Any story of California's convoluted water system must start where the water does: with snow in the mountains.

And this year, in many places, there just isn't any. New data show that California will be starting the summer dry season with a snowpack at about the lowest levels since record keeping began nearly a century ago. The data were collected as part of California's annual snowpack survey across the vast Sierra Nevada.

According to the U.S. Geological Survey, the Western United States gets as much as 75 percent of its water supply via snowmelt.

For cities and farms across California, the numbers show this is shaping up to be a summer like none other.

Nearly one-quarter of the latest measurements (56 of the 233, to be exact) show a snowpack that is less than 10 percent of what it usually is this time of year. At least a dozen had no snow at all, even above 7,000 feet elevation. Averaging all the measurements, the state is starting off the dry season with about 25 percent of the typical April 1 snowpack — which is where it started in 1977, the year with the least snow measured in California.

As you might guess, a warming world also means a world with less snow. After an exceptionally warm and dry winter, this year's snowpack was only 9 percent of average on slopes below 6,000 feet in elevation. Scientists expect these lower-elevation mountainsides to be the first to lose their snow as the climate warms.

The forecast of worsening drought — already perhaps the most intense in 500 years — has led to an unprecedented zero allocation of federal water to many farms within the state, a drinking water shortage in Silicon Valley, and increasingly drastic moves to protect wildlife, including transporting salmon upstream by truck.

"By the fall, we'll see reservoir levels that are dangerously low," said Dave Rizzardo, chief of snow surveys for the California Department of Water Resources.

"The fact you can drive up there in February and March and have no problem accessing the Sequoias … that's not usual," said National Weather Service meteorologist Paul Iniguez.

And it's not just the Sequoias that have been short on snow this year, Iniguez said. "We have a weather service observer [station] up at 7,800 feet elevation, in Lodgepole, California. In past years they put a chain-link fence to protect their cabin from the snow. They normally get around 35 feet of snow in a season. They've gotten just 5 feet this winter. I mean, Philly's had more snow than that!"

And that has consequences. Sure, the snow drought has hit ski towns hard this winter. But snowmelt from the Sequoias also typically provides the bulk of the water for agriculture in the highly productive Central Valley, via the heavily diverted Kern River. This year, farmers are resorting to groundwater pumping (and a lot of it) to make up the difference.

Snow depth is monitored throughout the winter by automated remote sensors that communicate with each other by bouncing radio signals off meteors. Then, these measurements are confirmed by hand around April 1 — the time of year that traditionally defines peak snowpack. Snowfall measurements taken this time of year form an especially critical piece in the state's water resource allocation decisions throughout the dry season, which runs from about now until next winter.

This year is effectively a preview of California's drought-stricken future.

It's simple, really. Winters without snow are going to become more and more common in the years to come.

Problem is, modern California just wasn't built to handle a world without snow. In California, it seems, all water pipes lead to Los Angeles.

These days Los Angeles gets its water from three main sources, and all start predominantly as snow. Predictably, they all have serious issues when you take climate change into account.

The Los Angeles Aqueduct was built more than 100 years ago and has caused environmental degradation near Mono Lake. In a recent settlement, the city agreed to limit water diversions from this sensitive area.

The California Aqueduct is the single largest user of energy in the state, pumping water from Northern California hundreds of miles (and over a mountain range) to homes in Southern California. In total, water pumping makes up 20 percent of California's electricity use.

The Colorado River Aqueduct diverts water to Los Angeles from as far away as Wyoming.

When you're that reliant on snowpack, you've got to start thinking outside the box.

Southern California expects an additional New York City's worth of water-guzzling people over the next 50 years, growing to 31 million by 2060. Meanwhile, California agriculture supplies a majority of the country's fruits and vegetables, and more than 90 percent of the world's almonds, pistachios and other specialty products. Clearly, something's gotta give.

Desalinization and water recycling are obvious future sources of water in Southern California. Still, in a state where agriculture uses 80 percent of the water, cities have a point when they ask: Why can't we get some of that? Farmers here have a quick reply: How many meals can you go without?