A new low in California's worsening drought was reached Monday when state officials reported that the state's snowpack is down to zero, an inevitability after the measurement of 5% of normal when the same measurements were taken two months earlier.

Despite the dire water measurement, power supplies statewide are basically unaffected, state officials said Monday.

The state grid operator is sticking with earlier predictions for adequate supplies of electricity this summer, even in the event of severely hot weather that pushes electricity demand far above normal levels (see Daily GPI, May 13).

While the state's hydroelectric supplies will be down, natural gas-fired, renewable and imported hydropower supplies are expected to more than make up the difference, according to the California Independent System Operator's (CAISO) outlook released last month. The state goes into this summer with a plentiful operating reserve margin of more than 25%, CAISO said.

In mid-April when CAISO developed its summer estimates, the snowpack was 4% of normal, and to that the grid operator adds 10%, so its estimates more than account for the complete wipeout of snowpack, a CAISO spokesperson told NGI on Monday.

"Besides all the other input assumptions, CAISO further reduces the snowpack estimates by an additional 10% to get to our projected hydro availability, which stretches from 1,511 MW under normal conditions [one-in two-year conditions] to 2,733 MW under the extreme scenario [one-in 10-year conditions]," the spokesperson said.

"So our conclusion remains the same now as when the assessment was released; the snowpack/melt runoff is not expected to have significant impact on hydro-electric availability."