> A medium size data center consumes 300k gallons of water per day
Not always true. This can vary greatly based on datacenter design. A medium sized datacenter proposed near me was planned to only use 300 gallons a day for example.
Your source even points to this being highly variable, assuming you pay attention to their wording.
> Large data centers can consume up to
"Can consume", "up to". Not some hard truth that they will consume that much.