Environmental Consequences of the California Drought

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In 2015, California was once more taking stock of its water supply, coming out of the winter season in its fourth year of drought. According to the National Drought Mitigation Center, the proportion of the state’s area in severe drought had not significantly changed since a year before, at 98%. However, the proportion classified as under exceptional drought conditions leaped from 22% to 40%. Much of the worst hit area is in the Central Valley, where the dominant land use is irrigation-dependent agriculture. Also included in the exceptional drought category are the Sierra Nevada Mountains and a large swath of the central and southern coasts.

There was much hope that the winter 2014-2015 would bring El Niño conditions, resulting in above normal rainfall across the state, and deep snow at high elevations. The encouraging predictions from earlier in the year did not materialize. In fact, in late March 2015, the southern and central Sierra Nevada snowpack was only at 10% of its long-term average water content and only at 7% in the northern Sierra Nevada. To top it off, spring temperatures were quite above average, with record high temperatures observed all over the West. So yes, California is really in a drought.

How Is the Drought Affecting the Environment?

  • Energy: About 15 percent of California’s electricity is provided by hydroelectric turbines operating on large water reservoirs. Those reservoirs are abnormally low, reducing hydropower’s contribution to the state’s energy portfolio. To compensate, the state needs to rely more on non-renewable sources like natural gas. Fortunately, in 2015 utility-scale solar power reached new heights, now at 5% of California’s energy portfolio.
  • Wildfires: California’s grasslands, chaparral, and savannas are fire-adapted ecosystems, but this prolonged drought is keeping the vegetation tinder dry and vulnerable to intense wildfires. These wildfires create air pollution, displace and kill wildlife, and damage property.
  • Wildlife: While much of the wildlife in California can weather temporary dry conditions, a prolonged drought can lead to increased mortality and reduced reproduction. Drought is an additional stressor affecting endangered species already burdened by habitat loss, invasive species, and other conservation problems. Many species of migratory fish are endangered in California, notably salmon. Low river flows due to the drought reduce access to spawning grounds.

People will also feel the effects of the drought. Farmers in California are heavily dependent on irrigation to grow crops like alfalfa, rice, cotton, and many fruits and vegetables. California’s multi-billion dollar almond and walnut industry is particularly water intensive, with estimates that it takes 1 gallon of water to grow a single almond, over 4 gallons for a single walnut. Beef cattle and dairy cows are raised on forage crops like hay, alfalfa, and grains, and on vast pastures that require rainfall to be productive. Competition for water needed for agriculture, domestic use, and aquatic ecosystems, are leading to conflicts over water use. Compromises need to be made, and again this year large swaths of farmland will remain fallow, and the fields that are farmed will be producing less. This will lead to price increases for a wide variety of foods.

Is There Some Relief in Sight?

On March 5, 2015, meteorologists at the National Oceanic and Atmospheric Administration finally announced the return of El Niño conditions. This large scale climate phenomenon usually is associated with wetter conditions for the western U.S., but due to its late spring timing, it did not provide enough moisture to relieve California from drought conditions. Global climate change throws a good measure of uncertainty in forecasts based on historical observations, but perhaps some comfort can be taken by looking at historical climate data: multi-year droughts have happened in the past, and all have eventually subsided.

El Niño conditions have subsided during the 2016-17 winter, but a number of powerful storms are bringing a copious amount of moisture in the form of rain and snow. It won't be until later that we will really know if it's enough to bring the state out of the drought.


California Department of Water Resources. Statewide Summary of Snow Water Content.

NIDIS. US Drought Portal.