From Google’s blog:

Last year, our global data center fleet consumed approximately 4.3 billion gallons of water. This is comparable to the water needed to irrigate and maintain 29 golf courses in the southwest U.S. each year.

From the WaPo article:

A large data center, researchers say, can gobble up anywhere between 1 million and 5 million gallons of water a day — as much as a town of 10,000 to 50,000 people.