Gathering water can be difficult when you still live in one of the towns that survived the flash.
Running water only works part of the time so you're never really certain when it will decide not to work for you - usually when you need it most. Winter is one of the worst times for the water to freeze up or when they can't get it fixed that quickly.
So, you do what our grandparents did and stock up.
Right now my basement is as stocked as a wine cellar - just with bottles of water. Anything that could hold water has been washed and converted into use. We are truly a 'Green' society because recycling isn't just a cool idea - it's a fact of life.
When the water goes out, it could take a week to get it turned back on. This is when people start dipping into their water cache for everything from flushing the toilet, doing dishes and sink-baths. Showers and baths are usually on hold until the water's back on.
In some parts of the town, you can't get running water because the pipes broke and they're too far down to dig by hand. Though we've been able to rebuild most of the digging machines after The Flash, we don't have any pipes to replace the ones that ruptured with the cold.