Droughts and dry spells are not a rare occurrence in California. But according to a recent study, the drought that has plagued the state for the past few years is the worst to parch the central and southern parts of the state in the past 1,200 years.

Record-high temperatures have exacerbated the drought, creating the driest soil conditions since the 9th century, according to a study published in the journal Geophysical Research Letters.

The research noted the lack of rain during 2012 to 2014 isn’t remarkable on its own; there have been three-year periods when less rain and snow fell. But the current drought also comes at a time of extreme heat.

According to the National Weather Service, California’s heat waves will make 2014 the warmest year in historical record. More heat means air evaporates more moisture from plants and the soil. Heat waves also cause more evaporation from streams, rivers and the mountain snowpack.

Regulations take hold
As early as January 2014, California Governor Jerry Brown declared a state of emergency. And in March 2015, he announced a $1 billion emergency legislative package to deal with the drought. That money would help speed up water projects and programs and provide aid to struggling California cities and communities.

Brown was quoted in a Reuters report saying, “As the drought continues, there will be a heightened sense of urgency, and we’ll act in extraordinary ways.”

This year marks the fourth consecutive year of record-breaking drought, and according to new regulations, residents cannot water their lawns within 48 hours of rain. Also, restaurants are prohibited from serving water unless requested.

Contributing factors
A drought is defined as a period of drier-than-normal conditions that results in water-related problems. When rainfall is less than normal for several weeks, months or years, the flow of streams and rivers declines, water levels in lakes and reservoirs fall and the depth to water in wells increases. If dry weather persists and water-supply problems develop, the dry period can become a drought.

One of the major contributors to drought is lack of snowpack. As of April 1, 2014, the California Department of Water Resources measured the statewide water content of snowpack at only 18 percent of the historical average. The measurement is crucial because this is when the snowpack is typically at its peak and begins to melt into streams and reservoirs.

About one-third of the water used by California’s cities and farms is provided by snowpack through runoff. According to a Reuters report, the Sierra Nevada snowpack, which (when it melts) provides up to a third of the state’s water, stood at just 12 percent of normal in mid-March.

In addition to snowpack runoff, the state’s reservoirs are suffering. According to data from NASA satellites, the total water in the Sacramento and San Joaquin river basins (including snow, river, reservoir, water in soils and groundwater) was 34 million acre-feet below normal in 2014. Jay Famiglietti, professor of earth system science at UC-Irvine, says that number is nearly 1.5 times the capacity of Lake Mead, America’s largest reservoir.

Famiglietti, who also works as senior water scientist at the NASA Jet Propulsion Laboratory/Caltech, posited in The Los Angeles Times that the state has only about one year of water supply left in its reservoirs and that groundwater is rapidly disappearing. He argued, “California has no contingency plan for a persistent drought like this one … except, apparently, staying in emergency mode and praying for rain.”

Although Famiglietti and others might not agree with the governor’s targeted approach and water-saving measures, it’s clear the issue isn’t going away anytime soon.

But, without question, it’s an issue state citizens are painfully aware of. A recent Field Poll showed 94 percent of registered voters in California consider the state’s water shortage to be at least “serious,” with a full 68 percent considering the situation “extremely serious.” It’s what happens next that could affect the entire state and its natural resources.

Did you know?

• California uses more water than any state.
• Each Californian uses an average of 181 gpd.
• Water use in the state has been declining since 1980.

For more information and statistics about California’s water use, visit the USGS.