New York is many things: dynamic and dense, artistic and competitive, vivacious and sometimes, particularly in summer, a bit smelly. The list of traits goes on and on, but the word “quaint” isn’t on it. And yet one of the city’s most familiar signposts is a charming, rustic throwback: the wooden water tank.

For over a century, the basic design of these tanks, which are essentially giant wooden barrels, has gone largely unchanged. So as each one ages out of its working life, it is replaced by another member of the same family, and the tradition marches on.

As it happens, the same can be said about the people who put them in place.

Installing, maintaining and replacing wooden water tanks in the city is largely handled by three companies: Isseks Brothers, the Rosenwach Group and American Pipe and Tank. Each is an old family business that has operated for at least three generations, and each has a next generation who parents and grandparents are hoping will take over.

“It’s kind of in our blood, I would say,” said Henry Rosenwach, 23, who spent summers in high school and college scrambling around on rooftops with tank crews, always with strict instructions to keep both of his teenage feet on the ground. But the final decision to join up, he said, arrived at a practical moment. “I think it was at the point when it was time for me to get a job,” he said.