California shakes off 'abnormally dry' conditions, flipping the drought state's drought map

A rainy few weeks may not guarantee a wet winter, but they helped California shake off an "abnormally dry" designation from the U.S. Drought Monitor.

On Thursday, the team behind the weekly updates released a map showing nearly the entire state – 96.4% – was clear of any drought conditions.

Just a few weeks ago, conditions were flipped.

Roughly 94 percent of California had been moving toward drought, with most labeled abnormally dry, the least severe of five stages.

"In California and Nevada, rainfall over the last three weeks has helped to make up for the slow start to the water year," wrote Deborah Bathke at the National Drought Mitigation Center.

Northern and Southern California got hit by rain and snow in late November and early December.

But it's still early.

Experts say a few rainy weeks don't mean a wet winter and the long-range precipitation outlook is murky.

In strong La Niña conditions, forecasters typically say California is in for a drier year. In a strong El Niño, the forecast calls for more rain and snow.

This year, neither made an appearance.

At this point, trends lean toward below-average precipitation in Southern California, according to the National Oceanic and Atmospheric Administration.

A wet November

All of Ventura County was dubbed "abnormally dry" on Nov. 12.

That persisted until Thursday. The designation was removed and nearly all of the county had reached above-normal rainfall for this time of year. The rain year runs from October through September.

From Oct. 1 through Dec. 12, rainfall ranged from a low of 3.2 inches in Thousand Oaks to a high of 6.2 inches near Matilija Canyon.

Those preliminary figures from the Ventura County Watershed Protection District mostly stretched above normal for 2½ months into the rain year. 

Rainy days and some snow got rivers and creeks moving – at least, for a little while.

A still drought-stressed Lake Casitas got a small boost. But the lake has a long way to go to climb back to normal.

With no imported water, Casitas depends on local rainfall and river runoff, including through a diversion canal above the lake.

Year after year of drought conditions left the manmade reservoir at historic lows. As of Dec. 12, the lake was 41 percent full.

The season's early storms don't produce much runoff. Instead the rain tends to soak into the dried-out river and creek beds.

But enough water flowed down the river to divert some to the lake on Dec. 4, said Casitas General Manager Mike Flood. He estimated about 100 acre-feet was diverted in a canal that winds down to the lake.

"It was back to a trickle the next day," he said. 

More:Water agency closer to getting permits to fix Lake Casitas diversion issues

A drought-stressed lake

The Thomas Fire in December 2017 added a new challenge for the lake.

As storms charge rivers and creeks, Casitas can open a canal, diverting water from the Ventura River into the manmade reservoir.

But now, as rain slams into burned hillsides, debris and ashy muck floods into the Robles diversion facility along with the water. Screens designed to keep fish in the river and let water spill into the canal clogged.

In all, between 80,000 and 100,000 cubic yards of material has built up in the forebay, a sort of mini-reservoir where a small earthen dam captures the river water. This year, officials planned to clear 50,000 cubic yards.

The more than $1 million project to clear the current pile of muck would give the silt and sediment a place to settle before it reaches that equipment.

District officials were concerned about another year of problems as the start date pushed closer to rainy seasons as they waited for required permits to be approved.

But work started Nov. 4 and crews finished moving dirt on Nov. 17, said Casitas engineering manager Julia Aranda. They worked 10 hours a day, Saturdays, Veterans Day and one Sunday to try to beat the rain.

The overtime and double-pay for the holiday will hike the price tag, but the project was completed. Plans call for clearing more of the pile next year.

Two years since the fire, officials expect less sediment to come down the river this winter. For now, Flood said, the small diversion seemed to be OK.

But, he added, the area has yet to face the test of a significant storm.

See your city's rainfall

Read more Ventura County weather news:

• Ventura County to enjoy sunny skies after three rainy days
• County expected to start weekend with light rain
• Ventura County will receive more rain from atmospheric river

Cheri Carlson covers the environment for the Ventura County Star. Reach her at cheri.carlson@vcstar.com or 805-437-0260.