California’s weather is weird and wild.  California has more extreme precipitation years (dry and wet) per average year that any other state.  Coefficient of variation for annual precipitation at weather stations for 1951-2008.  Larger values have greater year-to-year variability. SOURCE: M. Dettinger, et al. 2011. “Atmospheric Rivers, Floods and the Water Resources of California.” Water 3(2), 445-478.

By Jay Lund 

California is a land of extremes – where preparing for extremes must be constant and eternal.

The last six years demonstrated California’s precipitation extremes. From 2012-2015, California endured one of its driest years of record.  2016 was an additional near-average year, classified into drought because water storage levels were so low.

2017 will likely be the wettest year on record in northern California and one of the wettest years ever in most of California.  Most of California has over 160% of average precipitation, with over 150% of average snowpack. Reservoirs today are about 2 million acre feet above their long-term average for this date (having been about 8 million acre ft below average 2 years ago).

After wondering for years if the drought would end, the drought is definitively over, even as some impacts to forests, fish populations, and groundwater levels will persist for decades.  Last Friday, Governor Brown lifted his drought emergency declaration for the state, with a few exceptions.  But to keep drought lessons alive, this lifting also stressed a need to reduce wasteful water use and was accompanied by a state plan to make “conservation as a way of life.”

What should we have learned (or re-learned) from this decade’s dance with extremes?

• California is a land of water extremes. California is a dry place, that is sometimes much drier than usual for long periods of time – we call these droughts.  California also can become very wet – which can cause floods if inadequately managed and prepared for.
• California must manage for both extremes. Wet years allow gathering water into aquifers and reservoirs, but we can never economically capture all water in wet years. Even in dry years, we need to prepare for floods, in preparing infrastructure and emergency management. In all years we need to improve capabilities and coordination among water agencies (local, state, and federal).
• Conditions can change quickly. The drought took two years to develop and two years to end (although some effects will last for decades).  Floods move faster and more violently, as Oroville’s spillways tore themselves apart in mere hours.
• Groundwater is key to sustainability and prosperity for California’s human water uses. Increased groundwater pumping replaced about 70% of the drought’s agricultural water shortage. Groundwater provides by far the most water storage in California, and is the predominant storage for longer droughts.  The 2014 Sustainable Groundwater Management Act shows that this lesson was learned, but implementation remains a challenge.
• The southern Central Valley will see large reductions in net water use. This uncomfortable truth is now widely accepted following the drought. About 15 percent of the southern Central Valley’s agricultural land depends on groundwater overdraft. Problems in the Delta and increased outflows for the San Joaquin River threaten perhaps another 15 percent of supplies.  Soil salinization, urbanization of agricultural land, technology, and climate change will also mostly push to reduce irrigated acreage.
• Preparation is key to managing extremes – for both droughts and floods. Most cities and farmers did well in the recent drought and floods. A roughly 30% loss of water supply reduced statewide agricultural revenue by about 2-3% and urban losses were financially inconvenient but economically negligible.  Local impacts were sometimes much worse, especially for some rural communities. The biggest losses were in areas least prepared. Ecosystems were unprepared for this drought, with often devastating effects.  This wet year saw widespread minor flooding, but little major flooding, and identified some areas needing more attention and funding.
• Future droughts and floods will be a bit different. This drought was worsened by higher temperatures, hit an agricultural economy with many more permanent (and more profitable) crops, and hit a system with more effective water supply agency cooperation, and a different composition of species in the Delta ecosystem.  We need to prepare for future droughts (and floods).
• We need to do better. The extreme drought and wet year served to identify weaknesses in California’s water management. We must learn from these tests, and improve local, regional, and statewide water management.  Learning from past droughts and floods has make California’s water management as successful as it has been, and remains vital for sustaining a major dynamic civilization in such a dry and increasingly variable climate.

The last few years have shown some major problems:

• Groundwater. Implementing the Sustainable Groundwater Management Act remains one of California’s greatest water challenges.
• The Sacramento-San Joaquin Delta is a second key to sustainability and prosperity for California’s water system. We are still struggling with this one.
• Rural water supplies. California still has 1-2% of its population with substandard drinking water quality. The drought highlighted the problems of these mostly small rural water systems. Some progress is occurring, but will require stronger county responsibility, oversight, and capability, aided by others.
• Ecosystem management. The drought showed the weakness of remaining native ecosystems and pretty dreadful drought capability and preparation by agencies for their environmental responsibilities. State and federal agencies are neither organized nor funded to succeed here.
• Investments in flood infrastructure. While most of California’s flood infrastructure did pretty well, the floods showed a need to invest in maintenance and updating of major flood infrastructure – and Californians will need to pay for this.
• California lacks a coherent state water technical and scientific program, integrated across agencies. Lack of a common effective water balance, inadequately organized, transparent and expeditious data and modeling, fragmented science, and incoherent fragmentation of technical efforts add confusion, delays, costs, and hassles.  The state’s major drought, flood, groundwater, water right, rural drinking water, and environmental management problems mostly span agency responsibilities, requiring a common coherent technical program.  State effectiveness is hobbled without this.

As a mostly dry place with a highly variable climate, California’s water problems are eternal and will always be punctuated by floods, droughts, and other emergencies.  These are tests which invite, focus attention, and can help guide improvements.

If we want to continue to move forward, we cannot go back.

Jay Lund is a professor of civil and environmental engineering and director of the Center for Watershed Sciences at UC Davis. @jrlund113

Further reading

Alvar Escriva-Bou, Henry McCann, Ellen Hanak, Jay Lund, and Brian Gray (2016), Improving California’s Water Accounting, 28 pp. Public Policy Institute of California, San Francisco, CA.

Hanak, Lund, Dinar, Gray, Howitt, Mount, Moyle, and Thompson. 2011, Managing California’s Water: From Conflict to Reconciliation, Public Policy Institute of California, San Francisco, CA.

Kelley, Robert (1989), Battling the Inland Sea: Floods, Public Policy, and the Sacramento Valley, University of California Press, Berkley, CA.

Lund, J., “The banality of California’s ‘1,200-year’ drought,” CaliforniaWaterBlog.com, 23 September 2015.

Lund, J. “You Can’t Always Get What You Want – A Mick Jagger Theory of Drought Management” CaliforniaWaterBlog.com, 21 February 2016.

Lund, J. and E. Hanak, “Resistance is futile: Inevitable changes to water management in California” CaliforniaWaterBlog.com, 7 January 2014