The Metropolitan Water District of Southern California shared the award with the Canadian town Clearbrook, British Columbia.They beat 120 rivals at the Berkeley Springs International Water Tasting.
And while the winner may have been wet, there were no acceptance speech waterworks like those at the Oscars.
"It's not the first time Los Angeles has won, they've won a number of times over the years," said Jill Klein Rone, the competition's organiser.
"It means they give special care and attention to their water and how it is processed."As at LA's more famous awards ceremony, short-listed candidates came from across the globe.
They included entrants from New Zealand, Romania, Macedonia and the Philippines.Unlike the Oscars, however, selection criteria was based on taste, smell, texture, after taste and clarity.
A panel of 10 judges - mostly comprising journalists and food critics - supped sparkling, tap and bottled water from 19 US states and 9 other countries.The awards were the 18th to be held in Berkeley Springs - reportedly the world's largest and longest-running water-tasting competition.
While Oscar winners can expect a flood of offers of lucrative work on the back of their success, there will be financial windfalls for winning waters too.
"The people who won, particularly the bottled water people, their phone will be ringing off the hook," said Ms Rone.The award for best sparkling water went to Salvus Mineralwasser Medium of Emsdetten, Germany.
And in the bottled water category, newcomer Tumai Water of Martinsburg, West Virginia, won over. The company donates profits to Aids relief and water needs in Africa.