Wellington councils which take more water than they are allowed under their resource consents could be penalised in the future.
Wellington Water is preparing for an acute water shortage in the capital this summer.
If the region reaches that level, it is likely they will have to take more water than allocated in their resource consents.
Greater Wellington Regional Council chair Daran Ponter has written to councils warning that breaching those conditions falls short of their duty under the law.
Ponter said the situation was untenable for the regional council as both a regulator and bulk water supplier - so it needed to consider all options to protect water sources and supplying the region's cities.
One of these options was charging councils for breaching their water allocations.
The Wellington Regional Water Board Act 1972 gives the regional council power to set allocation limits and impose surcharges on their four councils - Upper Hutt City Council, Hutt City Council, Wellington City Council and Porirua City Council.
To enact the changes - which have never been implemented before - they need to consult with the councils on the allocations and the amount of the surcharge.
Ponter said he would discuss the need for the changes and whether to start implementing them in the next three years.
The letter also detailed the regional council's position for the need to implement universal water metering.
The latest Wellington Water Committee Meeting indicated there was varying support to install smart metering among councils, he wrote.
"This situation does not reflect the Water Shortage Summit agreement that we plan for all three measures to address our projected water shortage - fixing leaks, universal water metering and increasing supply.
"I acknowledge the fiscal constraints you face but generally it seems your councils are relegating our shared resolution behind other priorities."
Ponter has asked the city councils to communicate their intentions to formally consult with their communities on water metering as part of their Long-Term Plans and their initial comments on imposing surcharges before 31 January.
RNZ.
