The answer to 'why is my water heater leaking water' is that there are several common causes, including a faulty temperature and pressure (T&P) relief valve, a crack in the tank, or a loose connection in the plumbing. Leaks can also be caused by sediment buildup or corrosion inside the tank.
If you notice water pooling around the base of your water heater, it's important to address the issue promptly to prevent water damage. Depending on the cause, you may be able to fix a minor leak yourself, but for more serious issues, it's best to call a professional plumber.