Usually you notice a few days before when your stock is starting to run out. If you make coffee every day, would you be surprised that you're out of coffee one morning, or would you notice the day before that you need to buy some coffee?
My understanding is that these areas are services by a single well or spigot that serves an entire small community. Like in rural (poor) India. So you don't stockpile water for days, you're fetching it daily. But then meanwhile there's also "traditional" (unclean/less clean) water sources available much closer to or in the homes.
