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California Drought Is The Worst In 1,200 Years, New Study Says

By Paul Rogers, San Jose Mercury News (TNS)

The last three years of drought were the most severe that California has experienced in at least 1,200 years, according to a new scientific study published Thursday.

The study provides the state with breathtaking new historical context for its low reservoirs and sinking water tables, even as California celebrated its first good soaking of the season.

Analyzing tree rings that date back to A.D. 800 — a time when Vikings were marauding Europe and the Chinese were inventing gunpowder — there is no three-year period when California’s rainfall has been as low and its temperatures as hot as they have been from 2012 to 2014, the researchers found.

“We were really surprised. We didn’t expect this,” said one of the study’s authors, Daniel Griffin, an assistant professor in the University of Minnesota’s department of geography, environment and society.

The report, published in the journal of the American Geophysical Union, was written by researchers at Massachusetts’ Woods Hole Oceanographic Institution and the University of Minnesota.

The scientists measured tree rings from 278 blue oaks in central and southern California. Tree rings show the age of trees, and their width shows how wet each year was because trees grow more during wet years.

The researchers compared the information to a database of other tree ring records from longer-living trees such as giant sequoias and bristlecone pines, dating back 1,200 years.

Meanwhile, the rain that California received this week provided a promising start to a season that water managers say needs to be relentless and drenching to break the drought cycle.

“It’s a good beginning,” said Art Hinojosa, chief of hydrology at the state Department of Water Resources. “But we need storm after storm after storm if we have any hope of getting out of the drought this year.”

By April, he said, California needs at least eight more major storm systems like the one this week — as well as many smaller systems — to fill its dangerously low reservoirs and break the drought. Rain and snow this winter needs to be at least 150 percent of average for the reservoirs to fill, Hinojosa said.

This week’s storm was the biggest to hit California in roughly two years. Many parts of the state received between two and four inches of rain, doubling or tripling their totals since July. Through Thursday night, San Jose received 3.79 inches, San Francisco 4.43 inches and Oakland 3.01 inches, bringing each city above normal for the first time this year.

More important, several of the state’s large reservoirs began to receive moderate amounts of runoff, as the parched ground became saturated. Lake Shasta gained about 6,000 acre-feet through midnight Wednesday, and Oroville Reservoir in Butte County added 17,000 acre-feet. But that new water boosted Shasta’s storage by less than 1 percent, leaving it at only 23 percent full. It added 3 percent at Oroville, which is now 26 percent full, the lowest level in its history for this time of year.

The Sierra snowpack told a similar story. A week ago, it was at 24 percent of the average for this time of year. Thursday, after a week of snow, it was at 39 percent — still far below normal.

But more rain and snow is on the way.

In the San Francisco Bay Area, another cold front will be moving in on Friday and will hang around a couple of days, according to the National Weather Service.

“There will be rain Friday night and into Saturday and then partly clearing on Sunday,” said forecaster Diana Henderson. “Then there will be a few more showers on Monday, and the next system on the horizon will come in at the end of next week.”

The Weather Service issued a report late Thursday saying that because of storms brewing as far away as Hawaii, projections out to Dec. 18 show that “wetter than normal conditions are favored.”

Experts emphasize that a three-year drought cannot be erased in a few days. Not only are reservoirs low, but there are huge “rainfall deficits” built up from the past three years.

San Jose normally receives 42.9 inches of rain in an average three-year period, for example. Between June 2011 and June 2014, it received just 22.8 inches, leaving the city 20 inches short. Similarly, San Francisco is 19 inches behind, Oakland 24 inches.

Overall, 94 percent of California remains in “severe drought,” according to Thursday’s edition of the Federal Drought Monitor, a weekly report from the U.S. Department of Agriculture and other agencies.

It was the tree-ring study showing California suffering its worst drought in 1,200 years, however, that received the most attention Thursday.

The researchers took core samples, which don’t harm the living trees, of oaks as old as 500 years and oak logs dating back more than 700 years, the University of Minnesota’s Griffin said. And they sanded down the wood with extremely fine-grain sandpaper, magnifying the rings 40 times under a microscope and measuring them to within one one-thousandth of a millimeter.

