The mod Snow is water [B41.74 Legacy] (or its variations) fixes a logical gap in the base game: by default, rain barrels do not collect water during winter when it snows.
Snow typically fills containers at a slower rate (often 50% ) compared to rain. The mod Snow is water [B41
The phrase you are referring to typically points to a popular community-created mod for the survival game . Project Zomboid Mod: "Snow is Water" The mod Snow is water [B41
It allows Rain Collectors and Metal Barrels to be filled while it is snowing. The mod Snow is water [B41
There are "Rainbarrel only" versions and "Project Realism" versions that focus on melting snow for drinking water. General Concept: Melting Snow for Water