Just last year, researchers were saying there was no end in sight for California’s recent drought. During the past four years—the driest the state has been in a half-century— reservoirs and lake levels plummeted, leaves on giant trees grew brittle, plants shriveled and groundwater was depleted through excessive pumping for agricultural use.
But things are looking up. El Niño has swept into the Golden State and is breathing life back into the area. To many, it might seem that this storm front could end the drought and set California back on track. And it is making a difference, but like all things climate-related, it’s complicated and hard to predict.
Will this season’s El Niño end the drought?
No. We’re in a water deficit of at least two years in most of California. This means we would need more than a year of precipitation like this. We’d probably need more like two years to restore it.
How likely is this to happen?
It’s not likely we’ll come out of this drought. With climate change, California and the Southwest are predicted to get drier overall with warmer weather and, subsequently, more evaporation. Even with a wetter season this year, even next year, the climate is very likely to continue to be drier. Some are predicting another La Niña next year, which could offset the positive effects of this year’s El Niño.
How do meteorologists determine when we’re out of a drought?
Being out of a drought means restoring water levels in all the places that water is stored—natural lakes, reservoirs and the ground—to the long-term average. The groundwater is another story because it’s been pumped so much. There’s no way we’re going to replenish that in two years.
Although the drought won’t end this season, what are some of the positive impacts of El Niño?
The rain itself is already filling the reservoirs. Statewide, the reservoirs had dropped to 45 percent of the historical average. It’s hard to predict how much they’ll fill up by the end of the season because it depends how much it rains and how much runoff goes into the reservoirs—in a drought, the rain doesn’t produce as much runoff because it’s first permeating into the dry ground. By the end of this season, reservoirs could be halfway there, maybe up to 70 percent.
The snowpack is already above average statewide, at about 105 percent, so going into spring and summer, the snow will melt and continue to fill up the reservoirs, so that’ll carry over into the summer and fall.