After praying for rain over five dry years, Californians are now praying for a break.
The state is being soaked. Its biggest reservoirs, once at record lows, are at capacity or overflowing from record-setting rain and snow. That includes the Oroville Lake reservoir behind the Oroville Dam, where nearly 200,000 Northern California residents were evacuated for fear that an eroding wall that holds water back would crumble and wash them away.
The drama caused by massive amounts of precipitation raises a question: Is California’s epic, record-setting drought, five years long, finally over? The answer is yes and no.
According to the National Oceanic and Atmospheric Administration (NOAA), the northern half of the state that gets more winter rain is drought-free, while much of the middle and southern portion is still in moderate to severe drought. Santa Barbara County, where a lake that supplies its water remains at 16 percent capacity despite rain elsewhere in the state, is still experiencing extreme drought.
“The further south you go, well, it’s pretty arid down there,” said David Miskus, a meteorologist for the Climate Prediction Center at NOAA. Lake Cachuma, shared by Santa Barbara and the Santa Ynez Valley, fell as low as 7 percent of capacity in October, but the area is “target zero for some heavy rain coming in the next few days.”
There were also high expectations for the end of the drought when snow poured onto the northern Sierra-Nevada Mountains, accompanied by a little rain in the south. But the snow quickly melted, the skies warmed and drought conditions returned.
That was then, Miskus said, and what’s happening now is a potential game changer. California’s last abnormal winter, 1982 to 1983, brought precipitation that was 88 percent higher than the 30-year average. This winter’s precipitation is nearly 120 percent higher. Together with last year’s high winter precipitation, it’s making a huge dent in the drought.
Last year the snow stopped a bit too soon. This year there’s so much more that “if it stops snowing completely and melted normally,” Miskus said, precipitation is so high that it would remain significantly above normal by April 1, when California’s winter ends and state water officials measure the amount of snow that will recharge rivers and reservoirs.
That’s good news, but nothing to celebrate yet. “Luckily, they got one record setting winter this year, which is great,” Miskus said. “But what will happen next year? You don’t know what next winter will bring.” Scientists at Stanford University and NASA have predicted a future of prolonged droughts for California and the Southwest.
Drought in the region is normal — it happens all the time. But when state water officials ventured to the Sierra-Nevadas to measure snow pack in April 2015 and saw nearly zero, Gov. Jerry Brown (D) ordered emergency mandatory water restrictions for urban areas, the first in state history.
Soon the restrictions spread to agriculture, where farmers pumped so much water from rivers and the ground that fish had problems making it to the ocean and the wells of homeowners in areas such as East Porterville went dry. On top of that, the land started to sink significantly as aquifers were drained.
It will take years for the state’s overburdened groundwater reserves to recharge. The surface is another issue. California’s blessing and curse right now are rivers in the sky.
Atmospheric rivers are picking up moisture over the Pacific Ocean and carrying it north to Oregon and elsewhere, dumping copious amounts along the way. Usually, in a good year, there’s one atmospheric river. This year, they are coming back to back to back.
It’s dealing a major blow to the worst drought California has ever had. But Oroville is paying a price. The Los Angeles Times quoted Cal-Fire incident commander Kevin Lawson saying that if a wall holding back water at the dam collapses, a “30-foot wall of water coming out of the lake” would be the result, threatening hundreds of lives.
Miskus said that precipitation “comes so quickly it has to top out” at the dam, and they have to get rid of it quickly.
Article by: Darryl Fears
Published: February 13, 2017, by The Washington Post
Read original here.