Our Projects


South West Water

Improving drinking water quality

Chemical reactions with water mains can cause drinking water to become discoloured. While not hazardous to health, such discolouration understandably tends to alarm customers.

South West Water (SWW) needed to minimise the risk of discoloured drinking water in a cost-effective manner, balancing water mains replacement and mains cleaning to deliver solutions for the lowest total expenditure.

In 2012 we presented a discolouration risk management strategy to the client based on our unique Discolouration Propensity Modelling (DPM) tool. The approach is now driving the client’s investment in this area.

We created DPM in collaboration with Exeter University. Highly innovative, it identifies those water mains presenting the greatest discolouration risk by integrating complex data, analysing it and then evaluating multiple potential solutions.

The robustness of our approach contributed significantly to appropriate parts of the client’s PR14 Business Plan, which was one of only two to be awarded ‘Enhanced’ status by Ofwat.

Evidence is already emerging that the approach will dramatically improve the cost-effectiveness of SWW’s discolouration management in their AMP6 asset management programme and allow customers to take crystal clear drinking water for granted. 


'Thanks to Mouchel’s innovative thinking and solutions, South West water now has a truly comprehensive and highly cost-effective programme for sustainable discolouration management.'

Julian Collingbourne, Clean Water Network Planning Manager, South West Water