Be realistic about water crisis

Water regulator Taumata Arowai has been warned it needs to be realistic about the region’s ability to deal with the water crisis over coming years.

Taumata Arowai wrote to Wellington Water and the four metropolitan councils in February saying it was not confident that the councils were doing enough to prevent a severe water crisis over coming summers.

Wellington Water wrote to Taumata Arowai asking to use emergency powers to take more water than current consents allowed.

Taumata Arowai chief executive Allan Prangnell asked Wellington Water to provide a plan that showed the steps it would take to mitigate the risk.

Wellington Water, Greater Wellington Regional Council and council chief executives have written back spelling out the challenges. “The current environment is not perfect, and we would rather be realistic about our situation than hopeful,” the letter said.

The letter shows that councils, which are currently working on their long-term plans, continue to underinvest in fixing leaks.

The biggest spender is Hutt City Council, which has allocated $13.5 million to deal with “acute water loss activities”. It is aiming to get on top of its backlog by the end of the year.

Despite Wellington City being the biggest city, it is spending the least at $5.8m.

The chief executives note that if all the councils agreed to provide enough funding to get on top of the backlog of leaks, the “market would struggle” to meet demand.

Reducing the risk of having to declare a “water emergency” in coming years would not be straightforward for the councils.

“To mitigate risks and ensure a smooth water supply, we need to increase the amount of water we input into the system, reduce authorised consumption of water, and minimise real losses.”

Accurately predicting the chance of a water emergency in coming years required better modelling of water use, which Wellington Water planned to do in coming months.

Until more accurate modelling was carried out, Wellington Water estimated that it needed to reduce demand by up to 30 million litres a day or increase supply by a similar amount.

This year’s modelling showed that there was approximately a 33% chance of demand triggering Level 4 restrictions, which would require a ban on all outdoor water use.

Wellingtonians would also be expected to take two-minute showers and just one load of laundry a week.

It could also result in boil water notices as reservoirs ran dry.

The latest figures show that Upper Hutt is losing 52% of its water to leaks. Wellington City is losing 41% and Hutt City 46%.

In a “perfect world” Wellington Water would be able to increase storage at the Te Marua Lakes and clear the backlog of leaks, the joint letter said.

Wellington Water believed it could make changes that would reduce the risk of a summer emergency but was warning Taumata Arowai that it must be realistic about what could be achieved.

In January, head of regulatory Steve Taylor said Taumata Arowai was concerned about Wellington Water’s management of the water shortage.

“Before declaring a drinking water emergency, we expect the supplier to have exhausted all other avenues to manage the risks to their supply and a clear and serious risk to public health must be established. This includes confirming that work on repairing leaks is no longer effective in keeping up with demand.”

Prangnell told Wellington Water the current situation did not meet the threshold to declare an emergency.