They then compared the findings to the North American Drought Atlas, a detailed collection of other tree-ring data that goes back 1,200 years and includes measurements from ancient trees such as giant sequoias and bristlecone pines. The atlas calculates temperature and rainfall for those years by comparing the tree rings with tree rings from the past 100 years, when modern records were kept.

Although there are 37 times over the past 1,200 years when there were three-year dry periods in California, no period had as little rainfall and as hot of temperatures as 2012-14, the scientists concluded.

With climate change already warming the earth, the last three years in California could become a more recurring event, they said.

“This kind of drought is what we expect to see more of in the future,” said Griffin. “Maybe the future is now.”
___
(Staff writer David E. Early contributed to this report.)

Photo via Wikimedia Commons

Strong El Nino, Which Could Bring Soaking Winter Storms To California, Fizzling Out

By Paul Rogers, San Jose Mercury News

SAN JOSE, Calif. — A powerful El Nino that had been emerging in the Pacific is fizzling out, evaporating hopes it will deliver a knockout punch to California’s three-year drought.

A new report from scientists at the National Oceanic and Atmospheric Administration decreases the probability of an El Nino — the condition that occurs when warm Pacific Ocean water at the equator affects the jet stream — to 65 percent starting in October, down from 82 percent in June.

More significantly, researchers said, the ocean water that had been warming steadily through the spring has cooled off in recent months. So most of the world’s leading meteorological organizations now say that if an El Nino arrives this winter, it is likely to be a weak or moderate one — not the kind historically linked with wetter-than-normal winters in California.

“It’s fair to say that it’s plateaued,” said Michelle L’Heureux, a meteorologist with the NOAA Climate Prediction Center in College Park, Md.

Other researchers are more blunt.

“We’re back to square one. It’s finished. I don’t think we even have an El Nino any more,” said Bill Patzert, a research scientist and oceanographer at NASA’s Jet Propulsion Laboratory near Pasadena.

“If I were a betting man, I’d say it’s 75 percent that we’ll have another dry winter,” he said. “The unfortunate fact is that it looks like the last three years all over again.”

To be sure, California could still have a wet winter to help fill depleted reservoirs, replenish streams, and raise over-pumped water tables.

If a steady series of low-pressure systems develops off the Pacific Coast later in the year, that could bring tropical storms dumping rain in large amounts. The trend, known as an “atmospheric river” or “Pineapple Express,” has soaked the state in the past. But it has been all but shut down over the past three years as unusually persistent ridges of high pressure off the coast pushed winter storms north to Canada instead.

But the possibility that a strong El Nino won’t be there to help is “not good news, especially if we are using El Nino as an optimism index. It’s not what we want to see,” said meteorologist Jan Null, with Golden Gate Weather Services in Saratoga.

“It’s like in poker,” he added. “If you have one fewer spade out there, the odds of getting that flush are less.”

Generally speaking, the warmer the ocean water during El Nino years, the greater the likelihood of heavy winter rainfall. During mild El Nino years, when the ocean water is only slightly warmer than historic averages, there are just as many drier-than-average winters in California as soaking ones.

Since 1951, there have been six winters with strong El Nino conditions. In four of them, rainfall from the Bay Area to Bakersfield was at least 140 percent of the historic average, Null found.

But in the 16 winters since 1951 when there was a weak or moderate El Nino, California experienced below-normal rainfall in six of them. There was average rainfall in five and above-normal precipitation in the other five.

Thursday’s NOAA report was based on ocean temperature readings from dozens of buoys, wind measurements, satellite images, and more than a dozen computer models from scientific agencies around the world.

In April, the report noted, Pacific Ocean waters were nearly 4 degrees Fahrenheit warmer than normal along the equator from the surface down to about 1,000 feet deep. But by last month, they had cooled — and are now half a degree cooler than normal. Wind bursts from Indonesia that had pushed warm water toward South America and the United States diminished. And huge amounts of heat dissipated and failed to trigger weather changes in the atmosphere.

“We’ve seen very lackluster atmospheric response,” said NOAA’s L’Heureux. “What typically happens with warm water in the eastern Pacific is that you see rainfall and winds shifting around. But it didn’t happen. It didn’t coalesce.”

As a result, none of the world’s major meteorological agencies is forecasting strong El Nino conditions this year. Most expect that Pacific waters will range from 1 to 2 degrees Fahrenheit warmer than the historic average this fall, which would signal a weak El Nino.

