The vast majority of California is categorized as being in at least a "severe drought" condition, but some residents are affected more than others.
A new analysis by NASA, based on data from NASA's Gravity Recovery and Climate Experiment satellite, says it will take about 11 trillion gallons of water to recover from California's ongoing drought. NASA also found snowpack in the Sierra Nevada mountains was down to half of previous estimates.
"Spaceborne and airborne measurements of Earth's changing shape, surface height and gravity field now allow us to measure and analyze key features of droughts better than ever before, including determining precisely when they begin and end and what their magnitude is at any moment in time."
Famiglietti said the technology used for the study is an "incredible advance and something that would be impossible using only ground-based observations."
Natural oceanic and atmospheric patterns are the primary causes of California's ongoing drought, a National Oceanic and Atmospheric Administration (NOAA) sponsored study released Dec. 8 said. It found no conclusive evidence linking human-caused climate change to the drought, drawing criticism from climate experts.
Persistent high pressure off the U.S. West Coast prevailed for three winters from 2011 to 2014. This phenomenon blocked important wet season storms that usually provide California with a majority of its annual snow and rainfall that replenish water supplies, the study said.
"Multi-year droughts appear regularly in the state's (California) climate record, and it's a safe bet that a similar event will happen again."
Climate experts said the study was flawed for not including how higher temperatures worsen a drought, irrespective of what reduces rainfall.
A study published Dec. 4 found the drought is the worst going back to the year 800. Researchers looked at tree-ring samples from hundreds of blue oaks. They identified 37 droughts over 1,200 years that lasted at least three years. Not only is the current drought worse, it's already more severe than droughts that lasted 4-9 years.
The U.S. Drought Monitor reported Dec. 4 that just over 55% of the state was still facing extreme drought (shown in dark red above). The news comes as U.S. House Majority Leader Kevin McCarthy (R-CA) said Congress will take up a bill to provide emergency drought relief during the second week of December.
Voters overwhelmingly approved a $7.5 billion water bond measure in November. The bond will pay for new dams and reservoirs, as well as watershed restoration, groundwater cleanup and water recycling projects. The measure had nearly unanimous support from state lawmakers.
An official at the agency that supplies water to half of California's population said Sept. 22 that the state's reserves could be exhausted in about 18 months if the drought and current rate of usage remains unchanged.
"Nobody has any idea how disastrous it's going to be. Is it going to create more fallowed land? Absolutely. Is it going to create more groundwater problems? Absolutely. Another dry year, we don't know what the result is going to be, but it's not going to be good."
California's $44 billion-per-year agriculture business will take an estimated $2.2 billion hit this year due to the cost of water and smaller crops. Corn production is expected to drop 45%, oranges 4%, grapes 9% and wheat 40%. Acres of cotton planted were down 23% and acres of rice were down 25%.
Statewide residential water usage dropped 10.3% year-over-year in September, according to state data. The overall rate of conservation was slower than August's 11.6% decrease. Areas with the lowest per-capita water use, like the San Francisco Bay Area, also saw some of the biggest drops in usage.