The Apple HomePod is not waterproof. Apple suggests keeping your HomePod away from all sources of liquid. This means you should not store your HomePod in the kitchen near your sink, bathroom, and so on. Do not take your HomePod near swimming pools, spas, and so on.
The Apple 1 year limited warranty does not cover "damage caused by accident, abuse, misuse, fire, liquid contact, earthquake or other external cause."You can purchase an AppleCare+ plan to protect against accidental damage.