It's the Worst Drought in 500 Years and California Is Draining Its Reservoirs

As the drought in California drags into it's fourth year — punishing farmers and exacerbating unemployment and drug use — federal flood control measures may be worsening the dry conditions in some areas.

Back in 2013, the US Army Corps of Engineers (ACE) required officials to empty more than 15 billion gallons of water from at least two reservoirs in Northern California: Lake Mendocino and Sonoma Lakes. ACE was following a set of guidelines aimed at reducing the likelihood of flooding — a manual that determines safe water levels at any given reservoir.

Reservoir levels at Lake Mendocino were above a 23 billion gallon threshold, so the federal regulations required a release of about 6.5 billion gallons. When rainfall and reservoir levels are around the historic average, the release helps prevent flooding of rivers and streams. But during a drought that water is needed, say water experts, to help keep reservoirs from becoming depleted.

A recent editorial in the Press Democrat, a newspaper that serves Northern California's Sonoma County, urged Congress to amend the federal guidelines in order to prevent a repeat of the 2013 scenario.

"To better fulfill the dual mandates of preventing floods and supplying water, Lake Mendocino's managers need relief from a pre-Sputnik matrix that dictates water levels without regard to modern science," the editors said.

The worst drought in 500 years. Watch the VICE documentary.

In an average year everything would have been fine, with the rains continuing for several months, and the emptying saving potentially deadly flooding. But, it barely rained in months after the release, worsening water shortages in the region. "No one predicted that it wouldn't rain," Mike Dillabough told VICE News. Dillabough is Chief of Operations and Readiness for the San Francisco division of ACE.

ACE didn't have a choice. The regulations were developed decades ago and, while providing some flexibility, they don't allow holding potential floodwaters above a set, maximum level. And once that's reached, they're required to release water.

"I understand that it may be archaic for some, but when you start getting into the flood pool area, that's when we have to release the water," JD Hardesty Chief of Public Affairs for the San Francisco district of ACE told VICE News. "Not doing so could compromise the safety of people downstream, as well as threaten endangered species and wildlife. The manual expects so much rain over a certain period of time."

In part that's because doing so could have deadly consequences, resulting from massive and uncontrolled flooding due to the rupture of a dam. "It's a damned if you do, damned if you don't situation," Dillabough said, referring to the undesirable choice of risking lives or helping to relieve the drought.

The Sonoma County Water Agency, which works closely with ACE and oversees some of the affected drought areas, did not return several telephone calls from VICE News.

ACE says they're attempting to solve the issue as well — relaying concerns up the chain of command, even when at this point in the year, most reservoirs are just too low to even consider releasing water.

But, one of the ongoing hurdles has been weather prediction, Dillabough explained. "Weather modeling has improved in the past decades, but we need at least five days notice in order to safely release water. We need the National Weather Office to say: 'Yes, we can give you 5-7 days notice.' It's a big issue that it's trying to resolve."

Should ACE have sufficient notice from the weather office, they could update the manuals and hold onto water until there is far more certainty that the coming rain would fill a reservoir beyond safe limits.

An act of Congress could also change the management plans. Representative Jared Huffman, a Democrat representing San Rafael, introduced a modernization bill last year, aiming to update aging water control regulations with the latest and best scientific techniques available from the National Oceanic and Atmospheric Administration. The bill failed to make it into the drought relief bill passed by the House of Representatives in early December.

The worst drought in 500 years. Watch the VICE documentary.

At the moment, the state's 154 reservoirs are not in great shape. Water reserves are about 67 percent of normal, or about 4.8 trillion gallons, according to data from the state's Department of Water Resources. Normally such reservoirs carry about 7 trillion gallons in December, and almost 10 trillion gallons by the end of the rainy season in March.

A state of emergency remains in effect in California and a lack of rainfall in January has meteorologists at the US Department of Agriculture (USDA) concerned.

"We're at the half way point in accumulation season," USDA Meteorologist Brad Ripey told VICE News. "It's alarming that the snow pack is exceptionally low in the Sierra Nevada Mountains. It's less than a third of average for this time of year and a sixth of the average peak snow pack. Unless we get snow, there's not going to be much flowing into the reservoirs."

Follow Max Cherney on Twitter: @chernandburn