Wellington water woes, and what's recommended for emergency supply

Friday, 22 December 2023

Wellington residents have been warned that even if an average amount of rain falls this summer they could have to “significantly” reduce water use.

Regional water services provider Wellington Water has a range of suggestions for how residents can limit the risk of restrictions, and how they should prepare in case more severe restrictions are imposed.

One of those suggestions is that they should store water.

On that matter, the Wellington Region Emergency Management Office (WREMO) has chipped in with some advice.

Residents needed to store enough water to last seven days, WREMO said.

The recommended amount of stored emergency water for each person was 140 litres – enough for 20l per person per day.

“This recommended amount should be enough for drinking, food preparation, hand washing and other basic hygiene (brushing teeth and a sponge bath),” WREMO said.

Suggested options for storing water were plastic drink bottles, 10l to 20l containers, 200l water tanks, and even larger tanks.

WREMO advised against using milk bottles because any milk residue would contaminate the water.

As a result of an arrangement between WREMO and manufacturer The Tank Guy, the 200l tanks can be bought for about $115.

According to WREMO those tanks are easy to transport and install, are made of food grade UV resistant plastic, and come with all the necessary fittings.

Based on the 140l per person advice, a dwelling with four people in it would need three of the tanks – 4x140=540.

The tanks are fairly compact – 65 centimetres in diameter and 1.2 metres high – so many households could probably find somewhere to put them, but it could be more of a challenge for say two couples sharing a two-bedroom apartment.

A range of smaller water containers can easily be found online at a variety of prices. A 20l container on sale for about $34 is 37.5cm high, with 29cm sides.

A person living on their own would need seven of the containers, while a four-person household would need 28. The listing doesn’t say whether the containers can be stacked on top of each other.

Towards the lower end of the price range, The Warehouse is advertising 20l water containers for $13.50, although it also lists a 22l product for $62.

For those re-using plastic bottles, 140 1l bottles would be needed for just one person, or 94 1.5l bottles, or 70 2l bottles.

That’s a lot of bottles, and they need to be stored in cool, dark places. The National Emergency Management Agency (NEMA) advises against glass containers because of their weight and risk of breaking.

There’s also talk online of using plastic rubbish bins to store water, but a Google search didn’t turn up any official agencies suggesting bins as an option.

NEMA suggested a sturdy, watertight bin, with a snug-fitting cover could be used as a basic emergency toilet, but so far there’s been no suggestion Wellington’s water woes are so bad that’s going to be needed.

The five councils covered by Wellington Water – South Wairarapa, Upper Hutt, Wellington, Porirua and Hutt – are all on level 1 restrictions, which limits the use of sprinklers.

At restriction level 3, all residential outdoor water use is banned and people are urged to “consider” reducing indoor use. At level 4, Wellington Water says, people should take 2-minute showers and do 1 load of laundry per person each week.

According to Wellington Water, the problem is due to a combination of increasing leaks, relatively high use, and a growing population.

It estimates 45% of drinking water is being lost through leaks, with a “sharp and unexpected rise” since mid-2022.

“There are a lot of leaks out there and due to the current resources available to us, we simply can’t fix them all,” Wellington Water said.

Storing water in containers takes a bit of care. WREMO has a rookie’s guide to doing in safely. The steps include – but are not limited to – adding bleach, storing in a cool dark place, and cleaning and refilling every 12 months.

Before stored water is used it should be boiled, or more bleach should be added.