Customers supplied from our Knapp Mill water treatment works in Christchurch may notice periodic slight changes in the colour of the water supply during the autumn/winter period following heavy rainfall. Typically, this colour change is identified in bathtubs or sinks (when the water is deep against a white background) and described as being clear of particles but with a slight green/yellow colouration. This colouration does not clear by flushing it through your system by running your taps.

We've put together some answers to some frequently asked questions to help.

Long-term solution

Construction is already underway at our Alderney site, where we are installing advanced treatment technologies and planning is progressing at our Knapp Mill site. These improvements are part of our ambitious plan to build state-of-the-art facilities at both our water treatment sites in Bournemouth and Christchurch (Knapp Mill). We are investing £113 million at our Alderney site and £85 million at Knapp Mill over the next few years and aim to complete them by 2026.

The delivery of the upgraded Knapp Mill water treatment works will: 

• improve the region’s drinking water quality
• improve the security and resilience of the region’s water supply against extreme conditions
• use the latest technology in addition to our water treatment process
• ensure the environmental impacts of the work has been assessed and improve the site’s ability to attract wildlife by 10% without impacting the natural habitat of the River Avon.

Please accept our apologies for any inconvenience caused and be assured it is fine to continue to use the water as you normally would. The colour will return to normal as the impact of the enhanced treatment processes take affect and the concentrations of colour within the river return to normal levels.  You may notice the colour for several days but if you have any concerns, please contact us and we can further discuss the issue.