Tinaco

What it is

The black plastic tank on the roof. Look at any Mexican city from above and the dots you see on every building are these, and they are the reason water comes out of a tap in a place where the street supply is not continuous.

For a tenant it is the thing that runs out. Se acabó el agua almost never means the city has none - it usually means your tinaco is empty and something upstream of it did not do its job.

Literal meaning

Tinaco is a large tina, a tub. The name is plain and the object is plain: a container that holds water until you need it.

The reason it exists is the supply. Water reaches many neighborhoods on a schedule rather than continuously, so buildings store what arrives. The tinaco sits high on purpose - gravity does the work of pressurizing the taps, which is also why the shower on the top floor is often the weakest in the building: it has the least height between the tank and the showerhead.

It is black for a plain reason too. Sunlight would grow algae in a translucent tank, so the standard one is black outside and white inside.

How it works in Mexico

Mostly in the middle of a problem. Se vació el tinaco, no sube el agua al tinaco, hay que revisar la bomba. If you rent here, these are among the most useful sentences you will learn.

The first question is whether the whole building is dry or only you, because many CDMX buildings give each apartment its own tinaco. Whole building means the cisterna is empty or the shared pump has failed. Only you usually means your own tank did not fill - and the usual culprit is el flotador, the float valve, which sticks and either stops the tank filling or sends it overflowing down the front of the building. La llave de paso, your stopcock, is the other thing to check before calling anybody.

Learn the rest of the building vocabulary while you are at it, because it all arrives in the same conversations: el boiler for the water heater, el gasero and el tanque estacionario for gas, el conserje for the caretaker and la administración for whoever actually decides things. Newer buildings sometimes skip gravity entirely and run on un hidroneumático, a pressure system.

Tandeo is the word for a rationed supply schedule - water arriving on set days rather than continuously. In parts of the city it is a normal fact of life, and it is why the tinaco matters as much as it does.

When the supply fails for long enough, somebody orders a pipa. The alcaldía supplies them free on request and a private one costs money but comes faster, and buildings coordinate either through la administración. A pipa can fill a tinaco directly by hose as well as filling the cisterna.

And the thing nobody tells a newcomer: the water in the tinaco is not drinking water. Everybody buys garrafones - twenty-liter bottles from the corner store or from a truck that comes down the street - and the tinaco itself gets washed once or twice a year.

Common mistake

Assuming no water means the city has none. Far more often your own tank did not fill, and the cause is a stuck flotador or a closed llave de paso. When the pump really is the problem it is rarely a switch you can flip - a tripped pastilla, the electroniveles, a burnt-out motor, or a pump that ran dry and needs priming - and in most buildings you do not have access to it anyway.

Drinking it. The tinaco stores municipal water in a plastic tank on a roof, and nobody here drinks that. Garrafones are what you buy, and in most of the city they are delivered to the door.

Mixing up tinaco and cisterna when reporting the problem. They are at opposite ends of the same system - roof and basement - and telling a plumber the wrong one sends him to the wrong place.