Source: SQRD
Given that the average flow rate of a shower is 9.5 liters per minute, we recommend not exceeding 5 minutes.
Have you spent 4 minutes or less underwater?
Congratulations! Considering that it's recommended to drink between 2.7 and 3.7 liters of water a day, you've saved at least enough water for 3 people!
By the way, fill up your Bora Boréal water bottle and put it in the fridge so you'll always have a fresh bottle of water during your stay.
Source: SQRD