Water meters are being installed at 600 houses in Wellington, Lower Hutt and Upper Hutt to monitor domestic water usage.
A two-year project is being carried out to detect leaks and obtain a better idea of how much water people use.
Meters can cost up to $600 each and are funded by Capacity, a council-controlled organisation.
Infrastructure services engineer Martin Gribble says the exercise is not to trial water meters as some people have suggested.
Mr Gribble says Wellington City Council is seeking permission to install the water meters in houses that have been randomly selected.
However, the other councils - Upper Hutt and Lower Hutt - have opted not to consult property owners.