by Jay Lund, Deirdre Des Jardins, Kathy Schaefer

“Old superlatives have been dusted off and new ones count to better describe the tragedy, damage, and trauma associated with the State’s latest ‘unusual’ weather experience.” DWR Bulletin 69-83, California High Water 1982-83, p.1

“California’s climate has often been described as variable, inconsistent, and unpredictable. The meteorological events of the last few years give additional credence to those observations. The two extremes of weather patterns the record back-to-back dry years of 1976-77 and the all-time record of consecutive wet water years, 1981-82 and 1982-83 — have now been recorded in less than a single decade!” DWR Bulletin 69-83, California High Water 1982-83, p.1

In July 1984, the California Department of Water Resources issued Bulletin 69-83, California High Water 1982-83.  It insightfully reviewed what is still California’s wettest water year in more than a century.  Reading this report gives a sense of California’s broad and eternal flood vulnerabilities and management problems.  Despite important advances since that time, many similar ideas could be written today.

Here are a few long-term lessons from the 1983 and 2023 experiences:

1. California often has wet and very wet years, just as it often has dry and very dry years.
2. Flooding can occur in all parts of California, and many parts can flood in the same year.  Few areas should feel entirely safe from floods. Flood hazard zones should be updated to consider subsidence, land use changes and climate change.
3. Floods have many causes, including regional flooding from major rivers, local tributaries, very local storm drainage, coastal storm driven waves, and infrastructure failures.  All cases can cause sizable property damage and deaths.
4. Effective infrastructure really helps.  For major river flooding, California’s systems of flood bypasses, levees, and reservoirs were highly effective, but will have vulnerabilities for extreme wet conditions which are becoming more likely with greater climate variability. Flood-fighting by local and state agencies greatly improve levee reliability, but local levee breaks must be expected and prepared for in a system with thousands of miles of levees.
5. Warnings and evacuations greatly reduce deaths from flooding, but reducing property damages requires investments and regulations to reduce flooding and flood vulnerabilities.  Most deaths are from people traveling through flood waters (often by car) and local levee failures. 
6. The Flood Operation Center was a beehive of activity this winter, as it was in 1983. The co-located activities of the Department of Water Resources and the National Weather collaboration are a valuable service to the State. Sharing resources, expertise, and technology has been an excellent investment.
7. This year’s emergency conditions in the Tulare Lake basin also occurred in 1983 and disrupted agricultural production in the region for two years.  (DWR 1984, p. 73)
8. Agency postmortems for major events are vital to improve understanding of present and future problems.  However, public agency documents usually find it easier to recount the history of events, losses, and successes, than to identify specifically and broadly causes of failures. Identifying systemic improvements must usually occur outside these documents, but is vitally important.  It is important to systematically reflect on, discuss, and learn from the experiences of each extreme event, wet or dry (Pinter et al. 2019).  Postmortem reports from major extreme events are opportunities to improve the understanding and functioning of California’s water system and should be expected and discussed to facilitate improvements.

This year (2023) we were lucky enough to have a cool spring to slow snowmelt.  In 1983, “There was, of course, a little bit of luck: Recall the termination of the rainfall and the unseasonably cool temperatures during the peak of the snowmelt period in the southern Sierra Nevada, which moderated the melt and possibly averted disastrous flooding in the San Joaquin Valley.” (p.4).  Luck always helps, but we should not count on it. 

Floods require serious long-term organization and preparation for past and still larger extremes.  Prepare with diligence and humility, for preparation is never perfect.  “There is no question that the various entities involved achieved some degree of success in managing the 1982-83 flood fight. We must realize that, although man’s ability to manage the extremes of the elements is sometimes successful, Nature bats last!” p. 4

Let’s hope that old agency postmortems and reflections can again be made available conveniently on the web to help us reflect on present and coming challenges.  These are helpful for understanding and restoring faith and pride in government, and perhaps more important for fostering the kinds of conversations we need professionally and publicly.

California has seen incredible floods and flooding in the past and must prepare for major flood events in the future.  Floods and droughts are inevitable in California, just as hurricanes are inevitable on the US Eastern seaboard and tornadoes are inevitable in the Midwest.  In all these cases, loss of life and economic damages are greatly reduced by preparation, infrastructure, warnings, and analytically-informed discussions and decisions.

Be prepared. 

Jay Lund is a Professor of Civil and Environmental Engineering and Vice-Director of the Center for Watershed Sciences at UC Davis.  Deirdre Des Jardins (@flowinguphill) is a tenacious researcher and policy advocate on climate adaptation in California water. Kathy Schaefer is a PhD Candidate at the University of California – Davis completing a dissertation on community-based flood insurance.

Further Reading/Listening

Bertino, M. (2023), “Tulare Lake Basin Flooding: An update for early May,” Bountiful Ag blog, May 12, 2023

California Department of Water Resources (1984), California High Water 1982-83, Bulletin 69-83, July. [Alas, State agencies no longer maintain historical documents on their public websites.]

California Department of Water Resources (2022), Central Valley Flood Protection Plan, Update 2022.

Department of Water Resources (DWR) (1978), The 1976-1977 California Drought – A Review, California Department of Water Resources, Sacramento, CA, 239 pp. [Alas, State agencies no longer maintain historical documents on their public websites.]

California Department of Water Resources (2021) California’s Drought of 2012–2016: An Overview..

Lund, J.R. (2012), “Flood Management in California,” Water, Vol. 4, pp. 157-169; doi:10.3390/w4010157.

Pinter, N., J. Lund, and P. Moyle. “The California Water Model: Resilience through Failure,” Hydrological Processes, Vol. 22, Iss. 12, pp. 1775-1779, 2019.

Swain DL, Langenbrunner B, Neelin JD, Hall A. (2018) Increasing precipitation volatility in twenty-first-century California. Nature Clim Change. 8(5):427–433. doi:10.1038/s41558-018-0140-y.

Tulare County Master Flood Control Plan (1971), https://tularecounty.ca.gov/_api/render/file/?fileID=8045B502-5056-A959-DB0F3AB7DEC64B50

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