Could El Niño Actually End California's Drought?

Snowpack is really the key here.

As East Coast cities brace for a menacing blizzard, California is preparing to enter its fifth year of drought. But with another El Niño storm headed for the state this weekend, could the end of the drought be in sight?

According to the L.A. Times, a storm system moving through northern California—which, with most of the state’s big reservoirs, needs precipitation most—could lay up to an inch of rain in San Francisco, two inches in Sacramento, and up to three feet of snow in the Sierra Nevada mountains.

El Niño storms are “starting to make a dent, definitely,” Alan Haynes, hydrologist for the National Weather Service in Sacramento, told the L.A. Times. “If storms continue and we keep getting wet into the spring, like we’re projecting because of the El Niño ... we have a good shot at filling up the reservoirs and building up the snowpack.”

Still, it may be overly optimistic to hope one season of rain will do it. Snowpack is really the key here: The Sierras need enough of it to slowly melt and feed to the state’s freshwater bodies throughout the warm months. State officials have estimated that the Sierras need snowpack equal to 150 percent of average by April 1 to have a shot at clinching the drought. Right now, snowpack is at about 113 percent of average.

Snow is piling up at @YosemiteNPS on one of @YoseConservancy's webcams! Winter Wx Advisory goes until 10 pm. #CAwx pic.twitter.com/Ao9fcJLy4O

— NWS Hanford (@NWSHanford) January 19, 2016

The lack of water is most visible at California’s big reservoirs, which remain well below their historic averages. Sufficient snowmelt would help fill them up over the rest of the year, but they also use more above-average rainfall while El Niño is here.

Plus, experts don’t all agree on what “ending the drought” means. State climatologists believe that once the reservoirs are back at average levels, California will be in the clear. Others believe that a replenished groundwater supply will signal the end. With the excessive groundwater pumping that’s gone on during the drought, that’s going to take “many, many years,” according to B. Lynn Ingram, a Berkeley climate scholar.

Ultimately, it’s up to Governor Jerry Brown to decide when the drought is over. He’ll be the one to eventually rescind the statewide drought emergency he declared in early 2014.

The good news is that, so far, storms have been hitting northern California in a fairly steady, orderly way (southern California is another story), which allows for some groundwater restocking and a fair amount of snowpack accumulation. “I’d almost venture to say it’s coming in an ideal fashion,” state snow survey chief David Rizzardo told the L.A. Times.

And if rain keeps coming, it could lift California a considerable way out of its hole.  

Still, drought isn’t just about a lack of rainfall, lost groundwater, or shrinking reservoirs. It’s also about human demand relative to supply. In California, water rights are already over-allocated. As I reported in July, Californians will have to continue to adapt to nature’s fluctuations, as well as to each others’ needs, especially as population grows. Conserving, reusing, and recycling water will have be the norm—whether there’s a drought or not.