Hydroelectric generation should make up only 6% of the power load in California this year as historic drought conditions ravage the West, the U.S. Energy Information Administration (EIA) said Wednesday.

In its Short-Term Energy Outlook, the EIA said hydroelectric generation in California in 2021 would be 19% lower than last year. It is seen falling to 13.6 million MWh in 2021 from 16.8 million MWh in 2020. 

However, researchers said higher prices would prevent natural gas from making up for the lost output. 

Most of the West is experiencing intense and historic drought conditions, with California one of the most severely affected states, according to EIA. As of June 22, the entire state was experiencing some degree of drought and more than one-third had been categorized as under exceptional drought conditions, the most intense classification.

“The extreme drought in the Northwest and California is straining water reserves, which we expect to cause a significant decrease in electricity from hydropower this year,” said EIA’s Steve Nalley, acting administrator.

The drier conditions mean that mountain snowpack, which serves as a natural reservoir and provides water throughout the spring and summer as it melts, is lower than normal. In California, snowpack water content peaked at only 60% of normal, according to the Northwest River Forecast Center. 

Most of the snowpack melted quickly because of higher spring temperatures. The EIA indicated that as of June 1, measurable snow was present at only three of 131 monitoring stations.

“Meltwater from the snowpack often didn’t reach reservoirs in California this year because it was absorbed by drought-parched soil and streams, leaving reservoirs across the state at low levels,” EIA said.

Shasta Lake, the largest reservoir in California, was at 48% of its average capacity, according to the agency. Lake Oroville, the second-largest reservoir in the state, was at 40% of its average.  Oroville’s water level was expected to fall even lower, likely forcing the Edward Hyatt Power Plant to shut down for the first time since it opened in 1967.

The lower water levels already have taken a toll on hydroelectric generation in California. 

The EIA said in the first four months of this year, hydroelectric generation in the state was 37% less than in the same four months in 2020. It was 71% less than that period of 2019.

Despite the decline in hydroelectric output, which is expected to modestly rise to 7% in 2022, natural gas is not forecast to make up for the lost generation, according to EIA. The government’s researchers said the share of electric power generation produced by natural gas in the United States should average 36% in both 2021 and 2022, down from 39% in 2020.

“Our forecast for the natural gas share as a generation fuel declines because we expect a higher delivered natural gas price for electricity generators,” EIA said.

Calling All Power Sources

For its part, the California power grid operator is working to ensure reliability in what usually are  the hottest months of the year.

The California Independent System Operator (CAISO) is working with the California Public Utility Commission (CPUC) and the California Energy Commission (CEC) to procure additional energy resources for July and August “out of an abundance of caution.” CAISO could seek additional supplies through September if conditions do not improve.

“Summer has barely begun and we have already had repeated extreme heat events creating dangerous conditions and shattering records across the country,” the state agencies said July 1. CPUC, CEC and CAISO “have all taken significant steps in recent months to better prepare our electric grid for this new climate reality, and that work is ongoing.”

Although regulators approved rules earlier this year aimed at improving reliability in the state, drought conditions have worsened, reducing hydro capacity by about 1,000 MW. Thermal resources also have declined, with at least 300 MW of capacity not available this summer.

Regulators noted that high heat events across the West began earlier than usual and have exceeded historic temperature levels. During the week of June 14, CAISO issued the summer’s first Flex Alert and first Grid Warning. The same week, Gov. Gavin Newsom signed an emergency proclamation to free up additional energy capacity. He also called for public conservation.

Most recently, an unprecedented heat wave blanketed the Pacific Northwest in the final days of June. “Collectively, these heat events in California and throughout the West began earlier in the year than expected and will most likely impact the ability of California to import more energy beyond the resource adequacy obligations,” the state agencies said.

Meanwhile, CAISO may not be able to rely on some of the resources planned for the summer. The CPUC recently received notice that several power resources would be delayed, “and in some cases will push online dates past the summer window.”

In addition, resources used to meet gross peak load are not adequately supporting net peak in extreme conditions, according to regulators. There are also time limits associated with the resource adequacy compliance processes.

“The aforementioned events have resulted in a material difference from what the CPUC assumed for the resource adequacy program in establishing requirements for summer 2021 and caused a material change in system conditions,” the agencies said.

CAISO has exercised authority to procure more power supplies before, most recently during last summer’s regional heat waves. It called the jurisdiction “an essential backstop” to ensure a balance of demand and supply on the state’s power grid.

California’s previous drought, which lasted from 2012 to 2016, led to significant declines in hydroelectric generation and the first-ever mandatory water restrictions in 2015.