NASA’s top water scientist says California only has about one year’s worth of water left in storage, and its groundwater – often used as a backup for reservoirs and other reserves – is rapidly depleting. He suggests immediately rationing water.

California just had the driest January since record-keeping began in 1895, with groundwater and snowpack levels at all-time lows, NASA scientist Jay Familglietti wrote in a column for the Los Angeles Times. He said the state has been running out of water since before the current years-long drought and storage levels have been falling since at least 2002, according to NASA satellite data.

“California has no contingency plan for a persistent drought like this one (let alone a 20-plus-year mega-drought), except, apparently, staying in emergency mode and praying for rain,” said Familglietti. “In short, we have no paddle to navigate this crisis.”

A team of NASA scientists, using the Gravity Recovery and Climate Experiment (GRACE) satellites, discovered that the state’s Sacramento and San Joaquin river basins were 11 trillion gallons (41.6 trillion liters) below normal seasonal levels. The researchers say that water levels have steadily dropped since the launch of GRACE in 2002.

Californians use an average of 181 gallons of water each day and a total of around 2.5 trillion gallons a year, according to data from the USGS website.

READ MORE:11 trillion gallons of water to relieve California drought - NASA

Familglietti called for an immediate and dramatic rationing of water, including for domestic, municipal, agricultural and industrial uses. A recent Field Poll shows that 94 percent of Californians surveyed believe the drought is serious, and one-third support mandatory rationing.

Other solutions to rationing are desalination plants. San Diego is building the largest ocean desalination plant in the Western Hemisphere. The $1 billion project will deliver 50 million gallons of drinking water a day and is scheduled to open in 2016, while 15 other plants are planned along the coastline from Los Angeles to the San Francisco Basin.

READ MORE:California drought worst in 1,200 years – study

But there are a few drawbacks: the San Diego plant requires more electricity to produce than any other water source, and in order to get 50 million gallons of drinking water it has to process 100 million gallons of seawater, which once returned to the ocean as discharge water has double the saline level.

A $1 billion #desalination plant to turn seawater to #drinkingwater is set to open this year for San Diego County. http://t.co/5GKTbCSK6B — Used to Useful (@UsedtoUseful) February 7, 2015

“This plant can’t come online fast enough,” Bob Yamada, water resources manager at the San Diego County Water Authority, told the Sacramento Bee. The Authority serves 3.1 million people and is buying all of the plant’s freshwater production.

“It’s drought-proof. That’s one of the most important attributes. It will be the most reliable water source we have,” he added.

READ MORE:California drought may leave entire communities with no water in 2 months

Desalination has been adopted by other nations with fewer natural freshwater supplies – Israel, Australia and Saudi Arabia, for example.

Another remedy being considered by California municipalities is wastewater recycling, which involves treating city sewage to drinking water standards and using it to refill reservoirs.