A recent research paper titled “Large and Inequitable Flood Risks in Los Angeles, California,” was published in the journal Nature Sustainability by the CLEWS (Climate, Land, Energy Water Solutions) group at UCI. The study employed a new flood modeling and mapping technique called PRIMo (Parallel Raster Inundation Model) to demonstrate the effects of a 100-year flood in almost every house’s detail. The research discovered that the current assessments were highly inaccurate, and the outdated waterway control system was not equipped to handle a severe flood.

Lead author Brett Sanders, a UCI professor of civil and environmental engineering, says, “We knew that the paper would garner attention because we demonstrated that the number of individuals at risk is 30 times higher than the federally established flood plains suggest. Additionally, we discovered significant racial and economic imbalances in the flooding risks that residents confront.”

Within a month of its publication, Los Angeles County Supervisor Janice Hahn utilized the research findings as a basis for a motion that was instantly and unanimously approved. The motion directs the county to assess its stormwater infrastructure and address disparities in the current system.

California Assemblywoman Cottie Petrie-Norris, who represents Huntington, Newport, and Laguna beach cities and Irvine in the 74th District, states, “The paper highlights how immediate and pressing this threat is. For a long time, when we discussed flood hazards and sea-level rise, people assumed it was a hundred years away. However, the reality is that it is here, it is now, and it is urgent. The state of California’s response must reflect that urgency.”