A “disproportionately high” number of written complaints received by Thames Water skewed the sector’s overall performance in 2020/21, a report by CCWater has revealed. The consumer group’s annual report compares the performance of water companies on the number of written complaints they received per 10,000 connections, as well as assessing how well complaints were handled. It found that complaints from households to the water industry rose for the third successive year, with an 11% increase on 2019/20.