Photo via WikiCommons

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17 California Communities Could Run Out Of Water Within 60 To 120 Days, State Says

SAN JOSE, Calif. — As California’s drought deepens, 17 communities across the state are in danger of running out of water within 60 to 120 days, state officials said this week.

In some communities, wells are running dry. In others, reservoirs are nearly empty. Some have long-running problems that pre-date the drought.

The water systems, all in rural areas, serve from 39 to 11,000 residents. They range from the tiny Lompico County Water District in Santa Cruz County to districts that serve the cities of Healdsburg and Cloverdale in Sonoma County.

And it could get a lot worse.

“As the drought goes on, there will be more that probably show up on the list,” Dave Mazzera, acting drinking-water division chief for the state Department of Public Health, said Tuesday.

Most of the affected water districts have so few customers that they can’t charge enough money to pay for backup water supplies or repair failing equipment, leaving them more vulnerable to drought than large urban areas.

The state health department compiled the list after surveying the more than 3,000 water agencies in California last week. The list will be updated weekly, Mazzera said.

State health officials are in discussion with leaders of other agencies, including the state Office of Emergency Services and the Federal Emergency Management Agency, to work on immediate solutions, he added. Those could include everything from trucking in water to the health department providing emergency funds for drilling new wells or connecting faltering systems to other water systems.

A similar list of vulnerable communities was compiled during California’s last drought, which lasted from 2007 to 2009. But the current drought is more severe. Less rain fell in 2013 than in any year since California became a state in 1850.

Even though some rain is forecast for Thursday, major storms are desperately needed this winter and spring to replenish depleted reservoirs, rivers and the Sierra Nevada snowpack — which on Tuesday stood at 14 percent of normal.

“This is a statewide drought. This is a serious drought,” Bill Croyle, director of the state Drought Task Force, said Thursday. “It’s all hands on deck.”

Croyle, an official with the state Department of Water Resources, made his remarks at a meeting of the Delta Stewardship Council, a state board of water experts.

Asked by board member Hank Nordhoff, a San Diego businessman, where the water will come from to bail out small systems, Croyle said he’s working on it.

“You are going to get it wherever you can get it,” he said.

Retorted Nordhoff: “That’s a frightening reply.”

Croyle cited the possibility of new pipe connections to other water systems and trucking in water.

“On the Central Coast, they have in the past looked at desalination,” he added. “So if we lose our groundwater and surface water, we are going to go to the ocean. It is going to be expensive, but you bring in mobile plants and fire them up.”

Since California’s last major drought, which ran from 1987 to 1992, most major urban areas have spent millions of dollars to store water underground, fund conservation programs, build new reservoirs and construct wastewater recycling plants. As a result, their residents are feeling little effect so far.

On Tuesday, the San Francisco Public Utilities Commission announced a voluntary 10 percent cutback for its 2.6 million customers in San Francisco, San Mateo, Santa Clara and Alameda counties. Similarly, the Santa Clara Valley Water District has requested a 10 percent voluntary cutback. Others, such as the Contra Costa Water District and the East Bay Municipal Utility District, have not yet asked customers to meet conservation targets.

The story is different in many rural areas.

Lompico County Water District, in the Santa Cruz Mountains near Felton, has long-standing water supply issues and is exploring a possible merger, but so far has been stymied by nearly $3 million in needed upgrades — a hefty bill for the district’s 500 customers.

“We have been unable to take water out of the creek since August and well production is down, and we didn’t have that much water to begin with,” said Lois Henry, a Lompico water board member.

Henry said she hopes the state comes with funding to help the agency find more reliable water. The district could soon have to begin trucking in water, she said.

“I’m frankly worried,” Henry said. “I know people turn their faucet on and say, ‘Oh, everything’s fine.’ And I know it’s not.”

In Cloverdale, where 9,000 Sonoma County residents draw their water from four wells, low flows in the Russian River prompted the City Council last week to put in place mandatory 25 percent rationing, which includes a ban on lawn watering. The city raised water rates 50 percent to put in two new wells, which should be completed by July, said City Manager Paul Caylor.

“Hopefully,” he said, “we’ll be able to get through the summer and the development of this project will pay off.”

Photo by  shrff14 via Flickr