In 1973 and again in 1979, Americans were slammed with natural-resource shocks. Back then, the resource was oil, and the shocks were politically induced shortages, the results of upheaval in Middle East petro-nations. The scenes that resulted, captured in black-and-white photos, now define a bygone era: Americans sitting in their cars in gas lines that stretched for blocks. Many people actually changed the way they lived, trading in those Detroit-made land yachts for smaller, foreign-built econo-boxes.

Today in California, a different kind of resource shock is unfolding, and it too may end up, a generation hence, defining an era. This time the resource is water, not oil. Today’s California drought is starting to force similarly life-changing choices, this time in the nation’s most populous state, long a bellwether and, according to some counts, the world’s eighth largest economy. The land of milk and honey has begun in recent weeks to get serious about its water crisis: Farmers are ripping out crops, religious believers are praying for rain, and local governments are ordering restaurants to stop serving glasses of water except to diners who specifically request them. This comes at a time when America’s domestic supply of the natural resource it has cared most about—fossil fuel—is more plentiful than ever.

What remains to be seen is whether California’s water shortage will produce lasting change: whether it will induce Californians to get much more efficient in the way they consume a commodity that, every bit as much as oil, powers the state’s economy. California has wrestled with water pressure for decades. Everyone in the state—including homeowners, farmers, and environmentalists—has failed to make the tough choices that now stare them in the face.

The scary statistics of California’s drought read like a latter-day version of the 1930s Dust Bowl crisis. Last year was the state’s driest since the start of record-keeping in 1895, and this year is likely to be even drier. The state’s snowpack, the source of roughly one-third of the water used by California cities and farms, is hovering at only about 20 percent of its normal water content. The amount of water in certain crucial reservoirs is lower now than it was in 1977, which was one of the two prior driest years on record. About a month ago, the state announced that 17 rural communities were within 100 days of running out of drinking water, given current patterns of water supply and demand. California Governor Jerry Brown, who’s running for reelection, warned in February that the state is facing a “mega-drought.” Some water experts predict California’s dry spell will last for decades; others say it’s too early to tell.

How did California get here? This winter’s infamous “polar vortex,” which has blocked storm fronts from reaching California, hasn’t helped. But the state was facing dry conditions long before this winter. Whether climate change is at play is a question on which scientists disagree: Some say yes, citing in particular the thinning snowpack, and some say no, citing climate models that predict global warming will make California wetter, not drier. Regardless, the current drought merely tipped into crisis a state whose water woes have been worsening for decades. California would be better prepared to withstand its current lack of rain had various constituencies conceded to tougher water-saving measures over the years. Which constituency is most culpable is subjective. Your answer depends largely on your politics.