By every measure, it's been dry

Nature is pulling a triple whammy on Southern California this year. Whether it's the Sierra, the Southland or the Colorado River Basin, every place that provides water to the region is dry.

It's a rare and troubling pattern, and if it persists it could thrust the region into what researchers have dubbed the perfect Southern California drought: when nature shortchanges every major branch of the far-flung water network that sustains 18 million people.

Usually, it's reasonably wet in at least one of those places. But not this year.

The mountain snowpack vital to water imports from Northern California is at the lowest level in nearly two decades. The Los Angeles area has received record low rainfall this winter, contributing to an early wildfire season that included Friday's blaze in the Hollywood Hills. And the Colorado River system remains in the grip of one of the worst basin droughts in centuries.

"I have been concerned that we might be putting all the pieces in place to develop a new perfect drought," said UCLA geography professor Glen MacDonald, who has researched drought patterns in California and the Colorado River Basin over the last 1,000 years.

"You have extreme to severe drought extending over Southern California and also along the east and west slopes of the Sierra, and then you have it in the Colorado [basin], particularly Wyoming."

That, coupled with wet winter weather patterns in the southern Great Lakes region and the Northeast, MacDonald said, "is extremely similar to the last time we had a perfect drought, which was the late 1980s, early 1990s."

Thanks to a bountiful Sierra snowpack in the spring of 2006, the state's reservoirs are in good shape. Southern California water managers say they have ample supplies in reserve and are better prepared for a prolonged dry spell than they were two decades ago.

"We're watching this. We're not pleased. We're not worried, either," said Jeffrey Kightlinger, general manager of the Metropolitan Water District of Southern California, the region's major water wholesaler. "If it does continue, we have prepared ourselves for a multiple-year drought.

"It used to be we thought that geographic diversity was enough" protection, he added. "In 1990 or so, we realized it really wasn't."

Since then, the water district has constructed a large reservoir in Riverside County and is storing more water underground.