Snow survey says 178% of average in central Sierra. Here’s how PG&E determines that

Pacific Gas & Electric Co. hydrologists estimate the central Sierra Nevada snowpack is about 178 percent of average after several heavy winter and early spring storms.

That was the call from PG&E’s latest monthly snow survey, part of the California Cooperative Snow Survey.

A PG&E team flew by helicopter Monday into the Kings River watershed above the Helms hydroelectric plant. The team made nine stops including at 10,300-foot Blackcap Basin to check snow depth and water content.

Hydrologists return to the same mountain areas every month during the winter to check the snow, said PG&E spokesman Denny Boyles. The estimates help forecast how much water will be available for hydroelectric systems and how much surface water will be coming down rivers during the spring and summer runoff.