by Jay Lund
2022 is another drought year, although we won’t know exactly how dry for about another month. Precipitation and snowpack this year in California are below average. In addition, the prolonged dry and warm months of January through March of this year’s “wet” season will have evaporated more water from watersheds and reduced snowpack, reducing runoff and groundwater recharge from this year’s modest precipitation and likely lengthening this year’s wildfire season.
Some reservoirs did refill during the wetter-than usual December, but many of the largest reservoirs remain significantly lower than at this time last year, in the 2nd year of this drought. This dry year already has more precipitation than 2021, and hopefully more runoff, but we enter this year with less stored water.
Agricultural surface water deliveries are already scheduled to be significantly reduced, some urban areas will likely have mandatory water use reductions, and prospects for salmon and other native species are not promising. This now three-year drought could go on for still more years (something we won’t know for sure until March 2023).
What should we do for this third year of drought?
Overall, California is fairly well prepared for drought, but some sectors and regions are much more vulnerable than others and require special attention. We naturally and usefully focus on California’s drought weaknesses,
Urban areas
Urban areas are a small proportion of human water use in California, but about half of urban water use is for landscape irrigation. So urban areas have considerable potential to reduce their water use, in percentage terms, but even large percent reductions, though useful, usually do not provide large volumes of water for the environment.
Water conserved in urban areas can serve several purposes: a) saving water in storage for urban users to use in additional dry years, b) increasing water available for more junior agricultural water users, c) making more water available for the environment. Prudent urban water managers tend to maximize storage of water for additional dry years, with some of this stored water becoming available to others in future wet years. Remaining conserved water tends to mostly become available for the larger thirstier agricultural sector. Only sometimes does conserved urban water make large amounts of water available for struggling ecosystems.
Maintaining the financial sustainability of urban water systems is challenging with drought. Urban water supply costs are largely fixed (for infrastructure and people) and vary little with water delivery volumes. Indeed, drought raises costs as management effort increases (for increasing water conservation and using more expensive water sources). Urban water utilities already having special drought rate structures are better prepared for the financial problems of drought. But water utilities lacking special drought rate structures already are likely to see their financial reserves tested or risk having unpopular rate hike proceedings detract from simultaneous requests for additional water use reductions. Urban water utilities in California should all have pre-established drought water rate structures that can be called upon.
Agriculture
Agriculture is by far the largest organized water use in California. Overall, agriculture again will see much larger water supply reductions than urban areas, even after farmers pump additional groundwater to make up for reduced surface water supplies. In 2021, the drought cost agriculture about $1 billion, about a 2% reduction in crop revenues and several thousand jobs lost for lower-income communities. Last year, these impacts were disproportionately felt in the Sacramento and Tulare basins, and were also substantial elsewhere (Medellin et al 2021).
Drought impacts are especially severe for rural counties and lower-income workers there, where agriculture is often the major economic engine and employer. Overall, the state economy is well insulated and prepared for drought, and is in a position to redress some of these regional economic impacts. The growth of more profitable permanent crops has increased agriculture’s economic ability overall to endure droughts, so long as groundwater and more fallow-able annual crops also exist.
This and future drought impacts on agriculture will extend beyond the end of this dry period, as future cropping will need to be reduced to replenish the additional groundwater pumping during this drought to comply with the Sustainable Groundwater Management Act and prepare for the next drought. Some large agricultural areas have begun assessing pumping fees exceeding $300/acre-foot to reduce long-term water use and fund groundwater replenishment. In the long run, ending groundwater overdraft and reducing agricultural drought impacts will require reducing irrigated acreage statewide by about 10-15%, mostly from less profitable crops grown on less productive soils.
Rural drinking water
Rural drinking water supplies from wells are again threatened and will be interrupted by falling groundwater tables from additional agricultural pumping during drought. These problems affect about one hundred small community water systems and thousands of rural household wells. Short-term water-hauling and long-term consolidation into bigger systems when possible, deeper wells, and ending groundwater overdraft are the only solutions. These are individually expensive solutions (some more than others) that often face local political difficulties. The state is getting better with organizing relief for some of these systems, but the state, counties, and local systems themselves have a long way to go.
Ecosystems
Ecosystems are the water use sector hardest hit by recent droughts and the current drought. Wild spawning of winter-run salmon was reduced by 95% in 2021 and needed to be supplemented by emergency hatchery releases. The drought also reduced other salmon runs and populations of other native fishes and birds.
Despite valiant efforts to rescue several endangered species during drought, California is not nearly prepared or effectively organized for preparing habitats and other conditions for native ecosystems to be sustained through drought. The magnitude and ubiquity of native habitat destruction over 150 years has overwhelmed the naturally evolved substantial drought adaptations of California’s aquatic ecosystems. A bright spot and example of effective management is how Pacific Flyway bird species are being sustained by long-term development of permanent and seasonal wildlife refuges with additional operational support and management during droughts – involving close coordination among state and federal agencies as well as environmental organizations, hunters, and land owners.
Forests and wildfires are the areas most affected by drought. Drought increases stresses and deaths of forests, which increases the severity of wildfires extending years after dry years end. The $9 billion direct costs of the 2012-2016 drought were dwarfed by the many tens of billions of dollars in damages and many deaths from worsened wildfires in the following years. Indeed, the biggest urban impacts of the previous drought were undoubtedly from air quality economic and health impacts from the ensuing worsened wildfires.
Conclusions
California’s climate has always had frequent and sometimes prolonged droughts. Urban and agricultural water users have developed major infrastructure and water management to largely dampen the effects of such droughts. Changes in climate, especially higher temperatures, are making these droughts deeper and probably longer, which will require additional preparations.
The same infrastructure improvements that have insulated human water users from drought, have helped overwhelm the ability of native aquatic ecosystems to endure droughts. Similarly, the prolonged suppression of forest fires has made forests more vulnerable to large wildfires.
We do not know long much longer this drought will last beyond its third year. We can be sure that, if water is managed well, this drought will not soon be devastating to California, overall. Nevertheless, this drought will have major impacts to some regions and sectors, which should motivate improvements to water and ecosystem management for the long term.
California has become more resilient to drought with steady adaptation and improved preparation from each drought, particularly from better human organization of water management (Pinter 2019; Lund et al. 2018). Natural evolution also made California’s natural ecosystems relatively resilient to droughts until this resilience was overwhelmed by human land and water management. Today, these human and natural systems are mutually-dependent for their sustainability, and we must better organize these combined efforts for this and future more severe droughts.
Further readings
Lund, J.R., J. Medellin-Azuara, J. Durand, and K. Stone, “Lessons from California’s 2012-2016 Drought,” J. of Water Resources Planning and Management, Vol 144, No. 10, October 2018.
Medellín-Azuara, J, et al. (2022), Economic Impacts of the 2021 Drought on California Agriculture – Preliminary Report, UC Merced.
Pinter, N., J. Lund, and P. Moyle. “The California Water Model: Resilience through Failure,” Hydrological Processes, Vol. 22, Iss. 12, pp. 1775-1779, 2019.
Jay Lund is a Professor of Civil and Environmental Engineering and Co-Director of the Center for Watershed Sciences at the University of California – Davis. He writes this after recently traveling across northern California’s watersheds, where reservoir levels are low and snowpack almost non-existent for mid-March, fire scars for several years of wildfire are prevalent, and more orchards are being planted than removed.
