Because of recent serious flooding here in Central Texas, Austin is now on its third day of a Boil Water Notice (the first it has ever had). So far there has been no problems with bacteria or anything like that, but the water treatment plants are falling behind on supplying treated water due to high turbidity in the Colorado River, so we are also on a slight water conservation regime. It's interesting. Since floodgates are still open and we are still getting rain, estimates for how long this will last are anywhere from a few more days to two weeks. So far I haven't been affected myself much at all (I always have on hand an emergency supply of drinking water for several days, and in the kitchen almost the only thing I regularly use water for anyway is tea), but it's interesting how much it changes things broader afield -- a lot of little things, like there being no soda fountains, and restaurants having to change their menus. Bottled water has been vanishing from the shelf almost as soon as it is put there; breweries, which have to boil large amounts of water for a long time anyway, have been cutting back on brewing (to conserve water) and devoting part of their time to boil water specifically to give to those who need it, including restaurants and coffee shops.
Most of civilization, its infrastructure and component parts, is in the background of our lives; we only really see it when it is put to the test.
UPDATE (October 28): The Boil Water Notice has been lifted.