After a series of storms drenched the region with a record 9.4 inches of rain in December, the Los Angeles River became a roiling, violent torrent in its concrete channel, before finally spilling into the Pacific Ocean.

The storms transported an estimated 29.5 billion gallons of fresh water into Long Beach Harbor — 62% more water than the nation’s largest desalination plant in San Diego produces in an entire year. It was enough to supply as many as 181,000 families annually.