LOS ANGELES (Reuters) - California's recent spate of epic Pacific storms has blanketed the Sierra Nevada range in a snowpack at or above record levels, state water resource officials said on Monday at a measuring station where less than 3 inches was documented last April.

The bounty of mountain snow, on which California has long relied as a critical natural storehouse of fresh water during dry weather, comes as welcome relief after three years of record drought that had still gripped the state a few months ago.

But this year's abundant Sierra snowpack also poses a severe risk of renewed flooding to parts of California, especially the lower San Joaquin Valley, during the spring thaw, according to state Department of Water Resources (DWR) officials.

Some areas, especially California's central coast and agricultural heartland, are still recovering from floods, mudslides and shoreline damage unleashed by a string of Pacific storms that deluged the state in heavy downpours week after week for three months.

The same storms dumped paralyzing loads of snow in the Sierras and upper elevations of California's coastal mountains, leaving some ski areas such as Mammoth Springs buried almost up to the rooftops of winter cabins.