Water, the lifeblood of California, will be where the state experiences the most severe impacts of climate change. Unfortunately, most water agencies have yet to adjust to this “new normal” and are operating on outmoded assumptions and practices that place the state at risk of water shortages and worse. And while the recent rains may convince some that no action is needed, the science tells a different story.
Gov. Jerry Brown has set California on a smart course by calling for new long-term water-use targets for urban water agencies, targets that focus on the efficient use of this precious resource. Now it is up to the state Legislature to adopt a package that puts that plan into statute.
California has the most variable climate in North America, and a few storms can make the difference between a wet and a dry year. Climate models forecast that California will see more extreme events like the floods we are now seeing, or the severe drought we have been experiencing for the last five years. A recent Stanford study predicted that California’s dry years will likely see even less rainfall in the future. In other words, California’s future droughts will be more severe.
Warmer temperatures will make our water challenges even more daunting. The winter storage of snowpack, and its release during spring and summer months, is the backbone of California’s water system. The consensus view among scientists is that California will be 3 degrees to 5 degrees Fahrenheit warmer by midcentury, causing more precipitation to fall as rain rather than snow.
Additionally, as a UCLA study currently in peer review found, under current trends, Sierra runoff will occur significantly earlier than historic norms by the end of the century. So even in years with average rainfall, runoff will occur much earlier and more sporadically, increasing the likelihood of floods during the winter months and droughts during the summer months.
Add problems of saltwater intrusion in coastal aquifers because of rising seas, and warmer temperatures that increase evaporation from reservoirs and plants’ need for water, and the picture becomes frighteningly clear.
Business as usual won’t cut it. We need to rethink how we use and manage California’s precious water resources.
Los Angeles depends on imported water. Approximately 58 percent of the water used in Los Angeles County comes from outside the region. And within the city of Los Angeles, nearly 90 percent of the water supply is imported. With those imported supplies now at risk from climate change, the most cost-effective way to protect our region from crippling water shortages is to dramatically improve the efficiency of our water use.
Investing in efficiency is the smart new business model for water agencies, and setting and adhering to locally appropriate water budgets is a fair way to proceed.
During the drought, the Water Board implemented emergency conservation targets to achieve a 25 percent reduction in urban water use. These targets helped the state weather the drought emergency. But they don’t necessarily ensure we are all using water efficiently.
For the long-term approach, the governor has proposed a budget-based framework based on standards for efficient indoor and outdoor water use, as well as limiting leaks in the water delivery system.
Some water suppliers are already using water budgets to help their customers use water more efficiently. The data and tools are available and can be used across the state to develop an effective and equitable system for improving water conservation and efficiency. These new standards recognize that communities have different water needs and savings potential, but require everyone to do their part.
Our research shows us that in the future, it will be much more difficult to to meet the water demands of a growing population and a thriving economy. A meaningful, long-term focus on water conservation and efficiency is the best way to ensure a sufficient and affordable supply of our most precious resource for all Californians.
Alex Hall is a professor in the Department of Atmospheric and Oceanic Sciences and the Institute of the Environment and Sustainability, and director of the Center for Climate Science, at UCLA.
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