When the first major storm of the season is upon us, a common thought will be that the drought of four years has ended. Hopefully the rains this year will be plentiful and without flood damage. But the drought will likely continue.
First, California’s precipitation deficit over the past four years has been huge, leading to more than 15 million acre-feet of groundwater and reservoir depletion – equivalent to 15 full Folsom Lakes – and very dry watersheds.
It will take a long time to recover from this deficit, especially because much of it is groundwater in the driest parts of the southern Central Valley, making it hard to refill.
Second, damage to the ecosystem from the drought is likely to take more time to recover. California’s ecosystems were highly stressed before the drought and were further stressed by the drought.
Many native fish populations are at their lowest levels ever, and some native species have been wiped out in many streams. The need to manage and dedicate water to restoring these fish populations will likely prolong the drought’s effects into wet years. This happened following the 1988-92 drought, when accumulated damage to ecosystems brought additional endangered species listings that have since reduced many water deliveries.
Finally, this drought, like all droughts, has led to major changes in policy and public thinking about water use and management.
Most of us now expect to use less water in our homes and businesses. Lower water use in households and businesses brings challenges for funding water utilities and higher water rates. But the conservation effort will ease future drought management, lessen demands on systems overall and remind us that California is a dry place.
The plights of many small water systems are now more widely known because of the drought. Hopefully this will lead to more effective state and county remedies. The state’s new Sustainable Groundwater Management Act will bring groundwater use into better balance over the long term. This is particularly important for agriculture and rural communities, which heavily rely on groundwater to get by during droughts.
However, balancing groundwater use will require reduced use of surface water and groundwater in wetter years and, for some areas, substantial overall reduction in irrigation.
Even if the drought ends this winter, its effects will long be with us.
Jay Lund, a professor of civil and environmental engineering, is director of the Center for Watershed Sciences at UC Davis.