water supply


The Sorry State of the Salton Sea

As more water flows to the coast, California’s largest inland water body teeters on the brink

By Sam Harnett

The Salton Sea, northeast of San Diego, is an important stop on the Pacific Flyway for migrating birds. Millions of birds stop there every year.

Last month the California Supreme Court upheld a water transfer deal that sends billions of gallons of water a year from Imperial County farms to cities in San Diego County. The 2003 deal is the largest agriculture-to-urban water transfer in the history of the United States, and it will have major environmental and economic impacts on the region. One of the areas most dramatically affected will be California’s largest — and in many ways its most notorious — inland body of water: the Salton Sea.

The Salton Sea has a fraught history. It used to be part of the Colorado River Delta, but with the diversion of water the area has become desert. In 1905, a massive flood caused the formation of the current Sea, and during the following decades it became an iconic resort location, drawing fishermen and pleasure seekers from across the country. In the 1970s, the Sea fell from favor. Rising salinity killed all the sport fish, celebrities stopped coming, and the resort developments were abandoned. Today, the only water the Sea receives is agricultural run-off from nearby farms, and without that water, the Sea will disappear in a matter of years. Continue reading

New Reports Highlight Climate Challenges to State Water Supplies

Good news, bad news for California: we’re well-prepared but still vulnerable

The Sacramento-San Joaquin Delta is the hub of California's complex water system.

California is both highly prepared and highly vulnerable to the effects of climate change on its water systems, according to two recent studies.

Released today, the National Resources Defense Council’s “Ready or Not” report ranked states in terms of overall water preparedness. The rankings took into account susceptibility to various climate-related factors – such as coastal erosion, saltwater intrusion and flooding – as well as steps being taken to curb carbon emissions and to recognize and tackle vulnerabilities to a changing climate. Continue reading

Snow Survey Says: It Could Have Been Worse

Thanks to last year’s wet winter, California’s reservoirs are still in good shape

In January of this year, snow was still sparse at high elevations in the Sierra Nevada.

Researchers from the Department of Water Resources conducted their April manual snow survey today. It’s the most important snow survey of the season, because it’s supposed to capture the Sierra snowpack at its peak. The DWR found that statewide, snow water content is 55% of average for this time of year.

Still, it could have been worse. The previous manual snow survey, which took place on February 28, measured snow water content at only 30% of normal for that date. So the rain in March did help.

“This was certainly a moderately good March at least,” Jeanine Jones, the Interstate Water Resources Manager at the DWR told me. “But the downside is that we are now getting outside of our peak precipitation window. On average about 75% of statewide precipitation comes between November and March.”

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Wet Enough For Ya? California Precip Makes Sprint for the Finish Line

The rainy weather has helped, but the state’s still in deficit for the year

Heavy rain flooded the parking lot at San Francisco's Ocean Beach over the weekend.

California’s water supply is in better shape after this weekend’s storms and the wet weather earlier in the month (though the parking lot at San Francisco’s Ocean Beach is in worse shape). The water content of California’s snowpack is hovering around fifty percent of what’s considered “normal” for this time of year — not quite cause for celebration but much better than it had been; on February 28, the date of the most recent manual snow survey, water content was only 30% of normal.

So this winter isn’t going to be the driest on record, or even the second-driest, but it’s bound to be on the dry side, regardless of what happens now. It’s just too late in the year to catch up, even with more storms heading our way this week.

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Humans and the History of Water

Q & A With Brian Fagan, archaeologist and author of Elixir: A History of Water and Humankind

The Sacramento-San Joaqiun Delta provides water for tens of millions of Californians.

While many work to understand the world’s current water problems with a laser focus on the present, a few, such as University of California at Santa Barbara emeritus professor of archaeology, Brian Fagan, have chosen to look back, at the water engineering efforts of past civilizations. In his recent book, Elixir: A History of Water and Humankind, Fagan finds striking historical parallels to California’s myriad challenges.

He agreed to answer some questions for Climate Watch.

JEREMY MILLER: In previous books such as The Long Summer and The Great Warming you have written about the influence of climate on ancient civilizations. How did you decide to make water the focus of your latest book, Elixir? Did living in California play any part in your decision?

BRIAN FAGAN: I got into the history of water as a result of giving a talk to the California Water Policy Conference on medieval drought, where some participants strongly encouraged me to undertake such a history.

Two experiences have shaped my perspective on water. The first was living in East and Central Africa for six years when I lived among subsistence farmers and saw the problems of drought first hand. The second is, of course, California, which has a classically erratic rainfall pattern that varies greatly one year to the next. In both cases, I learned just how precious water is to us.

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After a Dry February (sigh), Drought Looms on Central Valley Farms

Farmers, used to water shortages, prepare for bad news

Pistachio trees on a drip irrigation system. Drip systems can dramatically reduce water loss from evaporation.

UPDATE: Despite snow closing Interstate 5 over the Grapevine Pass on Monday, state snow surveyors returned from the Sierra today with more forlorn figures. The third snowpack measurement of the season showed water content in the accumulated snow at just 30% of the average for this date and 26% of the average for April 1, typically when the snowpack reaches its peak for the season.

