Apparent and real losses

The two kinds of water loss in the IWA water balance. Apparent losses are water that is used but not measured or billed correctly: meter under-registration, data handling errors and unauthorised use. Real losses are water that physically escapes through leaks, bursts and tank overflows before the customer meter.

The fixes differ: apparent losses call for better meters, reading and billing, while real losses call for leak repair and pressure control. Knowing the split tells a utility where to spend first.