In another sure sign that California is steadily recovering from the yearslong drought, the snowpack in the Sierra Nevada — a major source of water for the state — is currently larger than the last four years combined, according to NASA.
As of April 1, when it was last measured by NASA’s Airborne Snow Observatory, the snowpack in the Sierra’s Tuolumne River Basin came in at 1.2 million acre-feet, according to the latest data.
To put the amount in perspective, the figure is enough to fill the 92,000-seat Rose Bowl in Pasadena almost 1,600 times.
“The 2017 California snowpack is close to the largest on the record, which consists of decades’ worth of snow measurements made at ground level,” according to a NASA news release.
The snowpack, which is made up of layers of snow that accumulate in the winter and spring months in the Sierra Nevada, is critical to California because it’s the key to the state’s water needs.
During warmer months, the melting snow filters down the mountains into creeks, streams and rivers as it makes its way into the Golden State’s water system.
Most of California’s annual precipitation — roughly 80 percent — comes as snow.
The Tuolumne Basin’s snowpack measures twice the volume from last year, and is roughly 21 times larger than the one two years ago, which the agency said is the lowest ever recorded.
In fact, the current snowpack is greater than the amount measured from 2013 through 2016, a stretch when the state was mired in deep drought.
The historically high levels are what ultimately helped propel California out of drought conditions, which in turn prompted Gov. Jerry Brown to declare an end to the state’s drought emergency earlier this month.
And, as NASA noted, there was still plenty of snow in mountainous areas at the start of spring.
“In much of the Central Sierra, snow lies 25 feet deep (8 meters). In some high mountain basins, it’s deeper than 80 feet (24 meters),” the agency said of the latest measurement, pointing out that there’s been even more snow since the analysis was conducted.
At Mammoth Mountain, in the Eastern Sierra, the resort has experienced record snowfall, and plans to remain open through July 4.
Hit with storm after storm this winter, the Mammoth area was buried in so much snow that last month, the California National Guard was called in to the village to help remove 4,000 tons of it, the Los Angeles Times reported.
According to NASA, the recently performed April 1 evaluation is a critical annual event that looks at the amount of snow for the state.
The Airborne Snow Observatory conducts the comprehensive examination with the help of scientific instruments aboard an aircraft; it is the only program that takes a critical look at snow depth, snow water equivalent and how much sunlight snow reflects over an entire basin, NASA said.
In addition to California, the snow-monitoring program flies in Colorado, Oregon, Nevada and Idaho.
“Before ASO, water managers had intense stress worrying about how much potential runoff was stored in the mountain snowpack, with little historical information about snowpack years as large as this to guide reservoir management and allocation decisions. With ASO, we will be precisely quantifying this volume and how it changes through the spring,” said Tom Painter, principal investigator of NASA’s Jet Propulsion Laboratory.
CNN contributed to this story.