What is the typical capacity of the water storage tank in an old style flush type water closet?

The typical capacity of the water storage tank in an old style flush type water closet is often around 6 gallons. This design was common before regulations and water conservation measures began to promote the use of lower-capacity tanks. Older toilets, particularly those manufactured before the 1990s, usually featured larger tanks to provide the necessary water volume for effective flushing.

Understanding this typical capacity helps highlight the advancements in toilet design and efficiency, as modern water closets use significantly less water, often between 1.28 and 1.6 gallons per flush. Recognizing the historical context of plumbing fixtures aids in grasping how building codes and environmental considerations have evolved over time to promote conservation and efficiency in plumbing systems.