If you’re a Dirty Jobs fan, you’ve probably seen the episode in which Mike helps a crew in New York City to build a rooftop water tank. It’s one of my favorite episodes, and it’s available here, on the website of the company that builds those tanks.
in 2009 I spent a couple of nights in Manhattan. From the 30th floor of one hotel I was able to see lots of these rooftop tanks on other nearby buildings.
Last weekend I spent a night in downtown Chicago, on the 29th floor of the Marriott on Michigan Avenue. Looking out the window, I didn’t see a single tank anywhere. Not one. Wazzupwidat? Where are Chicago buildings keeping all of their water???
Perhaps you noticed that enormous lake immediately to the east of the city? THAT is the water supply for the city of Chicago. Unlike the water surrounding New York City, the water next to Chicago is fresh and drinkable. Well, at least in theory, you probably do want to treat it first, but the point is, it’s fresh and not salt.
There are a few roof-top water tanks in Chicago, but they’re pretty rare. Most of what you see downtown in the Loop area are fairly recent buildings that rely on pumps to maintain water pressure rather than rooftop reservoirs. Out in the rest of the city, the structures are either, again, recent buildings relying on pumps or low rise buildings where the municipal water pressure is sufficient they don’t need pumps.
Yep. The water treatment plant for Chicago (pumps it and treats it…for reference that is Navy Pier just next to it) was within easy walking distance of where the OP was staying.
Happens to be the largest water treatment plant in the world. Processes around a billion gallons of water per day.
Water tanks in New York don’t exist to hold a store of fresh water. They’re there to maintain water pressure to the higher floors of buildings, a problem that presumably exists anywhere there structures more than a few stories tall. That said, New York seems to be the exception in having tanks for individual buildings, so most cities apparently solve this problem differently.
All tall buildings need water tanks. It isn’t for storage it’s for pressure. Street pressure isn’t sufficient for tall buildings, so in order to have water pressure higher up the water needs to be pumped up. To maintain pressure for the upper floors you can use gravity such as that created by putting the water up higher in a tower or you can use pressure tanks that store pressure using air. There are constant pressure systems that could be used as well but those are ‘newer’ technology that pretty much sucks in practice.
New York has a law requiring the maintenance and replacement of existing water tanks. They are kept because someone along the way thought the historic look of them is an important visual to New York. I don’t think newer buildings require external tanks. Other cities like Chicago don’t have the same limitation and can use whatever method they want.
The newer way of creating the same effect is using dozens of smaller internal tanks on the upper levels of the building. At least some if not all of them are pressure tanks that way the top most floors still have pressure.
My question was not about the source of water, but rather about how water is supplied (at adequate pressure) to the upper floors of Chicago buildings. City water pressure is typically around 50 psi, which is not enough to propel water higher than about the tenth floor (at which point the supply pressure will be pretty close to zero). all buildings higher than a few floors require their own pumps to drive city-supplied water up to the higher floors and deliver it to the taps at a satisfactory pressure (i.e. something close to 50 psi).
I guess this must be the case for Chicago, and perhaps other cities - but using interior space for water pressure tanks seems like a waste of valuable, rentable real estate, leaving the rooftop space (which is not particularly rentable) empty/wasted.
The high rises that I have worked in have city water to the 4th or 5th floors. And a boosted water supply pump to pump the water to the higher floors. The tanks required on a pumped pressure system are a lot smaller than a gravity feed system. The tanks function is to stabalize the water pressure not provide water. Depending on the building they normally are about 3 feet around and 5 feet tall not much space required.
Dumb question time: How do they prevent the rooftop water tanks from freezing in the winter? I’m having trouble picturing how our many feet of drifted snow wouldn’t cause issues…
The classic rooftop round cypress tanks were for firefighting, not for everyday water pressure. Changes to building codes and industrial uses have made them mostly obsolete. But they’re much appreciated as part of the cityscape. There’s a book about them and several art projects, and a city ordinance that tries to preserve them.
North Michigan Avenue is not prime territory for spotting them because it was not a 19th century industrial area, and has been so redeveloped in recent years. But there’s no shortage in the South Loop, West Loop, or River North.
Yet again (in the OP’s question) we encounter the expectation that great cities must be like New York, regardless of local tradition, circumstance or law.
We don’t assume Chicago’s pizza should be foldable, its hot dogs dressed with sauerkraut, or its speech studded with dropped r’s. Why assume its buildings must have wooden tanks? Even if, as Mr Downtown informs us, some of them really do?
First of all, there’s no such thing as Chicago “pizza.”
But the question is a perfectly valid one. There’s no getting around the law of gravity. All tall buildings require a source of water pressure, and water towers on the roof are an obvious, simple, cheap, time-tested solution. It’s perfectly reasonable to ask why they are common in one place and unapparent in another.
Ya know, the deep dish isn’t the only indigenous style here. There’s a thin crust that is also particular to this area (which Wikipedia details). I’d venture to see it’s the far more common style locally, although deep dish has its adherents.
Actually, yes. Around here, “New York Style” is a large, always triangular slice in which the pepperoni is on top of the melted cheese. As opposed to Chicago style thin crust, which may contain a multitude of toppings, and they tend to be placed underneath or mingled with the cheese, and the pizza likely cut into square or diamond shaped pieces. (I’ve never noticed a “New York Style” slice with anything other than pepperoni, but that may just be my perception.)
As a Chicagolandier, I’m calling shenanigans (Chicagolandians?) on calling the thin-crust style original to Chicago.
I live in Chicagoland, but c’mon. The thin crust type - it’s great, don’t get me wrong. But I had it growing up in Madison; in fact all over Wisconsin. And it’s certainly not rare in Michigan.
It’s great, and I’ve come to like it more than deep dish, but I strongly object to the claim that this is a “Chicago” thing. It’s a northern Midwest thing.
Basically, if you have a bar, pub or tavern with wood paneling or at least one woodland creature mounted on the wall in the northern Midwest, that establishment will probably serve a mean thin-crust “Chicago :rolleyes:” pizza.