Even though more snow is on the way, as I explain in my radio story for The California Report, Central Valley farmers are getting ready to face a fourth dry year in the last five.

I visited with Fresno County farmer Ryan Ferguson in his pistachio orchard near the Lemoore Naval Air station, to ask him how he’s coping with the news that he may get just 30% of the water he’s asking for from the canals of the federal Central Valley Project. Continue reading

Water Efficiency May Ease Colorado River Woes

Study shows most western cities aren’t wasting as much water

Lake Powell, the Colorado River's second-largest reservoir, in April 2010 (Photo: Gretchen Weber)

There’s some good news for the 35 million people in the Western United States who rely on the Colorado River for their water, says a new study from the Oakland-based Pacific Institute.

No, the supply isn’t increasing.  And yes, the population is still growing.

But according to the paper, entitled Municipal Deliveries of Colorado River Basin Water, more efficient water use by water agencies across the West is making the supply/demand gap a lot less painful than it could be.

“Although population growth has increased very quickly, the amount of water delivered has not kept pace,” said study author Michael Cohen. “That shows that people have been getting much more efficient with their use of water.” Continue reading

Running Drier: The Colorado 50 Years Out

A new federal study says the Colorado River may carry 9% less water by 2060.

Lake Mead, the Colorado River's largest reservoir in May, 2010 (Photo: Gretchen Weber)

The Colorado River is a critical source of water for more than 30 million people throughout the western United States. California alone gets more than a trillion gallons of water each year from the Colorado. But over the years, recurring droughts and the growing demands of urban populations have stressed the river system, which the Bureau of Reclamation now characterizes as “over-allocated.”  In efforts to plan for the region’s future water needs, the agency, in collaboration with Western states, has undertaken a two-year study to look at what lies ahead for the river and the cities, farms, and families that rely on it.

On Monday, the agency released the first interim report of the “Colorado River Basin Water Supply & Demand Study,” which projects changes in the river’s flow under four different scenarios. A model that incorporates predicted impacts of climate change shows a nine percent reduction in the Colorado’s flow within 50 years.  The study also projects more frequent and more severe droughts throughout the system. Continue reading

Snow Surveys of the Future

A white fir outfitted with snow sensors in the Southern Sierra Critical Zone Observatory. (Photo: Sasha Khokha)

Trying to interview guys who wear backcountry skis to work can be tough…especially when trudging behind on snowshoes with a pack full of recording equipment. But my visit to the Southern Sierra Critical Zone Observatory was worth the slog.

It’s a patch of forest at about 6,000 feet near Shaver Lake in the Southern Sierra, in what’s known as the rain-snow transition zone. The snowpack at this elevation is likely to be the first to reflect climate change as temperatures warm and snow turns to rain. Scientists at UC Merced’s Sierra Nevada Research Institute, in conjunction with UC Berkeley, have developed new, high tech sensors to intensively monitor snow melt and runoff here. Continue reading

California Losing Groundwater Rapidly

Nearly lost amid the three-ring circus of Copenhagen coverage is the annual gathering in San Francisco of the American Geophysical Union. We’re doing our best to staff selected sessions there. Climate Watch contributor Lauren Sommer was there for some grim new research on groundwater in the Central Valley.

California’s Central Valley has lost nearly enough water in the past six years to fill Lake Mead, according to NASA scientists presenting at the American Geophysical Union Conference in San Francisco this week. Nearly two-thirds of that loss–20.3 cubic kilometers of water–is from groundwater depletion.

With the recent drought, groundwater has been an important water source for California’s Central Valley agriculture, but getting a picture of that water use hasn’t been easy. Water districts haven’t been required to report groundwater pumping in their areas. That’s something the recent Delta overhaul package of legislation now requires, but according to Jay Famiglietti of UC Irvine, the records to date aren’t very complete. Wells are sparse and the measurements have been sporadic.

The majority of the water loss since 2003 has been focused in the San Joaquin Basin at the southern end of the Central Valley, which is losing 3.5 cubic kilometers of water each year. The bulk of that loss is the result of groundwater depletion.

Famiglietti says this is due to a “triple threat” in California.  First came the drought, then decreased water allocation and more groundwater pumping. Finally, with less surface water, the groundwater aquifers have a reduced opportunity to recharge. Famiglietti says it’s clear that California is using groundwater at an unsustainable rate, which “poses significant threats to food production in US and the California economy.”

Groundwater basins in the Central Valley. Image: NASA

Groundwater basins in the Central Valley. Image: NASA

This large-scale picture of California’s groundwater comes from NASA’s Grace project. Twin satellites orbiting the Earth detect changes in the gravitational field, caused by the movement of water. Those satellite measurements act like a“scale at the bottom of the ocean weighing how much water is in each of these spots,” according to NASA’s Michael Watkins.  They also detect changes in snow, surface water and soil moisture.

The Grace project, though, is becoming a “senior citizen,” according to Watkins and is reaching the end of its technological life. He says quality of their water research, which has included other spots around the globe, speaks to the need for another generation of the project.  Famiglietti says, though this data can’t replace ground measurements, he hopes it will be taken into account by state agencies faced with making the tough choices about California’s aquifers.