La Nina Winter

It’s here. La Niña that is.  How does it differ from El Niño? Simply put, La Niña is characterized by unusually cold ocean temperatures in the Equatorial Pacific, compared to El Niño, which is characterized by unusually warm ocean temperatures.  

At the September Central MWD Caucus, Long Beach Water Department’s General Manager, Kevin Wattier reminded us how the La Niña weather pattern is shaping up to be a drier winter in Southern California.

As NASAs Jet Propulsion Laboratory’s climatologist and oceanographer Bill Patzert so aptly calls it, La Niña is earning its title as the “Diva of Drought”. 

Although La Niña creates drier and warmer weather in the Southwest, especially Southern California, precipitation can fall somewhere between well below normal to slightly above normal, so we should not be surprised to see short periods of unexpected heavy rain during the dry winter.

Concerns for Lake Mead: with a drier winter on the horizon, Lake Mead could be in trouble.  Kevin also pointed out how over the past 10 years, there has been a 120 ft drop in elevation, with October 2010 coming in as the lowest elevation level on record for this important California reservoir.

Rain, rain, please don't go away!

While mudslides and traffic have plagued local communities during the recent heavy rains, the Southern California water community is hoping for more. It’s hard to believe that our state is still thirsty, with the snow-packed mountains and seemingly endless showers. But, experts warn, the impact of El Niño is exaggerated, and we’re not out of the drought yet.

“These storms may have left many consumers with the misperception that the region’s water supply problems are over. Nothing, however, could be further from the truth,” said Jeffrey Kightlinger, General Manager of the Metropolitan Water District of Southern California.

So, while local residents will enjoy a break from the downpour this weekend–with temperatures expected to reach the high 70s– water supply experts are hoping this sunny break will be short-lived.

A thirsty Lake Oroville

What does this mean? SWP provides water to businesses, homes and farmers, mostly located in Central and Southern California. According to DWR, under the 5% allocation, only 200,000 of the total 4 million acre-feet of water that has been requested, will be delivered.

“Five percent sends a very strong message that the state is in a water crisis,” said Central Basin’s general manager, Art Aguilar.  In fact, California’s water woes may take the national scene in the near future: Rep. Grace Napolitano said last week she is planning a congressional hearing in Southern California to examine what steps to take in the water situation.

There are several other reasons for this tiny allocation, the lowest in the agency’s history. Haunted by three years of drought and depleting reservoir levels, our tight water situation is compounded by federal mandates that restrict the amount of water that can be pumped from the Sacramento-San Joaquin Delta in order to protect endangered fish species.

However, estimates are historically conservative. With a relatively wet winter, we may see springtime allocations increase, as they have in the past. Take a look at a graph comparing initial estimates to actual allocations.

With the California Department of Water Resources reporting last week that Sierra snowpack is at 118% of normal for this time of year (compared to 63% of normal at this time last year,) area papers today theorize on how climate change will continue to impact our future supply. Here are two interesting articles:

In the North County Times, UC San Diego research marine physicist Tim Barnett explains how a warmer world could mean drastically less water for Southern California.

Meanwhile, the LA Times today takes a look at Gin Flat, one of the primary sites for recording state snow levels. The story would not be complete without the interview with Frank Gehrke, California’s snow survey chief. Known as the “don of the Sierra Snowpack,” he points to climate change as the major cause of our erratic snow levels.

This month, a few Colorado Senators are going so far as to propose a change in their state law, to allow people to take full advantage of seasonal downpour by harvesting rain for later use. If you’re inspired, or perhaps just amused by this, here’s an interesting news clip on rain harvesting with the LA-based TreePeople Organization. (Video behind the cut)

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Is California Still in a Drought?

Well, it depends on who you talk to. There are two kinds of drought: the weather kind and the man-made kind.

Let’s discuss the weather kind first. Even with recent rains, dry conditions persist throughout the state. Still, a “drought” has not been formally declared by the California Department of Water Resources (DWR). 2007 was just considered a very, very dry year.

For Southern California, we are off to a very good start. According to the Los Angeles Civic Center we have just over 12 inches of rainfall to date, which puts us at 162% of average for this time of year, and at 80% of average for the entire year. With the traditionally wettest months still ahead, things are looking good.

Now, let’s discuss the man-made kind of drought. Back in August, a federal judge made an important decision about the amount of water agencies can take from the Sacramento-San Joaquin Delta, also known as the California Delta. Because of the rapidly declining population of a small fish, the Delta Smelt, the Judge reduced the amount of water that both the State Water Project and the Central Valley Project can take from the Delta by 2 million acre-feet. Because the Metropolitan Water District is the largest water contractor from the SWP, the Southland will get hit the hardest–losing up to 500,000 AF of water annually! This has the effect of creating a man-made drought for all areas of the state that receive water from the SWP.

This reduction will stay in effect until major improvements are made to the California Delta, which is why you may be hearing a lot about the “peripheral canal” or other, similar projects that will move water around the Delta instead of through it.

So there you have it. As a result of these factors, we are now more susceptible to the whims of weather conditions than ever before. And it’s going to stay that way for many years.

I invite your comments.

Dave Hill

Water Resources & Planning Manager

Central Basin Municipal Water District