Save water today.

Meaning: This means to conserve water by using it wisely and not wasting it. It's like saying, Be mindful of how much water you are using.

Choice of Words: Save is a verb that means to keep something from being lost, destroyed, or used up. Water is a noun that refers to a colorless, odorless, and tasteless liquid that is essential for all living things. Today is an adverb that means at the present time or on this day.