Water

In our village (and I assume also in others) we have to pay for the drinking water and for the wastewater. For the drinking water we have a water meter, and we pay for every cubic metre. The wastewater is not measured, but it is assumed that the same amount that comes in is also going out. So we pay also a certain amount of money for wastewater but per cubic metre of drinking water.
Now, as many people with a garden, we use part of the drinking water for this very garden. And hence don't produce no wastewater that would go into the sewerage. And greedy as we are :) we don't like to pay for something we don't produce.
So, we have an extra water meter in the waterpipes that go out of the building. The amount measures is subtracted of the assumed amount of wastewater, and reduces our costs.

Why do I come with it today? Well, every six years an new, calibrated meter has to be installed. And that was going to be early this morning. A bit tricky, because we had another appointment a bit later.
What happened? The plumber cancelled due to a water leak somewhere else. He will now come tomorrow. (And the other appointment was a "no-show". Pretty annoying.)

The red arrow turns 360° for every litre that goes through the pipe. So 1,000 times per cubic metre.

Thanks to freespiral for hosting the Tiny Tuesday challenge.