The California Data Exchange Site has lots data and some nice graphs that show how much water is in the California reservoirs, however there was one particular view that I was interested in that I never found. So, I went ahead and made the graph myself using the historical data downloaded from the CDEC query tools.
This is a stacked bar graph that shows the amount of water in each of the 12 major California reservoirs. For a reference, I plotted the historical average data as well (it is repeated), and the total reservoir capacity as well. The reservoir data is daily data taken from Jan. 1, 2009 to Jan 1, 2015, and the historical average data is monthly.
What does this graph tell us? For one thing, it is obvious that as of Jan. 1, 2015, we are well below our historical average, and this dry spell in January is not helping. You can also see how the major rainstorms in mid-December helped us quite a bit, pulling us out of the lowpoint on the graph and actually made it so that the total amount of water in our reservoirs as of Jan 1, 2015 is close to the level in Jan. 2009.
I am working on something to automatically update this graph on a daily basis, so stay tuned. This data was downloaded and processed using Python/Numpy, and then graphed in Matlab.