California drought or dream? Jerry Brown at a hinge of Golden State history.

Gov. Jerry Brown must decide if he can keep his father's expansive vision for the state alive at a time when California is dealing with a severe drought.

If ever there was a California governor made for this moment, Jerry Brown might well be it.

Fifty years ago, Governor Brown's father sat in the same seat that the son now occupies, and from the political smithies of Sacramento he forged the modern image of the Golden State. More than any other man, perhaps, Pat Brown fashioned California's sense of itself – a land of unapologetic possibility, dappled with sun, dusted with dreams, and outlined only by the limits of the imagination.

Be it the building of roadways or universities or water works, Pat Brown always thought big and bold, and California sprang into being in his likeness.

Now, the son is tasked with saving the California of his father's creating.

Amid a drought unprecedented in the state's history, Gov. Jerry Brown is steward over not only 38 million Americans and the world's seventh-largest economy, but also of a unique idea that has launched Disneyland and Apple and President Ronald Reagan.

Nature has sought to tarnish the Golden State's luster before, but earthquakes and mudslides require fortitude and persistence. If, as the younger Brown says, the current California drought is the product of changing climate patterns, it would seem to require an altogether less-Californian value: parsimony.

Perhaps Brown will again be able to turn California's considerable ingenuity into unseen solutions, as he did during his first stint as governor from 1975 to 1983, when he oversaw the state's remarkable march toward cleaner skies. But if the way forward requires sacrifice – as he himself has suggested – Brown's greatest legacy might be presiding over a moment when the legacy of plenty created by his father began to come up against the stark realities of that vision – a land increasingly pushed to its environmental limits by its continued success and climate changes.

For politicians who shudder at the fallout from snowpocalypses or supercharged superstorms, Brown's would seem to be the most unenviable of tasks – a Sandy unspooling over months and years instead of minutes. But Brown's credentials are impeccable.

As governor of California in the 1970s and '80s, Brown was a band leader for the rise of modern environmentalism. His battles against Big Oil and his vision of greater energy efficiency, green power, and strong anti-smog measures profoundly shaped generations to come. In his inauguration address for this fourth term as governor this year, he put his political bulls-eye on global warming.

Moreover, from the moment Brown returned to the governor's office in 2011, he has been a political plumber in search of stuck toilets. He returned to Sacramento to fix California, and from the start he has acted as though he was short on time. Already, he has played a significant role in reversing the outlandish state deficits from the 2000s; California is back in the black.

Like his father, Brown is not afraid of thinking big on any topic.

He wants to link Los Angeles and San Francisco with a $68 billion high speed rail network. He wants to build two 40-foot-wide, 35-mile-long tunnels to bring water from the north to the south at a cost of $23 billion.

But California's current water crisis appears to be beyond the scope of any legislative lug wrench. Brown himself says so.

He has told Californians that their lives are changing. "The idea of your nice little green grass getting lots of water every day, that’s going to be a thing of the past,” he said last week, announcing new drought measures.

And facing those who insist that climate change has nothing to do with the situation, Brown has been almost evangelical. "But remember, the weather that's happening in California, that weather will be reflect and show up in other parts of the world," he said on ABC's "This Week" Sunday. "And I can tell you, from California, climate change is not a hoax. We're dealing with it, and it's damn serious."

What is less clear is what Brown intends to do about it. Last week, Brown issued an executive order calling for cities and towns to reduce their water usage by 25 percent. But if the drought continues, that will amount to very little. More than 80 percent of the state's water is used by agriculture.

For a state that produces 84 percent of the world's almonds, as well as a global market basket-full other nuts and fruits, that is perhaps not surprising. But Mother Jones notes that, in some cases, it takes 1.1 gallons of water to produce a single almond, and the Sacramento Bee reports that rising global demand has spurred a huge expansion of almond farming in areas without the water resources to sustain it.

"It will take courage for the governor to rein in these agricultural interests," writes the Bee's Adam Scow, noting that one major producer "is not only the largest grower and packer of almonds and pistachios, he is one of the biggest individual contributors to all major politicians in California, including Brown and U.S. Sen. Dianne Feinstein."

Generally speaking, Brown has signaled a willingness to at least consider such actions.

"Some people have a right to more water than others," Brown said on "This Week," speaking of agriculture. But, he added, "if things continue at this level, that's probably going to be examined."

More broadly, however, the problem might be the Brown legacy itself.

Pat Brown oversaw the California Water Project, which allowed 80 percent of Californians to live in the south – where only 20 percent of the water was.

"I loved building things," he said, according to a Washington Post account. "I wanted to build that ... water project. I was absolutely determined I was going to pass this California Water Project."

He built it, and Americans came, literally by the tens of millions.

"When you added a couple of lanes to a freeway or built a new bridge, cars came out of nowhere to fill them," wrote Marc Reisner in "Cadillac Desert: The American West and its Disappearing Water," as recounted in the Post. "It was the same with water: the more you developed, the more growth occurred, and the faster demand grew. California was now hitched to a runaway locomotive."

For much of the past 50 years, that engine – that sense of reengineering nature to bend it to the will of the California Dream – has brought the Golden State unprecedented prosperity. Now, it is Jerry Brown's job in likely his last four years as governor to decide whether his term will be on some level a bookend to that vision or, somehow, the renaissance of it under the most trying circumstances.