Lake Oroville, a key component of California’s water supply, looks noticeably fuller after a series of January storms.

The atmospheric rivers dumped trillions of gallons of moisture on the state, spurring widespread flooding and destruction but also providing a healthy boost to snowpack and drought-sapped reservoirs.

Lake Oroville, the largest reservoir on the State Water Project, was at 68% of its capacity on Friday — up from 28% just two months prior, according to state data. The State Water Project is a system of reservoirs, canals and dams that supplies water to about 27 million people.

The reservoir had fallen to such perilous lows that in 2021 officials closed Oroville’s hydroelectric power plant for the first time since its completion in 1967.

Shocking images that year illustrated the worsening drought conditions, including exposed portions of Oroville’s lakebed and a distinct “bathtub ring” indicating just how far the water had receded.

But photos captured by Times photographers this week showed a considerable improvement. Since its lowest point — an elevation of just 628.63 feet on Sept. 30, 2021 — Oroville has risen about 189 feet, reaching an elevation of 817.41 feet as of Friday.

Jeanine Jones, Interstate Resources Manager for the Department of Water Resources, said in a statement the storms “certainly helped reservoir storage in California following the driest three years in the state’s recorded history.”

However, it’s important to continue conserving supplies, she said. Last year, a wet December was followed by the state’s driest ever January through March on record.

“Over the next two months, it is important that we still see periodic rain and snowstorms to keep an above-average pace for our precipitation totals,” Jones said. “ While this has been a strong start, the most important measurement will be April 1 when the snowpack is typically at its highest. Californians should continue to use water wisely so that we can have both a thriving economy, community and environment.”

Jones noted that groundwater, or the state’s system of underground aquifers, is much slower to recover from depletion and has a long way to go before it can fully be replenished.

What’s more, Southern California’s other major supply of water, the Colorado River, did not benefit much from the atmospheric river storms and is still dwindling toward perilous lows. Federal officials have ordered California and six other states that rely on that river to drastically cut their use.

The wet start to the year “shouldn’t take the momentum away from us continuing to work on building resiliency, recycling water and storing water when we have it,” Adel Hagekhalil, general manager of the Metropolitan Water District of Southern California, told The Times last week. “We should conserve as much as we can so we can save water to have it available when we need it.”

The state remains under a drought emergency declaration issued by Gov. Gavin Newsom in 2021. MWD also issued a regional drought emergency for all of Southern California in December.

Jones said the rest of the wet season will prove critical for California. The latest seasonal forecast from the National Oceanic and Atmospheric Administration shows equal chances of wetness or dryness in most of the state through April.

“For every day it doesn’t rain or snow during our wettest months, we are drying out,” she said. “A lot of uncertainty remains about the next two months and water managers are maintaining reservoirs to hold as much water supply as possible while also managing flood control requirements.”

Oroville is indeed capable of getting too full. In 2017, heavy rainfall flooded the area and nearly overtopped the Oroville Dam.