This year's ‘Beast from the East’ freeze thaw and prolonged summer heatwave has had what is described as an “enduring impact” on leakage for Thames Water, despite the utility's best repair performance in 10 years.

Leakage rose to 683 Ml/d, compared to 665 Ml/d for the same period in 2017, according to the utility’s interim results for April to September 2018 published today.

The rise was despite 1,431 leaks fixed per week,Thames’ best performance since 2008/9, and up 37% year-on-year. To date the company has installed 26,987 leak-detecting acoustic loggers and a further 44,105 smart enabled water meters, with a total of 265,000 transmitting data to help pinpoint leaks.

Supply interruptions and complaint volumes were also affected by climate events - household written complaints rose to 11,083 (Sept 2017: 8,242).

Steve Robertson, Chief Executive Officer of Thames Water Utilities Limited, said:

“During the intense summer heatwave we worked tirelessly to protect our customers from supply restrictions. However, along with the impact of the ‘Beast from the East’, it has delayed our progress on leakage and other performance measures. We remain focused on building a better future for our customers and the environment.

“Our profit decreased over the period as we brought forward regulatory penalties, to benefit customers, and hired more employees to improve customer service and tackle leakage. Our capital investment increased, with £554 million spent on improving our water and waste networks.

“Our long-term investors are committed to the high investment levels required to face the challenges created by climate change and population growth, and continue to not take any dividends. Our record £11.7 billion business plan for 2020-25 will help to further transform our infrastructure and customer service, as well as provide the necessary extra support for people in vulnerable circumstances.”

During the period the water company increased water production by 450 Ml/d, or 17%, and managed high demand through direct text message engagement with customers in hotspots to prevent restrictions during the summer heatwave.

Thames has also increased support for customers in vulnerable circumstances, including:

• Homes on social tariff at 53,671, up 10%
• 62,671 customers on priority services register, up 4.4%
• 3,353 customers supported through customer assistance fund

Operational performance in other key areas included:

• Water quality compliance at 99.96% (2017: 99.96%)
• Pollution incidents at 217 (Sept 2017: 202)
• 10% year-on-year reduction in incidents from wastewater pipes
• 301km of proactive sewer maintenance
• 762 sewer sensors installed since January 2018 as part of plans to digitise sewer network

Thames is currently on track to migrate the first small tranche of customers to a new billing system from December 2018.

The major review Thames has been conducting to demonstrate cross-sector leadership in governance is nearing completion, including the appointment of hree new Independent Non-Executive Directors. Cayman Islands entities are also no longer subsidiaries of Thames Water and are in the final stages of closure.

A new dividend policy is now in place and no dividends will be paid to external shareholders until 2020/21, with “modest dividend payments” of c.£20 million per year planned for between 2020 and 2025.

Thames has submitted an ambitious AMP7 investment plan for 2020-25 based on feedback from 1 million customers which sets out a £11.7 billion spend, including extra £2.1 billion to improve resilience.