Investigation into cause of Hampshire loss of water supply failure published

An investigation into the reason why customers in South Hampshire lost their water supply in mid-February has now concluded. 

Following repairs to a filtration tank at our Otterbourne supply works, a valve was not properly closed, which resulted in water of insufficient quality passing into a second tank. 

As the error was detected successfully, the site immediately shut down, without any of the affected water entering public supply. Customers were affected between 15 and 19 February 2023.  

Tim McMahon, Southern Water’s Water Director, said: “We are very sorry to those who were impacted by this disruption. We have carried out a thorough internal review into what happened, in order to prevent it happening in future. It is important we are transparent with customers when we fall short of expectations.   

“February’s incident was a case of human error and there are important lessons to be learned. The report has made a number of recommendations, and I’d like to reassure our Hampshire communities that we are already taking action. We are also investing around £350 million over eight years at Otterbourne to improve the resilience of our site. 

“In recognition of the distress caused by this incident, particularly as it came only two months after a separate loss of water in the same area, we doubled our guaranteed standards of service payments for customers and provided a £50,000 donation to local food banks.” 

Southern Water’s outreach team will also attend Otterbourne’s village summer fete on Sunday 25 June 2023, offering water saving tips, information about billing, and other support. The annual event will raise funds for St Matthew’s Church, with Southern Water contributing to that sum. 

The investigation’s findings are available here. Any customer who would like a paper copy can contact us on papercopies@southernwater.co.uk.