Timaru Water Discolouration

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Published: 22 Dec 2021

Timaru water Update 21/12

Thanks for everyone’s patience as we deal with this issue. We’ve got a few updates for today, and something that you can start doing now to help with the issue.

Following last week’s storms, the water in the Pareora River has cleaned up enough that we’ve been able to switch the supply back on. This is our best source, and turning it back on will help refill the reservoirs and begin to resolve the discolouration.

But we need your help!

We need your help by reducing non-essential water consumption to give our reservoirs time to refill, so please no watering of lawns, and only use sprinklers when they are most effective between 6-8 am or 6-8pm.


We think the source of the algae was our secondary source at the Opihi, so we’d like to keep this source switched off for the time being. This means we have to rely solely on Pareora to both supply everyone’s needs and refill the reserve, which we can’t do at peak summer water volumes, so we need everyone to do their bit to help get us back to normal.

What else are we doing?

  • We’ve had divers in the Claremont Reservoirs today to make sure there was nothing unusual in there, and it all looked okay.
  • We’re waiting for the results of specialist testing just to provide absolute surety to our conclusions, we’re expecting these shortly.
  • The water continues to meet the drinking water standards and is suitable for consumption.
  • The tankers of water from will continue to be at Aorangi Park, Caroline Bay and Sir Basil Arthur Park during the day until further notice. Please bring your own clean container.

Timaru Water Discolouration Update 20/12/21 11.30
Thanks for everyone’s patience. We’re taking this incredibly seriously and have been working on finding a definitive cause. Although you can continue to drink the water, for anyone not wanting to do so, we'll have three tankers available for you to pick up water in your own clean container.
Key points:
  • The water doesn’t look good, but it meets the drinking water standards. We’ve been liaising with the Drinking Water Regulator, and they are satisfied with our process.
  • We’ve ruled out a number of potential causes including cross-contamination, backflow, rust in pipes and silt from source water. We can confirm that none of these are the cause.
  • Having ruled out all of the above, we believe the most likely cause of the discolouration is non-toxic microscopic algae in the raw water which is common in summer, and is killed by our water treatments. This reaction can discolour the water.
  • Samples of raw water have been sent to a specialist laboratory to confirm this.
  • Last week’s storm has exacerbated the problem by us not being able to take any water from either of our usual sources. This is normal following a wet weather event.
  • If you are still concerned and do not wish to drink the water, we will be making free water available from a different town supply.
From 2pm until 6pm today and from 8.30am tomorrow morning you will be able to bring your own water containers and collect water from a water tanker at any of the following locations:
- Caroline Bay (by the playground)
- Aorangi Stadium
- Sir Basil Arthur Park.
We apologise for this inconvenience, we’re continuing to work on solutions and will be regularly testing the water to ensure that it continues to meet water standards. We’ll have updates here as we continue to work.


Update Monday 20/12/21 0903
We apologise for the continued discolouration in the Timaru Urban water scheme.
While this is not up to our usual standards for colour it is still passing all drinking water standards tests, so is still safe to consume.
Our waters team are continuing to work on the issue at the moment and are testing frequently to ensure that the water is still meeting standards.
We'll have a more detailed update later today.
UPDATED - 17/12 11:54am
Council staff have undertaken a number of tests to get to the bottom of reports of discouloured water in Timaru. Our tests indicate that the water is safe to drink - the chlorine is doing its job.
We also have tested our turbidity and UVT (ultra-violet treatment) levels. The results indicate that these are at a good level and meet Drinking Water Standards
We are continuing to investigate the cause of the discolouration.
We do encourage all residents to report the discolouration they’re experiencing to our Customer Services Team. Please give us a call on 687 7200.
Kia ora koutou, we're aware that some people in Timaru are seeing  discolouration of their tap water. The team are currently investigating, our ozonation and chlorination plants are running as normal so treatment isn't compromised.
We'll have updates here when we know more.

Last updated: 22 Dec 2021