How Severe is the 2015 Drought Situation on the West Coast?

""California's reservoirs have about a year's worth of water left. Groundwater levels, seen as a "savings account" that the state can draw from in dry times, are at an all-time low. The US Drought Monitor comes out with weekly drought maps based on satellite imagery, precipitation, and water flow data; the Central Valley—America's bread basket—is covered in dark red, "exceptional drought."

What exactly is groundwater, and why are people in California freaking out about it? Groundwater is the water that seeps through the ground when it rains. Over the centuries, it accumulates in vast underground aquifers, with older water found deeper in the earth's crust. Accessed through wells, groundwater is often compared to a savings account in California—good to have in dry times but difficult to refill. The issue now is that with reservoirs (above ground) so depleted, groundwater use is spiking. Farmers are drilling deeper and deeper for water—using water that fell 20,000 years ago. Usually, groundwater makes up about 40 percentof the state's freshwater usage, but with the recent drought, that number has leapt to 65 percent. This year, it may rise to 75 percent.

What are the state's biggest water users? Farming in general, and alfalfa (used to feed cows) and almonds in particular. California grows half of the fruits and veggies produced in the States, including more than 90 percent of the country'sgrapes, broccoli, almonds, and walnuts. Here are some of the state's most thirsty crops:

Alfalfa is a superfood of sorts for cows, and it's in high demand in the Golden State, which leads the country in dairy production and is also a major beef producer. (Fun fact: It takes nearly 700 gallons of water to grow the alfalfa necessary to produce one gallon of milk, and 425 gallons of water to produce 4 ounces of beef.) Almonds are second from the top, both because it takes a lot of water to produce nuts (a single almond takes a gallon of water) but also because the crunchy snack is in vogue in the United States and abroad. The water that's used to grow the California almonds that are exported overseas in one year would be enough to fuel Los Angeles for nearly three years.""

http://www.motherjones.com/environment/2015/04/everything-you-wanted-know-about-california-drought