A drop of water from a faucet in, say, Flushing—how’d it get there? There’s your pipe, water tower, service line, water main, water tunnel, holding reservoir (Yonkers), ultraviolet disinfecting station, monitoring reservoir (Valhalla), and hundred-and-six-year-old aqueduct snaking ninety-two miles, plunging way down under the Hudson and back up again, which delivers fresh mountain water from the Catskills that departed three or so days earlier from a third, bigger reservoir. But what of the reservoirs? How’d those get there?

“When I first lived in Delaware County, there was a drought,” the writer Lucy Sante said the other day. “Somebody said, if you go to the Pepacton Reservoir, you’ll start seeing church steeples poke up.” Not true, it turned out. “They burned everything and even hauled away the ashes. The only thing you’ll see are cellars and roadbeds. I was kind of haunted by that.”

Sante, who now lives in Kingston, has just come out with a book on New York City’s water system and the people in its way. The city, at various stages, considered various schemes: dams in the Hudson and in the Long Island Sound, a pipeline from the Great Lakes. Each time, the city opted instead to flood a few small villages upstate—remote places full of people whom the city folk referred to as “apple knockers.” The eviction-and-construction process repeated nineteen times. The book is called “Nineteen Reservoirs.” Sante was on a drive around one of them, the Ashokan.

Sante, who has long pale hair and speaks with a relaxing slowness, rode shotgun. In the mountains leading to the spillway, she said, “During the construction of the reservoir, there would have been blind tigers and whorehouses along this road.” For a time, starting in 2000, Sante lived there, too. She wasn’t a natural at apple knocking. “It was a very, very, very hard time for me because I didn’t want to leave the city,” she said. Alas: newborn baby, job at Bard, parents’ death, wife’s insistence. “I was pulled out.” She asked to stop near an old Second Empire-ish farmhouse, built pre-reservoir. “This is it. The house was beautiful on the outside but fatally renovated on the inside. Completely soulless nineties renovation. We did sell it for two or four times as much as we paid.”

Sante has long been fascinated by infrastructure. (In an essay for a book accompanying a new show at the Met, she describes water towers photographed by Bernd and Hilla Becher as “alarmingly penile glans-topped cylinders” and “gold-miners’ cabins moldering in Western ghost towns.”) She lived in the Catskills for decades before getting around to researching the book. She’s a quick writer, once she starts. “Reservoirs” took her a few months. (In 1991, “Low Life,” more than four hundred pages, took her nine.) “The next book is my trans memoir, and I’m planning to write this book as quickly as I possibly can,” Sante said; she transitioned last year.

The reservoir appeared behind a berm, formerly the crest of a valley. “Bishop Falls, the old beauty spot, is now at the deepest point,” Sante said. Near the causeway across the reservoir was a barricaded turnoff. “They closed this road after 9/11,” she said. “There were paranoid mutterings about jihadists putting LSD in the water supply.”

In the nineteen-tens, entire towns in the path of the Ashokan relocated wholesale. Thousands of graves were moved. On Route 28, Sante pointed out a row of houses that had been transplanted using log rollers. “They were likely pulled by oxen,” she said. “There were people who were eager to move into the future and those who wanted to hold on to the past. As ever.”

A few minutes later, Sante said, “This is the stolen church.” The Methodists of Glenford had plopped it on land technically owned by the railroad. “The railroad and the reservoir were both fine with the church,” Sante said. “It was just New York City that decided to be pricks, as they made the decision to be pricks at almost every point.” The city sued and won forty-five dollars.

When did city people start bragging about how good the water tastes? “Oh, that far predates the reservoir,” Sante said. “A company in Pine Hill would package jugs for tourists. People in the city could order a cartload. Not so much these days. The Delaware River reservoirs, especially Cannonsville, have introduced a higher level of bad stuff.”

Time for lunch. At a noodle place in Kingston, tap water was requested. “Where do we get our water from?” Sante said. “Well, we’ve got our own reservoirs.” The Ashokan isn’t for locals, so they use Cooper Lake, farther into the mountains. Served cold on a ninety-seven-degree day, it tasted pretty good. ♦