The answer to 'why is my water line frozen' is that your water line has likely frozen due to cold outdoor temperatures. This is a common issue that can happen when the water in your pipes freezes, preventing water from flowing properly.
Some common causes of frozen water lines include lack of insulation, drafty areas around the pipes, and prolonged exposure to freezing temperatures. Symptoms may include no water coming out of faucets, low water pressure, or burst pipes. Solutions can include insulating exposed pipes, using a space heater or heat tape to thaw the line, or calling a professional plumber to address the issue.