continue as the state evaluates how to turn the recommendations into policy and market changes. - The report’s core challenge is to make flood risk reduction visible in the data, credible in the models and transparent in the markets.