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Our leakage performance

We're passionate about protecting water - a precious resource - and we’re working hard to reduce leakage. We’re using increasingly innovative techniques to find and fix leaks.

In 2020/21, we met our target for leakage reduction for the second year in a row, after missing it for three years. We achieved a 5.4% reduction of our revised baseline leakage level, compared to a performance commitment target reduction of 4.1%. You can read more about our overall leakage performance for 2020/21 in our Annual Performance Report.

Despite meeting our target, our leakage going into April this year was higher than expected due to the colder than average winter of 2020/21 which extended into the 2021/22 reporting year. To increase our confidence of achieving our leakage reduction target, we replanned our leakage activities. As a result, we’ve planned to increase our overall activity, such as repairs and pressure management, by over 20% for the year.

All figures used in this report are based on the updated leakage reporting allowances used in 2020/21 and our updated plan.

Illustration of a Thames Water engineer kneeling to look at a water meter

Headlines for July 2021 (published August 2021)

This is our fourth monthly leakage report for 2021/22. It explains our performance for July 2021.

  • Monthly leakage for July was 548 Ml/d, 11 Ml/d better than our internal target.
    This is due to a combination of a better-than-forecast recovery from the cold start to the year and lower demand over the summer, due to the wet weather. That means less pressure is required to move water around our network, so we lose less water through existing leaks.
  • We fixed 3,896 leaks in July, but that’s below the 5,266 that we’d planned to do.
    This is because we’ve focused on fixing a fewer, larger, more complex leaks that have been leaking for longer than we would like. It’s also because – due to the impact of Covid-19 and external market forces – we’ve had fewer teams available to do repairs, and we haven’t been able to increase them as quickly as we would like. We’re actively engaging with our repair partners (suppliers who help us with our leak repair and maintenance programme) to resolve these issues as quickly as possible.


Ml/d means megalitres, or millions of litres, of water per day. One Olympic sized swimming pool contains around 2.5 Ml.


The information provided is, to the best of our knowledge, accurate, but may be subject to change from time to time. The information does not represent formal annual regulatory reporting.

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