Mexican Water System

Here in Chapala, I’m told the public water system doesn’t pump water 24 hours. So how is water pressure maintained in the house all day? A tinaco, or roof tank.

Often the tinaco just sits on the flat roof, but sometimes it is set on a little platform above the roof. The higher it is, the more water pressure there is in the home.

In our casa, municipal water flows into a small cistern in the ground, with a floater valve in it like a toilet tank. This cistern looks to be about 15 gallons or so. When the water gets low, it turns on a valve to the public water until the cistern is full again.

On our roof is a tinaco, a big 50-gallon water tank, with a similar valve.

There’s an electric pump in the wall that pulls water from the cistern into the tank on the roof.

When a faucet is turned on in the house, it simply uses gravity to push water through the faucet. That means that water pressure is higher in the first floor than the second. The higher the tinaco from the faucet, the higher the water pressure.

Varying Water Pressure

There’s an interesting phenomenon that first noticed within a few days of our arrival. Because the roof tank is fully enclosed, when the pump is pushing water into it the water pressure in the house increases dramatically. For some reason, the pump doesn’t run in the early morning, so showers before 8 am don’t have a lot of pressure. After that, it can be quite strong. I can’t find a timer on the pump, or see any other reason why it doesn’t pump sometimes. But I’ve just come to accept that a 6:30 am shower will be a little wimpy.

I also noticed that when you turn on the faucet, it starts with a bit of water pressure, which decays for a second or two, then jumps considerably when the pump kicks in to start refilling the tinaco.

When a Tinaco Drains Empty…

One morning, Angela got up to find no water pressure at all in our bathroom. She went downstairs to shower, but even there it was just a trickle. I checked the tank on the roof, and found it nearly empty. Apparently one of the toilet tank valves didn’t completely shut off, and the slow leak drained the roof tank. The pump apparently has an auto shut off, to prevent leaks from wasting water.

I flipped the electrical breaker to the pump, and it came back on. It only took a few minutes to fill the tank, and our water was back.