India, Jan. 16 -- A special annual calendar by photographer Bijoy Chowdhury, gifted to friends and associates, captures Kolkata's last remaining vistiwalas through his lens-preserving a vanishing profession and an essential fragment of the city's living heritage for generations to come.

Kolkata has always carried its past lightly-sometimes in stone and mortar, sometimes in people.

Long before pipelines and plastic tanks, the city depended on human rhythm and muscle. Among these quiet lifelines were the vistiwalas, the traditional carriers of water, once an inseparable part of old Kolkata's daily pulse.

In the early 1980s, they were everywhere. From dawn till dusk, men moved through narrow lanes and crowded crossings with a mashq-a wate...