snowpack

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Snowpack Buildup “Too little, too late”

Frank Gehrke at Tamarck Flat last winter.

Frank Gehrke at Tamarack Flat last winter.

That’s how Frank Gehrke described the somewhat improved numbers in the latest Sierra snowpack survey. Gehrke has been trekking up to the snow courses for decades to do the seasonal surveys. Today, the statewide average for water content in the snowpack came in at 80% of normal for this date.

Northern Sierra locations clocked in a bit better at 84%, southern locations at 77%. These are an improvement over last month’s tally, when the state averaged only 61% of normal–but reservoirs are not filling fast enough to make up for the long, dry winter that preceded this recent string of storms.

Not that the recent rains haven’t helped. Oakland, Long Beach, Riverside and San Diego are among several spots that have now had at least 90% of their normal precipitation–and some local reservoirs have been catching up. But up in the Sierra, where it really counts for the Big Picture, they’re not catching up fast enough. The main holding “tanks” for the state’s two major water supply systems, Shasta Lake and Lake Oroville, are still at 60% and 55% of normal, respectively.

The recent storms have been relatively warm, too, with precipitation falling as rain all the way up to 7,500 or 8,000 feet. This is precisely the condition that climatologists have been warning about. Snow sticks to the mountain and makes its own reservoir, slowly releasing water well into the spring, as it melts off. But rain at those high elevations is double trouble. It runs off immediately into the rivers and also accelerates the snow melt. That means less water for later in the season, when we really need it.

That may be why the Governor didn’t wait around for today’s numbers. He went ahead and declared a statewide drought emergency on Friday, urging urban water users to cut consumption by 20%.

Snowpack Slips Further

bay_2981.jpgAfter the puny amount of precipitation we had in January, you sort of knew this was coming. Sure enough, after the second survey of the season, the statewide average for water content in the Sierra snowpack has slipped further.

As of today’s survey, the state’s Dept. of Water Resources says the snowpack’s water component is 61% of normal for this date. A month ago it was closer to three-quarters. Normally water content increases over the course of the snow season.

It only serves to cement growing fears that the coming summer will make last year’s water restrictions look like a tea party. In an unusually blunt statement, DWR Director Lester Snow said “We may be at the start of the worst California drought in modern history.” Reports are already coming out of the Central Valley of farmers planning to take more acreage out of production this year, and some cities anticipate going to court to get their desired water allocations.

Today’s survey combines manual tests at four alpine locations with readings from a network of electronic sensors. Even more alarming are some of the readings from key reservoirs. Lake Oroville, the main holding tank for the State Water Project, is at 43% of “normal” and just 28% of total capacity.

A developing La Nina condition in the Pacific may divert the jet stream and hold more rain at bay, as the season winds down. There are about two months left in California’s core “wet” season.

Photo by Heidemarie Carle: San Pablo Bay after some sparse January rain.

Sierra Snowpack Levels Below Normal

3151697945_495462fcb0_m.jpgYes, heavy snow closed Interstate 80 for several hours on Christmas, and true, four feet of snow fell on North Lake Tahoe in the days since then. But this season’s first snow survey reveals that California still has far to go to make up for two years of drought.  Teams from the Department of Water Resources (DWR) found that statewide the water content of the Sierra snowpack is still only 3/4 of where it should be this time of year.

Conducted today by teams across the state, the survey revealed snow water levels at 54% of normal for the northern Sierra, 76% for the central Sierra, and 99% for the southern Sierra.

Today’s numbers are an improvement over this time last year, when the water content for snow in the Sierra statewide was just 60% of normal, but they are not high enough, say DWR officials.

After two years of drought and last year’s driest spring on record, reservoirs across the state are far below normal levels. Lake Oroville, which we wrote about in the fall, contains less than half the amount of water that’s normal for this date.

The Sierra is going to have to see a lot more snow this winter if Californians want to avoid water restrictions and another big fire season come next summer.

Craig Miller reported on the snow survey on this morning’s broadcast of The California Report.

Use the player below to hear more about the current state of California’s water supply from Department of Water Resources Senior Meterologist Elissa Lynn.

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Cities, Farmers, Ski Resorts Sweat Out the Snowpack

“Better late than never”is about all you can say if you’re keeping a wary eye on the Sierra snowpack. Winter finally arrived in the Lake Tahoe region, just in time for Christmas skiers–but maybe not in time for water consumers looking ahead to next summer.

As of Christmas Day, the three key reservoirs in northern California were all at less than half of their “normal” levels for this time of year; Shasta (47%), Oroville (45%) and Folsom (44%). Oroville, a critical link in the State Water Project, was at just 22% of its total capacity.

With the winter’s first hands-on Sierra snow survey coming up next week, Elissa Lynn, Sr. Meteorologist for DWR tells me that readings from the network of automated snow sensors indicate that we’re about 15% of the way toward a full “normal” season (as measured on April 1st). That means we have a lot of catching up to do.

Ski resorts are already having a lean year and as Tom Knudson writes in today’s Sacramento Bee, some are looking ahead to when climate change might cause this kind of year to become the norm.

CA is “Extra Vulnerable” to Climate Change

3115732217_d7901f1545_m.jpgClimate change will most likely affect California more dramatically than it does many other places, according to researchers speaking Tuesday at the American Geophysical Union’s annual meeting in San Francisco. The panel featured new research into climate change impacts on sea level rise, agriculture, water evaluation and planning, air pollution, and extreme climate events.

Climate researcher Dan Cayan, from the Scripps Institution of Oceanography, described California as “extra vulnerable” to climate change and gave a broad (and somewhat scary) overview of the reasons why. The state’s temperature increases are expected to be similar to the global average temperature rise in the coming decades, making for hotter summers with longer heat waves. Given the expected increase in population in California’s interior, longer and harsher heat waves could have significant public health implications.

On top of the more intense summers and milder winters, precipitation across the state may well decrease, especially in Southern California. These drier conditions will be compounded by a significant withering of the Sierra snowpack. Even with a moderate increase in temperature (2 degrees C), Cayan says more than half of the historic California snowpack will disappear by 2100, as the mountains get more rain than snow at higher elevations. That can increase flooding and coupled with expected sea rise over the next century, the San Francisco Bay and the Sacramento/San Joaquin Delta may be in for some extreme events.

Fortunately, others are looking into sea level rise and what it’s going to mean for the San Francisco Bay Area and the coast of California. Peter Gleick, president and founder of the Pacific Institute, spoke about a new study currently under review focused on the projected impacts of sea level rise, including flooding and erosion, and the potential responses. The study will evaluate flood and erosion potential, create detailed maps of California’s vulnerable areas, estimate risks to populations and structures, anticipate costs of various adaptation strategies, and make policy recommendations. Gleick cited one immediate need as a catalog of the state’s existing levees and their conditions.

The report’s results should be out in February, which is also when we should see the draft version of the first California Adaptation Strategy, which aims to compile information on expected climate change impacts for the state and provide policymakers and resource managers with strategies for addressing them.