The ongoing California drought is evident in these maps of dry season (Sept–Nov) total water storage anomalies (in millimeter equivalent water height; anomalies with respect to 2005–2010). California’s Sacramento and San Joaquin river basins have lost roughly 15 km3 of total water per year since 2011 — more water than all 38 million Californians use for domestic and municipal supplies annually — over half of which is due to groundwater pumping in the Central Valley. Graphic: J. S. Famiglietti, 2014

By J. S. Famiglietti   
29 October 2014 (Nature Climate Change) – The ongoing California drought is evident in these maps of dry season (Sept–Nov) total water storage anomalies (in millimeter equivalent water height; anomalies with respect to 2005–2010). California’s Sacramento and San Joaquin river basins have lost roughly 15 km3 of total water per year since 2011 — more water than all 38 million Californians use for domestic and municipal supplies annually — over half of which is due to groundwater pumping in the Central Valley. Graphic: J. S. Famiglietti, 2014

The global groundwater crisis