Trickle-down effect works best when you go with the flow

It was all going swimmingly until we reached Membrane Processing, then came perilously close to the jagged rocks at Dosing Coagulants before the rapids engulfed us at the Flocculation Reaction stage. My guide, all wide-eyed enthusiasm and with expressive hands as quick as her feet, was as much in her element as I was out of it. I was getting the low-down on water filtration, in high-volume Mandarin.

I didn't know what to expect at the Beijing Waterworks Museum, but let's just say it's more complicated than a brewery tour, where everything becomes clear in the end－with those free samples of a wet substance. The complications begin with finding the place. After leaving Dongzhimen subway station, you may spot the first of the small signs for "Funny Water Works"; follow them and the laughs are at your expense.

Coming to my rescue in a fast-paced shuffle was a force of nature swaddled in winter layers, and with those eyes beaming out from under a pink woolen cap. I hadn't been looking for a guide, just the right path on a wind-swept Dongzhimen North Road. But she took charge, accosting her fellow senior citizens who had gathered for exercises and seemingly challenging them on why airy hand movements behind them was the best they could come up with. A tug at my elbow had me trailing after her to a guard post and the first of several uniformed types she quizzed in the hunt for a mysterious shrine dedicated to the foundation of life.

In the middle of a housing estate, we ran up against locked gates－another Beijing mystery to me, along with the ubiquitous pavement barricades. Through the bars of one gate, security guards pointed out a circuitous route to the museum, and that it was closed. They were half right. I soon had a ticket in my hand and found myself in a bright space under a vaulted ceiling that was only a few sofas short of being a hotel lobby. Alas, no hard hat and wellies required.

I also found myself alone. The woman who made all this possible had declined my offer of a ticket (5 yuan, or 72 cents, but it's the thought that counts). As I was fumbling with the English-audio guide, I felt that tug on my elbow again. She was back. My neighborhood guardian pulled at the gray hairs from under her cap to indicate she had landed a seniors freebie (mental note made for future reference).

And with that, she led me on pinball-like, random encounters with the exhibits, reading from the display panels－all in Chinese－and with a theatrical flair. I had begun cursing my Chinese textbooks for the lack of hydrology-themed dialogues by the time we barreled into Flocculation Reaction. I confess my mind wandered during my guide's explanation and she may well have told me that the Bill and Melinda Gates Foundation is working on a cure.

You could call it a thirst for knowledge that led me to leave the museum with my guide and exchange cheery goodbyes, and then sneak back in. The audio guide was a little quirky but I nodded along when told that flocculation is a process in which fine particulates clump together into a floc. If you don't know what a floc is, I can point you in the direction of a 75-year-old woman in Dongzhimen North Road.

There's also a certain Mr Water Man who appears in video panels. Our androgynous hero is rather spotty before undergoing filtration and emerging clear-faced and chipper at the end. There are takeaways for your 5 yuan. We're told that we'll each drink up to 200 tons of water before we raise our last glass. Fall well short of the advised two to three liters a day and you risk dehydration. Dry lips, wrinkles and a haggard face are the telltale signs, and "you may fall into a trance". I instinctively reached behind me for a seat. And I had thought it was the rapid-fire Mandarin that induced the state I was just emerging from.

If you visit Dongzhimen's best-kept secret, walk around the corner and check out Beijing's first waterworks from 1908－from behind more metal. They no longer simply toss in bleaching powder. Be thankful of that if you wake up on the first day of 2020 looking haggard and in need of hydration.