California has been suffering from a three-year-drought that is the worst the region has seen in more than a millennium. Now an analysis conducted by NASA has revealed that in order for the state to recover from its current predicament, it's going to have to gain 11 trillion gallons of water back somehow.

That finding was part of an overall review of the drought's recent peak, which was conducted by NASA experts and presented Tuesday at the American Geophysical Union meeting in San Francisco.

The primary driver of that jaw-dropping 11 trillion gallon estimate is that it will take as much to refill California's Sacramento and San Joaquin river basins to what is considered "normal" levels - sufficient enough to support the water needs of the state and its extensive agricultural industry.

What's stunning is that droughts in California are not exactly unusual, and a frequent want for rain the arid parts of the region are considered in determining what is "business as usual." However, the intensity of this current drought is overwhelming, plunging a whopping 55 percent of the state into "exceptional drought conditions," which is the most severe classification, according to the US Drought Monitor.

Data from NASA's Gravity Recovery and Climate Experiment (GRACE) satellites has shown that the region's water-loss deficit has grown steadily since 2002, exacerbating the conditions of a dropping water table - which began with the drought in 2011. (Scroll to read on...)

"Spaceborne and airborne measurements of Earth's changing shape, surface height and gravity field now allow us to measure and analyze key features of droughts better than ever before, including determining precisely when they begin and end and what their magnitude is at any moment in time," Jay Famiglietti of NASA's Jet Propulsion Laboratory (JPL) said in a statement. "That's an incredible advance and something that would be impossible using only ground-based observations."

Where'd the Water Go?

However, even armed with this knowledge, the NASA team admits that a solution to California's current water needs is not evident. That's because that 11 trillion gal. figure mentioned earlier is a stunning 1.5 times the maximum volume of even the largest US reservoir.

The researchers added that the state's water loss since 2011 actually totals to far more water than what California's 38 million residents use each year for domestic and municipal purposes.

So where is all this water going? Nearly two thirds of the loss is due to depletion in groundwater beneath California's Central Valley, NASA reports, with the heavily agricultural region slowly and inevitably drying up, despite its growing drain on nearby reservoirs. (Scroll to read on...)

Away With the Snow

Worse, reservoirs and groundwater tables aren't being replenished nearly as effectively as they usually are, because abnormally sparse snowpack along the Sierra Nevada mountain range has led to little runoff.

"The 2014 snowpack was one of the three lowest on record and the worst since 1977, when California's population was half what it is now," added Airborne Snow Observatory principal investigator Tom Painter of JPL. "Besides resulting in less snow water, the dramatic reduction in snow extent contributes to warming our climate by allowing the ground to absorb more sunlight. This reduces soil moisture, which makes it harder to get water from the snow into reservoirs once it does start snowing again."

Still, don't go blaming global warming on these conditions, no matter how extreme. The NOAA recently released the results of an extensive investigation that revealed that its primary drivers are all perfectly natural. The consequences of the drought, however, may still have been exacerbated by carbon-driven climate change.

Famiglietti added that aside from implementing stricter water conservation practices, and making smart choices about crop and land management, California may simply have to outlast its drought.

"It takes years to get into a drought of this severity," he said, "and it will likely take many more... to crawl out of it."

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