MEDIA RELEASE

For immediate release

7 June 2023

Discoloured Water Update  

Kawerau District Council is aware of the ongoing issues with discoloured water that have escalated in recent months. There has been more service requests lodged and residents have also been advising elected members and staff via other forums.

Council apologises for these ongoing issues and the impacts on whānau. We appreciate that it is frustrating and impacts residents’ lives.

Why is water discoloured?

The District drinking water suffers from sporadic browning due to manganese and iron in the water supply and infrastructure. Manganese and iron becomes black and brown in the presence of chlorine.

In general, the manganese and iron concentrations in our spring water sources are too low to cause any colour. However, the minerals can build up in the water supply infrastructure and cause colour under certain conditions.

Council currently does not know the exact causes and sources of the recent colour in the reticulation and is going through a systematic process to eliminate potential sources. Council staff believe it is likely caused by the low water usage during the past nine months.

What is Council doing?  

To find and resolve the issues Council is doing the following actions:

Large scale flushing of the reticulation to reduce ‘dead’ spots in the reticulation. When water is stagnant in the reticulation during lower use periods, colour release from older pipes builds up and when cause sporadic colour during higher use periods;

• Cleaning of all reticulation and valves on an ongoing basis;
• Replacing the oldest reticulation during the large reticulation replacement program. Council has brought forward key parts of the program in areas that may cause colour such as the Monika Lanham trunk main line. This work has been brought forward from 2025/26 to 2023/24.
• Changing the water sources and testing different treatment processes. Council has used three sources for drinking water: Umukaraka Spring, Pumphouse Spring and the Tarawera Bores.

In the previous three weeks, Council only utilised the Pumphouse Spring to see if the possible cause is Umukaraka Spring or Tarawera Bores.

From next week, Council will only use the Tarawera Bores for a period of three weeks, and will revisit the availability to use Umukaraka Spring with the landowners.

• Cleaning and inspecting the district’s three water reservoirs. Council is currently cleaning and removing any residue in the reservoirs that may cause colour.
• Evaluating water treatment options and processes. Council is evaluating the use of lime in its process and replacing it with other methods. Council is also rebuilding the main pump station with modern energy efficient pumps and valves.

It is very important that Council staff receive feedback from the community telling us where dirty water is occurring. This will help staff to pinpoint the causes and rectify the problem.

Please contact Council on 07 306 9009 (if it is after hours press option 2). 

[ENDS]

For more information, please contact Manager Communications and Engagement Tania Humberstone on 027 464 3785.