Ordinarily, a blog about the weather would be boring and inappropriate for DKos. However water is a political issue in California for 2 reasons. First is the history of water rights and the tactics used by the Metropolitan Water District to bring water to LA, which rankles many around the state and the West, but is not the subject of this diary. Second the extreme drought/deluge pattern we have been observing here may or may not be related to global warming and climate change, depending on who you ask.
It’s been raining in Los Angeles this month. A lot. Through December 15, there have been 3 days with measurable rainfall, and 2 of them broke records at LAX (Dec 2 and 12). (Update: it is raining today, even as I write this - more good news.) Other parts of California have also seen similar weather patterns, with rainfall records broken in many places. For instance, Palmdale airport saw 1.18 inches on December 2, which shattered the previous record of 0.46 inches for that date. So, does that mean our 100 year drought is over? Well, not actually, but at least the news is good for a change.
In LA, the 2014-2015 water year is well ahead of normal rainfall levels. In Los Angeles, we have had 3.67 inches since July 1 - almost an inch above our normal YTD - with 2.82 inches falling at LAX in 2 weeks in December alone. An average December sees 2.05 inches, so we have eclipsed a normal December already and are ahead of a normal year. But the meteorologists tell us that we will need several full years of above normal rainfall to bring our ground water levels and our reservoirs back to health.
Of course, rain in LA doesn’t really help much with our local water supply, since so much of it is imported. The real test is the water levels in the lakes, rivers, and reservoirs around the state. The California Dept of Water Resources Data Exchange Center website lists 12 major reservoirs throughout California that are part of the CA water system. They range from Trinity Lake in northern California to Pyramid Lake just north of Los Angeles. These reservoirs are an important, but not the only, source of water throughout our state. All of them are well below normal levels (except Pyramid Lake, which is currently at 106 percent of normal level), but this month’s rain has at least reduced the severity of the deficits. Lake Shasta in northern California is by far the largest with a capacity of 4,552,000 acre-feet. On December 1 it was at 23 percent of capacity, which represented 39 percent of its historical normal level for that date. But on December 15, just 2 weeks later, the level stands at 32 percent of total capacity, or 52 percent of normal, an increase of 13 percent of normal. This is even better news than it sounds, since the “normal level” represents an increase over those 2 weeks that would reflect normal rainfall in that district, so just to remain at 39 percent of normal, the area would have to see a normal amount of rain. The fact that it improved from 39 to 52 percent of normal indicates that the rainfall in northern CA was far greater than average in December. Nine of the twelve major reservoirs in the state saw an increase in the percentage of normal levels over the past 2 weeks, and only one has dropped, as welcome rainfall has blanketed the state. Five of those saw increases of 9 percent or more of normal. Overall, December’s rainfall has added more than 1 million acre-feet of water to our parched reservoir system in just 2 weeks. And that doesn’t count the ground water, and water in other reservoirs, lakes, rivers and waterways that has also been restored. The war’s not over, but it’s a start.
Meanwhile, what does the pattern of drought-to-deluge mean in terms of climate change and global warming? Scientists and skeptics will have different views, of course, but it seems clear to me that we have entered a new normal, where extreme weather patterns will be far more common. As we conclude what may be the warmest year ever recorded on the planet, how could we expect anything different?