Can drinking a lot of water flush alcohol out of you system fast?

No, It immediately enters the blood stream then is processed through your liver. If your liver is impaired it can take longer. The alcohol rate of absorption is also influenced by whether you started drinking on a full or empty stomach. An average weight man can drink approx. 1.5 ounces of alcohol and process it within an hour. An average weight woman 1ounce per hour. Water will help prevent dehydration while drinking which is the main cause of a hangover.