News & Events

City water pipe to be cleaned

Monday July 20 2020

One of the two main pipes that get water from the Turitea Dam to the city’s homes and businesses is being cleaned to ensure the city’s water remains in pristine condition. We’re planning for this to occur this Wednesday evening, 22 July.

Photo shows Palmerston North's water reservoir in the Turitea Valley.

Turitea Dam.

As we will be using large amounts of water, we need to ensure the river’s flow rate and the murkiness meets resource consent conditions, before we can confirm it’s going ahead. We should be able to do this by Wednesday morning. This will be confirmed on the Council’s Facebook page and website and media will be informed.

The Council’s Water Operations Manager, Mike Monaghan, says water supply will continue as normal, but one of the potential side effects of cleaning the pipes is that it can cause the water to discolour for a brief period.

“If you find your water isn’t clear late Wednesday night or on Thursday morning, run your cold tap for 20 minutes. If the water hasn’t run clear, then please call us and we will get the pipes near your home flushed.”

Longburn, Kelvin Grove, Bunnythorpe and Ashhurst have their own water supply so are not affected by the pipe cleaning.

Mr Monaghan is thanking the public for their understanding.

“Palmerston North’s drinking water is even cleaner than recommended in the National Drinking Water Standards, and we want this to stay the case. Regular maintenance like this ensures our residents continue to have the cleanest water possible.”

Questions and answers

Why do we clean the pipes?

The pipes need to be cleaned regularly to flush out any build-up of manganese. The water is naturally slightly rich in the mineral as it comes from a dam. Almost all the manganese is removed during the treatment process, but minimal amounts can remain. The mineral is safe to drink but can cause water to discolour. Cleaning the pipes ensures this isn’t a problem.

How do you clean the pipes?

We start by shutting off certain valves (or gates) to the main pipe. This causes the water to be stuck behind these gates. We then insert a giant sponge into the pipe. Then we open those doors and the pressure of the water pushes the sponge through the pipe. As it moves through the pipe it cleans it. Near the river we remove the sponge, so it doesn’t end up in our precious awa. The water and any sediment are then flushed into the Manawatū River. Our consent conditions have very strict rules about when we can do this work to ensure the effects on our river are as minimal as possible.

Why can’t you give us an exact date when the pipes are being cleaned?

When we clean the pipes, we need to discharge a lot of extra water into the Manawatū River. We have a resource consent to do this, but we need the river to be in certain conditions to ensure the environmental impacts are minimal. Mainly this is about the flow of the river, and how murky it is.

We'll give you 12 hours notice and let you know on our website and Facebook page.

Why does the water become dirty?

Our dam has slightly higher levels of manganese. We remove almost all of it during the treatment process, but we can never get it all. Over time this can build up in the water pipes. We remove it so that you don’t have discoloured water often.

Why can’t I wash my clothes that night?

Try not to do loads of washing overnight on the night we clean the pipe. If the water does become discoloured it might stain your clothes – and we don’t want that to happen.

Will I get dirty water?

Sometimes when we clean the pipes it can cause the water to change colour briefly. We can never predict if this will happen, or where.

If you live in Ashhurst, Bunnythorpe, Kelvin Grove or Longburn you have your own water supply so won’t be affected by this work.

My water is dirty, what do I do?

If you find your water is discoloured, please run a cold tap for 20 minutes. If it doesn't become clear, get in touch and we will flush the pipes near your property.