How come?
Centrifugal pumps are magnificent machines. If properly maintained they can work for long periods of time without you ever noticing they are there. But here comes the negative part of all these apparent awesomeness, you surely are spending more money than you should.
Pumps start deteriorating from the first instant you start operating them. Being a mechanical equipment, they start deteriorating or wearing out from moment zero.
To compensate for this mechanical deterioration, pumps employ more energy to do the job. it is not that the demand has increased, it is that to convey the same amount of water more energy is required.
In most cases, you don't notice this increase because it is a subtle but gradual increase. Like the frog in water until it boils. You might have heard about this tale.
How to develop awareness about this unnecessary expenditure?
A couple of issues appear here. One is how to calculate the power consumed by a pump, and the other is how to effectively track its development over time.
For the first one, there are hundreds of articles that show how to estimate the current pump's energy consumption such as this one I wrote a few years ago. You can check it here.
For the second one, almost nobody is worried about monitoring this consumption. It could be that people that operate the pump don't pay the electric bill, so why bother?
The undeniable fact is that somebody is paying for this and it is the whole organization that suffers the consequences of poor energy management.