California’s FY 2022-23 budget provides huge, once in generation capital investments. And extreme flooding is a growing climate risk, as the ARkStorm 2.0 study by XingYing Huang and Daniel Swain illustrates.
In November of 2021, after the extreme flooding in British Columbia, we called for California to prepare for extreme flooding, citing a 2018 study by Daniel Swain, Baird Langenbrunner, J. David Neelin and Alex Hall, which suggested “that California’s major urban centers (including San Francisco and Los Angeles) are more likely than not to experience at least one” storm sequence on the same size as the Great Flood of 1862 over the next 40 years.
Swain’s ARkStorm 2.0 study shows that megastorm risks will steadily increase on a business as usual emissions trajectory.
Unfortunately, Governor Newsom’s FY 2022-23 budget has proposed spending California’s budget surplus on water supply projects to mitigate drought effects, but not on major investments in flood risk reduction.
As we wrote in “Budget negotiations could determine the future of California’s Central Valley,” California Senate’s Climate Budget proposed spending $1 billion on flood management and dam safety. But SB 154, the budget bill passed in June, had only $246 million for flood risk reduction, including $146 million for urban flood risk reduction, and $100 million for systemwide flood risk reduction. There was $538,000 for multi benefit flood risk reduction projects.
Money from the Safe Drinking Water, Water Quality and Supply, Flood Control, River and Coastal Protection Fund of 2006 was allocated to support DWR’s development of the California Water Plan, and California’s many conservancies, but not flood risk reduction.
SB 154 also had $100 million for dam safety, but that was deleted in the June budget trailer bill, SB 178 / AB 178. Extreme flood inflows put many dam spillways at risk.
For climate adaptation investments, California needs to prioritize protecting vulnerable populations, and that means greatly increasing our investments in flood risk management.
Further Reading
California Department of Water Resources. Central Valley Flood Protection Plan.
Colgan, D. Climate change makes catastrophic flood twice as likely, study shows. UCLA Newsroom. August 12, 2022.
Swain, D. ARkStorm 2.0: Climate change is increasing the risk of a California megaflood
Related blog posts
Budget negotiations could determine the future of California’s Central Valley, June 20, 2022.
We need to plan for extreme flooding in California, Nov 22, 2021.
Principles for State Investment in Climate Adaptation, Sept 16, 2019.
Urban Delta – 235,000 people at risk from levee failure in Stockton area, Feb 27, 2017.
Great work, Deirdre, as always.